Attention Page 1

Attention

What is attention?

• Concentrating and focusing of mental effort that is:

o Selective--focus on some things while excluding others

o Divisible--able to focus on more than one thing at the

same time (but at a cost)

o Shiftable--able to change focus

Selective Attention

• How well can we select one focus and block out others?

• Under what circumstances is it under conscious control?

• Are there costs associated with ignoring?

Dichotic listening (shadowing)

• Usually recall very little from unattended channel

o remember nothing of content

o do not notice a language change

o do notice if becomes series of beeps

Early Selection

• Repeat attended channel quite accurately

• Do not notice if message on unattended channel

o changes from English to Russian

o changes speakers

• “Hear” name only about 30% of time

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Attention as a filter with a bottleneck

Predictions of the model

• Operates solely on the physical characteristics (voice, location,

intensity) not on meaning.

• ‘Filtered’ materials on the unattended channels will be lost.

• Limited capacity--only a certain number of things can get

through into consciousness.

‘Cocktail Party Effect’

• Seem to hear important information (like your name) even in

situations in which you are supposedly filtering out irrelevant

info.

Treisman’s attenuation model

• Instead of completely filtering out all unattended info, it gets

through just at a lower intensity (it is attenuated).

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• Important messages (like your name, fire alarms) are set to a

lower threshold of awareness.

• However, there is evidence that low-priority messages get

through.

• Often “follow” message from attended channel to unattended

channel

• Shows extracting even low-priority information

More Evidence

• Experiment:

o Attended ear: ‘They were throwing stones at the bank.’

o Unattended ear: ‘Money’

o Test: Yes/no: ‘They were throwing stones at the shore.”

o More likely to remember the sentence when one

disambiguating word was in the unattended channel.

Late selection theory

• All information is processed for meaning but only one response

can be made.

• Difficulty in dealing with the finding that there is little conscious

knowledge of unattended channel.

Maybe a different perspective is needed…

• Cocktail party effect revisited

o Only about 1/3 of subjects notice their own name.

o Look at individual differences in working memory

capacity.

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Capacity theories

Yerkes-Dodson Law

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Circadian Rhythms

• Temperature and Visual Search

• Temperature and Memory

Interim summary

• Attention is selective and certain individuals seem to be better

at selecting than others.

• Most of the shadowing results can be explained by an individual

differences approach in which individuals have varying capacity

to process/ignore unwanted info.

• This capacity can change over time and circumstances (such

as arousal).

Divisible

• If there is a ‘pool’ of resources, one should be able to do more

than one thing at a time up to a limit.

Dual task methodology

• Measure performance on each task by itself

• Measure performance on each task when done concurrently

• The difference between those is the ‘cost’ of doing two things at

once.

Is there only one resource pool?

• Is there always a cost to doing two tasks?

Selective Interference

• Brooks (1968)

o Task 1: Hear a sentence

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Respond “yes” or “no” to indicate if a word is a noun

o Task 2: Imagine

Respond “yes” or “no” to indicate if an angle is

greater than 100°

o Selective Interference

o Task 3: Say response

o Task 4: Point response

• Multiple Resources

o Attention involves different resources

o Verbal resource

for both speaking and processing

o Spatial resource

for both angle judgment and pointing

Problem: How many resources?

–As many as the data need

•explain everything, predict nothing

Shiftability of attention

• Controlled v. Obligatory

o Controlled: Spatial Cueing of Attention

Posner et al. (1980)

• press a key as fast as possible when a target

is detected

• Fixation

• Neutral Cue

• Valid Cue

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• Invalid Cue

Results

• Neutral: ~300 ms

o baseline performance (control condition)

• Valid: ~275 ms

o ~25 ms advantage of have attention waiting

• Invalid: ~335 ms

o ~35 ms disadvantage of having to move attention

Unilateral Neglect

• An extensive lesion of the right hemisphere including damage

to the parietal lobe

o Ignore the affected half of space

o Conversations initiated by someone to the left of the

patient may be ignored

o Only food located on right side of plate will be eaten

o The left half of the face may not be shaved.

Spatial cueing in neglect patients

• Show normal cuing effects for the side opposite their lesion if

the cue was valid.

• However, when a cue went to the same side as their lesion

and the cue was invalid they didn’t detect the target.

• Implies that they can shift attention but cannot disengage it.

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Attention and Automaticity

Automatic

• take few or no attentional resources

• occurs without intention

• must run to completion

• not open to awareness

• parallel processing

Reading

Non-automatic

• requires attentional resources

• cannot occur without intent

• can be interrupted

• open to awareness

• serial processing

Tying shoe laces

Parallel v. Serial processing

Parallel

• Multiple processes occurring at once.

• No deficit in either process when the other is occurring

• Serial processing

• One process at a time.

• Each process must finish before the next gets started.

• Deficit shown when more than one process occurs

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Practice helps move from serial to parallel

Reading

Arithmetic

Driving a car

Applications

• Learning to read/do math

• Human factors building design

• Smoking relapse

• Expertise of any kind

Stroop Effect

• Say name of color out loud as fast as possible (Stroop, 1935)

• Automatic process of reading interferes with non-automatic

process of color naming

Developing Automaticity

•Practice, practice, practice.

•If the stimulus doesn’t change much in different contexts, can

develop automatic processing.

•If it is variable, can’t automatize.

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Attention and automaticity in perception

• Feature integration theory

• Two stages

o Pre-attentive processing--based on basic features of the

stimulus (color, orientation, size), no attention necessary,

doesn’t take any resources, parallel processing.

o Conjunctive processing--based on a conjunction of

features, attention necessary, takes resources, serial

processing.

Triesman’s ‘glue’

• Attention is the glue that binds the basic features together into

objects.

Visual Search

• Simple feature search: target’s features do not overlap with

distractors’ features

o “Pop-out”

o Doesn’t require attention

• Conjunction search: target’s features do overlap with

distractors’ features

o No “Pop-out”

o Requires attention

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Visual search CogLab homework

• IVs:

o feature v. conjunction search

o Yes or No response

o number of distractors

• DV:

o response time

Feature integration theory

• In the feature search condition, no attention was needed,

parallel processing, so the responses are fast, automatic and

aren’t affected by how many distractors.

• In conjunction, attention needed, serial processing, so the

responses are slow and are affected by the number of

distractors.

Illusory conjunctions

X A * M R

• On some trials report seeing red R or blue X

• Real-world example: Computer solitaire

• Attention needed to ‘glue’ together features

Change Blindness

• Don’t attend to all aspects of a scene equally.

• Top-down processes “fill in”

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Attention summary

• Attention is Concentrating and focusing of mental effort that

selective, divisible, shiftable

• Original conceptions of attention was that of a filter with a

bottleneck (early, late selection)

• Later conceptions included the idea of a pool of resources

(single, multiple)

• Certain brain areas are associated with the ability to move

attention

• Through practice, some processes can become ‘automatic’ in

that they require no attention and occur in parallel

• Attention summary

• Feature integration theory demonstrates the multiple steps in

attending to a visual scene

• Change in the visual scene is often not noticed (top-down

processes are used extensively)