Chapter 6: Visual Attention

Question 1

Define Selective Attention

Answer 1

Focusing on specific objects and ignoring others

• Important because of bombarding information the sensory systems have to make sense of

Question 2

How does the structure of the retina help with selective attention?

Answer 2

There’s high detail vision in the fovea + cortical magnification

There’s a constant blurry periphery (but brain fills in details)

Question 3

Define Overt Attention

Answer 3

Attention involving directly looking at objects

Question 4

Define Covert Attention

Answer 4

Attention without moving eyes

Question 5

Define Saccades

Answer 5

Small quick eye movements used to scan a scene

Question 6

Define Fixation

Answer 6

Pauses between saccades, used to gather information

Question 7

Define Stimulus Salience

Answer 7

Characteristics of the environment that stand out because of physical properties (high contrast, colour, orientation)
- People tend to focus first on high salient regions, then meaningful regions (except in natural environments)

Question 8

What is a Saliency Map?

Answer 8

A map showing fixations are related to meaning and saliency

Question 9

Define Scene Schema

Answer 9

Observer’s knowledge about the type of scene can influence the order of fixation

Question 10

What are 2 findings that support the idea of Scene Schema?

Answer 10

1. Shinoda: observers notice stop signs more at an intersection (45%)
2. Vo+Henderson: observers fixate longer on objects that don’t belong (a printer in a kitchen)

Question 11

Define Spatial Attention

Answer 11

Attention to specific locations

Question 12

Explain Posner’s experiment involving spatial attention

Answer 12

Observers had to look at a fixation point, then press a button when a target stimuli was presented in the side (reaction time measured)

• Result: reaction time was faster when given a cue of which side the target would be on
• Finding: information processing is more efficient where attention is directed

Question 13

Explain Egly’s experiment regarding spatial attention

Answer 13

Observers had to viet 2 raft angles, there were cues as to where targets may appear, and task was to press button when target appeared

• Finding: fastest reaction time at targeted position
• Finding: “enhancement” effect for non-target in same target rectangle
• *check notes for drawing**

Question 14

Explain O’Craven’s experiment involving the FFA and PPA activity

Answer 14

Participants observed a double exposure of a house and face, while being monitored with an fMRI

• Result: while attending to the face, enhanced activity in FFA
• Result: while attending to the house, enhanced activity in the PPA

Question 15

What is Inattentional Blindness?

Answer 15

A stimulus is not perceived even when the person is looking directly at it

Question 16

Explain Simons + Chabris’ experiment involving inattentional blindness

Answer 16

Observers were asked to count the number of passes in a short film of teams passing a ball, a gorilla passes through
- Result: 46% of observers do not notice the gorilla

Question 17

Define Change Blindness

Answer 17

Difficulty detecting changes in a scene

Question 18

Explain Rensik’s experiment involving change blindness

Answer 18

Two photos were shown. In the second, a coke bottle is replaced with a water bottle

• Result: only 11% of people detected a change (if told there would be changes)
• Finding: if important information that draws your attention (motion) is missing, it’s difficult to see the change

Question 19

Can you have perception without direct, focused attention?

Answer 19

Yes

Question 20

Explain Li’s experiment involving 3 tasks

Answer 20

Observers performed 1/3 tasks:

1. Central task: determine whether letters flashed on center of the screen are the same
2. Peripheral task: determine whether the image contained an animal or not
3. Dual task: do the same as peripheral and determine colour of a disk

• Result: dual task had larger effect on colour tasks
• Result: better at attending to animal rather colour

Question 21

How long does it take to identify the gender of a face?

Answer 21

150ms

Question 22

What do attention maps show?

Answer 22

Directing to a specific area of space activates a specific area of the brain

Question 23

Define Task Irrelevant Stimuli

Answer 23

Stimuli that do not provide information relevant to the task

Question 24

Explain the Load Theory of Attention

Answer 24

There is a capacity for attention

• Perceptual capacity
• Perceptual load: requirement of task (high load vs low load)

Question 25

Explain Foster + Lavie's experiment involving the load theory of attention

Answer 25

Reaction times of various tasks (easy-difficult) are recorded - Result: there is greater impact on easy load if there is distraction - Explanation: with hard tasks, already hits capacity so there's less of an affect

Question 26

What is Binding?

Answer 26

A process where physical features (colour, form) are combined to create perception of an object Binding is necessary because of the many areas of the brain involved in processing all aspects of an object

Question 27

What is the Binding Problem?

Answer 27

We have to group very different information (motion, colour, form) to perceive objects as single units

Question 28

What is the Feature Integration Theory?

Answer 28

Attention has major role in solving binding problem

Question 29

Define Illusionary Conjunctions

Answer 29

Features associated with one object that are incorrectly associated with another (Supports feature integration theory)

Question 30

Explain Treisman + Gelade's experiment involving feature integration theory

Answer 30

Observers were shown 4 shapes and 2 numbers simultaneously, then were asked to report figures - Result: Observers mixed up properties of shapes, unless asked to attend to shapes' colours - Finding: there is a Preattentive Stage where features are separate, focusing attention causes the Focused Attention Stage

Question 31

Who is Patient R.M. (feature integration theory)?

Answer 31

Parietal lobe damage caused Balient syndrome (where he couldn't focus on objects individually, making illusionary conjunctions)

Question 32

How often to incorrect associations of features occur (when not asked to focus on a target object)?

Answer 32

18% of the time

Question 33

What is a Conjunction Search?

Answer 33

Finding a target with 2 or more physical features

Question 34

Explain Klin's experiment involving the effects of autism on attention

Answer 34

Autistic and non-autistic participants watched films while their eye movements were recorded - Result: autistic observers looked at socially irrelevant stimuli while non-autistic observers focused on the eyes of actors and the direction actors pointed at - Finding: where autistic individuals pay attention in social situations may lead to perceiving the world differently

Question 35

Explain Pelphrey's experiment involving the effects of autism on attention

Answer 35

Participants watched a cartoon character (while STS was monitored) that: 1. Moved his eyes toward a checkboard (congruent) 2. Moved eyes away (incongruent) - Result: activation of STS in non-autistic individuals was higher for incongruent conditions while it was higher in both conditions for autistic individuals - Finding: autistic individuals cannot read intentions of others