4) Attention

8/12/2019 4) Attention

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Slide 1

ATTENTIONEXP3604C


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Slide 3

Selective or Divided?

An example of divided attention. The player has to attend to several things on screen at once.


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Slide 4

Selective or Divided?

The only way to reliably find Waldo is to focus attention (selectively) on the spot yourecurrently looking at while ignoring everything else


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Slide 5

Overt or Covert?

Clearly, they are all paying attention to something up high. Theyre eyes and other bodylanguage can be used to infer what they are focusing on. This is overt attention.


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Slide 6

Overt or Covert?

Even though her eyes give her away from the front, she is being careful to prevent her bodylanguage from indicating from behind that shes listening to their conversation (covertattention)


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Slide 7

SELECTIVE ATTENTIONFocus on one thing, ignore everything else

We selectively attend often in tasks like those pictured


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Slide 8

Selective Attention Ignoring unwanted information

http://www.youtube.com/watch?v=lyVjd8TpOXs

Some examples

- Al Gore can get some work done despite the distracting clutter. - The video shows what its like talking to people in a crowded convention center a difficult

place to focus your attention on the conversation youre trying to have.


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Slide 9

Filtering Tasks Dichotic Listening

Filter out some information

Shadowing Repeat 1 message aloud

We study selective attention by having people do filtering tasks.

The participant hears 2 messages 1 in each ear and is tasked with ignoring one and payingattention only to the other. This is called dichotic listening (which is a type of filtering task).

They are also instructed to shadow the message they are supposed to be selectively attendingto (i.e., to repeat it out loud see image) thats how the researcher knows they are actuallydoing the task as requested.

Later, the experimenter will ask questions about what they heard in order to study selectiveattention


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Slide 10

Theories of Selective Attention Early Selection

Bottom up processing No meaning analyzed before consciousness

Late Selection Bottom up processing meaning is processed, but may not reach consciousness

Early selection models of selective attention filter out unwanted information shortly after it isperceived. i.e., important perceptual details are selected early (while unwanted perceptualinformation is filtered out) and the selected content gets to go further into the brain foradditional processing (e.g., the meaning of the words heard).

Late selection theories suggest that ALL the incoming perceptual information is processed, andthen meaning is processed (e.g., word meaning), and ONLY THEN does some of it get selected tomake its way into consciousness.


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Slide 11

Broadbents Filter Model An early selection model

a.k.a. A bottleneck theory

The most prominent theories of attention are collectively referred to as bottleneck theories.They all assume that a lot of information comes in from the environment, but due to ourprocessing capacity limits, only a little of this information gets processed and into consciousnessat a time.


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Slide 12

Broadbents Filter Model

1. Sensory Memory Incoming info store

E.g., visual, auditory processing

2. Filter Allows through only attended message

3. Detector Processes meaning (semantics) All info that gets through is processed

4. Short-term Memory i.e., into consciousness

One of the most prominent bottleneck theories is Broadbents filter model.

This is an early selection model.

All the sensory information from the environment comes in through our senses (stage 1), andthen is immediately filtered in stage 2 to prohibit all but the stuff we want to get through foradditional processing (i.e., we can direct our attention, and that is what determines what getsthrough).

Only then does meaning get processed (the detector in stage 3), and only after that does thisinformation make its way into our consciousness


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Slide 13

Evidence to the Contrary Cocktail Party Effect

Processing meaning !

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Dear

Aunt

Jane

BUT if selective attention relies on early selection of important information for furtherprocessing, then how do we explain the cocktail party effect? Imaging having a conversationat a party, focusing attention on the people in front of you and ignoring all the noise behind you,when someone on the other side of the room says your name. You notice! How can thathappen if the other information in the room isnt getting processed for meaning (as inBroadbents early selection model)?

Another example: the Dear Aunt Jane Study. During the dichotic listening task, informationlike that above (in the slide) would be presented. If the participant is tasked with listening tothe left ear, they should hear: Dear 7 Jane. But when asked later what they heard, they replyDear Aunt Jane. So the unattended information coming in from the right ear must be gettingsome processing for meaning. This isnt predicted by Broadbents early selection model it is acontradiction to that theory.


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Slide 14

Treismans Attenuation Theory Selection takes place at needed level

Example: Male vs. female voice early filtering based on sound Female vs. female voice later filtering based on

meaning

Treisman suggests a theoretical modification to allow early selection models to remain viable.She argues that we can do early selection based on stimulus surface features e.g., male vs.female voice. But if this information isnt available (e.g., 2 female voices) then it is not possibleto selectively attend based on this feature, and both voices go on for further processing. Oncemeaning is processed it becomes possible to filter from then on (i.e., filter out what you dontwant to enter consciousness and memory).


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Slide 15

Treismans Attenuation Theory

Unattended messages are attenuated Made thinner

Attended message gets more processing Is amplified

Dictionary unit processes meaning i f needed Thresholds

Some words always get processed (Fire!, your name)

Treisman suggests that some information always gets through for meaning processing. Yourname or important words like fire always get processed. But for the most part you can limitthe processing in terms of meaning to what you want to focus on.


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Slide 16

Late Selection Models

Meaning is always processed at some level Can influence if attended to

then Which is closer to what youheard?

They threw stones towardThe side of the river

They threw stones at thesavings and loan

They threwstones at the

bank

Attended

money

Unattended

Other theorists argue that ALL incoming information first gets perceptual processing, and thengets meaning processing, and only THEN does filtering occur (i.e., late selection of informationto get into consciousness and memory)

This is demonstrated by the example study above.


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Slide 17

Attention & Cognitive Resources

Attention interacts with the amount of cognitive resources we have available at a given time.

The circles above represent the total cognitive capacity we have at our disposal. The coloredpart indicates how much of this capacity is being used by the task were primarily engaged in.So the image on the left shows that if our primary task is a low cognitive load task (i.e., an easytask), then we have a lot of cognitive capacity left to think about other things. A high cognitiveload task (right) eats up all our available resources, and we are unable to multi - task.


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Slide 18

Some real world examples. Driving on a country road or relaxing in front of the TV leavesenough resources to think about other things. Not so for biking in the city or driving and talkingon the phone.


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Slide 19

B A BA B AX C XB C BD A DX B XB D B

A C AX A X

Flanker taskRespond to A or B with left handRespond to C or D with right handRespond based on MIDDLE letter!

The flanker task is a simple experimental task designed to examine our ability to selectivelyattend. The participant is to quickly respond with their left hand if the center letter is either anA or B. If a C or D, they are to quickly respond with their right hand as they go through thesequence of letter triplets one by one (i.e., imagine each row of 3 letters is shown on the screenone at a time, and the participant is to respond as soon as they can once the letters appear)


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Slide 20

0

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e. g. , XAX, XC X e.g. ,ABA, DCD e. g. , BCB, DAD

neutral compatible incompatible

R e s p o n s e

t i m e

( m s

)

Implies early or late selection? (writeanswer)

Attention & Cognitive Resources Unintentional processing!

Response time is fastest if the letters that surround the target (center letter) are in the sameresponse category (i.e., compatible). See the middle bar in the chart.

Response time is slowest if the flankers (i.e., the letters that flank the target on each side) arefrom the opposite response category (see the right -most bar).

These results indicate that even when we try to ignore irrelevant information , it is difficult.

This argues for late selection models, since the flanker meaning is clearly being processed inorder to provide this interference.


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Slide 21

Task Irrelevant Stimuli Interfere : you process anyway!!

The Stroop task is a classic example of interference from irrelevant information.

Try naming the color of the font from each word in the list as fast as you can. Dont read thewords, just say the colors as fast as possible! (Really, try it!)

Did the word meaning slow you down? (I.e., did that automatic process of reading interferewith what you were trying to focus attention on?)


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Slide 22

A

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OO

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C

BO

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BD O

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FR

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K

D A

J

PL

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ACH

NF

QY

compatible

incompatible

incompatible

compatible

incompatible

incompatible

Cognitive Load Reduc es Interferenc e !!Flanker task: target (A,B,C, or D) in the circle, distractor alongside

Amazingly, if you make the flanker task more difficult like on the right (the participant has torespond quickly to the target that appears in the circle, although there are a lot of otherirrelevant letters) people actually experience less interference from the flanker (the letterappearing outside the circle).

Can you guess why this might happen?! (Really, try to answer this before going on)


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Slide 23

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compatible incompatible compatible incompatiblelow load low load high load high load

Hi-load: Flanker Interference Gone!!

These are hypothetical average response times for the 4 conditions shown in the previous slide.

Under low cognitive load (the easy task in RED), there is a big difference between compatibleand incompatible flankers (compare the height of each red bar).

In the high load conditions (YELLOW), though, the compatibility or incompatibility of the flankerbecomes irrelevant.

Why??


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Slide 24

Some real world examples.

Along the top sitting in the bar watching a game doesnt require much of your cognitiveresources. In this case, the person could become distracted by the people celebrating behindhim.

Along the bottom playing a video game can consume most of our available resources. In thiscase, the person wouldnt be distracted by other things going on behind him.

This explains the flanker task data in the previous slide. If all your cognitive resources arealready occupied, other things in the environment cant distract us as much. In fact, we mightmiss them almost entirely. If you have a lot of free resources, you have extra capacity to noticeand be distracted by other things.


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Slide 25

Endogenous/Exogenous Attention

Endogenous Internally initiated i.e., goals

Exogenous Externally initiated i.e., environment

Attention can be directed either from internal thoughts or by external events.

In the endogenous examples, you initiate where your attention goes (find a word, findsomething in briefcase). In the exogenous example, the ball flying at your face will dictatewhere your attention is! (exogenous means an external event)


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Slide 26

OVERT, COVERT ATTENTION


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Slide 27

Overt Attention Obvious attention shifting

Eyes move (other parts of body?)

Saccades, fixations http://www.youtube.com/watch?v=YsU1Yb6wkJ0&feature=related

Eye Tracking http://www.youtube.com/watch?v=lo_a2cfBUGc

Eye movements indicate where a person is focusing attention.

Eye tracking devices can be used to record where a person is looking and for how long. Fromthis we infer when and where the persons attention was! This is valuable for design and forunderstanding cognition as it unfolds in time.

Watch the videos to see examples of saccades (individual eye movements) and what can berecorded with eye tracking devices.


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Slide 28

Overt Attention Bottom-up Feature salience (prominence)

Drives attention Corners, edges

Overt attention can be driven by exogenous factors.

This is a bottom up processes (i.e., driven by the visual system, not by higher - level thoughts).Certain features are more telling than others. While looking at a face, for instance, we focusmostly on eyes and mouth this is where the most variation lies from moment to moment. Theimage on left shows eye - tracker data red means more time spent looking at these spots.

The image on the right shows the features tracked by software designed to classify the emotiona person is expressing. Notice its mostly eyes and mouth information.


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Slide 29

Overt Attention Top-down Make Tea (fill the kettle)

just in time eye movement

Endogenous goals can also exert control over where our overt attention cues (e.g., eyemovements) are directed.

When placed in this scene and asked to make tea, peoples eyes first look for the pitcher, andthen look at the faucet only when it is needed. This is opposed to planning these things out inadvance and looking back and forth to see where everything is. This indicates somethingvaluable about how attention and cognition progress over time.


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Slide 30

DIVIDED ATTENTION Attend to multiple things at once


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Slide 31

Can we Really Divide Attention?

Sure we can

But not always!

We divide our attention all day long.

But some types of divided attention are very difficult. Can we really listen to talk radio andread at the same time (not really)? Or listen to 2 conversations at the same time (not really)?

We can rapidly switch back and fourth between tasks, but it is difficult.


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Slide 32

Automatic vs. Controlled Processing

Controlled Processing Have to think about what youre doing!

Automatic Processing Dont have to think about it

Examples?

One of the reasons were able to divide our attention between tasks is because some thingsbecome easier as we gain experience with them.

All tasks start out as controlled tasks - they require active attention to what were doing.Imagine when you were first learning to type how slow, effortful and mistake prone this was.Eventually it becomes an automatic process and you can do it without thinking about it.

In fact, thinking about what were doing too much during an automatic processing task canactually cause us to make mistakes!!


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Slide 33

Controlled vs. Automatic

Making a sandwich likely doesnt become automatic, although if you work at Subway it mightmove in that direction!

Flying a plane likely involves a combination of controlled and automatic tasks.


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Slide 34

Divided Attention Lab Study Do 2 tasks simultaneously

Hold info in memory Look at other info (and make a decision)

7 4

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TARGET

X R

T Y

Any target items?

A classic study of divided attention looks at our ability to do multiple things at once, especiallywhen transitioning from a controlled to an automatic task.

The participant first briefly sees the target square (which can have 1 -4 items in it), followed by along series of squares with letters and numbers. These are presented at an extremely fast rate!The task is to then decide whether any of the elements from the target square were shown inthe rapid sequence.


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Slide 35

7 4

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K R

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B N

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A H

T B

(This demo works in the PPT version of these slides just use an arrow key to move through thesquares rapidly)


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Slide 36

From Controlled to Automatic Processing

People are initially terrible at this task. In fact their performance is at chance (like a coin flip;see trial 0 in the chart).

Over a long series of trials, they actually become able to do the task, and in fact it becomeseffortless (automatic).

At that point they are very good at doing these 2 things at once holding the target in memorywhile viewing the series of items that follow it, and then making a decision. (the up arrow attrial 600 shows the point where the task probably becomes automatic)


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Slide 37

From Controlled to Automatic Processing

Dividing attention gets easier with experience! Performance gets better!


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Slide 38

ATTENTION & VISUALPERCEPTION

Attention can interact with what we actually perceive visually


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Slide 39

Inattentional Blindness

Inattentional blindness means that we will not see details that appear in places where ourattention is not focused.

See the video for a classic demonstration! http://www.youtube.com/watch?v=2pK0BQ9CUHk

This indicates that our attention is strikingly limited in scope, even though we dont realize it!!!


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Slide 40

Inattentional Blindness If not paying attention, you can miss things in plain sight!

See next slide


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Slide 41

Change Blindness

What is different in these 2 images?


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Slide 42

If the images are made to overlap, and one were to toggle back and forth between them, it isimmediately obvious what the difference is between the images (a flower appears/disappearsin the bottom right portion of the image; see previous slide)

(in the PPT version of these slides, you can see the difference easily on this slide by using anarrow key to go back and forth between images)


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Slide 43

What does this tell us about attention? Write answers

Need focused attention to detect change (if orienting responseisnt available)

In mental representation rather than in the visual system!

http://www.youtube.com/v/vBPG_OBgTWg

The results of studies like these tell us something about how attention works.

They suggest attention is like a spotlight a narrow beam that we can point and fix on alocation or object for cognitive processing. And it is slow and effortful to move it around ascene, as opposed to some of the rapid/automatic things that the visual system does.

The video shows the now classic demonstration of change blindness actually swapping out 2different people in a conversation!!!!

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4) Attention

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