Sensation & Perception Flashcards Preview

SP MCAT Psych/Soc > Sensation & Perception > Flashcards

Flashcards in Sensation & Perception Deck (26)
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1
Q

Define Sensation

A

the conversion of physical, electromagnetic, auditory and other information from the internal and external environment into electrical signals in the ns

2
Q

Define Perception

A

processing of sensory information to make sense of its significance

3
Q

What are sensory receptors?

A

nerves that respond to stimuli and trigger electrical signals

4
Q

What are sensory ganglia?

A
  • collections of cell bodies outside the CNS

- associated with sensory receptors

5
Q

What is sensory stimuli transmitted through?

A

projection areas in the brain that further analyze sensory input

6
Q

Define threshold

A

minimum amount of stimulus required to cause a change in signal transduction

7
Q

Define absolute threshold

A

minimum amount of stimulus energy needed to activate a sensory system

8
Q

What is the threshold of conscious perception?

A

minimum amount of stimulus energy that will create a signal large enough in size and long enough in duration to be brought into awareness

9
Q

What is the difference threshold (just-noticeable difference)?

A
  • minimum difference in magnitude between two stimuli that can be detected half the time
  • the smallest difference that is sufficient for a change in a stimulus to be perceived
  • the more sensitive the sensory system, the smaller the threshold
10
Q

What does Weber’s Law state?

A
  • the just-noticeable difference for a stimulus is proportional to the magnitude of the stimulus and this proportion is constant over most of the range of possible stimuli
  • the change in a stimulus required to meet the difference threshold is a certain fraction of the originally presented stimulus
  • the fraction is constant for each sense but differs based on the original stimulus and what sense we are using
  • predicts a linear relationship between incremental threshold and background intensity – plotting I against delta I is constant
11
Q

What is subliminal perception?

A

the perception of a stimulus below a given threshold

12
Q

Signal Detection Theory

A
  • the effects of nonsensory factors (experiences, motives, expectations) on perceptions of stimuli
  • the ability to detect a meaningful stimulus in the midst of vast amounts of sensory info increases an organism’s chances of survival
  • there is always some amount of error in the process of distinguishing signal from noise, but a higher hit rate will increase sensitivity by the organism
13
Q

Response Bias

A
  • tendency of subjects to systemically respond to a stimulus in a particular way due to nonsensory factors
  • ex. person answers survey questions untruthfully b/c they feel pressure to give answers that are socially acceptable
14
Q

Adaptation

A
  • decrease in response to a stimulus over time
  • leads to a rise in the difference threshold for a sensory response – difference in stimulus required to evoke a response must be larger
15
Q

What is the pathway of a stimulus that reaches conscious perception?

A

sensory receptor -> afferent neuron -> sensory ganglion -> spinal cord -> brain (projection areas)

16
Q

List sensory receptors and their function (5)

A
  • hair cell: sense motion of fluid in inner ear
  • nociceptor: sense painful physical stimuli
  • olfactory: sense volatile chemicals
  • osmoreceptor: sense changes in blood concentration
  • photoreceptor: sense electromagnetic radiation in the visible range
17
Q

Weber’s Law Equation

A

K = delta I / I
I =intensity of stimulus
delta I = just noticeable difference

18
Q

Object Recognition Processes – Bottom-Up Processing

A
  • object recognition by parallel processing and feature detection
  • brain takes individual sensory stimuli and combines them together to create a cohesive image before deterring what the object is
19
Q

Object Recognition Processes – Top-Down Processing

A
  • driven by memories and expectations that allow the brain to recognize the whole object and then recognize the components based on these expectations
  • allows us to quickly recognize objects without needing to analyze their specific parts
20
Q

What idea do Gestalt Principles follow?

A

the idea that the principles provide ways for the brain to infer missing parts of a picture when it is incomplete

21
Q

Law of Proximity

A
  • Gestalt principle

- elements close to one another tend to be perceived as a unit

22
Q

Law of Similiarity

A
  • Gestalt principle

- objects that are similar tend to be grouped together`

23
Q

Law of Good Continuation

A
  • Gestalt principle
  • elements that appear to follow in the same pathway tend to be grouped together
  • tendency to perceive continuous patterns in stimuli rather than abrupt changes
24
Q

Subjective Contours

A
  • Gestalt principle

- perceiving contours/shapes that are not actually present in the stimulus

25
Q

Law of Closure

A
  • Gestalt principle
  • space enclosed by a contour tends to be perceived as a complete figure
  • such figures tend to be perceived as more complete/closed than they really are
26
Q

Pragnanz

A

reality/perception is often organized reduced to its simplest form possible (regular, simple, symmetric)