Chapter 3-Perception

Question 1

Perception is

Answer 1

Experience resulting from stimulation of the senses

Question 2

Basic concepts of perception

Answer 2

1. Perceptions can change based on added information
2. Involves a process similar to reasoning or problem solving
3. Perceptions occur in conjunction with actions

Question 3

Is it possible that true human perceptual process are unique to humans?

Answer 3

Yes-attempts to create artificial forms of perception have been met with limited success

Question 4

Problems with designing a perceiving machine

Answer 4

Inverse Projection Problem

• involves determining the object responsible for a particular image on the retina
• involves extending outward from retinal image to the source of that image

Objects can be hidden or blurred

Objects look different from different viewpoints
-object invariance

Question 5

Direct perception theories

Answer 5

-Bottom up processing

Perception comes from stimuli in the environment, parts are identified and put together, and then the recognition occurs

Question 6

Constructive perception theories

Answer 6

-top down processing

People actively construct perceptions using information based on expectation

Question 7

Bottom up processing

Answer 7

• Perception may start with the senses
• incoming raw data
• energy registered on receptors

Question 8

Top down processing

Answer 8

• perception may start in the brain

- person’s knowledge, experience, expectations

Question 9

Top down processing examples

Answer 9

“Blob experiment” confirms perception is not only based on inputs

Speech segmentation

Question 10

Experiencing pain

Answer 10

Can be be bottom up process (early model that emphasized nociceptors that sent pain messages directly to brain)

Can be top down model because of expectations, attention, distraction can affect how we experience pain (Placebo effect, play games during bandage change)

Question 11

Bottoms up processing: behavioural

Answer 11

Recognition by components theory (RBC)

• we perceive objects by perceiving elementary features
• Geons: three dimensional volumes
• objects are recognized when enough information is available to identify objects geons’s

Question 12

Geons are _______

Answer 12

Innate

Specific objects and their spatial relations are not

Question 13

The more Geons the more ________ we are to recognize the object

Answer 13

Confident

Question 14

Geons

Answer 14

Discriminability: Geons can be distinguished from other Geons from almost all viewpoints

Resistance to visual noise: Geons can be perceived in “noisy” conditions

Distinct: 36 different geons have been identified

Question 15

Visual search

Answer 15

• Triesman
• visual perception and visual attention

Identification of objects involve two stages:

1. A preattentive stage that automatically identifies basic features
2. An attentive stage that combines the basic features to form objects

Identification of objects also depends on what else is visible

Question 16

Visual search can be used for two basic purposes:

Answer 16

To identify the basic features of visual perception that are identified preattentively

To investigate the nature of the attentive stage

Question 17

Visual search is a

Answer 17

Bottom up process

Question 18

Preattentive stage

Answer 18

If search time is independent of the number of distractors (1 dimensional)

Question 19

Attentive stage

Answer 19

If search time increases with the number of distractors

Question 20

Exogenous cue

Answer 20

A unique value that draws attention

Search slope=0 (pops out)

Number of distractors is insignificant if there is only one feature

Question 21

Serial process

Answer 21

• need to combine properties to detect target
• combination is not automatic
• attention is needed to “weld” properties together
• search is a serial process-time needed depends on number of items
• spotlight travels at about 50ms/item

Question 22

Feature integration theory (FIT)

Answer 22

For preattentive stage

• automatic
• no effort or attention
• unaware of process
• object analyzed into features

For focused attention stage

• attention plays a key role
• features are combined

Question 23

Treisman and Schmidt

Answer 23

• participants report combination of features from different stimuli
• illusory conjunctions occur because features are “free floating”

Question 24

R.M.-Balint’s syndrome

Answer 24

Inability to focus attention on individual objects

High number of illusory conjunctions reported

Question 25

Feature integration theory (FIT) is

Answer 25

Mostly bottom up processing Top down processing influences processing when participants are told what they would see