Perception 1

Question 1

Define perception.

Answer 1

Process of acquiring knowledge about environmental objects or events via senses

Perception of reality - product of perceptual process, we do not directly perceive the world.

Question 2

What two stages is perception broken down into?

Answer 2

Sensation - transforming physical stimuli to electrical signals (sensory receptors to neural impulses sent to the brain)

Perception - interpreting these signals for conscious awareness and action.

Question 3

Describe the perceptual process

Answer 3

Distal stimulus - as it occurs in world
Proximal stimulus - from object to body
Sensation - converts energy to neural signals
perception - processing and interpretation in brain

Question 4

Outline the evolutionary utility of perception. Give example

Answer 4

Needed for survival - seek out desirable objects and avoid dangerous.
Senses can evolve to make more beneficial
Example - reindeers can sense light into UV spectrum, enabling to detect camouflaged predators.
2nd example - elephants detect low frequency sounds = communicate over long distances

Question 5

What are illusions? Give examples of different types of illusions.

Answer 5

Situations in which perception differs from reality.

Failure to perceive object - lilac chaser, Hermann grid

Perceptual distortions - Ponzo illusion, Ebbinghaus illusion

Bistable illusions - multiple distortions of same stimuli - Rubins vase

Impossible objects - pentose triangle, schusters conundrum

Question 6

Examples of ambiguous sounds

Answer 6

auditory stream segregation - either hear as triplets of as two separated streams.
OR
Laurel Yannie - measures relative sensitivity to low and high sounds

Question 7

What is the top down approach to interpreting perception?

Answer 7

Using prior and existing knowledge about structure of world to influence perception - conceptually driven

Question 8

What is the bottom up approach to interpreting perception?

Answer 8

Processes information from senses and makes judgements about nature of world based on information, as its received - data-driven

Question 9

Describe constructivist theories of perception

Answer 9

Helmholtz- inadequate info from senses augmented by unconscious inference
Gregory - Perception is the ‘dynamic searching of best interpretation of available data’ - ‘ going beyond immediately given evidence from senses’

Argues that illusions are rational inferences rather than perceptual errors

Question 10

Describe direct theories of perception

Answer 10

Gibson said that constructivists underestimate richness of sensory evidence
Variety of cues in natural world which gives structure to environment - perceiver not passive observer but interactive with environment.

Question 11

Outline techniques to study the perceptual process

Answer 11

psychophysics = measure relationship between stimuli and perception
neurophysiology = between stimulus and physiological response
psychophysiology and brain imaging = physiology and perception and action.