conceptual spaces and consciousness: integrating cognitive and affective processes

CONCEPTUAL SPACES AND CONSCIOUSNESS:

INTEGRATING COGNITIVE AND

AFFECTIVE PROCESSES

ALFREDO PEREIRA JÚNIOR

UNESP, State University of S~ao Paulo,

Institute of Biosciences, 18618-000,

Botucatu, SP, Brazil

[email protected]

LEONARDO FERREIRA ALMADA

UFG, Federal University of Goias/UNESP,State University of S~ao Paulo, 18618-000,

Botucatu, SP, Brazil

[email protected]

In the book \Conceptual Spaces: the Geometry of Thought" [2000] Peter Gärdenfors proposes anew framework for cognitive science. Complementary to symbolic and subsymbolic [connec-

tionist] descriptions, conceptual spaces are semantic structures �� constructed from empirical

data �� representing the universe of mental states. We argue that Gärdenfors' modeling can beused in consciousness research to describe the phenomenal conscious world, its elements and

their intrinsic relations. The conceptual space approach a®ords the construction of a universal

state space of human consciousness, where all possible kinds of human conscious states could be

mapped. Starting from this approach, we discuss the inclusion of feelings and emotions inconceptual spaces, and their relation to perceptual and cognitive states. Current debate on

integration of a®ect/emotion and perception/cognition allows three possible descriptive

alternatives: emotion resulting from basic cognition; cognition resulting from basic emotion, andboth as relatively independent functions integrated by brain mechanisms. Finding a solution for

this issue is an important step in any attempt of successful modeling of natural or arti¯cial

consciousness. After making a brief review of proposals in this area, we summarize the essentials

of a new model of consciousness based on neuro-astroglial interactions.

Keywords: Consciousness; conceptual spaces; correlations; methodology; homeomorphism.

1. Introduction

The scienti¯c study of subjectivity displays important lines of development in the last

50 years. In the human sciences, the qualitative methods of empirical research, using

a diversity of tools to collect and analyze data and developing its own validation

procedures, was progressively accepted by the scienti¯c community. Scienti¯c

methods derived from philosophy, as the phenomenological and dialectical ones, have

International Journal of Machine ConsciousnessVol. 3, No. 1 (2011) 127�143

#.c World Scienti¯c Publishing Company

DOI: 10.1142/S1793843011000649

127

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http://dx.doi.org/10.1142/S1793843011000649

been incorporated into the methodology of these sciences. At the same time, several

e®orts have been made to correlate subjectivity with objective processes studied by

neurobiology and biophysics. Neural bases of psychological processes as learning,

memory formation, attention and emotion have been identi¯ed for several biological

species. The search for correlates of conscious experience has brought important

results, as the oscillatory synchrony in the thalamo-cortical system correlating with

conscious perceptual processes [see, e.g., Rodriguez et al., 1999]. However, while there

is remarkable progress in the identi¯cation of specialized brain regions involved in

several kinds of conscious processing, few advances have occurred in the under-

standing of how the informational content of brain states emerge as conscious lived

experiences.

A neurobiological explanation of the processing of conscious content would begin

by identifying what is there to be explained, or the explanandum, in the terminology

used by Hempel and Oppenheim [1948], Hempel [1965] and Popper [1963]. Such an

explanandum refers to all possible kinds of human conscious subjective experiences,

which can be mapped as the state space of human consciousness (for the use of the

notion of \state space" in this context, see Stanley [1999] and Fell [2004]). This task

depends on the analysis and categorization of empirical data, composed of reports of

individual human conscious experiences, implicitly assuming that subjectivity has a

universal structure.

In this paper, we acknowledge Peter Gärdenfors' proposal of constructing con-

ceptual spaces as a descriptive tool for a science of consciousness, corresponding to

the ¯rst step of de¯ning the explanandum of this science. We also pose the question of

how to integrate perceptual/cognitive with a®ective/emotional states in a conceptual

space that aims to describe the actual structure of human (and possibly human-based

arti¯cial) consciousness. We claim that a®ect/emotion and perception/cognition are

processed as relatively independent functions and integrated by a supplementary

mechanism.

A second step in the scienti¯c methodology for the study of human consciousness

is to de¯ne the explanans, the kind of biophysical process in the brain (and its

interactions with the body and environment) able to account for the processing of

conscious content. A coarse-grained mapping of brain regions involved in each kind of

conscious processing is not su±cient for this task; it is also necessary to identify how

information is encoded and processed by neuronal and glial cellular populations.

According to Gärdenfors [2000], one central property of conceptual spaces is the

existence of correlations between dimensions, a feature that would correspond to the

existence of large coherent patterns of activity in the brain. A positive matching of

such structures (the state space that describes the contents of human consciousness,

and the state space of biophysical information processing in the brain), displaying

isomorphic or homeomorphic inter-relations, would validate this methodology. In

this regard, we make a review of the literature on cognitive and emotional functions,

discussing how their integration can be described in conceptual spaces without

128 A. Pereira Jr. & L. F. Almada

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disrupting the intended correspondence with brain physiology. The results are

applied for the understanding of conditions to be satis¯ed by conscious arti¯cial

systems.

2. From Intersubjective Validation to Universal Conceptual Spaces

Frith et al. [1999] proposed a method to study the neural correlates of consciousness

that is based on the temporal co-occurrence of registered/measured brain activity

(using EEG, MEG, fMRI, PET-scanning, etc.) and conscious states reported by the

subject who is having his/her brain activity monitored. In our analysis of this

method, we make a distinction between conscious episodes instantiated by brain

activity and lived experiences involving brain-body-environment dynamical inter-

actions [Pereira Jr. and Ricke, 2009]. For instance, currently available \mind-reading"

technology [e.g., Kay et al., 2008] can access coarse-grained brain functional con-

¯gurations but cannot measure lived experiences. Partial accessibility of the latter to

the experimenter depends on verbal and/or non-verbal reports made by the human

subject. Therefore, what this methodology actually gets is a correlation between

measured brain activity and reports made by the subject about the content that he/

she experienced while the activity occurred.

The above procedures are too weak to determine a causal or law-like relationship

between brain states/processes and conscious states/processes, but su±ciently strong

to be considered as scienti¯c. A part of the weakness derives from the limitation of

isolated studies, where the correlations may be biased by cultural or individual

peculiarities. Therefore a possibility of adding a further strength to this methodology

is by crossing the results obtained by several subjects and several experimenters, in

order to identify the common aspects of reported human experiences.

The crossing of several experiments in the cognitive neuroscience of consciousness

makes possible an inter-subjective validation of the method. The rationale is that it

would be extremely unlikely that several human subjects, sharing the same class of

biological (genetic and phenotypic) constraints, interacting with the same kind of

experimental setting, and not being a®ected by any well-known psychopathology or

under e®ect of psychotropic drugs, would have di®erent lived experiences.

It is important to consider that one stance of inter-subjective validation always

occurs in any cognitive neuroscienti¯c experiment, when the experimenter makes a

confrontation of the subject's report and his/her own perception of a presented

stimulus (e.g., when the experimenter presents an object that he/she perceives to be a

blue circle, he/she expects the subject to report seeing a blue circle and not, for

instance, a red triangle). The idea of crossing subjective experiences is implicit in

Dennett's proposal of a hetero-phenomenological approach [Dennett, 1991], but his

approach was conceived as a refutation of ¯rst-person approaches to consciousness,

not as a procedure of inter-subjective validation as we are proposing here. The

original hetero-phenomenological method also lacks an appropriate framework to

plot the result of studies made by di®erent researchers analyzing di®erent subjects.

Conceptual Spaces and Consciousness 129

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This kind of framework is provided by Gärdenfors. It is composed of geometrical

tools (quality domains, similarity judgments as measure of proximity) used for the

construction of conceptual spaces. Therefore, an important advancement provided

by this new approach is to allow the progressive build-up of results of individual

hetero-phenomenological studies into what might be called the universal state space

of human consciousness.

The lived experience of an individual human subject, as long as it can be com-

municated to others, would correspond to a trajectory in this state space. Considering

that ¯rst-person lived experiences are partially available to empirical (third-person)

science by means of verbal or non-verbal reports, this framework can support the

interpretation of \qualitative" data (i.e., reports of lived experiences) in the context of

cognitive sciences. The state space model can be useful as a referential framework also

for introspective and phenomenological approaches.

More importantly, for this scienti¯c methodology the distinction of ¯rst- and

third-person perspectives is secondary, while keeping centrality from a philoso-

phical perspective. Perceptual concepts and \qualia" refer to the same entities,

suggesting the possibility of partial inter-translation of third-person and ¯rst-

person descriptions. If a set of common results is reported by di®erent subjects,

e.g., if they agree on the perceptual content elicited by a stimulus, the di®erence

between the perspectives disappears for practical purposes. As the term \qualia"

has a long and disputed history in philosophy, when possible we prefer to avoid its

usage and refer to the corresponding concepts. One of the problems is that a

\quale" includes both the subjective feeling (e.g., \what it is like for Adam to be

looking at a red apple") as well as apparently objective informational properties

(e.g., \the redness of red").

The partial conclusion we draw here is that the conceptual space approach is a

valuable tool for the science of human consciousness and practical applications, since

it a®ords the construction of a universal model representing the properties of the

\explanandum" of this science.

3. Conceptual Spaces and A®ective/Emotional States

Gärdenfors' approach is supported by empirical evidence from psychophysics, cog-

nitive psychology, linguistics and neuroscience. The use of data from cognitive

experimentation for the construction of perceptual spaces is possible because he

implicitly assumes a universal structure of human cognition. Then, the subjects'

reports of lived experiences in several experiments can be constructively mapped into

the theoretician's model.

A problem that appears for an approach to conscious processing based on con-

ceptual spaces is how to integrate a®ects and emotions with cognitive states. Since

a®ects/emotions are fundamental to conscious processes, they should be accounted

for by the conceptual space approach for this method being successful as a description

of the \explanandum" of consciousness science.


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First, it is necessary to clarify what we mean by \a®ect" and \emotions", and how

they di®er from cognitive states. \A®ect" refers to a class of subjective feelings, such

as those related to basic physiological functions (hunger, thirst, heat, pain, body

pleasure, etc.) and psychological states (love and hate, happiness, sadness, etc.).

\Emotion" refers to feelings related to the objects of action in a bio-psycho-social

context, e.g., anger (of something), anxiety (for something), fear (of something), etc.

The distinction is surely a fuzzy one.

Conceptual spaces are de¯ned as \theoretical entities that can be used to explain

and predict various empirical phenomena concerning concept formation" [Gärden-fors, 2000, p. 31]. They are made of quality dimensions, representing the qualities of

objects, like weight, brightness and pitch. The proximity or distance between

dimensions is established by judgments of similarity, which can be made in the

context of scienti¯c experimentation. Such judgments establish intra- and inter-

dimensional correlations. How could a®ects and emotions be included in conceptual

spaces? To answer this question, three issues are brought into consideration:

(i) A®ects and emotions are lived experiences, not concepts. One problem with the

proposal of a mathematical \qualia space" by Stanley [1999] was the con°ation

of concepts and experiences. Universal types of conscious experience can be

represented by concepts (which are indicated by terms as \pain" and \pleasure",

in the above examples). Conceptual spaces, of course, are not made by lived

experiences themselves, but by their concepts. In order to achieve a realistic view

of the human mind or any arti¯cial system that simulates or reproduces

activities of the human mind, the relations between concepts should have

a homeomorphism with actual relations. This correspondence is assured, in

Gärdenfors' case, by the method of construction of the model;

(ii) Conceptual spaces, as they were presented by Gärdenfors [2000], are heavily

based on perceptual and cognitive processes. The symbol grounding problem is

solved since perceptual domains \are tied to sensory input channels and hence

what is represented in these domains has some correspondence with the external

world" [Gärdenfors, 2000, p. 43, 44]. The learning problem of connectionist

networks is also approachable, since it provides an understanding of concept

formation by means of judgments of similarity. The frame problem is solved

when information is not conceived as modality-free, but sorted into domains.

The properties of objects are conceived as perceptual invariances located in

conceptual spaces. While properties are based on one quality domain, perceptual

concepts are based on several domains. Therefore, they aremultimodal instead of

amodal; e.g., the concept of \apple" involves the color, shape, texture, taste,

fruit and nutrition domains, see Gärdenfors [2000, p. 103]. How to apply the

same strategy of argumentation — based on the embodiment of processes — to

a®ective and emotional phenomena? In order to answer this question, it is

necessary to examine how scientists conceive the process by which the brain

supports lived experiences and discuss the inclusion (or not) of other parts of the


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body and parts of the environment in the process that generates a®ects/

emotions;

(iii) The location of a linguistic term in the conceptual space may vary, depending on

the context of the utterance. Conceptual spaces can also be used as a basis for

cognitive semantics, replacing realist approaches (both extensional and inten-

sional). Gärdenfors proposes that \meanings of linguistic expressions are mental

entities" [Gärdenfors, 2000, p. 154], at the same time holding that conceptual

structures of di®erent individuals become attuned to each other: \via successful

and less successful interactions with the world, the conceptual structure of an

individual will adapt to the structure of reality" [Gärdenfors, 2000, p. 156].He assumes a \socio-cognitive" position, accounting for social power in°uences

on conceptual structures. These constraints surely apply to a®ect/emotion,

mostly to the latter, since it is by de¯nition related to events in the body and

environment.

The construction of a universal conceptual space representing the universe of

conscious contents is proposed to be the ¯rst step in the methodology of a science of

consciousness. It requires collection of verbal and non-verbal reports of ¯rst-person

experiences correlated to measured brain and body activity; inter-subjective vali-

dation of the reports, and construction of a conceptual space of conscious contents.

An analysis of the structure of this space may further guide the search for arti¯cial

reproductions of consciousness.

The ¯rst step should be accompanied by a second one, the theoretical modeling of

brain activity at multiple spatio-temporal scales, composing a state space of brain

functions. This strategy implies that homeomorphisms [Fell, 2004] between the

structure of conscious contents and the structure of brain/body activity are going to

be found by means of a matching of the state space of human consciousness with the

corresponding state space of human brain functions.

Finding a solution for the issue of integration of emotional and cognitive pro-

cesses is an important step in any attempt of successful modeling of natural or

arti¯cial consciousness. A ¯rst move in the direction of including a®ective/

emotional processing as a fundamental component of consciousness is the Somatic

Marker Hypothesis (SMH), by Dam�asio and colleagues. According to the defenders

of the hypothesis, a®ects/emotions are related to somatic states, being preceded

and followed by cognitive processes. The latter include both basic and higher brain

processes, from simple perceptions and thoughts to attention, evaluation, and

decision-making. SMH considers a®ect/emotion as \a collection of changes in a

body state connected to particular mental images (thoughts) that have activated a

speci¯c brain system" [Dam�asio, 1994, p. 159]. Feelings of emotions are ¯rst and

foremost considered to be about the body: \they o®er us the cognition of our

visceral and musculoskeletal state as it becomes a®ected by pre-organized mech-

anisms and by the cognitive structures that have developed under their in°uence"

[Dam�asio, 1994, p. 159].


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However, SMH defenders also hold that emotional appraisal can interfere with

and even support higher cognitive functions, as decision-making: \individuals make

judgment not only by assessing the severity of outcomes and their probability of

occurrence, but also and primarily in terms of their emotional quality" [Bechara

et al., 2000, p. 305]. This part of their theory leads to what would be considered as

bad explanatory circularity, causing possible inconsistencies criticized by Bennett

and Hacker [2005] and Rolls [2000].

Recognizing the embodiment of emotion would require more than merely mapping

brain activity, since emotion is related to the actions of the living individual's body in

the environment. While the content of each feeling can be considered to be the

product of a specialized, epigenetically determined brain circuit or module, the

content of emotions vary according to the context (state of the body and environ-

ment). In this regard, SMH brings an important contribution to the understanding of

embodiment of emotions when taking into account the reciprocal signaling of brain

and body. In spite of a possible explanatory circularity in its framework, the SMH

may contribute to the description of integrative functions in the universal conceptual

space of consciousness, since lived experiences should necessarily include the dyna-

mical relation of brain, body and environment.

A second position, illustrated by the work of LeDoux [1996] and Panksepp [1998],

assumes the independence �� and, in many cases, a predominance �� of a®ects/

emotions on cognitive activity. This position is able to avoid most of the criticisms

made to SMH by Rolls, since it does not attempt to derive the content of feelings and

emotions from somatic activity, but take them as brain primitives. However, the

predominance of emotion over cognition con°icts with empirical evidence gathered

by SMH defenders, and contradicts theoretical argumentation by Bennett and

Hacker. The latter authors are opposed to Dam�asio and colleagues only regarding the

dependence of decision-making on somatic markers and related emotions.

Considering available evidence reviewed by the above authors, we suggest that it

could be encompassed by a third possibility of mapping the dynamics of cognitive and

emotional processing. Perceptual/cognitive and a®ective/emotional functions are

primitive brain functions, being able to occur both implicitly (unconsciously) and

explicitly (consciously). Modeling of perceptual/cognitive systems in conceptual

spaces was largely advanced by Gärdenfors [2000], while modeling of emotional

systems was advanced by Panksepp [1988], in a pioneering work that could equally be

translated to conceptual spaces.

According to Panksepp [1998], our cognitive representation of the world merges

within the processing of a®ective states. A®ective states are related to the awakening

of primitive emotional command circuits in the whole extended neural network,

including the operational systems he calls (using capitol letters) \SEEKING, FEAR,

RAGE, LUST, CARE, PANIC, and PLAY" [Panksepp, 1998; 2005]. These would

be fundamental dimensions of the human a®ective conceptual space that interact

with perceptual/cognitive dimensions. Cognitions re-evoke feelings in function of our


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past experiences and history of conditioning, thus interacting with emotional

self-regulation.

The dynamics of emotional systems tends to be more egocentric and uncondi-

tionally a®ective than cognitive functioning, since the goal of cognitive processes is

generally to provide more subtle solutions to problems posed by emotional arousal. In

hominids, the evolution of certain higher symbolic abilities provided ways for

organisms to solve con°icts that are very di±cult from an exclusively emotional

perspective. The increasing in°uence of cortical functions provides cognitive

resources to solve con°icts during human maturation. This evolution was critically

\guided by the pre-existing neurobiological exigencies of organisms" [Panksepp,

2001, p. 144]. In fact, these exigencies are related to subcortical emotional and

motivational abilities \which are generally more similar among living mammalian

species than their higher cortico-cognitive functions which have diverged more con-

siderably" [Panksepp, 2001, p. 144].

A®ective states re°ect evolutionary value codes. In this sense, the projection of

feelings onto environmental events and objects was one of the simplest ways for

evolution to persistently guide perceptual priorities of the cognitive apparatus. This

type of interaction occurs by means of global neurodynamic processes in the brain,

making possible that cognitive problems could be ameliorated simply by adjusting

the underlying emotional feelings, and vice versa. In other words, a®ective states of

consciousness \may, quite simply, be among the most robust and e®ective ways to re-

channel cognitive resources" [Panksepp, 2001, p. 152]. Cognitive forms of con-

sciousness were evolutionarily grounded \on the prior evolution of a®ective forms of

consciousness, which inform organisms what it might be worth thinking about"

[Panksepp, 2001, p. 152].

When brain functions occur consciously, there must necessarily be an integration

to de¯ne their access to the coordination of covert and overt behavior. This inte-

gration possibly happens in some kind of \Global Workspace" [Baars, 1997] embo-

died in brain activity. One possible implementation of the workspace is by means of

neuro-astroglial interactions, as recently suggested by one of us [Pereira Jr. and

Furlan, 2009; 2010]. In this approach, each brain circuit or functional module is

considered to be specialized for a speci¯c function, while the integration occurs by

means of the operation of a supplementary mechanism that involves virtually all

specialized circuits/modules, but is not identi¯ed with any of them.

4. From Arti¯cial Intelligence to Arti¯cial Consciousness

The project of \strong" Arti¯cial Intelligence was to construct machines able of

performing human cognitive functions. Critics soon noted that aspects of these

functions could not be performed by Turing machines; some of them also predicted

that these functions would not be reduced to digital computations, because of

several di±culties (as the combinatorial complexity and frame problems). The same

objections apply to projects of arti¯cial consciousness, which also poses two


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additional problems:

(a) What is required for an agent to be conscious, besides information processing?

(b) What is the (arti¯cially reproducible) biophysical mechanism su±cient to

execute it?

An attempt to overcome initial di±culties is the \embodied and embedded"

paradigm of cognition, which claims that the strategy of implementing computations

based on internal databases should be substituted by an analogue of brain-body-

environment interactions. One of the main attempts to bring this idea to reality was

Rodney Brooks' robot \Cog", which has a central processing unit embedded in a

human-like half-body and was \educated" by a woman playing the role of \mother"

in a human-like environment [Brooks et al., 1998].

Why would a robot like Cog not, in principle, become a conscious agent? More

simply, why a thermostat that measures and controls room temperature does not feel

hot or cold? The answer, of course, depends on the concept of consciousness that is

assumed. Before making a speci¯c proposal (see next section), we would like to review

some alternatives presented by several authors.

A ¯rst line of reasoning is that not any representation is conscious, but only a

subclass �� explicit representations. The problem here is to identify what features

make a representation explicit for the agent. For human beings, explicitness is often

related to symbolic and/or linguistic formulation of content. This line of reasoning

leads to di±cult issues of syntax and semantic processing, as those discussed by

Mandik [1999], leading to the suggestion of a \procedural psychosemantics" that

evaluates properties of introspective content of experiences (\qualia") regarding their

e®ects (instead of their causes). This reasoning does not apply to all qualia, but to

spatial properties related to motor control. In this regard, the theory of a \retinoid

system" by Trehub [1991] describes a brain subsystem able to construct an egocentric

three-dimensional transparent representation of the world. Like inMandik's approach,

this proposal is limited to the spatial structure of perceptual consciousness. The

retinoid system is a model of brain mechanisms supporting our egocentric spatial

representation of the world, leaving open the explanation of other dimensions of the

conceptual space and corresponding brain mechanisms.

Another possible requirement is the capacity of elaborating self-referential

representations, as in High-Order Thought theories of consciousness [Rosenthal,

2002; 2004]. Rosenthal [2002] begins by distinguishing between \creature con-

sciousness" and \state consciousness", assuming that animals like frogs and turtles

are creature-conscious while being fully state-unconscious (i.e., all their mental states

may well not be conscious). Arguing from what seems to ¯gure in the phenomenon of

state consciousness, he argues that \being aware of a mental state…is not a su±cient

condition for the state to be conscious". In his view, consciousness consists in a

thought to the e®ect that one is in the state in question, and the thought must not

rely on any inference. This holds for both conscious intentional states and conscious


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qualitative states, such as sensations. This is not an easy idea to implement in

arti¯cial systems, since before being able of self-reference it is necessary for the system

to have a Self ! This result is expected �� in the long run �� for evolutionary com-

puting paradigms, but there is no guarantee that it will occur. Other di±culties are

that the operation of self-reference is related to logical paradox, and possibly absent

in non-numan animals.

One scienti¯cally promising project is the attempt to quantify conscious inte-

grated information and related subjective experiences [Tononi, 2005; Balduzzi and

Tononi, 2009]. Tononi's theoretical framework is based on two ideas: that con-

sciousness is \informative" in the sense that any conscious state is a \reduction of

uncertainty" (it rules out many alternatives); and that conscious states integrate

brain information by means of causal interactions among its parts. He developed a

framework to measure the quantity of integrated information (phi) in brains that

may be useful for medical diagnosis and technological purposes, such as measuring it

in arti¯cial systems. A new development of the theory includes an approach to the

qualities of subjective experience (\qualia").

What would be the relation of integrated information with qualitative subjective

experience? Balduzzi and Tononi explain that \for integrated information to be high,

a system must be connected in such a way that information is generated by causal

interactions among rather than within its parts… The set of all submechanisms of the

system… conveniently captures all possible combinations of causal interactions"

[Balduzzi and Tononi, 2009, p. 5]. Then they introduce the concept of \informational

relationship" to represent \di®erences that make a di®erence" to the system. How

does a causal interaction \make a di®erence"? A condition of possibility is the

existence of a pre-existing conceptual space where entanglements (i.e., integrated

information relations) can be speci¯ed: \a fundamental property of q-arrows

(informational relationships �� APJ/LA) is their entanglement… the extent to

which an informational relationship does not reduce to its component relationships

(sub-q-arrows)" [Balduzzi and Tononi, 2009, p. 6]. Each \quale" corresponds to an

activation of the conceptual space (\qualia space", in their terminology) by causal

brain mechanisms; therefore, contrary to the model presented by Stanley [1999],

subjective experiences would not pre-exist in qualia space, but are constructed from

brain activity. Although mathematically well built, both models still lack biophysical

grounding. We suggest that the proposal reviewed in the next section provides what

is missing to understand the brain basis of information integration and/or to

implement the concept in an arti¯cial agent.

A sophisticated interdisciplinary approach is the \physics of mind" proposed by

Perlovsky [2009]. Conscious processes are conceived as the matching of forms at

several levels, e.g., from retina to prefrontal neurons in the visual system. The initial

vague patterns that drive top-down signaling are innate (given by the Knowledge

instinct). At some point in human ontogenesis, this process includes language circuits

(also innate �� the Language instinct), which allows us to use abstract forms that are


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not innate (\memes"). The matching process applies to cognitive functions of other

animal species. Conscious representations are those that become crisp along the

matching processes.

Perlovsky's model is not strictly Kantian, since in the faculty of understanding

described in Critique of Pure Reason there is no matching of internal (a priori) and

external (empirical) forms. All forms are a priori �� experience only gives us the

matter to ¯ll internal templates of space/time/causation/substance, etc. In Per-

lovsky's model, called \Dynamic Logic", the matching process a®ords an interaction

of externally originated and internal information patterns, avoiding the problem of

combinatorial complexity by means of an adequate use of Fuzzy Logics (instead of

the Principle of the Excluded Middle).

A criticism we make is about the relation of crispness and a®ective/emotional

states regarding consciousness. Possibly there is not a necessary connection between

the proposed con°ict-solving role of consciousness and crispness. A solution of a

con°ict of instincts/re°exes may be just choosing one of the vague unconscious

alternatives and abandoning the others. Of course, in some cases it may be better to

make a synthesis that uses parts of di®erent con°icting alternatives, but there is no

reason to assume that the synthesis has to be crisper than the original alternatives. In

fact, it may be even more vague if based on Fuzzy reasoning.

More importantly, we did not see a fundamental role for feelings in the conduction

of the process that leads to consciousness. Emotional feeling (as aesthetical feeling) is

regarded as a byproduct of good matching, not as a factor for selection of forms to

reach consciousness. It seems the model assumes �� like most of Modern Philosophy

and contemporary Cognitive Science �� that we are rational beings driven by cog-

nitive processes. We would better suggest that �� besides the Language and the

Knowledge instincts assumed by Perlovsky �� we also have A®ective instincts, as

argued in the context of Jaak Panksepp's A®ective Neuroscience (following Cannon's

and McLean's approach, also assumed by LeDoux and others).

If the a®ective instincts are introduced as fundamental �� together with the

knowledge and language instincts �� then the relation between crispness and con-

sciousness would have to be rede¯ned, since this property would not apply to feelings.

In fact, feelings are not \representations" measured as being more or less accurate

relatively to an intentional object or process. If feelings are considered to be

important players in the consciousness game, the crispness of representations

would not be the main parameter in the construction of scales to measure degrees of

consciousness.

In this section, we conclude for the need of an approach that goes beyond

SMH, inserting a®ective operational systems as fundamental dimensions of the

conceptual space. A question remains about the nature of a®ective states in the brain,

and how to implement it in arti¯cial systems. The next section is about a new

approach to the brain mechanisms underlying a®ective states and their putative

biophysical nature.


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5. A Viable Implementation of Universal Conceptual Spacesin Neuro-Astroglial Networks

In a recent work, Pereira Jr. and Furlan [2010] propose a new model of consciousness

that includes a central role for astrocytes. The principles of this model can be

extended to arti¯cial systems. The model departs from the sketch of a large scale Ion

Trap Quantum Computer (ITQC) adapted to biological conditions [Pereira Jr.,

2007]. In quantum computing models, it is assumed that the trajectory of particles,

under well known initial and boundary conditions (quasi-isolated micro-system fro-

zen to the ground state) is determined by fundamental physical laws. As these laws

are temporally invariant, computations carried in this kind of system are considered

to be reversible. In a biological macro-system, there are at least three factors that

indicate an incompleteness of quantum theory to describe the dynamics:

(a) The process of decoherence (or objective reduction or \collapse") of the wave-

function, attributed (by several authors) to supplementary factors;

(b) The many-body problem (discussed by Poincar�e as \three-body problem"),

leading to an impossibility of deterministic calculation of the trajectory. At this

point, Statistical Mechanics take the place of Quantum Theory in the expla-

nation of observed macro-phenomena;

(c) The Second Law of Thermodynamics, causing the evolution of the macro-system

to be irreversible.

Initial conditions of living systems include a database, the DNA, from which

Biological Maxwell Demons (enzymes) are built. The Second Law requires that the

work of enzymes, reducing internal entropy, must be compensated by means of

consumption of useful energy from the environment, implying that these systems

must consume food to survive. Both DNA information present in the initial state and

the necessity of consumption of low entropy from the environment are not theorems

of Quantum Theory. These conditions, necessary for the existence of life, are also

related to the formation of coherent calcium waves in astrocytes, since a class of

proteins crucial for brain activity, the ligand-gated ion channels (e.g., NMDA

channels) operate like Biological Maxwell Demons, controlling the °uxes of ions

through cellular membranes and compartments.

We conceive large calcium waves as composed of an ensemble of small standing

waves, each one inside an astrocyte microdomain. Their connection, forming a larger

pattern of coherent activity, is made by ATP signaling (in the case of the \domino

e®ect", see Pereira Jr. and Furlan [2010]) and by neuronal synchronous ¯ring (in the

case of the \carousel e®ect", see Pereira Jr. and Furlan [2010]). Microdomains are

subcellular, but the domino and carousel e®ects are assumed to transpose their

patterns to a collective of cells, thus composing a fractal multiscale pattern.

Also quantum entanglement of calcium ions possibly plays a role in intercellular

communication, but this communication can occur only after the waves are formed.

With entanglement, when a small wave inside a microdomain is formed, another


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small wave in a spatially distant region of the astrocyte network can be a®ected,

without any particle from the initial wave being actually transported to the second.

However, quantum entanglement cannot explain the formation of waves, since this

process requires mechanical causation. The two, domino and carousel e®ects, are

intended to explain the formation of waves; after formed, quantum entanglement

may occur within them. Considering both e®ects, the time needed to produce a large

coherent calcium wave is close to the time needed to form small calcium waves in

microdomains.

Our claim is that the brain substrate of feelings cannot be a FM (Frequency

Modulated), but has to be an AM (Amplitude Modulated) pattern. FM is very good

to transmit information and reduce noise. The problem is that it requires a decoder to

read the message. In the brain, FM a®ords a digital-like encoding of sensory and

motor signals. In the ¯rst case, the receiver is a CNS (Central Nervous System)

neuron; in the second case, a muscle or gland. However, the idea of FM information

transmission to consciousness would require an homunculus, which was resuscitated

by Crick and Koch [2003].

We conceptualize our feelings (e.g., pains and pleasures) as homeomorphic to large

and coherent AM astrocytic calcium waves, instead of Morse-like sequences of pulses

in millions of neurons. As the astroglial calcium wave is conceived as the ¯nal stage of

conscious processing, there is no need of a receiver. The ¯nal step would be an analog

reproduction (a \presentation", not a \representation") of the properties of the

world, by means of an AM waveform, which feedsback on the whole living individual.

Therefore, at the end of the line there should be a collective large-scale AM wave. The

only place for it in the brain is the astroglial network.

Neurons process information and trigger muscle/gland action without having the

feeling of what is going on. The dendritic graded potential is ¯ltered by the axon

hillock to generate a Frequency Modulated (FM) signal along the axon. Synapses

receives only this signal; they do not have access to the dendritic AM pattern. The

di®erence for the astrocyte network is the possibility of a collective AM wave. Phi-

bram [1991] and Hamero® [2010], appealed to dendritic ¯elds as substrates of con-

sciousness, but how would one dendritic tree transmit its AM pattern to others? The

solution found by Hamero® is to make electric synapses responsible for this task, but

the attempt fails because these synapses only transmit electric current that °ows to a

segment of a dendrite, not the information pattern present in the graded potential as

a whole.

All brain areas contain both neurons and astrocytes. Their cognitive functions are

mediated by glutamatergic transmission. Neurons operate as specialized information

processing detectors/¯lters/relays, but do not convey a feeling about the content of

the information they process. For example, in the amygdala, neurons ¯re to a®ective/

emotional salient/relevant stimuli, but the corresponding feelings are not instan-

tiated by them [see Pessoa and Adolphs, 2010]. Pereira Jr. and Furlan [2010] propose

that feelings are instantiated by a large astroglial network connected to the


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amygdala's astrocytes. In this view, it is not the amygdala that feels fear, or the insula

that feels pain or pleasure; the conscious subject is the whole brain/body of the living

individual, having the astroglial network as the main connector (Master Hub)

between his/her subsystems (blood, cerebral °uid, muscles, neurons).

According to model developed by Pereira Jr. and Furlan [2010], the Slow Cortical

Potential [He and Raichle, 2009] involved in default networks, as well as ERP waves

associated to conscious processing (P300, N400, etc.) would be mediated by the

astroglial network. Of course, scalp EEG does not tell us if the potential is mediated

by neuronal or astroglial transmission, but the relative slowness and concentrated

power of the wave suggests that it is mediated by the astroglial network instead of

neuron axon bundles (if so, the wave would be faster and have less impact on the EEG).

What would be the neurocentric interpretation of how the slow cortical potential

moves along brain tissue? The standard explanation is that the potential would move

along super¯cial layers of the cortex as a result of sequential excitation and inhibition

of columns. Thalamic glutamatergic input to a pyramidal neuron in deeper layers

elicit both a feedback to thalamus and an excitatory signal to super¯cial layers of the

same column. Excitation of this column leads to the excitation of inhibitory neurons

in adjacent columns, which inhibit the pyramidal neuron. Meanwhile, the super¯cial

layer neurons have propagated the excitation to another column, where the whole

cycle occurs again, and so on. The propagation would be by means of horizontal

cortico-cotical connections (endogenous) or by means of thalamic guidance (in the

case of an external stimulation). Magnetoencephalography would detect this move-

ment of the excitatory potential, while the EEG only detects the outcome.

The propagation of waves measured by scalp EEG by means of dendritic columns

is a hypothesis made to save the phenomena, but the hypothesis has never been really

proven. The clearest theoretical fact is that dendritic ¯elds in tripartite synapses

activate astrocytes and vice versa (astrocyte calcium waves feedback on neurons).

Therefore, the reasonable conclusion is that any slow cortical potential must involve

both dendritic ¯elds and astroglial calcium waves.

One most interesting test to check which one is more important to consciousness is

to identify which one is absent in non-REM sleep. An important result found by

Tononi and colleagues [Massimini et al., 2010] is compatible with the idea that lack of

connectivity during non-REM sleep results from deactivation of the astrocyte net-

work. Neurons continue to produce graded and action potentials during this phase of

sleep, the main di®erence being that they synchronize in slower frequencies (3Hz;

Delta). Pereira Jr. and Furlan [2009] hypothesized that the relevant e®ect of Delta for

unconsciousness is on astrocytes; with 3Hz, coherent large calcium waves are not

formed in the astrocyte network. However, a neurocentric explanation is also poss-

ible. Considering changes of concentration of available transmitters during slow-wave

sleep, it may be the case that one of the steps in the chain of neuronal events is

blocked. New results and computer simulations may helpfully indicate the causes of

reduced cortical connectivity during non-REM sleep.


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6. Concluding Remarks

In our view of brain instantiation of the universal conceptual space of human con-

sciousness, conscious states are conceived as a conjoint product neuronal and astroglial

activity. Paraphrasing the title of Dam�asio's book, consciousness is \the feeling" (or

sentience) of \what happens" (information contents embodied in spatially distributed

neuronal activity). Sentience is supported by wavelike processing in astrocytes, while

awareness (in the sense of information processing) would depend on digital-like infor-

mation transmission by neurons. Neuronal dendritic ¯elds are wavelike, but axonal

transmissions are not. Dendritic ¯elds contain the information that becomes conscious,

but consciousness occurs only when these patterns are integrated by the astrocytic

network into a wavelike unity.

Consciousness is conceived as astroglial integration of information contents carried

by neurons. In this context, we make terminological equivalences: [astrocyte analog

wavelike processing� ¼ ½information integration� ¼ ½feeling� ¼ ½sentience�. Then

consciousness is ½ðastroglialÞ sentience of ðneuronalÞ awareness� ¼ [the feeling of the

information content] ¼ ½\the feeling of what happens"�. Neither neuronal awareness

of information nor astroglial sentience (e.g., unconscious emotions) are fully conscious.

When they get together, higher degrees of consciousness occur. Speci¯city is neuronal.

Di®erent features are represented by means of activation of neuronal receptive ¯elds.

Astrocytes do not reproduce neuronal information with ¯delity. The astrocytic

wavelike response conveys the feeling, which is intrinsically di®use.

In the above view, exclusive neuronal or astroglial activation would correspond to

lower degrees �� proto-consciousness �� while conjoint activation would correspond

to higher degrees �� full consciousness, i.e., awareness with a feeling. \The feeling" is

also similar to Thomas Nagel's \what's like to be" that was important for Chalmers'

reasoning [Chalmers, 1995; 1996].

According to these guidelines, the generation of arti¯cial conscious agents

would require both computational and a®ective mechanisms to reproduce neuronal

functions �� specialized digital processing of features of information �� and astro-

glial functions �� integration of such a distributed processing and generation of a

feeling about the message carried by the signals. These mechanisms are physically

di®erent; the ¯rst one is based on ¯lters exchanging discrete signals, while the second

operate on wavelike patterns in a continuum medium. A universal conceptual space

of consciousness would correspond to invariants resulting from the conjoint operation

of both mechanisms. The degree of reproduction of human consciousness would

depend on the arti¯cial mechanisms being similar to those achieved in our evol-

utionary and historical pathways.

Acknowledgments

CNPQ (Brazilian funding agency �� grant conceded to APJ), Leonid Perlovsky,

David Balduzzi, James Robertson, Chris Nunn, Arnold Trehub, David Rosenthal,


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Antonio Chella and an anonymous reviewer, for discussion and suggestions that

helped to improve the text and the message.

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conceptual spaces and consciousness: integrating cognitive and affective processes

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