ch. 4: sensation and perception

Question 1

sensation

Answer 1

• process by which sensory organs in the eyes, ears, nose, mouth, skin, other tissues receive and detect stimuli
• how incoming environmental stimuli is converted
• describing structures and procedure involved into our visual system
• data based processing: earlier, more biological

Question 2

perception

Answer 2

• how we organize and interpret sensory stimulation
• knowledge-based processing: later, more psychological than biological

Question 3

psychophysics

Answer 3

the study of relationships between physical characteristics of stimuli such as their intensity, and our psychological experience of them

Question 4

⭐ absolute threshold

Answer 4

• minimum amount of something needed to be present to detect a particular stimulus 50% of the time
• going from nothing to something being detected

Question 5

Just noticeable difference (JND) / difference threshold

Answer 5

• minimum diff between two stimuli required for detection 50% of the time
• change from something to either something more or something less

Question 6

Weber’s law

Answer 6

• ratio
• changes depend on how much there was of that thing to start, proportional to the size of the original stimulus
• ex: volume from 10 to 12 (+20%)(2) or from 30 to 36 (+6)

Question 7

⭐ receptor cells

Answer 7

• specific ones exist for each sense
• stimulate neurons in the CNS
• without them, we can’t see, hear, etc
• they transduce (convert/translate) sensory input from the environment into action potentials

Question 8

cornea

Answer 8

transparent covering over the eye that sends the message or focuses the image to the back of the eye

Question 9

iris

Answer 9

• colored muscle that surrounds the pupil
• dilates and contracts the pupil to control the amount of light entering the eye

Question 10

pupil

Answer 10

hole, gets smaller with light

Question 11

lens

Answer 11

• focusing visual image to the back of the eye to retina
• looking at things nearby=lens gets thicker
• looking at things far away=lens gets thinner

Question 12

retina

Answer 12

thin sheet of cells that lines the back of the cell, has receptor cells for vision: rods and cones

Question 13

fovea

Answer 13

contains cones and ONLY cones, where the cones live

Question 14

optic disc

Answer 14

no receptor cells, blind spot

Question 15

optic nerve

Answer 15

exits back of each eye

Question 16

rods

Answer 16

• concentrated in the periphery of the retina (edges)
• black and white vision
• most active in dim illumination

Question 17

cones

Answer 17

• concentrated in the center of the retina (fovea)
• color vision
• most active in bright illumination

Question 18

pinna

Answer 18

funnel soundwaves down

Question 19

auditory canal

Answer 19

roadway that leads to #3 (eardum)

Question 20

ossicles

Answer 20

• contains malleus, incus, stapes
• pushes bones together on oval window of cochlea

Question 21

⭐ cochlea

Answer 21

• has receptor cells (hair cells)
• has vibrating fluid that bends hair cells in the basilar membrane, triggering action potentials in the auditory nerve
• hair cells are going to do for hearing what rods and cones do for vision

Question 22

bottom-up processing

Answer 22

• analysis that begins with the sensory receptors and works up to the brain’s integration of sensory info
• Constructive building → legos
• Take letters and combine them together to form words
  ex: learning how to read (s-t-o-p)

Question 23

top-down

Answer 23

• information processing guided by higher level mental processes as when we construct perceptions drawing on our experience and expectations
• filtering / sorting
• put new incoming info where it belongs

Question 24

priming

Answer 24

• prior information alter what we expect to perceive
  prepared to respond to something new that comes next - based off of something that we’ve been exposed to

Question 25

perceptual parsing

Answer 25

our visual system divides everything we see as two components

Question 26

reversible figures

Answer 26

when figure and ground are reversible

Question 27

Law of Proximity

Answer 27

• closeness, things that are near each other get perceived as belonging together

Question 28

Law of Similarity

Answer 28

things that are similar to each other get perceived as belonging together

Question 29

Closure

Answer 29

completing things that are missing, filling in the blanks

Question 30

depth cues

Answer 30

for the visual system can be divided into binocular depth cues and monocular depth cues

Question 31

binocular depth cue

Answer 31

• caused by the distance between the eyes
• known as binocular disparity
• brain uses the disparity between the images of each eye to compute distances to nearby objects

Question 32

interposition

Answer 32

• occlusion
• an object lying a top of another
• if x blocks out part of y, x is closer

Question 33

linear perspective

Answer 33

• convergence
• something is further away

Question 34

texture gradient

Answer 34

more texture=closer

Question 35

relative motion parallax

Answer 35

• Distance of objects from viewer determines their relative motion
  -Nearby objects appear to pass quickly
• Distant objects appear to pass more slowly

Question 36

perceptual constancies

Answer 36

• refers to the ability to retain an unchanging percept of an object despite variation in the retinal image
• what you’re getting on the retina is changing, but you know those things are still the same
• Size constancy
• Shape constancy
• Lightness constancy

Question 37

photoreceptors

Answer 37

cells in the retina that absorb light energy and turn it into electrical and chemical signals