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TESTING THE EFFICACY OF ROBOT-TO-HUMAN GOAL DIRECTED
ACTIONS
By
Alissa Baker-Oglesbee
A thesis submitted to the Graduate Faculty of
Fayetteville State University, North Carolina
In partial fulfillment of the
Requirements for the Degree of
Master of Arts in Psychology
DEPARTMENT OF PSYCHOLOGY
Fayetteville, North Carolina
July 2011
APPROVED BY:
___________________________________________________________
Dr. Daniel Cordoba-Montoya, Chair of Thesis Advisory Committee
__________________________________________
Dr. Matthew Lindberg, Professor of Psychology
_________________________________________
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Dr. Sambit Bhattacharya, Professor of Computer Science
ABSTRACT
Baker-Oglesbee, Alissa. Testing the Efficacy of Robot-to-Human Goal Directed
Actions (Under the direction of Daniel Cordoba-Montoya, PhD). Robotic technology
is rapidly being integrated into human life. One aspect of robotics is as an educational
tool to aide humans in learning skills. Prior research on the mirror neuron system has
posited that humans are able to discern the goal of motor actions enacted by humans even
when the action flow is incomplete. Theoretically, this effect is only observable when
humans see other humans perform tasks. If this is true, participants should have a more
difficult time accurately replicating motor tasks when demonstrated by a robot rather than
a human. Participants viewed either a human or a robot performing motor tasks. The
participants then attempted the motor task demonstrated while timed and tracked for
error. Measurements were analyzed revealing significant differences in error within group
but not between groups. Implications of research are beneficial in the novel combination
of the mirror neuron system with embodiment theory and in gauging a robot-human
interaction through a motor-teaching paradigm.
Keywords: robotics, mirror neuron system, goal understanding, embodiment
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ACKNOWLEDGEMENT
Foremost, I would like to formally thank Nathan Oglesbee, Sean Mobeley, Merei
Clouden, and Ashley Bofill for their assistance in various elements of my work. I would
like to express my thanks toward the educators in my life…my parents, grandparents,
nature, and great teachers. Of these teachers, there are a few that stand out and deserve
individual acknowledgement: Mr. John Spencer, Dr. Sharon Roberts, and Dr. David Scott.
Each in their own way exposed me to new ideas and ways of thinking. One cannot be
more grateful for the opportunity to experience that ultimate freedom of thought.
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DEDICATION
This labor, representing an immense amount of personal, professional, and
emotional growth, can be dedicated to no one but my sister Tara Davis and my husband
Nathan Oglesbee. You both are pivotal in my life and I am grateful for all your love and
support.
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TABLE OF CONTENTS
Page
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Chapter I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter II. Review of related literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Robotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Mirror neuron system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Embodiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
The current experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Chapter III. Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Chapter IV. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Chapter V. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Chapter VI. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Appendix B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Appendix C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
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LIST OF TABLES
Page
Table 1. Descriptive statistics for robot-viewing group . . . . . . . . . . . . . . . . . . . . . 38
Table 2. Tests for normality by group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 3. Mean times and standard deviations for time variable
between groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 4. Mean difference in time between second and novel puzzles for
robot-viewing group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 5. Mean backtracking error differences between groups . . . . . . . . . . . . . . 45
Table 6. Mean differences between novel and exposed errors
between groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
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LIST OF FIGURES
Page
Figure 1. Flow Chart of Experimental Procedure . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 2. Bar Graph for Time Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Figure 3. Bar Graph for Error Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
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CHAPTER I
INTRODUCTION
This could be an overly optimistic opinion, but I believe that it is currently a
remarkable time to be a scientist. Within the past 50 years, we as a global society have
been witness to a dizzying amount of technological innovation and sophistication. These
advancements have allowed new insights and methods for scientific study. While some
inventions have undoubtedly had a dubious impact (the atomic bomb, for example), the
general purpose of technology is to provide people an easier and more efficient way of
life. The many implications of technological application can be convoluted though. It can
be argued that any technological advancement creates its own set of complications. For
instance, the instantiation of text messaging into our daily lives can make sending a quick
communiqué simple, yet the overwhelming usage has been tied to increased vehicular
accidents (Hosking & Young, 2009).
Whatever a person’s philosophical stance is on the matter, it is unlikely that the
expansion of technology is not going to stop anytime soon. Some of the latest
technological developments have brought humans and machines closer than ever before.
The development of nanotechnology, for example, makes possible the introduction of
very small robots into our bodies to perform medical procedures or provide sensory
enhancement (Roberts, 2011). New areas of social research have developed alongside the
field of robotics as machines have become increasingly integrated into the human social
sphere. The increasing social sophistication of robotics is prompting new questions
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regarding a human’s relation to machines (Morana, Movellan, & Tanaka, 2011). This
study intends to delve into the area of human and machine interaction. In the face of
increasing incorporation of robotics into human lives, what are the possibilities of these
exchanges?
The goals of this study are to measure the capacity a human has for learning from
a robot in comparison to learning from another human; specifically whether a human is
able to ascertain a goal from a series of motor tasks from a robot as clearly as from
another human. The mirror neuron system has been indicated as the physiological area
for motor learning and goal understanding (Gallese, 2009), and for this reason will be
examined through existing literature to question its’ function in response to a robot or
human stimulus.
Additionally, the theory of embodiment will be examined as a potential theoretical
fit for future study of the human mirror neuron system. The mirror neuron system has
been indicated as the physiological area for motor learning (Gallese, 2009). Although
this element of the study is not directly tested in the design, it proposes a perspective that
may render deeper understanding of the function of the mirror neuron system while
underlining the philosophical problems of human-robotic interaction.
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CHAPTER II
REVIEW OF RELATED LITERATURE
The field of robotics is currently expanding into new applications through
personal robotics. This application of robotic technology finds uses for robots in more
intimate settings and is focused on creating a relationship between the human user and
the robot. These roles vary from small non-humanoid robots that vacuum a room or to
humanoid robots that can serve a user coffee or even teach a foreign language (Turner,
2006; “ASIMO”, 2010; Kanda, Hirano, Eaton, & Ishiguro, 2004). This type of personal
interaction has created a need for research on the ability for humans to relate socially to
robots. This study will examine the human ability to learn motor skills and derive goal
intentionality from robotic counterparts. An introduction to personal robotics and some of
the underlying theoretical assumptions of the cognitive scientists who pioneered the
development of digital computing will follow.
Physiologically, a human’s ability to learn motor actions and goals has been tied
to a particular region of the brain known as the mirror neuron system (MNS) (Rizzolatti
& Craighero, 2004). A brief overview of the history of study of the MNS and description
of its basic functions will be discussed, as well as some of the more controversial
proposed functions. The mirror neurons system’s role in learning motor actions, response
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to different stimuli (biological and non-biological), developmental changes in response,
and the ability for goal understanding will be of primary focus.
Finally, to ground this study in a proper theoretical framework as necessitated by
the goal understanding function of the MNS, a brief review of embodiment theory will be
discussed. Evidence of the rehearsal of motor actions in the mirror neuron system
(Gallese, 2009) will be shown to be better understood theoretically through the framing
of embodiment theory than the framing of the mirror neuron systems function through the
computational assumptions of cognitive science (the predominant theoretical approach
within the field). Examples of brain function and perception will be highlighted to exhibit
embodiment within a cognitive framework as opposed to the classical philosophical
construct made popular by Merleau-Ponty and Husserl (Dolezal, 2009).
Robotics
By and large, the exploration of robotic technology within the field of psychology
occurs almost exclusively by researchers in the cognitive science area of study. The
adoption of the study of robotics and artificial intelligence by cognitive psychologists is
found in the very early history of the field of cognitive science itself. Originally dubbed
cybernetics by its founders, two key symposiums in Cambridge and Dartmouth during
1943 presented the original foundations for theoretical development in cognitive science
(Varela, Thompson, & Rosch, 1993). The primary concepts that emerged as unique to
cybernetics were computational theory and symbolic informational-processing.
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At the time cybernetics was developing, the theoretical framework for psychology
was largely derived from behaviorism. The behavioralist foundations of objectivity and
quantifiable methodology produced great strides for the burgeoning field of psychology
by solidifying it as a natural science based on observable phenomenon as opposed to the
introspective techniques popular in the early history of American psychology. While
facilitating positive growth for psychology, the focus on overt behaviors also invariably
stifled any study that involved the mind or its processes. This lack of exploration of the
processes that occur between the administration of the stimulus to the organism and the
organisms’ resulting response is referred to as the “black box” approach (Varela et al.,
1993). The reason behaviorists chose not to engage in discussion or study of the mind lies
in their methodological philosophy. Observable behaviors were thought to be of utmost
importance, primarily because it is only observable behaviors that could be viewed in a
primarily objective sense and thus allow for more reliable and valid measures. The mind
and its processes are not observable and thereby not objectively reliable or easily
measured. The behaviorists did not believe that the mind was nonexistent or that it was
unimportant to explore, but they recognized that an objective methodology offered no aid
for such study.
Cognitive science found its way into field discussion by attempting to peer into
the “black box.” Cybernetics and later, cognitive psychology, found interest in trying to
define, measure, and specify the mental processes, or cognition, needed to process
information from stimulus to response. To approach these issues, a new theoretical
approach was devised that more allowed for a more effective look into the mind and its
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processes. Cyberneticists reframed psychological science by attempting to resolve a
classic philosophical quandary, the ‘mind-body problem’ (Anderson, 2001; Dolezal,
2009; Varela et al., 1993).
Most famously discussed by Descartes, but acknowledged even earlier in
philosophical history, the mind-body problem recognizes the apparent gap between
thoughts and the body or brain. The root of the problem lies in the observation of
Newtonian physics which states that only matter can affect matter. Thoughts have no
physical substance and, as it is generally accepted, one may not use thoughts in a way
that impacts the physical environment. The question arises, how does thought (which is
non-matter) cause change and movement in the body (which is matter)? Descartes’
solution, known as Cartesian dualism, states that the mind and body are two separate
properties, such as a gas and a solid. Descartes believed that the mind was housed within
the body and interacted with the body through the pineal gland in the brain. This premise
of mind and body being separate substances, properties, or sides of a spectrum formed an
ongoing philosophical perspective collectively termed dualism. Although dualistic
perspectives pervade both scientific and folk psychology, they have yet to effectively
solve the mind-body problem. Dualism does not provide an answer regarding how the
intangible mind can bridge the gap to communicate and guide the body (Anderson, 2001;
Dolezal, 2009; Papineau & Selina, 2002).
Cognitive scientists largely subscribe to a diametrically opposing perspective to
dualism. This perspective, termed monism, can be expressed in very different ways. The
primary division falls between idealism, which states that the physical world does not
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exist, and materialism which states that the physical world is all that exists. Cognitive
scientists are generally material monists. Regarding the mind and brain, the fundamental
principles of cognitive science presume that the mind and brain are the same property or
that mind is an emergent property of the brain. Following this assumption the study of the
brain is ultimately study of the mind (Anderson, 2001).
Computational theory is a strong example of the implicit presence of the material
monist philosophy, and also illustrates how philosophy can guide physical research of the
mind and brain. It is no small coincidence that as cyberneticists were honing in on the
foundations of cognitive science, computer science was moving leaps and bounds away
from early versions of adding machines to what is more representative of modern
computer technology. Analog technology was becoming more refined and many scientists
of the mind saw computer models as a way to conceptualize brain and mind function
(Abraham, 2002; Rav, 2002).
During a symposium in 1948, John von Neumann discussed his conceptual design
for the analog computer. Briefly, this model outlined the input of data, the manipulation
of data by the central processing unit or executive control into short term and long-term
memory, and the resulting output. Immediately following von Neumann’s presentation
was a discussion led by McCulloch on his publication ‘Why the Mind is in the Head’,
during which he presented the theory that the brain functions in a manner similar to an
analog computer. In this analogy, the brain operates as the hardware and mental processes
operate as symbolic information software. Warren McCulloch is credited for creating the
foundation of the computational theory of mind, officially uniting computer science with
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psychology (Rav, 2002; Varela, et al, 1993). Many psychology texts today still include
Von Neumann’s model for information-processing, which, although was originally
intended to serve as a model for computers, was usurped by psychologists as a model of
how the brain itself processes information.
Computational theory posits that the brain functions in a specific manner, as
directed by algorithms, and performs as an information processor. Information processing
constitutes taking information from the environment, transcoding that information
symbolically in the brain to allow for different cognitive functions to act upon the
information, and when necessary produce some type of output. This system is regarded a
cohesive integration of mind, brain, and body according to the material monist
philosophical foundation. This early interdisciplinary marriage between computer science
and psychology has made possible the creation of artificial neural networks, artificial
intelligence, robotics, and telepresence technology; all currently expanding fields of
research and development in private, federal, and academic sectors (Abraham, 2002).
Within the past decade, society has watched on as robots have begun to vacuum
carpets (Turner, 2006) and enable people to interact with others remotely via the robot
itself (Sofge, 2009). More and more often robotic technology is being integrated into the
private sector and our personal lives. Personal robots are robots that are designed to assist
with household and office tasks (Wang, Miller, Fritz, Darrel & Abbeel, 2011). According
to ABI Research (2010), personal robotics is a growing industry with a projected market
of $19 billion in 2017. During the six years after the prominent personal robotics
company iRobot® (the maker of the Roomba®) first released their initial models in
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2000, 3 million robots were purchased (LaGeese, 2008). The International Federation of
Robotics states there were 2 million personal robots in use in 2004, with a projected
increase of 7 million by 2008 as cited by Bill Gates (2007). Willow Garage® is a
burgeoning personal robotics company that has been making popular news with its
premier open-source personal robot model, the PR2®. Many of the tasks these personal
robots are capable of allow some simple tasks to be left to the machine, freeing up the
owner to pursue other activities (Alsever, 2010). The modern advent of personal robotics
is akin to the revolution that transformed the 1950’s kitchen, freeing housewives from
day-to-day drudgery through use of modern electric appliances.
Japan is a country on the cutting edge in the personal robotics industry. Large
advancements in the field are proving to be of more use to the Japanese population than
merely providing careers and lending status to the country as a sophisticated player in the
robotics field. Japan has been experiencing a negative growth rate that is only increasing
since 2007 (“CIA World Fact Book”, 2010; Yamaguchi & Shen, 2008). The inverse
relationship between births and deaths in the country has brought difficulties to the
business sector and robots have been considered as potential clerical workers in the midst
of a dwindling population (Yamaguchi & Shen, 2008). These are positions that rely in no
small way upon rapport, trust, empathy, and other emotional capacities for effective
service.
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Perhaps one of the most advanced examples is the Honda Corporation’s ASIMO®
bipedal humanoid robot. The ASIMO® was designed to operate easily within human
living and work spaces and to perform services for owners (“ASIMO”, 2010). Another
example is the Mitsubishi Wakamaru® robot model. Touted as the first domestic robot
with communication capabilities, the Wakamaru® was created specifically to be a house
sitter, watch over ailing owners, and perform secretarial duties such as answering the
phone, taking messages, and reminding the owner of meetings (“Domestic Robot to
Debut”, 2005).
A slightly different approach to designing personal robots as office workers is
taken by The Kokoro Dreams Company®, who focuses on developing android models.
An android is a specialized type of robot that is designed to look and behave like a human
(Prucher, 2007). Therefore, the Kokoro® robots look very much like real human beings
and have had great attention paid toward facial expressions, voice pattern and diction,
and body language. The Kokoro Company® rents its android models to businesses for
use in many roles. Potential positions are as a fashion model or hostess, a ‘booth
bunny’ (a slang term for models who sell products at tradeshows) or as a remote access
device for an absent employee at a meeting (Kokoro Company Ltd., 2008). Other
suggestions for use include nurse duties, performing as an ambassador, or acting as a
cabin attendant in an airplane. Curiously, the company states that the robot even “takes a
spiritual trip from time to time [on] pilgrimages” (Kokoro Company Ltd., 2008). One can
only imagine the specifications of religiously symbolic usage, but we can infer the extent
to which robots could be or are currently accepted in various roles in Japanese society.
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Robots have also been developed to participate as a player in multiple user
dungeons or MUDs, a role-playing game that relies on player interaction to advance.
Players explored a virtual world together with robots and collaborated in developing
strategies to defeat monsters, find success in the mock economy, and develop traits and
characteristics of the player’s avatar character. Good performance in these individual
tasks led to an overall goal of game success (Chung-Hsiang & Chuen-Tsai, 2007).
The use of robotics is also expanding into classrooms. Robots programmed to act
as a peer tutor and social partner to aid children in learning English were shown to
improve children’s English language skills significantly over children who did not
interact with a tutoring robot. A positive correlation between time spent with a tutor robot
and improved English language skills emerged (Kanda et al., 2004). Given these
examples, the potential for uses of robots in educational settings is intriguing. Certainly,
the above studies show how a robot can provide some elements of educational use to the
benefit of children and very likely, adults. There seems to be a foundation in which
humans are able to understand and develop skills in certain tasks gained initially through
interaction with a robot.
Language, a shared mode of information exchange, may enable robots to act as
effective teachers for human beings. The skills that are being developed and goals to be
attained are expressed through language, either spoken or written, and a large part of the
rapport is undoubtedly created by use of language as well. Language could perceivably
close the gap for a human in connecting with a robot that may not appear human-like or
is otherwise not engaging. Perhaps the ability for a robot to teach lies in its capacity for
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language; however, is it actually possible for a human to learn skills and understand goals
from a robot on an even more basic level of observational learning?
There are some notable problems when considering relying on the creation of
rapport with a robot on a visual or observational basis. First, a preeminent problem in
creating a basis for contextual understanding of human communication by robots is their
incapacity to recognize facial expressions (Nikolaidis & Pitas, 2000). On the other side of
the conversation, humans have exhibited feelings of apprehensiveness and fear in
reaction to communicating or even looking at robots who appear too human, a
phenomenon known as the “Uncanny Valley effect” (Mori, 1970). These are some
problems that might arise when a robot or android approaches more sophisticated levels
of social exchange. An aesthetically simpler robot could obviate these issues without
sacrificing the attempt to test the ability for the robot to teach a human through
observation.
To circumvent potential robot-to-human language barriers, an examination of
learned motor skills might be useful. Motor skills are often learned through observation
and practice, so a motor task is an appropriate way to find whether a robot can
successfully engage a human and teach a skill without the use of language. Motor skills
must expand beyond mere mimicry to establish more sophisticated learning. Mastery of
motor learning can be exhibited through use of the skills initially learned in one task used
to complete another task, understanding that the skills may be used to reach a similar goal
in a different task. The overall goal understanding of motor actions can signal more
meaningful processing than merely visual attending to stimuli. These processes are
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largely mediated by the motor cortex. Recently, a study has revealed that a specific area
of the motor cortex lends itself to processing the intended goals of motor actions. This
area has become known as the mirror neuron system (MNS) (Umiltà et al. 2008).
The Mirror Neuron System
To examine the capacity for a human to learn a motor task and achieve goal
understanding from a robot model, research on the mirror neuron system provides a
physiologically sound and theoretically expanding framework to guide hypotheses and
interpret results. The mirror neuron system is located in the motor cortex and is currently
being explored as a location for more than the delegation and execution of motor tasks, as
is the traditional functional view of the motor sensory area. Recent research presents
evidence that the mirror neuron system may be capable of actual learning and rehearsal of
motor tasks. Previously, learning and rehearsal tasks were considered too complex to be
performed in sensory areas. As prescribed by cognitive computational theory, information
that entered a sensory modality was thought to be transcoded and passed on to other areas
of the brain more suited for higher-order processing (Gallese, 2009).
The initial physiological evidence detailing the location and function of the MNS
was gathered from monkeys. Measurements collected from the mirror neuron system
demonstrated that the neurons fired at the same rate and time for a monkey observing
another monkey eat peanuts as if the observant monkeys had eaten peanuts themselves
(Rizzolatti & Craighero, 2004). While the original ‘discovery’ of the MNS was through
primate brain research, much of the evidence regarding primate’s MNS has carried over
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to inform the function and location of the human MNS. The location of the mirror neuron
system in a monkey’s brain is the F5 area of the premotor cortex (Rizzolatti & Craighero,
2004). Although the evidence for the MNS in humans is indirect, brain imaging
techniques such as electroencephalography (EEG), transcranial magnetic stimulation
(TMS), and functional magnetic resonance imaging (fMRI) as well as neurophysiological
study have created a strong case for the its presence. Human participants have exhibited
strong activation of the neurons in the lower part of the precentral gyrus, the posterior of
the inferior frontal gyrus, and the rostral area of the inferior parietal lobe while
performing motor actions and also while observing other humans perform motor actions
(Grezes, Armony, Rowe, & Passingham, 2003; Jokisch, Daum, Suchan, & Troje, 2005;
Kilner, Paulignan, & Blakemore, 2003). These areas are widely considered to be the
primary area of the proposed mirror neuron system in humans (Gallese, 2009; Gallese et
al., 2009; Oberman, McCleery, Ramachandran, & Pineda, 2007).
Prior to this evidence, learning and deriving goal understanding from actions was
largely regarded as functions of executive cognitive capacities, and thereby primarily
mediated by the frontal lobe region of the brain (Barsalou, 2008). The apparent mental
rehearsal and understanding of goals through motor actions by the MNS opens the door
to considerations that intentionality in some instances may be derived earlier in
processing than previously believed. Other evidence gathered from the MNS also shows
that this system may be responsible for categorizations of perpetrators of action, such as
whether they are human or not human (Shimada & Hiraki, 2006). This automatic
recognition of a conspecific (a member of one’s own species) seems to affect the
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rehearsal of the motor action being observed. In the event a motor action is performed by
an organism that the observer does not recognize as a conspecific, the MNS may not
activate (Calvo-Merino, Glaser, Grèzes, Passingham, & Haggard, 2005; Shimada &
Hiraki, 2006). It would be expected that if the motor action does not activate the MNS to
allow for automatic rehearsal that the motor action may not be performed as well as if the
action had been carried out by a conspecific (thereby increasing the probability of MNS
activation). As a robot would generally not be regarded as a conspecific, the MNS may
play a role in whether humans are able to fundamentally exchange, recognize, and learn
information from robots.
Although many accept the prevailing evidence for the existence of the human
MNS (Andric & Small, 2010; Engel, Burke, Fiehler, Bien, & Rosler, 2008; Gallese,
2009; Gallese et al., 2009; Iacoboni, 2009), the exact function of the system in humans
has created several hypotheses and respective counterarguments. A prime example of
contentious proposed MNS function (or more accurately, malfunction) is the role it may
play in the development of autism spectrum disorders (cf. Ferber, 2010; Hamilton et al.,
2007). Another lively area of debate is that of the phylogenetic development of language
as a coevolving process with the development of the mirror neuron system (Fisher, 2008;
Ramachandran & Hubbard, 2006). Regardless of the controversy involved in these areas,
there is almost ubiquitous agreement from researchers from all sides that the human MNS
is likely to exist. The present study will focus on the relatively accepted aspects and
functions of the MNS in the processing of observed motor actions and goal
understanding.
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Although it is generally accepted that the MNS functions optimally when
receiving stimuli from conspecifics, questions have been raised about the type of
conspecific stimuli the MNS will respond to. Interestingly, it has been shown that the
human MNS will fire in response to a conspecific performing motor actions that are
impossible. The human MNS was shown to fire when the participant observed impossible
movements in an artificial human hand, meaning that the hand performed movements
that are outside of normal physiology (Costantini, Galati, Ferretti, Caulo, Tartaro,
Romani, et al., 2005). This shows that the MNS can and will respond to motor actions
outside a preexisting representational motor repertoire and also outside of movements
that the participant has or can engage in themselves. Such evidence qualifies the ‘direct-
matching hypothesis’ that proposes that only movements that are already a part of an
organisms’ motor repertoire will elicit a response from the MNS (Rizzolatti, Fogassi, &
Gallese, 2001). Evidence suggests that the MNS may develop to respond more to direct
matches through natural age development or specialization of expert skills (via long-term
potentiation).
The sensitivity of the mirror neuron system to different types of stimuli appears to
change over the development of an individual from child to adult. In exploring the mirror
neuron system’s response to mediated realities, differences between adult and child
mirror neuron systems’ firing were tracked while the participants watched live or
televised actions. They found that a child’s MNS activated in both the live action and
televised action conditions while an adult’s MNS activated only in the live condition.
While the children’s MNS seems to react to both mediated or non-mediated motor
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stimuli, the adult’s MNS seems to be more parsimonious or specialized (Shimada &
Hiraki, 2006). Their evidence suggests that the MNS fires in response to different stimuli
over the developmental span of a human, although it is worthwhile to note that the
children used in the experiment may have had more exposure to mediated stimuli earlier
in life than the adult participants did. To highlight the potential of mirror neuron system
specialization through long-term potentiation processes, a separate study tracked a
dancer’s MNS response while the participant watched dance movements or capoeira (a
Brazilian martial art that can appear dance-like) movements and found that the dancer’s
MNS fired more readily during action observation of specialized action (dance) than
other action sequences (Calvo-Merino et al., 2005).
In conjunction with Shimada and Hiraki’s findings, this study suggests that an
adults’ MNS becomes specialized to activate for certain types of motor actions in certain
mediums, and fires more readily in a context that the motor system has more experience
with. This specialization seems to occur through both developmental and experiential
processes. This would suggest that while infant’s brains may behave like sponges,
tracking any activity to have the opportunity to learn, adult’s brains (or expert’s brains)
might be more selective about the stimuli it responds to. This evidence is important when
considering that much of research that focuses on a robot-to-human educational
interaction focuses on the use of child participants (Chung-Hsiang & Chuen-Tsai, 2007;
Kanda, Hirano, Eaton, & Ishiguro, 2004), and that any readiness of a child to learn motor
actions from a robot must be considered to be perhaps a more responsive example than if
an adult were the participant.
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The role of the MNS in deriving the goal of a given sequence of motor actions, or
deriving motor intentionality, is one of the leading theories of proposed function in the
MNS. Neuroscientists have hypothesized that this function would assist an individual in
learning motor processes (Gallese, 2009; Gallese et al., 2009; Pineda, 2008; Oberman et
al., 2007b). Another popular term for this phenomenon is goal understanding.
If the MNS were deriving action understanding in response to the observation of
motor sequences, this would suggest that at least some motor goals could be understood
through bottom-up processing. This would render the processing of the goals as non-
symbolic and modal in representation. Non-symbolic modal processing is a jarring shift
from the traditional computational symbolic models of information-processing that
created the foundations of cognitive science and still dominate theory today.
Computationally based information-processing models provided the field of psychology
the means to conceive of covert cognitive functions (often capitulated by bottom-up
processing of environmental stimuli) that would activate mental models and
representations accessible by the conscious mind for general thinking processes. The
theoretical paradigm of symbolic amodal processing mediated by executive function was
the assumption of much of the cognitive framework and quickly informed other
experimental subfields of psychology, including developmental, industrial/organizational,
and social psychology.
The ability of the brain to perform what is usually considered higher-order mental
tasks, such as recognizing intentionality, through a bottom-up approach requires an
alternate theoretical approach to logical computationalism. One of the currently
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expanding theoretical approaches that is able to account for such processing are the ideas
of embodiment or grounded cognition, which will be explored later in this paper.
Needless to say, it is likely this root issue of bottom-up versus top-down processing of
tasks that results in so much controversy and fascination concerning the study of the
MNS and its’ functions.
Yet, there would be no contest without evidence, and there exists ample evidence
to support the contention that the MNS derives goal understanding from motor actions. In
one such study, monkeys who had previously been trained to grasp objects were given
two different sets of pliers, one that opened with the normal squeezing action and another
pair that opened in reverse fashion by widening the hand’s spread. Monkeys operated the
pliers while the MNS was recorded. The different operations needed to open the sets of
pliers allowed researchers to dissociate the neural motor pattern from the neural goal
pattern (opening). The researchers found the same neural patterns in both cases of pliers
use, even though the motor operation of each set of pliers was different. This would
support a hypothesis that the neurons were firing in response to the goal of opening the
pliers, which is the same across the conditions, instead of merely firing to support the
differential movement of the hand in order to open the pliers, which would have resulted
in different firing patterns across the conditions (Umiltà et al. 2008).
Neural firing in response to goals has been demonstrated in the mirror neuron
systems of human participants as well. In one study, participants watched videos that
displayed a series of finger movements: in one condition the fingers moved toward and
touched red dots (a goal directed movement) while in the other condition the fingers
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moved the same way without the presence of the red dots (no-goal condition). Increased
blood oxygenation was detected via fMRI in the MNS in the goal condition, whereas
there was no increase in blood oxygenation in the non-goal condition (Koski et al., 2002).
In another study focused on goal understanding, participants who were familiar, but not
experts, with basketball watched videos of basketball related actions (dribbling, shooting,
man-to-man plays), which constituted a goal directed condition. Another video showed
non-basketball related actions (rolling the ball, carrying to goal, players crossing in front
of others with no action) to constitute a no-goal condition. fMRI readings showed
significantly greater activation of the superior temporal sulcus and the inferior parietal
lobule (part of the MNS) in the goal-directed condition (Takahashi, Shibuya, Kato, Sassa,
Koeda, Yahata, et al., 2008). While there is evidence that some goal understanding is
occurring in the MNS, it also seems that the activation to goal conditions occurs early in
the processing of information and that later in processing the system begins discerning
whether the observation included a conspecific (Costantini et al., 2005). This would seem
to indicate that there is room for both top-down and bottom-up processing of goals and
intentionality.
Another study compared the relative activation of goal understanding in different
areas of the brain by having participants view videos that displayed a woman drinking
coffee. Participants would view either an expected flow of events, extraordinary events
(woman puts coffee cup to ear instead of bringing to mouth), or extraordinary means
(woman has a power grip on the dainty cup). During exposure to the video stimuli, the
MNS and the social cognition areas of the brain traditionally considered responsible for
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‘mentalizing’ goals – the posterior cingulate cortex, frontal cortex, and superior temporal
sulcus, were monitored for activation. When the activation results were compared,
evidence for a complementary system of goal understanding emerged. Participants would
show more activation in the MNS area when observing of the extraordinary events
segment compared to the ordinary actions (ordinary means and events) segment. The
inferior frontal gyrus in the MNS activated whether participants were asked to focus on
intention or the manner of action. More activation was shown in social cognition areas
when participants were asked to selectively attend to the intentionality of the woman’s
actions (de Lange, Spronk, Willems, Toni, & Bekkering, 2008). This evidence shows that
the MNS consistently activates whether attention is directed to intention or actions (with
the enhanced activation to extraordinary events vs. ordinary actions showing selectivity
for intentions) during observation, but that a person must focus on intentions solely to
activate the social cognition areas. This suggests that these areas work together in a
complementary system of bottom-up and top-down processing.
To assess the role of context in deriving intentionality in the MNS, a study was
performed using a similar instrumental method as the previously discussed study. One
scene was created in which various sundries and containers were displayed as if in
preparation for a meal, all items untouched and organized. A separate scene was created
in which these objects and food items had been obviously consumed and were ready for
clean up; containers had been empty, crumbs and leftover food was left where untouched
food items had been previously, a jar was tipped over, and so on. A control scene was also
used wherein no object was displayed except for a single coffee mug. The mug was
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included in every scene and was filmed being grasped in two different ways, either using
the whole hand to pick the cup up around the lip or using a precision grip using the
fingers at the handle. The whole hand grasp is more suggestive of picking up the cup for
something other than drinking, and when used in the scene in which everything is ready
to be cleaned the grasp fits well contextually. The precision grip is contextually fitting in
the scene where it appears that a meal is about to be enjoyed, and that the cup is being
picked up to be drank from. Blood oxygenation level-dependent (BOLD) readings of the
MNS revealed significantly more firing (by way of heightened blood oxygenation) in the
contextually congruent grip and scene pairing for the precision grip and drinking context.
This effect was not present in the whole-hand grasp and cleaning context, which is
possibly because a whole-hand grasp is not used solely for cleaning and could
conceivably be used to pick up a cup to drink from (Kaplan & Iacoboni, 2006). These
studies suggest that goal understanding is occurring in the MNS, at least in part, and is
likely contextually sensitive.
As mentioned previously, the MNS has been shown to anticipate the goal of a
series of motor actions. Much of this research has used biological stimuli to elicit
activation, primarily in the context of a human confederate performing motor actions
with objects. There has been some research performed testing the ability of the MNS to
activate in response to non-biological action, although much of this research focuses on
the apparent self-locomotion of objects such as toys, balls, or other common household
items (Engel et al., 2008; Eshuis, Coventry, & Vulehanova, 2009). In the face of
increasing and more personalized technology (especially in the robotics field) an
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important question is if the mirror neuron system will derive intentionality from
observation of a robot as easily as from observation of a human.
To begin to address this inquiry, it is first important to find if the human mirror
neuron system will even fire in response to non-human movement. There has been a
range of experiments performed to see if the mirror neuron system will fire in response to
general non-biological movement, such as self-locomotion in shapes vs. human hand
movement. In studies such as this, the mirror neuron system does activate to non-
biological motion, but not as strongly as it does to conspecific actions. These results have
been interpreted as a side effect of the human tendency to personify moving objects
(Heider & Simmel, 1944) and also as a tendency to perceive movement as biological
simply because that is the type of movement encountered most often (Engel, Burke,
Fiehler, Bien, & Rosler, 2008).
The mirror neuron system has been shown to fire in response to robotic agents in
some cases (Gazzola, Rizzolatti, Wicker, & Keysers, 2007; Oberman et al., 2007a;
Oberman et al., 2007b), and not in others (Kilner et al., 2003; Tai, Scherfler, Brooks,
Sawamoto, & Castiello, 2004). Although the literature contains mixed results, it does
seem that more often than not a robot will activate the human mirror neuron system as
much as a human agent if the robot agent is more humanoid in appearance and is
performing an action that is similar to a human-like action, such as picking up a ball,
walking bipedally, or grasping a martini glass. Results have shown though that if one of
these actions is shown repeatedly, the mirror neuron system habituates to the action and
responds less aggressively to the robotic movement as compared to a human movement
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(Gazzola et al., 2007). These results may tie in with the function of goal understanding. If
a robot performs a singular action, such as picking up a martini glass, this action matches
well with the observer’s own motor repertoire and also is matched with the potential goal
of drinking. Yet if the action is performed repeatedly with no conclusion of the action
(lifting the glass to a mouth, or throwing a ball after grasping) the goal is never actually
fulfilled and the action is no longer perceived as a goal oriented action, resulting in
habituation of the mirror neuron system.
It can be extrapolated from the literature that it is likely that the human mirror
neuron system seems to fire in response to any motion (non-biological, biological,
possible or impossible) initially, but that it fires most readily to motion that infers a goal.
Research on more complex goal understanding using adult participants has been focused
on conspecific observation primarily (de Lange et al., 2008; Kaplan & Iacoboni, 2006;
Koski et al., 2002; Takahashi et al., 2008); while goal conditions involving a robot have
involved moving blocks from one area to another (Erlhagen, Mukovsky, & Bicho, 2006)
or picking up a glass (Gazzola et al., 2006). The goal conditions in these studies are far
more simplistic than the basketball paradigm (Takahashi et al., 2008) or the contextually
rich cleanup or drinking scenario (de Lange et al., 2008). The current study design
addresses the need for data concerning the ability for a human to recognize and learn
complex goal understanding from a robot engaged in a motor task.
There has been some research performed in which robots would perform more
complex tasks than moving an object to a new location or pick an object up. In one such
study, children watched either a human or a robot sort cards according to a specific
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conditional rule. The children were then asked to sort cards according to a different
conditional rule. It was found that the children who observed the human sort cards had a
more difficult time in the task than the children who observed a robot sort cards. The
results imply that the children’s mirror neuron systems were more engaged in simulating
the human’s actions than the robots, and that they were less able to move on to a new
condition because of the impact of the human rehearsal condition (Moriguchi, Kanda,
Ishiguro, & Itakura, 2010). A separate study showed that children were able to infer the
intended goal of a robot (‘intending’ to put beads in a cup, but ‘accidentally’ dropping
beads outside of the cup) better if the humanoid robot made eye contact with the children
during the task than if the robot made no eye contact (Itakura et al., 2008).
The increased rate of testing of human discernment of goal understanding in a
robot’s motor actions using children as compared to adult participants is undoubtedly a
result of the anticipation of the use of robots in primary education settings. Although
robots are being used primarily for educational interaction with children at the moment, it
is safe to assume that the growth of the robotics industry will eventually place robots in
roles through which adults will interact with robots. Also, considering the evidence that a
child’s mirror neuron system may react differently to alternatively mediated stimuli and
non-biological motion than an adult’s (Shimada & Hiraki, 2006), it would be unwise to
assume the data garnered using child participants would be directly replicated in with
adult participants. Current research is still unclear concerning evidence that of MNS
activation by robots in adults and very little complex goal-understanding research has
been studied using an adult population.
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Embodiment Theory
Embodiment theory can be viewed as a new and radical perspective on current
psychological research, or as a philosophical construct with roots as far back as the
origins of Eastern spiritual and metaphysical thought (Varela, et al., 1993). Although
there are several iterations of embodiment, the crux of the philosophy of embodiment
purports that nothing in this physical world exists as a singular and isolated entity,
including human beings (Barsalou, 2008; Varela, et al., 1993). To illustrate this idea using
a popular adage; “No man is an island…” (Donne, 1839). Human beings are not simply
the bodies we observe in the grocery store or the classroom, nor are they the mind alone.
In fact, even the union of the body and mind would not be a complete human.
Embodiment states that we are a continuous union of mind, body, and environment,
including the social environment (Varela et al., 1993).
More to the point of interest for this work, one aspect of cognitive embodiment
theory provides that the mind and brain rehearses some external stimuli in modal
(sensory) areas, rather than transforming all stimuli into logical abstractions of
knowledge per the computational approach (Glenberg, 1999). This perspective lends
itself well to what researchers know about MNS function. The MNS is rehearsing
observed motor stimuli in the motor area of the brain rather than acting as simply an input
area (Gallese, 2009). I am proposing that the MNS be considered a hard example of
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embodiment processing in humans. This proposal, to my knowledge, is novel in the field
of psychology. Rather than asking if the human MNS can learn motor actions from a
robot as well as a human, I feel it is more correct to ask whether the human MNS can
embody motor actions from a robot as well as a human.
The MNS is not the only example of modal processing in the brain. There have
been other modal processing areas and phenomena that highlight how embodiment can be
an attractive theoretical approach for further research and exploration. It has become
clear that the symbolic computational approach does not adequately describe or explain
information-processing in all instances.
Perhaps the most famous example of a cognitive process best understood through
embodiment theory is that of color vision. It has been understood for some time at this
point in the sciences that color does not exist in the natural world as we perceive it, but it
also does not reside solely within our brains. Color is actually a phenomenon, an
interaction between the environment and our visual perceptual faculties (Varela et al.
1993). This relationship highlights the dynamic exchange between the brain and the
environment, a contrast to the one-sided linear process operating within a static
environment as in symbolic processing theories.
Another example of a well-known psychological phenomenon that melds well
with embodiment theory is phi phenomenon, or apparent motion, as described by Gestalt
theorist Max Wertheimer in 1912. Phi phenomenon is the subjective perception that two
alternately flashing lights that are horizontally arranged in the field of vision appear to be
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one light moving back and forth. Wertheimer successfully rejected other explanations of
the phenomenon by illustrating that the perception was a product of the stimuli
movement (environment) and our perceptual system (mind and body) (Ammons &
Weitz, 1951). Arguably, many of the observations made by the Gestalt psychologists
are intrinsically descriptions of embodied phenomena.
A more modern example of embodied processing is Shepard and Metzler’s visual
representation experiments in the 1970’s. Participants were presented with sets of two
three-dimensional figures and asked to determine whether the set contained the same or
different figures. The sets that contained the same figure would present that figure at
different degrees of rotation. The researchers found a direct linear relationship between
the time it took to determine whether the figure was indeed a rotated version of the
primary stimuli and the degree of rotation of the figure (Shepard & Metzler, 1988).
Similar findings were produced in a separate experiment (Kosslyn, 1973) in
which a participant viewed a picture of an object (ex: an airplane) and was then asked to
focus on one particular element of the object (a propeller). After viewing the object for a
set amount of time the picture would be removed from view and the participant would be
asked to recall if the object had an element that would have been out of the area of
directed focus for the participant (vertical or horizontal fins on the tail). Results showed
that the length of time it took for participants to answer was relative to the distance of the
parts of directed focus and parts questioned about but not focused on.
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These experiments strongly suggest that the visual information available to
conscious processing was not represented in a symbolic manner as prescribed by
computational theorists, but were represented visually in their mind by actually
‘picturing’ the stimuli. These are strong examples of modal representation of information
and thereby embodied cognition. This evidence parallels the rehearsal process of the
MNS (Gallese, 2009).
Although the proposal for the MNS to be considered a structure that operates at
least partially in an embodied manner is novel, the potential for human embodiment of
robotic actions without consideration of the MNS has been studied at least once. In this
singular study, children played a drumming game with a humanoid robot. Both the child
and the robot had their own drums, and the game involved the children and robot taking
turns playing their respective drums. The children were asked to mimic the beats that the
robot would play. The first condition of the experiment would have the robot and child in
a room together (‘face-to-face’). The second condition was mediated, the children
watched a live video feed of the robot. In the final condition the children would play in
the same room as the robot, but the robot was behind a partition so they would not see the
robot but could hear the drumming. Children reported more enjoyment playing the game,
played longer, and made significantly fewer errors in the live condition than in either the
mediated or listening condition. It would appear that children embodied the live robot’s
actions better than the other conditions (Kose-Bagci, Ferrari, Dautenhahn, Syrdal, &
Nehaniv, 2009).
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There are two important differences to be considered when comparing this study
design with the current design: first, this experiment used an extremely human-like robot
(the robot looked very much like a child) and one would expect a greater degree of
embodiment from what could essentially be considered a conspecific visually and by
motor movement. Secondly, the research as outlined previously in the robotics section of
this work has shown that children’s mirror neuron systems are more predisposed to react
to robotic or mediated agents easier than an adult’s MNS (Shimada & Hiraki, 2006). This
does not negate the importance of the studies findings, merely suggests that there is a
need for varied inquiry.
These differences highlight that the current study’s use of adult participants and a
non-humanoid robot addresses a neglected area of study in the embodiment literature.
The suggestion that the MNS functions in a manner that supports the growing literature
on embodied cognition is a novel proposition. There is no proposal from the embodiment
literature concerning goal understanding, or whether embodiment of a robot will or will
not enable goal understanding to occur more easily. My hopes are that this experiment
can lend itself to further experimental study and consideration of embodiment theory in
robotics and psychology.
The Current Experiment
The current study is focused on assessing the potential for human motor learning
from a robotic teacher. Human-robot interactions are becoming an important aspect of
human life, and the personal robotics area is rapidly growing due to consumer demand.
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Personal robotics will play an increasing role in home service, and the use of robotics in
education is beginning to be explored. Motor learning and goal understanding will be an
important factor in building better interactions between humans and robots.
The capability for a human to learn motor actions and understand goals or
intentionality from a robotic counterpart is currently best assessed through findings on the
human mirror neuron system. Evidence has been gathered that shows that the human
mirror neuron system will fire most readily to conspecific movement, but will also fire in
response to non-biological motion such as a robotic arm movement. The mirror neuron
system will fire most readily to familiar movements, but will also fire in response to
impossible movements. The mirror neuron system also fires in response to goal related
sequences of movement more significantly than randomized series of movements. Some
study has been performed to assess the readiness of the human mirror neuron system to
fire in response to robotic movement, but no work has been done to assess the ability for
humans to perceive goal intentionality from a robot’s sequence of motor actions.
Determining whether humans are able to derive intentionality from a robot’s motor
sequences is the main point of question in this study. If humans are better able to
understand motor goals from conspecifics, the group that watches a robot perform motor
tasks should perform worse than the group who watches a human perform motor tasks.
Embodiment theory allows the current study to be viewed in a larger theoretical
perspective. The human mirror neuron system operates through automatic rehearsal of
motor actions when performed by a conspecific. This rehearsal is processed in the human
mirror neuron system as if the observer had performed the action his or her self. The
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simulation process is performed modally in the motor system and does not require
transmission of the information to other cognitive areas for learning (Gallese, 2009). Goal
understanding of motor actions has also been proposed as a modal function of the mirror
neuron system (Umiltà et al. 2008). Both functions, but especially the goal understanding
function (Hans, Henk & Ruud, 2012), had been previously determined to be solely top-
down symbolic processes while the modal areas served as sensory inputs (Palmer, 1999).
Embodiment theory proposes that at least some forms of cognition are represented and
interpreted modally, making the proposed functions of the mirror neuron system a good
example of embodied cognition. Current embodiment literature has very little study on
whether a human can embody information originating from a robot, and no work on
whether goal understanding or intentionality can be embodied. These missing points in
the literature are the secondary focus of this study. If the mirror neuron system is able to
embody the motor actions and intentionality of the robots, there should be little difference
in the times between groups on tasks and the groups should show similar execution of the
tasks in terms of repetition of observed movements. This study questions whether a
human can embody robotic motor actions and goal understanding as competently as
human motor actions. I hypothesize that a human will not embody a robot’s motor actions
as effectively as they would embody a conspecific’s motor actions. I also hypothesize that
a human will have less overall goal understanding of a robot’s motor actions than a
human’s motor actions.
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CHAPTER III
METHOD
The present experiment utilized a between-groups design (human-viewing x
robot-viewing), the first group was exposed to a human video stimulus and the second
group was exposed to a robot video stimulus. In the robot-viewing condition the
participant viewed two videos of a robot solving two different tangram puzzles. Tangram
puzzles consist of different geometric plastic shapes (ranging in size from 1 inch to 3
inches in area) that may be arranged to create large shape and figure silhouettes. In the
human-viewing condition the participant viewed two videos of a human solving the same
two tangram puzzles. After viewing each video, the participant was asked to solve the
puzzle they had just observed being solved and then solve a final novel tangram puzzle
they had not seen solved. The dependent variables are the amount of time it takes to
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complete the puzzles (a measure for each of the three trials) and how many times tangram
pieces are removed from the puzzle form while the participant is solving. The removal of
tangram pieces from the puzzle form during a randomized selection of solving time
served as a count for error.
Participants
Forty-one students from Fayetteville State University were tested in total, with 22
participants in the human condition and 19 participants in the robot condition. Six
participants were excluded from data analysis; 1 participant because of researcher error in
administration of the experiment tasks, and the other 5 for failing to complete two of the
three puzzles within the time limit of 15 minutes. Group counts after exclusions were 16
participants in the human group and 15 participants in the robot group. Twenty-six
participants were female and 5 were male. No significant differences were found on any
performance measure between males and females. No other demographic data was
collected on the participants. Nearly all participants volunteered for participation through
the university Participant Pool website. Four participants volunteered for participation
with the researcher directly. Undergraduate students received grade points for
participation in the research.
Instruments
The original experimental design was to use a Hanoi Tower puzzle as one of the
tasks, but was later cut due to the inability of the robot or the grabber arm to complete the
task. This task could allow for time measurement, a move count, and an error count as it
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requires the user to follow a specific pattern to correctly solve. Sets of tangram pieces
were chosen as an alternate puzzle to the Hanoi Tower puzzle, and puzzle forms were
drawn and laminated. For the human video, a female volunteer was filmed solving 5
different tangram puzzles. The camera aperture was focused on only her hands, the
tangram pieces and the puzzle form. Two of the puzzles with the shortest solution time
were chosen to serve as the human group instruments. After selecting the videos, they
were coded movement-by-movement and timed. To film the robot video stimulus, a long
arm grabber was purchased to simulate a robotic arm. The grabber arm was 30 inches
long with a gripping set of two arms with suction cups at the end which can be closed by
the pull of a trigger at the opposite end of the mechanism. Using the arm, the two puzzles
selected in the human condition were replicated for the robot video stimulus. The puzzles
were solved in an almost exact method to the human condition, although some elements
were unable to be replicated; such as picking up certain pieces and manipulating them in
the hand, or moving more than one piece simultaneously on the board. The stimulus films
were edited and copied to a DVD using iMovie™ and Microsoft Movie Maker™. The
puzzle solving was not edited aside from a frame rate manipulation and the insertion of a
blue screen at the movies’ starting and ending points.
As using the grabber arm slowed down the overall time to solve the puzzles in
comparison with the human condition films, the robot films had the frame rate increased
by 125%. This manipulation permitted the alignment of the different film conditions. It
was not readily apparent that any manipulation had been performed on the films. No
participant inquired or remarked about the speed of the robot condition.
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Participants watched the video stimuli on a 27-inch television that played the
DVD through a Zenith® DVD player. Participants viewed the films from a chair and
table centered in front of the television from a distance of 5 feet. Participants were filmed
solving the puzzles with a Kodak® EasyShare® digital camera and timed with a
stopwatch application on a Samsung® cellular telephone. The camera aperture was
focused on only their hands, the tangram pieces and the puzzle form. Data analysis was
performed using SPSS® v. 19 and G*Power™ v. 3. Any and all data collected from
participants were secured in a room only accessible by the researcher and Fayetteville
State University psychology faculty.
Procedure
Experimentation was performed on an individual basis. The experiment was
approved by the Internal Revue Board of Fayetteville State University (Appendix C).
After signing the consent forms (Appendix B) the participants were read the oral script
(Appendix A) by the researcher describing what they would be doing, which contained
information as to whether they would be watching a human or a robot solving puzzles.
The robot-viewing participants were read an additional statement to prime expectations
for viewing a robot: “The arm you will see is being manipulated by a robotic software
program.”
The script also informed participants that they had 15 minutes to solve each
puzzle and that they could quit at any time. To try and ensure the participants were fully
paying attention to the movies, they were asked to count the number of moves used to
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solve the puzzle, operationalized as how many times the tangram pieces were moved into
the black area of the puzzle. After the script was read participants had a chance to ask
questions and then participants watched the first film. Once the film had reached the blue
screen in between the first and second puzzles, the researcher paused the film and asked
the participant how many moves they had counted while watching the video. After
receiving an answer the researcher brought the participant the puzzle they had just
observed being solved from an adjoining room where the puzzles were kept out of sight
of the participant. The researcher filmed the participant working on the puzzle until it was
solved or the allotted time of 15 minutes had passed. The participant’s time was tracked
along with the filming.
After the first puzzle trial had been completed or timed out, the researcher cleared
the puzzle from the table and removed the puzzle to the adjoining room. The researcher
reminded the participant that they were to count the moves used to solve the puzzle and
started the film again, which played through the blue screen and the second puzzle. After
the film ended, the researcher asked the participant for the moves they had counted and
then retrieved the puzzle they had just observed being solved from the adjacent room.
Participants worked on the second puzzle trial while being filmed until the puzzle was
either complete or they ran past the allotted time of 15 minutes. The puzzle was then
cleared from the work area and the researcher brought out the final puzzle, which was
novel to the participants in that they had not seen the puzzle solved on a video or seen the
puzzle form before. Participants solved the novel puzzle under the same conditions as the
first two puzzle trials. After either solving or failing to solve within time, the researcher
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indicated to the participant that they had completed the experiment and thanked them for
their participation. At that point the participant was offered a copy of the experiment’s
consent form for their own records. A visual representation of the procedure of the
experiment follows in Figure 1.
Watch first film
Solve first puzzle
Watch second
Solve second
Solve novel
Figure 1
CHAPTER IV
RESULTS
Time and error served as the dependent measures to constitute an overall measure
of learning. Time of completion was the elapsed time of the participant’s engagement
with the puzzle. Time was measured until the participant would lay their hands on the
table along the sides of the puzzle form indicating completion as directed, or until the
participant requested to end the puzzle trial before completion. Error was operationalized
as the number of times a participant would remove pieces from the puzzle form in a
randomized 1-minute video sample from each puzzle trial. The error variable is called
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‘backtracking’, a term created by the author for this study. It should be noted that there
was one participant who did not backtrack during any puzzle trial (making them an
outlier on this variable), and another participant was missing a backtracking measure in
one of their three trials due to video failure during experimentation. These two
participants had group means placed into their missing values as an alternative to deletion
from the small sample size.
When assessing normality of the data the time measures were found to be
positively skewed. A log transformation was applied to the time measure, which
completely normalized the human-viewing group’s distribution, and nearly all of the
robot-viewing group’s distribution. After transformation, the robot-viewing group still
exhibited slight skewness in the first puzzle trial data as shown in Table 1. This
abnormality in the robot-viewing group’s first puzzle trial distribution is due to the high
number of participants that were unable to solve the puzzle before the 15-minute limit. As
the main considerations in analysis pertain to the second and third (novel) puzzle trials
there should not be grievous errors due to the first puzzle trial’s slightly skewed
distribution. The error variable satisfied assumptions of normality.
Table 1
Descriptive statistics for robot-viewing group
Table 1
Descriptive statistics for robot-viewing group
Table 1
Descriptive statistics for robot-viewing group
Table 1
Descriptive statistics for robot-viewing groupMeasures First Second Novel
Skewness 1.262 .352 -.469Std. Error of Skewness .550 .550 .550Kurtosis 1.829 -1.182 -.288Std. Error of Kurtosis 1.063 1.063 1.063
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Table 1 Descriptive TableTable 1 Descriptive TableTable 1 Descriptive TableTable 1 Descriptive Table
To assess the significance of the violation of normality, a Shapiro-Wilk test was
performed on each group distribution. In the human-viewing group the time variable for
the first puzzle trial, W(16) = .82, p < .05, and the backtracking variable for the first
puzzle trial, W(16) = .88, p < .05 were both significantly non-normal. In the robot-
viewing group the time variable for the first puzzle trial W(16) = .87, p < .05, and the
backtracking variable for the second puzzle trial W(15) = .87, p < .05 were both
significantly non-normal. Full results of the Shapiro-Wilk and the Kolmogorov-Smirnov
may be found in Table 2. Due to the near equal sample size in the groups and the
independent t-test’s robustness to non-normality, statistical analysis of the data is
considered appropriate. Assumptions for homogeneity of variance were met
satisfactorily.
Table 2
Tests for normality by group
Table 2
Tests for normality by group
Table 2
Tests for normality by group
Table 2
Tests for normality by group
Table 2
Tests for normality by group
Table 2
Tests for normality by group
Table 2
Tests for normality by group
Table 2
Tests for normality by groupTime and Error
Measurements, by group
Time and Error
Measurements, by group
Kolmogorov-SmirnovKolmogorov-SmirnovKolmogorov-Smirnov Shapiro-WilkShapiro-WilkShapiro-WilkTime and Error
Measurements, by group
Time and Error
Measurements, by groupD df p W df p
First puzzle time Human-
viewing
.231 16 .022* .829 16 .007*First puzzle time
Robot-
viewing
.200 15 .109 .877 15 .043*
First puzzle errorHuman-
viewing
.230 16 .023* .883 16 .044*
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First puzzle error
Robot-
viewing
.209 15 .076 .908 15 .127
Second puzzle
time
Human-
viewing
.164 16 .200 .972 16 .874Second puzzle
timeRobot-
viewing
.163 15 .200 .934 15 .310
Second puzzle
error
Human-
viewing
.246 16 .010* .893 16 .062Second puzzle
errorRobot-
viewing
.200 15 .110 .876 15 .041*
Novel puzzle
time
Human-
viewing
.134 16 .200 .916 16 .148Novel puzzle
timeRobot-
viewing
.158 15 .200 .951 15 .536
Novel puzzle
error
Human-
viewing
.150 16 .200 .957 16 .607Novel puzzle
errorRobot-
viewing
.227 15 .036* .889 15 .065
Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Table 2 Descriptives TableTable 2 Descriptives TableTable 2 Descriptives TableTable 2 Descriptives TableTable 2 Descriptives TableTable 2 Descriptives TableTable 2 Descriptives TableTable 2 Descriptives Table
An independent t-test on the time variable between groups showed no significant
differences. Table 3 and Figure 2 depict the mean log transformed times for the human-
viewing (n = 16) and robot-viewing (n = 15) groups across puzzle trials. Although not
significant, the second puzzle trial times are approaching significance, t (29) = 1.72, p < .
05, with the human-viewing group (M = 2.10, SD = .415) completing the puzzle faster
than the robot-viewing group (M = 1.87, SD = .309).
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Table 3
Mean times and standard deviations for time variable between groups
Table 3
Mean times and standard deviations for time variable between groups
Table 3
Mean times and standard deviations for time variable between groups
Table 3
Mean times and standard deviations for time variable between groups
Table 3
Mean times and standard deviations for time variable between groups
Puzzles and groups M SDFirst Puzzle Human-viewingHuman-viewing 2.49 .483
Robot-viewingRobot-viewing 2.30 .464Second Puzzle Human-viewingHuman-viewing 2.10* .415
Robot-viewingRobot-viewing 1.87* .309Novel Puzzle Human-viewingHuman-viewing 2.22 .281
Robot-viewingRobot-viewing 2.37 .357Note: *Mean values approaching significance at p < .05Note: *Mean values approaching significance at p < .05Note: *Mean values approaching significance at p < .05Note: *Mean values approaching significance at p < .05Note: *Mean values approaching significance at p < .05Table 3 Means and Standard Deviations TableTable 3 Means and Standard Deviations TableTable 3 Means and Standard Deviations TableTable 3 Means and Standard Deviations TableTable 3 Means and Standard Deviations Table
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To further explore the difference between the groups on the second puzzle trial, a
within-subjects paired samples t-test was performed. The paired samples t-test failed to
reveal a significant difference, t (15) = -1.12, ns, between the mean time on the second
and novel puzzle trials for the human-viewing group (n = 16), (M = -.121, SD - .432), as
expected by the results shown in Table 3. The results for the robot-viewing group (n = 15)
were highly significant, t (14) = -4.72, p < .05, in the time difference between the second
and novel puzzle trials as seen in Table 4. A visual representation of this data may be seen
in Figure 2.
Table 4
Mean difference in time between second and novel puzzles for robot-viewing group
Table 4
Mean difference in time between second and novel puzzles for robot-viewing group
Table 4
Mean difference in time between second and novel puzzles for robot-viewing groupPaired Puzzles M SD
Second puzzle time – Novel puzzle time
-.497* .408
Note: *Significant at p = .05, 2-tailedNote: *Significant at p = .05, 2-tailedNote: *Significant at p = .05, 2-tailedTable 4 Within-Group Paired t-Test Table 4 Within-Group Paired t-Test Table 4 Within-Group Paired t-Test
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Figure 2
Results of an independent t-test examining puzzle backtracking error between the
human-viewing group (n=16) and the robot-viewing group (n=15) found a significant
difference between groups in the novel puzzle trial, t (29) = 2.49, p < .05. The human-
viewing group (M = 4.31, SD = 1.778) committed significantly more errors than the
robot-viewing group (M = 2.73, SD = 1.751). This data is shown in Table 5 and
represented visually in Figure 3.
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Table 5
Mean backtracking error differences between groups
Table 5
Mean backtracking error differences between groups
Table 5
Mean backtracking error differences between groups
Table 5
Mean backtracking error differences between groupsPuzzles and groupsPuzzles and groups M SDFirst Puzzle Error Human-viewing 2.81 1.759First Puzzle Error
Robot-viewing 2.53 1.922Second Puzzle Error Human-viewing 2.25 1.693Second Puzzle Error
Robot-viewing 1.80 1.859Novel Puzzle Error Human-viewing 4.31* 1.778Novel Puzzle Error
Robot-viewing 2.73* 1.751
Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Note: *Significant at p < .05Table 5 Means and Standard DeviationsTable 5 Means and Standard DeviationsTable 5 Means and Standard DeviationsTable 5 Means and Standard Deviations
Figure 3
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Exploratory variables
As the design of this study focused on measuring a behavior that is unable to be
directly measured (learning), several different methods were used in an attempt to
appropriately measure the implied behavior. While not all of the methods provided
significant results, consideration of the methods and their results are still descriptive of
learning processes in their own right. These results may be used to develop future
research as a means of narrowing the scope of measurement.
The initial working definition of error as a variable was the number of ‘board
clears’ a participant would make throughout the course of solving in each puzzle trial. A
board clear was operationalized as each time a participant would clear the puzzle form