Lecture 7 Attention and Perception

Question 1

What is Blindness without Attention?

Answer 1

Basically when a person isn’t paying attention to something, they are blind to it

Question 2

Mark & Rock Experiment Findings and Implication

Answer 2

75% of people are inattentionally blind

Conscious perceptions occur with attention

Question 3

Change Blindness

Answer 3

Large changes are hard to detect in a scene when no one is paying attention to it or being aware of it

Question 4

Flicker and Fade-In Results

Answer 4

1) When motion perception is interrupted, change detection is very poor
Ex: Change that occurs in the background of a picture

2) Change perception improves when someone guides our attention towards it
Ex: When the Professor averts his class’ attention towards a building in the background that disappears/appears in a picture

Question 5

Flicker and Fade-In Implications

Answer 5

Change detection is poor, suggesting that: Our visual memory for scenes is sparse, not detailed, based on “gist”

Although perception is highly detailed, our internal representation of the external world is sparse

Question 6

Binding Problem

Answer 6

Focused attention is needed to bind different features of an object together

Question 7

Separate Processing Hypothesis

Answer 7

Retina has different set of cells that focus on different aspects of attention

Question 8

Parvocellular Pathway

Answer 8

Color Selection
Low Temporal Resolution
High Spatial Resolution

Question 9

Magnocellular Pathway

Answer 9

Color Blind
High Temporal Resolution
Low Spatial Resolution

Question 10

Feature

Answer 10

An attribute of an object or event that plays an important role in distinguishing it from other objects or events

Question 11

Visual Search

Answer 11

Focused attention is required to understand visual features

Ex: Color, Shape, Orientation, etc.

Question 12

Parallel Search

Answer 12

Attention isn’t required because target “pops out” at you

Ex: An orange rectangle looks different from a set of purple circles

Question 13

Serial Search

Answer 13

Attention is required because focusing on different features of a target helps in the search for it

 Ex: Have to focus on color and orientation in order to find correct target

Question 14

Prediction for Search Asymmetries

Answer 14

Hypothesis: Simple features are detected in parallel because they produce unique activation on a feature map

Prediction: The absence of a feature should be harder to detect than the presence of a feature

Question 15

Prediction for Illusory Conjunction

Answer 15

Hypothesis: Simple features are bound to an object or location by the operation of focused attention (Binding Problem)

Prediction: Without attention, features may be incorrectly bound to locations

Question 16

Illusory Conjunction Experiment

Answer 16

Primary task: Recognize digits at left and right

Secondary task: Ask you to report on the letters in the middle and what color they were

Question 17

Illusory Conjunction Results

Answer 17

Subjects sometimes think they saw an “illusory conjunction”, such as an Orange or Green D

Question 18

Familiarity Effect on Visual Search

Answer 18

Searching becomes easier and faster when we recognize something familiar to us

Question 19

Findings from Simons & Chabris Experiment

Answer 19

Detection of unexpected object depends on similarity to attended vs. ignored items