Cognitive%20Psychology

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Cognitive Psychology

• Attention

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What do these have in common?

• You are driving to a lunch date, and accidentally
  take the route to your job. After you correct
  your route, as you are driving by the theatre, a
  red ball chased by a child suddenly appears on
  the street, and you screech your brakes. You get
  to the restaurant and try to find your friend,
  who has flaming red hair. The restaurant is
  packed, its hard to make-out faces, but you can
  see peoples hair so you look for red hair. When
  you get to your table your friend asks if you
  noticed the Star Wars promotion with two costumed
  people fighting with light sabers. As you talk
  about important but dull business, your mind
  keeps drifting to your exciting first date last
  night. You force yourself not to think about it,
  but it keeps coming back.

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• Innatentional Blindness (original experiment)
• http//www.youtube.com/watch?vvJG698U2Mvo
• Change Blindness (office) https//www.youtube.com/
  watch?vdiGV83xZwhQ

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Change Blindness

• Counter experiment http//www.youtube.com/watch?v
  mAnKvo-fPs0
• Campus Door Demo
• http//viscog.beckman.uiuc.edu/flashmovie/12.php
• Construction door http//viscog.beckman.uiuc.edu/f
  lashmovie/10.php
• Gradual Change http//viscog.beckman.uiuc.edu/fla
  shmovie/1.php

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Aspects of Attention

1. Detection.
2. Filtering and selection.
3. Search.
4. Automatic processing.
5. Concentration.

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Architecture

• The box model

Sensory Store
LTM
STM
Filter
Pattern Recognition
Selection
Input (Environment)
Response
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Attention

• In this model, attention is
• The filter and selection boxes
• The arrows.
• The special job carried out by each of these
  boxes according to different theories of
  attention
• (Yes, this is cheating)
• In this model attention
• Puts together information from various sources.
• Gets information into STM
• Works in imagery

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Detection

• Two kinds of thresholds
• Absolute Threshold Minimum amount of
  stimulation required for detection.
• Difference Threshold (Just Noticeable
  Difference) Amount of change necessary for two
  stimuli to be perceived as different.

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Detection

• Absolute Thresholds
• Vision One candle, on a mountain, perfectly
  dark, 30 miles.
• Hearing A watch ticking 20 feet away.
• Smell A single drop of perfume in a three room
  apartment.
• Touch The wing of a bee on your cheek.
• Taste One teaspoon of sugar in two gallons of
  water.

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Determining Thresholds

• How to determine thresholds
• Method of limits
• Ascending Start with a value below the
  threshold, increase, ask for detection, increase
  At the point a person says detect, average
  that stimulus value with the value from the
  previous trial. Repeat to estimate threshold.
• Descending Same, but start above threshold and
  work down.
• Combining results from both directions will give
  you an estimate of the threshold.

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Determining Thresholds

• How to determine thresholds
• Method of constant stimuli
• Present a series of randomly selected stimulus
  values, ask for yes/no response for each. The
  value thats detected 50 of the time is the
  threshold.
• These methods can be adapted to determine
  difference thresholds.

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Determining Thresholds

• We think thresholds work like a step function,
  but they dont. They are sigmoid or ogive curves

This graph represents an ogive-curve and how
detection really changes it is a gradual slope.
The threshold is defined as a 50 detection rate.
This graph represents a step function. Below the
threshold there is 0 detection. Above the
threshold, there is 100 detection. This is the
way we normally believe our perception to work.
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Determining Thresholds

• Difference Threshold
• Webers Law K ?I / I
• K is the Konstant
• ? is the difference
• I is the stimulus intensity
• The formula states that the threshold for
  noticing a difference (whether its the length of
  a line or weight of a dumbell) is a constant
  ration between the old / background stimulus
  and the new / target stimulus.

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Determining Thresholds

• Early Researchers Noticed Thresholds Shift!

These are ogive curves for stimuli of the same
intensity but with different signal to noise
ratios or payoff matrix

• How to get around this problem A model that
  accounts for signal to noise ratios and payoff
  matrixes ? Signal Detection Theory

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Signal Detection

• Can estimate detection (sensitivity) independent
  of bias.
• Two kinds of trials
• Noise alone Background noise only.
• Signalnoise Background noise with signal.
• Two responses from observer
• Detect.
• Dont detect.

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Signal DetectionFour Situations
State of the world State of the world
Response Signal Noise
Yes (Present) Hit False Alarm
No (Absent) Miss Correct Rejection
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Hits(response yes on signal trial)
Criterion
N
SN
Probability density
Say yes
Say no
Internal response
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Correct rejects(response no on no-signal trial)
Criterion
N
SN
Probability density
Say yes
Say no
Internal response
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Misses(response no on signal trial)
Criterion
N
SN
Probability density
Say yes
Say no
Internal response
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False Alarms(response yes on no-signal trial)
Criterion
N
SN
Probability density
Say yes
Say no
Internal response
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Signal DetectionSensitivity and Bias

• We can estimate two parameters from performance
  in this task
• Sensitivity Ability to detect.
• Good sensitivity High hit rate low false
  alarm rate.
• Poor sensitivity About the same hit and false
  alarm rates.
• Response Bias Willingness to say you detect.
• Can be liberal (too willing) or conservative (not
  willing enough).
• For example, if the true signal to noise ratio is
  50 and you have a 75 detection rate, then your
  response bias is to be too liberal.

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Signal DetectionSensitivity and Bias

• Computing sensitivity or d (d-prime)
• Is a measure of performance (like percent
  correct, or response time)
• Typical values are from 0 to 4 (greater than 4 is
  hard to measure because performance is so close
  to perfect)
• A d-prime value of 1.0 is often defined as
  threshold.

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d-Prime

• d-prime is the distance between the N and SN
  distributions
• d-prime is measure in standard deviations
  (Z-Scores)
• In SDT, one usually assumes the two underlying
  distributions are normal with equal variance
  (i.e., both curves have the same standard
  deviation)

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Signal DetectionSensitivity and Bias

• Computing bias
• The criterion is the point above which a person
  says detect. It can be unbiased (the point
  where the distributions cross 1.0), liberally
  biased (lt 1.0), or conservatively biased (gt 1.0).

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Signal DetectionSensitivity and Bias

• Since sensitivity and bias are independent, you
  can measure the effect of different biases on
  responding to a particular value for
  detectability.
• Influences on bias
• Instructions (only say yes if youre absolutely
  sure).
• Payoffs (big reward for hits, no penalty for
  false alarms).
• Probability of signal (higher probability leads
  to more liberal bias).

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Signal DetectionSensitivity and Bias

• Receiver operating characteristic (ROC) curves
• For a given detectability value, you can
  manipulate the hit and false alarm rates. An ROC
  curve shows the effect of changing bias for that
  level of detectability.

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Sample ROC Curves
of Hits
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Optimal Performance

• Depending on the probability of a signal trial
  and the payoff matrix, the optimal placement of
  the criterion will vary.
• p(N) value (CR) - cost (FA)
• ?opt X
• p(S) value (H) - cost (M)
• You can compare performance to the ideal observer
  to assess the operator.

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Examples of Visual Search
Is there a threat?
Wheres Waldo?
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Search

• How do you use attention to locate items in a
  complicated array? Two kinds of search Feature
  Search and Conjunction Search.
• Feature search A single feature allows you to
  find the item you are searching for.
• Find the blue S.

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Search
X T X T
X T S X
T X X X
T T X T
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Search
X T X T T T X T
X T X X T X T T
T X S T X X T X
X X T X T X T X
T X T T X T X T
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size Treisman Gelade 80 Healey Enns 98
Healey Enns 99x
length, width Sagi Julész 85b Treisman
Gormican 88
line (blob) orientation Julész Bergen 83 Sagi
Julész 85a, Wolfe et al. 92 Weigle et al. 2000
closureJulész Bergen 83
colour (hue) Nagy Sanchez 90 Healey 96 Bauer
et al. 98 Healey Enns 99
density, contrast Healey Enns 98 Healey Enns
99
curvature Treisman Gormican 88
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Search

• How do you use attention to locate items in a
  complicated array?
• Conjunction search You have to combine features
  to find the item you are searching for. This
  should take attention and be more difficult
  (Treisman, 1988).
• Find the green T.

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Search
X T X T
X T T X
T X X X
T T X T
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Search
X T X T T T X T
X T X X T X T T
T X T T X X T X
X X T X T X T X
T X T T X T X T
X T X T
X T T X
T X X X
T T X T
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Simple feature search Look for an O
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Simple feature search Look for something red
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Conjunctive feature search Look for something red
AND O
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Conjunctive Search
Response Time
Simple feature search
Number of Stimuli in Display
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Properties of searches

• Feature searches
• Dont require attention (pop-out).
• No help from location cueing (dont need it).

• Conjunction searches
• Require attention.
• Affected by the number of distracters.
• Helped by cueing the location.

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Pop-Outs in Advertisement
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Scan Paths
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Feature Conjunction Attention as Glue
The significance between conjunctive and
disjunctive searches is that it means that
individual features like color and size are
loaded pre-attentively (attention is not
required), but a conjunctive search requires
attention to bind the two features to the object
to a location in space. You need attention to
know an object is both red and large and where it
is. The integration may happen in the visual
cortex as a result of synchrony, with attention
affecting the tuning properties of sensory
neurons, and preparing other cognitive processes
like working memory.
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Attention as GlueKeep your eye on the fixation
point below. A screen with colored letters will
be briefly flashed. Try to remember as many
letters with their colors as you can.

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L
S
O
P
Q
M
Q
H
U
X
B
T
K
V
Z
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Attention as a Glue

• What color was the X?
• Do you distinctly recall a particular letter
  being a different color? How did that happen? How
  did a color in one location get associated with
  an object in another location?
• This is attention as a glue

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Treismans Feature Integration Theory

• A two-stage theory of visual attention.
• Stage 1. fast parallel for single features
• Stage 2. Slow serial for conjunctions of single
  features.
• Several primary visual features are processed and
  represented with separate feature maps that are
  later integrated in a saliency map that can be
  accessed in order to direct attention to the most
  conspicuous areas.
• A parallel search, a red circle amidst green
  circles, takes no time no matter how many green
  circles (its cheap). A serial search, with
  conjunction features, like red circles amidst
  black circle and red triangles, requires you to
  check each distractor serially.

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Automatic Processing

• After practice, some tasks no longer require
  attention. Three criteria for automatic tasks
• Occur without intention.
• When the load is low
• Required reaction times are short
• The tasks are over-learnt or well-practiced
• No conscious awareness/Cant be introspected.
• Dont interfere with other activities.
• Fast processes -- the brain does them
  automatically, they are a basic feature
• You can tell how the process of automatization is
  going by doing dual task studies (primary and
  secondary).

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Automatic Processing

• Read the Words.
• Say the colors
• Which is harder?

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Automatic Processing

• You did the Stroop task.
• The interpretation is that you automatically read
  the word. If thats the task, the color doesnt
  interfere because you dont automatically
  register that. If youre supposed to name the
  color, automatic reading messes you up.

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Filtering

• So, thresholds shiftbut once set, then what?
  What happens when something gets over the
  threshold wherever it is? When does meaning
  become involved?
• How do we choose what to attend to? Is the choice
  made early or late?

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Themes

• Early or Late? In other words, does something get
  chosen before or after (respectively) the
  stimulus gets stamped with meaning
• What is attention?
• Some sort of bottleneck or filter?
• A capacity or resource (or several kinds)?
• Can we learn something by looking for it in
  brains?

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Filtering

• Early Broadbent. Selection happens at the filter
  and sensory store before pattern recognition. The
  selection is made at the EARLY STAGE of crude
  physical analysis.

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Filtering

• Early Evidence
• Dichotic listening. Two messages, one to each
  ear, played simultaneously.
• Shadowing Repeat out loud everything in one ear.
  What do people (or what dont people) notice in
  the unattended ear?
• Miss change of speaker.
• Miss change of language.
• Miss change of direction.

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Filtering
7-4-1
3-2-5

• Early Evidence
• Filter flapping Two sets of numbers come in, one
  set in each ear.
• Report by ear Easy.
• Report in order Hard.
• The argument is that the filter lets in all of
  one channel, then the other, no problem. To
  switch back and forth takes a lot of effort.

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Filtering

• Problem for early models
• People detect their name on the unattended
  channel (cocktail party phenomenon).
• Treisman (1960) If a shadowed story switches
  ears, people follow it, and then correct. They
  have to be attending to meaning to follow the
  story.

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Filtering

• Problem for early models
• Example 1
• I SAW THE GIRL/song was WISHING
• me that bird/JUMPING in the street
• Example 2
• AT A MAHOGANY/three POSSIBILITIES
• look at these/TABLE with her head

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Filtering

• Attenuation model
• Everything in memory is active at some resting
  level. Some stuff thats important has a high
  resting level, making it easier to respond to
  (e.g., your name).
• Other stuff has a low resting level, making it
  harder to respond to.
• As you think about something, you raise its
  activity level.

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Filtering

• Attenuation model
• The unshadowed ear is attenuated (the volume is
  low). This little bit of attention can reach
  something with a high resting level (your name, a
  story youre shadowing), but not some random bit
  of information.
• So, no filter, just attenuation.

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Filtering

• Capacity model
• You have a certain amount of attention, you can
  spread it around as needed. If you spend a lot on
  one task, then you have less for others.
• Primary task Do well on this no matter what
  (main focus of resources).
• Secondary task Also do this.
• By manipulating the difficulty of the primary
  task and measuring the secondary task, we can see
  how attention allocation affects performance.

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Filtering

• Capacity model
• For example, Johnston and Heinz (1978) had two
  tasks
• Primary Shadow one ear for a change that is easy
  (gender) or a change that is hard (category).
• Secondary Detect a light.

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Filtering

• Capacity model Johnston and Heinz (1978)

Primary Secondary
Shadow one list (control) 1.4 error 310 ms
Easy (gender) 5.3 error 370 ms
Hard (category) 20.5 error 482 ms
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Filtering

• Capacity model
• What this implies is that the filter can be early
  (gender) or late (category), the amount of your
  resources that you allocate to it determines
  where the filter is.

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Emotion Driving Attention

• Detecting a Snake in the Grass (Ohman, Flykt,
  Esteves, 2001)
• Stimuli snakes, spiders, mushrooms, flowers
• Presented in 2x2 or 3x3 displays
• Task Do all the pictures belong to the same
  category?

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Emotion Drives Attention

• Reaction time to detect target in ms.

Fearful Neutral
2x2 950 1010
3x3 950 1010
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Emotion Drives Attention

• The Emotional Stroop Effect
• You are slower at naming a color of emotionally
  charged words than neutral words
• Taboo words vs neutral words

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Emotion Drives Attention

• Classical Stroop

RED GREEN BLACK YELLOW BLUE RED BLACK
RED GREEN BLACK YELLOW BLUE RED BLACK
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• Attic

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• Bitch

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• Shit

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• Anus

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• Frame

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• Dyke

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• Senate

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• Note

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• Bank

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• Queer

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• Scrotum

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• Wife

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Emotion Drives Attention
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Emotion Drives Attention

• Emotional Stroop effect occurs with
• Taboo words
• Alcohol words (beer) in alcoholics
• Smoking words (cigarettes) in smokers
• Spider words (web, crawl) in arachnophobics
• Food pictures in females with anorexia
• Threat words (disease) with people with anxiety
  disorders

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The Dot Task Detection in PTSD
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Mood and Attention Levels of Focus (Gasper
Clore, 2002)

• Hypothesis Affective cues may be experienced as
  task-relevant information, which then influences
  global versus local attention.
• Mood Manipulation Subjects randomly assigned to
  write about a happy or sad event in their lives
• Each participant randomly assigned to a drawing
  chain, where the first person in each group saw a
  drawing of an African shield with the title of
  Portrait of a Man. In a later session, a 2nd
  person saw the 1st persons reproduction from
  memory, and so on.

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Local Global

• Lesions in LH produce deficits in local
  perception
• Lesions in RH produce deficits in Global

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Mood and Attention Levels of Focus (Gasper
Clore, 2002)

• Happy Mood condition more likely than Sad Mood to
  contain schema-relevant details like title and
  facial features
• Sad Mood drawings became less face-like down the
  chain but not Happy Mood drawings
• Sad Mood drawing looked less like original

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Mood and Attention Levels of Focus (Gasper
Clore, 2002)

• Experiment 2 employed a task in which the same
  objects were sometimes the global and sometimes
  the local stimulus (Kimchi Palmer, 1982).
  Participants saw an overall shape (e.g., a
  triangle) made up of smaller geometric figures
  (e.g., triangles). Their task was to indicate
  which of two other figures (e.g., a square made
  of triangles or a triangle made of squares) was
  more similar to this target figure.

Result Sadder people base their decisions on the
local features, and report doing so.
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Posner Cueing Task
Peripheral Cue condition triggers exogenous
attention/ Reflexive attention Bottom-up
Central Cue condition triggers endogenous
attention / voluntary attention Top-down
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Inhibition of ReturnThe Been There, Done That
Reflex

• We are faster at unpredicted cues after a long
  enough pause
• IOR prevents going over the same ground, promotes
  searches for novel stimuli

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• The findings from patients with brain damage led
  Posner to construct a model for attention that
  involves three separate mental operations
• Disengaging of attention from the current
  location
• Moving attention to a new location
• Engaging attention in a new location to
  facilitate processing in that location.

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Psychological Refractory Period (PRP)Timing the
Central Bottleneck

• A Multiple sensory input
• B Serial Decision maker
• C Multiple action output

A
B
C
Stimulus 1
A
B
C
PRP
Stimulus 2
SOA
Time
Slope 1
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Embodied cognition of attention is Cognition
Time-Pressured?

• If we were designed to perform under pressure, we
  would be good at it.
• But, the reality is that, under time pressure we
  fall apart
• We actively avoid operating under conditions
  where we are time pressured
• Most of daily behavior consists of mundane,
  routine behavior

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Embodied Cognition is Time PressuredWilson, 2002

• Summary
• Perceptuomotor processes are time-pressured, but
  that does not illuminate cognitive performance
  under time pressure
• Difficult to interpret whether cognition is time
  pressured means we evolved to perform under
  pressure or that our cognitive abilities must be
  understood in the context of coping with
  (unsuccessfully) or avoiding time pressures

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• Line Bisection and flower drawing are examples of
  spatial-based neglect.
• The dumb-bells are an example of object based
  neglect

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IMPLICIT ASSOCIATION TEST

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CATEGORY SWITCH
?
?
Get Kristin's demo
?
?
?
?
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WORD CATEGORIZATION
?
?
?
?
?
?
?
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IMPLICIT ATTITUDES
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IMPLICIT BELIEFS
2000
Reaction Time
1500
1000
500
0
Insects Good
Insects
Bad
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Stereotype Threat(Beilock McConnell, 2004)

• People perform in compliance with stereotypes
• In one of the first studies on stereotype threat,
  Steele and Aronson (1995) had high-achieving
  African American and Caucasian students at
  Stanford University complete a portion of the
  graduate record exam (GRE).
• Prior to doing so, some students were told that
  the test was diagnostic of intellectual ability
  whereas others were told that the test was a
  laboratory problem-solving task not diagnostic of
  intellectual ability.

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Stereotype Threat(Beilock McConnell, 2004)

• Results demonstrated that after controlling for
  SAT scores (to equate past academic performance),
  there was no difference in GRE performance
  between White and Black students for whom the
  test was not framed as diagnostic of intellectual
  ability.
• Of those students who were told that the test was
  diagnostic of intellectual ability, however,
  African Americans performed significantly worse
  than Caucasians.
• Steele and Aronson argued that informing students
  about the diagnosticity of the test activated the
  negative cultural stereotype that Blacks are not
  as intelligent as Whites, which contributed to
  the less-than-optimal performance of African
  Americans on a test assumed to gauge intelligence.

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Stereotype Threat Memory or Attention(Beilock
McConnell, 2004)

• How does stereotype threat work?
• One proposal is that stereotype threat produces
  reduces working memory capacity
• But past research has shown that stereotype
  threat effects are most pronounced for expert
  athletes, for whose abilities are highly
  proceduralized, relying little on working memory.
• On the other hand, expert athletes choke when
  they start to pay too much attention to the steps
  of their automatized processes this increased
  attention can backfire and disrupt what should
  have been fluent, proceduralized execution. This
  idea is often termed the explicit monitoring
  hypothesis.

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Stereotype Threat Memory or Attention(Beilock
McConnell, 2004)

• Do stereotype threats reduce working memory
  capacity, or do stereotype threats prompt
  explicit monitoring of automated procedures
• Expert male golfers perform a putt, before or
  after hearing a stereotype (men are poorer
  putters than women) or receiving control
  information (putting performance differs as a
  function of skill level).
• Experts who received stereotype did worse

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Stereotype Threat Memory or Attention(Beilock
McConnell, 2004)

• Now how to determine it is attention? Introduce a
  dual-task
• Experiment 2 (Beiock et al, 2003)
• Two groups with stereotyped and non-stereotyped
• One group performs putting alone
• Second group putts while listening for target
  word
• Results. Performance was the same for putters in
  the dual single task who had no stereotype
  threat. For putters with stereotype threat,
  performance was better in dual-task condition
  (Stereo-type Threat affects attention, not
  memory)

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The End
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Quizz

• You drove home and did not stopping at the store.
• This was due to a search failure because the sign
  for the store did not pop-out.
• You have a lot on your mind, and you are easily
  distracted
• Going to the store is a conscious decision, but
  you were filtering based on perceptual features
• Driving home is an automatic process
• Driving home is a conditioned response

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Quizz

• Youre walking to class and thinking about a quiz
  thats coming up. Someone calls your name, but
  you dont hear them.
• a) Your ROC curve is high.
• b) This counts as a hit
• c) You are filtering for perceptual features
• d) You are filtering for categorical or semantic
  information
• e) You didnt study and you cant hear people
  while throwing-up

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Concentration

• Our last topic has to do with the task of paying
  attention.
• Sometimes you have to concentrate on something in
  which you have no interest.
• Sometimes you have to not think about something
  in which you have an interest.

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Concentration

• Wegner, Schneider, Carter, and White (1987).
• Try not to think of a white bear.
• Five minutes, measure the number of times people
  do it.
• Or, try to think of it.
• Both are hard, with less activity later on.

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Concentration

• Wegner, Schneider, Carter, and White (1987).
• After suppression, its easier to keep thinking
  about a white bear.
• After expression, its still hard not to think of
  a white bear at first, but people adapt.

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Embodied cognition of attention is Cognition
Time-Pressured?

• Cognition happens in real-time or runtime
• Cognition must cope with predators, prey,
  stationary objects and terrain as fast as the
  situation dishes them out.
• How do you get robots to think about walking on
  uneven terrain, or to swing from branch to
  branch, or looking around a crowded room looking
  for a soda without bumping into something
• Story of legalizing sightdogs.

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Embodied cognition of attention is Cognition
Time-Pressured?

• Examples for
• Skilled hand movements, or time-locked
  perceptuomotor activity (catching, throwing,
  tying, walking)
• Inhibition Of Return
• Exogenously driven attention
• Examples Against
• PRP
• Task-switching
• Trade offs between speed and accuracy in attention

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Quizz

• You are looking for a friend at a party. This
  person has brown hair and is very tall.
• You are performing a serial search, that will be
  affected by the number of people there
• You are performing two serial searches, and the
  person will pop-out
• You are performing a conjunction search which
  will be affected by the number of people there
• You are performing a conjunction search and the
  person will pop-out because there is nobody
  else there with those two qualities.

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Quizz

• The Titanic hitting an iceberg would be a pretty
  good example of a
• hit
• miss
• false alarm
• correct rejection

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Quizz

• Bob, an electrician, is trying to see how faint
  he can make a light. He starts by turning the
  light ON to its maximum, then turning it down
  until he cannot see it.
• a) Difference detection methods of limits
  ascending
• b) Difference detection method of constant
  stimuli random
• c) Absolute thresholds method of limits
  descending
• d) Absolute thresholds constant stimuli random

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Quizz

• In Signal Detection Theory, which of the
  following is not true
• attention requires more hits than false alarms
• there is a normal distribution for signal and one
  for noise with the distance apart measured in
  Z-scores
• d-prime measures the difference between signal
  and noise
• bias and sensitivity are independent