psychology 100:12 chapter 5 sensation & perception part v

Psychology 100:12

Chapter 5

Sensation &

Perception

Part V

Outline• Pattern recognition• Attention

> Bottleneck theories

> Capacity theories

> Cells phones and driving

Study Question:

• Why might a proponent of Kahneman’s attention theory feel that driving a car while talking on a cell phone is a bad idea?

PerceptionFeature

detectors Perception

– Visual Illusions, attempt II.>Fraser Illusion>Lines>Perspective>Stereokinetic object

– Auditory Illusions> Never ending auditory staircase

Shepard Illusion

Perception• Other evidence for feature theory:

Stabilized retinal images.• Physiological nystagmus

PerceptionFeature

detectors Perception

d

a

b

c

Perception• Problems with Feature theory

– How features go together are as important as the features themselves.

PerceptionPerceptionFeature

detectors Perception

Perception• Structural Theories

– Like feature theories, except that they also consider the structure of the features (i.e., How they go together.

– Biederman’s Theory of 3-d object recognition.>Geons: 3-D ‘volume’ features

PerceptionPerceptionFeature

detectors Perception

-> Eliminating information about the relationship between geons should be detrimental to pattern recognition.

E.g.,

PerceptionPerceptionFeature

detectors Perception

-> What are these objects?

Recognition accuracy

70 %50 % 100 %

PerceptionPerceptionFeature

detectors Perception

Perception• The word superiority effect

PerceptionPerceptionFeature

detectors Perception

R A I D

XXX X

D

Perception• The word superiority effect

D

XX X X

_ _ _ D

W O R D

XX X X

_ _ _ D

R U E D

XX X X

_ _ _ D

-> It is easier to identify a letter in the context of a word than by itself.

PerceptionPerceptionFeature

detectors Perception

• The interactive - activation model: Bottom-up

PerceptionPerceptionFeature

detectors Perception

PerceptionPerceptionFeature

detectors Perception

• The interactive - activation model: Top-down

Pattern Recognition

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Perception Perception

• Dichotic listening § Shadowing

Doughnuts TV

Pork rindsFootball

Cheap meatBeer

WorkDieting

Romantic moviesLiterature

OperaBallet

Doughnuts ,TV, Pork rinds, Football, Cheap meat, Beer ...

PerceptionPerceptionFeature

detectors Attention

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683

1 7 4 6 8 3

Attention• Bottleneck theories: Early selection

– The bottleneck metaphor>Cherry (1953): What do we perceive in

the unattended ear? Physical characteristics Not meaning Where’s the unattended message?

>Broadbent’s all-or-nothing filter

TableHorseChairDeskPaperHouse

TreeRock

HomerBarnStreet

Table, horse, chair, ..Homer...

• Problems with the all-or-nothing filter

– Moray’s (1959) experiment

Attention

• Treisman’s experiment

I saw the girl song was wishing

Hand me that bird jumping in the street

I saw the girl jumping inthe...

Attention

Capacity theories of attention

• Different tasks require different amounts of mental effort

§ i.e., Automatic vs. Controlled processing

e.g.1, Attentional resources and Driving

e.g.2, Automaticity and word recognition

The Stroop Effect

Attention

PURPLE

BLUEYELLOWPURPLEGREENBLACK

ORANGEGREEN

REDYELLOW

BLUEGREEN

BLUE

YELLOWPURPLEGREENBLACK

ORANGEGREEN

REDYELLOW

BLUEGREENPURPLE

Capacity theories of attention

• Kahneman’s Model

§ Limited resources to allocate to different tasks

§ Spreading attention out over multiple tasks results in performance decrements

e.g., Mowbray’s (1953) experiment

- Trying to copy notes and listening to a lecture

Attention

Resolving the locus of the bottleneck

• Johnston & Heinz’s (1978) multimode theory- Measured the amount of resources required to shadow using a dual task

procedure.

- Participants shadowed on either the basis of pitch (early) or semantic category (late)

- Viewed a computer monitor and had to hit a button quickly whenever a dot appeared on the screen (detection).

• Results

Attention

No list 1 list 2 lists 2 lists (pitch) (semantic)

Detection time 310 ms 370 ms 433 ms 482 msShadowing errors n/a 1.4% 5.3% 20.5%

• Johnston & Heinz’s (1978) multimode theory- Measured the amount of resources required to shadow using a dual task

procedure.

- Participants shadowed on either the basis of pitch (early) or semantic category (late)

- Viewed a computer monitor and had to hit a button quickly whenever a dot appeared on the screen (detection).

• Results

Attention

No list 1 list 2 lists 2 lists (pitch) (semantic)

Detection time 310 ms 370 ms 433 ms 482 msShadowing errors n/a 1.4% 5.3% 20.5%

Attention• The cell phone diversion

– Strayer’s Research> Used a driving simulator

Single vs. dual task Hands free vs. hand held

• No difference

> Can drivers recognize objects that they have fixated on? Recognition accuracy for fixated objects about half when

conversing• Even when fixation duration is equated performance was far

worse

> The inattentional blindness hypothesis Cell-phone conversation disrupts performance by diverting

attention from the external environment associated with the driving task to the cellphone converstation.

Demo

Attention

Attention• The cell phone diversion

– Strayer’s Research> What about strategic reallocation?

There are important and unimportant objects

> Two-Alternative forced choice recognition Drivers rated the importance of the items.

> Performance was significantly poorer in the dual task. even when fixation duration is controlled. Absolutely no effect of the importance of the object on the

inattentional blindness effect.

Attention

Attention• The cell phone diversion

– Strayer’s Research>Conversing on the phone vs. with a passenger

>Instructed to drive 8 miles down a freeway and exit at a truck stop.

Only 12% of drivers with a passenger missed the exit. About 50% talking on a cell phone missed the exit

• The passengers assisted the drivers

Attention

Attention• The cell phone diversion

– Strayer’s Research>Conversing and driving vs. drinking and driving

Car-tailing paradigm Compared .08% alcohol intoxication with hands held

and hands free.• No differences were observed between the cell

phone conditions• Both Alcohol and phone groups showed impaired

driving• 4 of the cell phones talkers rear-ended the pace

car (none of the drinkers had a collision)

Attention