Psychology of Perception

Question 1

What is perception?

Answer 1

Perception: Recognition, integration and interpretation of raw sensory information/stimuli

Question 2

What is the bottom up theory?

Answer 2

• The physical characteristics of a stimuli result in a particular perception
• Info is purely based on sensory data
• Suggests a realist view on the world

eg Square = square, bc. has 4 equal sides and right angles–> match features with stored knowledge to objectively identify squares in our environment, using perception

Question 3

How does the bottom up theory relate to visual perception?

Answer 3

In visual perception, patterns of light received by the retina are all that is necessary for perception to occur

Question 4

What are the 3 mechanisms by which the bottom up theory works?

Answer 4

Texture gradient: More closely packed elements appear further away

Perceiving motion: Things that are closer to you appear to move faster

Horizon ratio: Used to judge the vertical size of an object- ie when the object is positioned approx at the same ground level as us, we can fairly accurately determine height in relation to themselves

Question 5

What is the purpose of the bottom up theory? Give specific examples

Answer 5

Using visual info like this, we can determine the uses and abilities of objects – aka the affordances of the objects

Under this view objects suggest uses by their structural configuration. E.g. the plug affords (“wants”) to be plugged in

Listening to music and randomly picking up an object to use in an “appropriate way” – e.g. pen becomes drumstick

Question 6

What is the top down theory?

Answer 6

Sensory info is insufficient in explaining recognition and interpretation of stimuli

Psychological constructs, e.g. expectation and previous experience are needed to provide context

Question 7

“Sensory info is insufficient in explaining recognition and interpretation of stimuli
∴ combined w psychological constructs to provide context”
What are these psychological constructs?

Answer 7

Perceptual grouping: we perceive certain objects as going together, e.g. phone digits

Past experience: e.g. seeing hidden image in optical illusion, but if you see optical illusion in future, you immediately see the hidden image

Expectation effect: What we expect to see affects how we perceive objects.
eg putting bins out at night and expecting lurking person – think a bin is a man.

Question 8

What is the disadvantage of the top down theory?

Answer 8

• Complete top down approach = lose yourself in your own fantasy
  o You will only perceive what you expect/hope to

Question 9

How can perception be measured?

Answer 9

1) Behavioural method: Qualitative measurements=Say what you see/feel
Not objective and will often not make sense from a medical perspective, e.g. perceptions of pain differ between ppl

2) Psychophysical method: Quantitative measurement–> min intensity required for senses to perceive stimulation at least half of the time – absolute thresholds. Not always reliable across individuals

3) Subliminal priming

Question 10

What is the subliminal priming method?

Answer 10

• Involves presenting stimuli at speeds faster than we can consciously recognise the target (approx. 14ms)
• Critical info is detected more effectively (e.g. cocktail party effect – overhearing your name among several conversations)
• Stimuli processed but without conscious input

Question 11

What are factors affecting perception that are clinically important?

(give 5)

Answer 11

Personality: diff personalities behave diff in situations
Emotion: depression = interpret info/pain worse
Anxiety: enhanced perception for threatening info
Motivation: perceive info as relating to their needs
Perceptual set: prone to seeing what we expect to see
Physiological: perception affected by injury/disease, e.g. fluent aphasia
Attention: Pain lower when distracted
Attentional bias/addiction: drug dependent individuals distracted by drug stimuli