1.4 Sensation and Perception

Question 1

sensation

Answer 1

• basic registration of light, sound, pressure, odor, or taste from the environment
• hardware

Question 2

perception

Answer 2

• the organization, identification, and interpretation of a sensation in order to form a mental representation
• software

Question 3

transduction

Answer 3

takes place when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system

Question 4

psychophysics

Answer 4

• the subfield of psychology devoted to the study of physical stimuli and their interaction with sensory systems.
• methods that measure the strength of a stimulus and the observer’s strength of a stimulus and the observer’s sensitivity to that stimulus
• participants are asked to make simple, more objective judgements

Question 5

absolute threshold

Answer 5

the minimum intensity needed to just barely detect a stimulus in 50% of trials

Question 6

just noticeable difference (JND)

Answer 6

the minimal change in a stimulus that can barely be detected

Question 7

weber’s law

Answer 7

just JND of a stimulus is a constant proportion despite variations in intensity

Question 8

weber’s law example

Answer 8

• If 105 g can only be distinguished from that of 100 g, then the JND is 5 g
• If the mass is doubled…
  - The difference threshold also
  doubles to 10 g
  - So 210 g can be distinguished
  from 200 g

Question 9

sensory adaptation

Answer 9

sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions

Question 10

length in light waves

Answer 10

• distance from top arch to top arch or bottom curve to bottom curve
• hue or what we perceive as color

Question 11

amplitude in light waves

Answer 11

• the height of the wave from top arch to bottom curve
• determines brightness

Question 12

purity in light waves

Answer 12

• shows saturation/richness of colors
• dark blue vs light blue

Question 13

cornea

Answer 13

clear, smooth other tissue allowing light to pass through

Question 14

retina

Answer 14

• light-sensitive tissue lining the back of the eyeball
• has rods and cones

Question 15

accommodation (eyesight)

Answer 15

• the process by which the eyes maintain a clear image on the retina
• causes near-sightedness and far-sightedness

Question 16

rods

Answer 16

• photoreceptors that become active under low light conditions for night vision

Question 17

cones

Answer 17

photoreceptors that detect color, operate under normal light conditions, and allows us to focus on fine details

Question 18

gestalt perceptual grouping rules:
simplicity

Answer 18

• the visual system tends to select the simplest or most likely interpretation
• we see an arrow rather than a triangle on top of a rectangle

Question 19

gestalt perceptual grouping rules:
closure

Answer 19

• we fill in missing elements of a visual scene to complete an image

Question 20

gestalt perceptual grouping rules:
continuity

Answer 20

we perceptually group together edges of contours with the same orientation

Question 21

gestalt perceptual grouping rules:
similarity

Answer 21

regions that are similar are perceived are belonging together

Question 22

gestalt perceptual grouping rules:
proximity

Answer 22

objects that are close together tend to be grouped together

Question 23

gestalt perceptual grouping rules:
common fate

Answer 23

elements of a visual image that move together are perceived as parts of a single moving object

Question 24

frequency (wavelength) in sound waves

Answer 24

• measured in Hertz (Hz)
• perceived by humans as pitch
• depends on how often the peak in air pressure passes the ear

Question 25

amplitude in sound waves

Answer 25

- height of the sounds waves - perceived by humans as loudness

Question 26

complexity in sound waves

Answer 26

- simple (one wave) = pure tone - complex (multiple waves) = mix of frequencies

Question 27

Thermoreceptors

Answer 27

- nerve fibers that sense cold and warmth

Question 28

vestibular system

Answer 28

- three fluid-filled semicircular canals and adjacent organs located next to the cochlea in each inner ear - allows us to maintain our balance

Question 29

smell

Answer 29

- only sense directly connected to the forebrain - has pathways into the frontal lobe, amygdala, and other forebrain structures - suggests that smell has a close relationship with emotional and social behavior

Question 30

olfactory receptor neurons (ORNs)

Answer 30

- receptor cells that initiate the sense of smell - odorant molecules bind to sites on these specialized receptors

Question 31

pheromones

Answer 31

biochemical odorants emitted by other members of its species that can affect an animal's behavior or physiology

Question 32

papillae

Answer 32

small bumps on the tongue that contain hundreds of taste buds each