sensation and perception

Question 1

define perception

Answer 1

staged process of sensing, understanding, identifying, recognizing and preparing reactions to sensation

Question 2

define transduction

Answer 2

conversion of one form of energy to another form of energy ex. light to neural impulses

Question 3

stages of perception

Answer 3

1. sensation - external stimuli trigger action potentials of sensory neurons that travel to the brain
2. perceptual organization - process of synthesizing sensory features into internal representations of an external stimulus
3. identification and recognition - process of creating perception by identifying and assigning meaning to perceived sensation

Question 4

thresholds of transduction

Answer 4

1. absolute threshold - minimum amount of physical energy needed to produce a sensory experience
2. difference threshold - magnitude of difference between sensations required for stimuli to be considered different
3. just-noticeable difference - a measure of how different the intensity of a stimulus has to be before an individual can tell it has changed
4. sensory adaptation - diminishing responsiveness of sensory systems including transduction to prolonged stimulus input

Question 5

Which area of the brain does the first level visual association cortex occur?

Answer 5

adjacent areas of occipital lobe

Question 6

which area of the brain does the second level visual association cortex occur?

Answer 6

parietal and temporal lobe

Question 7

which area of the brain does sensory relay occur?

Answer 7

thalamus

Question 8

which area of the brain does motion (motion agnosia), depth and brightness occur?

Answer 8

magnocellular channel

Question 9

which part of the brain does colour, form and texture (visual agnosia and propagnosia) occur?

Answer 9

parvocellular channel

Question 10

theories of colour vision

Answer 10

1. duplicity - cones (colour vision) rods (night vision)
2. trichomatic - suggests thall there are 3 types of colour receptors (primary colors) and all other colors are additive/subtractive combinations of the three
3. opponent process theory - suggests all colour experiences arise from relative differences in the stimulation of 3 types of cones (short, medium, long)

Question 11

categories of colour blindness

Answer 11

1. rod monochromats- non functional cones, poor visual acuity, shades of gray
2. tritanopia - defective short cones, insensitive to blue and yellow
3. deuteranopia - defecive medium cones, insensitive to green
4. protanopia - defective long cones, inability to distinguish red and purple

Question 12

elements of sounds

Answer 12

1. frequency - number of cycles the wave completes in a given time
2. amplitude - strength of the sound wave
3. pitch - highness or lowness of sound
4. loudness - amplitude of the sound wave
5. timbre - perceived complexity of a sound

Question 13

transduction for hearing

Answer 13

• basilar membrane vibrates and produces shearing action to the cilia, attached to the techtorial membrane, bend
• bending action allows potassium to flow from cell facilitating action potentials in the spiral ganglion cells that travel to the auditory nerve and then to auditory cortex
• travelling waves within cochlea
• high frequency waves collapse early (base)
• low frequency waves collapse later (apex)
• there is an orderly layout of frequency coding along basilar membrane cells
• volley principle allows us to use the orderly layout to perceive sounds beyond 1000 Hz

Question 14

transduction for smell

Answer 14

• receptors in olfactory cilia embedded in olfactory mucosa that send neural impulses to the olfactory bulb
• up to 1000 different molecules can stimulate receptors
• odours based on complex coding
• activity passed to olfactory bulbs and then to limbic system

Question 15

transduction for taste

Answer 15

• soluble chemical substances
• taste bud receptors located within trenches of papillae or tongue
• microvilli make contact with saliva
• different types of molecules stimulate receptors for sour, sweet, salty, bitter and umami (savoury)
• different papillae contain different distributors of receptors

Question 16

somatosensory senses

Answer 16

skin senses, internal senses, vestibular senses

Question 17

gate control theory of pain

Answer 17

suggests that cells in the spinal cord act as neurological gates, interrupting and blocking pain signals and allowing others to get through to the brain

Question 18

neuromatrix theory of pain

Answer 18

incorporates the reality that people experience pain without a physical cause

Question 19

laws of perceptual grouping

Answer 19

1. law of proximity - we group together the nearest elements of a stimuli
2. law of similarity - we group together the most similar elements of stimuli
3. law of good continuation - we experience stimule as continuous even when they are interrupted
4. law of closure - we fill in small gaps to experience stimuli as wholes
5. law of common fate or region - we group together stimuli that are moving in the same direction or regionally grouped

Question 20

elements of perceptual learning

Answer 20

attention - a state of focused awareness on a subset of the available perceptual information
figure - object-like regions of the visual field that are distinguished from the background
ground - background areas of visual field, against which figures stand out
spatial/temporal - information is combined from fixations of different locations in space or time
integration
constancies - perception involves inferential problem solving that often depends on learned biases that some things remain constant

Question 21

types of perceptual learning

Answer 21

bottom up or data driven - analysis and integration basic features into a perceptual unit
hierarchial organization - formation of perceptual units through increasingly complex connections between simple units
conceptually driven processing - the use of concept to guide perception