Module 2 - Sensation & Perception

Question 1

signal detection theory

Answer 1

detection of a stimulus involves decision and sensory processes

Question 2

liberal vs conservative bias

Answer 2

liberal: more likely to say “yes, signal present”
conservative: more likely to say “no, signal absent”

Question 3

types of visual search

Answer 3

• feature search (one-dimensional, preattentive stage)

- conjunctive search (multi-dimensional, focused attention stage)

Question 4

what do the Ganzfeld Experiments study?

Answer 4

study sensory adaptation

Question 5

what are the findings from the Ganzfeld Experiments?

Answer 5

• sensory receptors are sensitive to change
• in a constant visual field, eventually perception fades to grey
• some people experience hallucinations

Question 6

what are the types of photoreceptors?

Answer 6

• rods (sensitive to light/dark)
• cones (sensitive to colour)
• ganglion cells (sensitive to blue wavelengths)

Question 7

optic ataxia

Answer 7

person can’t use visuospatial information to guide their movements

Question 8

hemispatial/contralateral neglect

Answer 8

patient is unaware of the contralesional half of space

Question 9

akinetopsia

Answer 9

inability to perceive motion

Question 10

apraxia

Answer 10

inability to produce discretionary or volitional movement in the absence of muscular disorders

Question 11

apperceptive visual agnosia

Answer 11

impaired object recognition

Question 12

associative visual agnosia

Answer 12

impaired object identification

Question 13

theory of direct perception (Gibson)

Answer 13

• the environment usually provides enough context to interpret everything we are seeing
• we don’t need higher level cognitive processes to understand and interpret

Question 14

template theories

Answer 14

• we have stored templates for patterns we might encounter

- match the patterns we’re seeing to a template to identify objects and interpret what we see

Question 15

feature matching theories

Answer 15

• we identify objects by matching them to sets of features stored in memory
• inexact, fuzzy matches

Question 16

in the Navon Task, what occurs when local features are tightly organized?

Answer 16

• identification of global features is not slowed by incongruent local features
• identification of local features is slowed by incongruent global features

Question 17

in the Navon Task, what occurs when local features are loosely organizes?

Answer 17

• identification of global features is slowed by incongruent local features
• identification of local features is not slowed by incongruent global features

Question 18

what are feature detectors?

Answer 18

neurons that respond selectively to very specific features of more complex stimuli (orientation, movement, edges, colour)

Question 19

feature integration theory

Answer 19

preattentive stage: feature detectors gather information about colours, shape, movement
focused attention stage: combining features of an object requires attention

Question 20

bottom-up processing

Answer 20

• helps us recognize new or unfamiliar objects

- examining in detail

Question 21

top-down processing

Answer 21

• reducing workload

- quick judgements about vague stimuli