The psychology of perception and misperception

Question 1

What is the difference between sensation and perception?

Answer 1

• Sensation = process of detecting presence of stimuli by sensory organs
• Perception = recognition, integration and interpretation of raw sensory info/stimuli

Question 2

What are the two theories of perception?

Answer 2

Bottom-up

Top-down

Question 3

What does the bottom-up theory suggest?

Answer 3

Perception is a direct process that is determined by the information that is presented to the sensory organs. This basic information is then used to build up a meaningful representation of the scene.

Allows us to identify:

• texture gradients
• perceiving motion
• horizon ratios

Question 4

What does the top-down theory suggest?

Answer 4

Simple sensory information is insufficient in explaining perception. Top-down theory argues that perception is an active process that is influenced by our knowledge and expectations of the world.

Question 5

What are the two approaches in measuring perception?

Answer 5

• Behavioural
• Physiological

Question 6

What are th two most widely used behavioural techniques for studying perception?

Answer 6

• Phenomenological method
• Psychophysical method

Question 7

What is the phenomenological method?

Answer 7

• Qualitative measurements ‘say what you see or feel’
• Descriptive info
• Important as perception not reliably objective

Question 8

What is the psychophysical method?

Answer 8

• Quantitive relationships between stimulus and perception
• Measures thresholds, whether or not stimulus detected

Question 9

What is an absolute threshold?

Answer 9

The minimum intensity required for the senses to perceive stimulation, at least half of the time

Not reliable across individuals/situations

Question 10

What is subliminal priming?

Answer 10

Involves presenting stimuli at speeds which do not allow for conscious recognition of the target.

When presented with affective stimuli, individuals are able to guess, more accurately than chance would predict, the valence of -ve stimuli.

Question 11

List factors affecting perception

Answer 11

1. Personality
2. Emotion
3. Motivation
4. Perceptual set/Expectations
5. Demographic
6. Attention
7. Physiological

Question 12

How does personality affect perception?

Answer 12

People with different personalities show a tendency to behave differently in different situations.

It also appears that some aspects of personality can have an effect on perception (e.g. introverts have more sensitive visual perception and are better at perceptual tasks that require sustained attention than extroverts.)

Question 13

How does emotion/psychopathology impact on perception, specifically in depression and anxiety?

Answer 13

• Depression - perceive ambiguous info more negatively, report pain as worse
• Anxiety - show enhanced perception for threatening information

Question 14

How does motivation impact on perception?

Answer 14

People are often likely to perceive information as relating to their needs. (e.g. Therefore, sometimes patients may overestimate the benefits of a particular treatment).

Question 15

How do expectations impact perception?

Answer 15

Context, expectations and past experience all effect our interpretation of the perceptual information that we receive.

We are prone to seeing what we expect to see and hearing what we expect to hear (e.g. If we are trying to stop smoking everywhere we look we will notice stimuli connected with smoking).

Question 16

How does demographic impact perception, particularly age, gender and culture?

Answer 16

• Age – Older people are less able to ignore irrelevant information and selectively attend to specified information than younger people.
• Gender – males have better visual acuity in daylight conditions, while females’ vision adapts more quickly to the dark.
• Culture – individuals from cultures who take part in ceremonies that involve hanging from steel hooks embedded in their backs report feeling no pain. Less spectacularly, individuals from Western cultures appear to be more susceptible to visual illusions.

Question 17

What happens in agnosia?

Answer 17

individuals with this disorder are able to see accurately, but have an inability to make sense of visual information.

Question 18

What is fluent aphasia?

Answer 18

Arising typically as a result of brain damage, fluent aphasia results in production of fluent speech in the absence of the ability to comprehend words.

Question 19

How does attention impact on one’s ability to perceive?

Answer 19

The vast majority of sights, sounds, etc., pass us by without becoming part of our conscious awareness. On the whole, in order for us to receive information we must pay attention to that which is most pertinent.