Unit 5: Sensation and Perception

Question 1

Sensation

Answer 1

process of sensory organs detecting stimuli and converting them into electrical signals for the nervous system

Question 2

Stimulus

Answer 2

something that elicits a reaction from sensory organs

Question 3

Transduction

Answer 3

transformation of sensory stimulus energy into neural impulses

Question 4

Perception

Answer 4

brain’s interpretation of electrical signals created through sensation to create an internal representation of the world

Question 5

Bottom up processing

Answer 5

interpretation of raw sensory data to create a representation

Question 6

top down processing

Answer 6

interpretation of prior knowledge, experience, and expectations

Question 7

psychophysics

Answer 7

study of relationship between physical stimuli and the mental experience of them (psyche)

Question 8

Absolute threshold

Answer 8

min amount of stimulus that can be detected at least 50% of the time
(lower threshold = higher sensitivity)

Question 9

liberal bias

Answer 9

low threshold for detecting signal, more hits but also more false alarms

Question 10

conservative bias

Answer 10

high threshold for detecting a signal, less false alarms, but also less hits

Question 11

difference threshold

Answer 11

smallest difference between two stimuli that can be detected 50% of the time (measured like a ratio)
weber’s law states that as stimuli gets larger, the difference threshold rises

Question 12

adaptation

Answer 12

the tendency to stop noticing a stimulus that remains constant over time

Question 13

Vision

Answer 13

processing of light reflected from objects

Question 14

Visible Light

Answer 14

electromagnetic radiation emitted from light sources that can be detected by the eye

Question 15

Cornea

Answer 15

transparent tissue that covers the front of the eye and focuses light

Question 16

Iris

Answer 16

Opaque muscle that encircles the pupil and changes the size of the pupil to determine the amount of light that enters the eye

Question 17

Pupil

Answer 17

hole in the iris where light enters the eye

Question 18

Lens

Answer 18

membrane at the front of the eye that focuses incoming light on the retina

Question 19

Accomodation

Answer 19

adjustments of the lens’s thickness by specialized muscles in order to change the degree to which it bends light (deteriorates with age)

Question 20

Retina

Answer 20

surface in the back of the eye that contains receptor cells (photoreceptors) that are specialized for transducing light

Question 21

types of photoreceptors

Answer 21

rods and cones

Question 22

rod

Answer 22

photoreceptor cell that supports nighttime vision
- can only contain one photopigment:(rhodopsin) which allows us to see in the dark but breaks down in bright light
-concentrated in central periphery
- converge more before attaching to neural cells

Question 23

cone

Answer 23

photoreceptor cell that supports high-res colour vision
- contains one of three types of photopigments
- concentrated in the fovea (small pit in the center of the retina)
- have more direct connections to neural cells and more cortical representation
- more accurate where rods are more sensitive

Question 24

optic nerve

Answer 24

electrical signals generated by photoreceptors are transported along the optic nerve

Question 25

blind spot

Answer 25

area in the middle of the visual field where there are no photoreceptors and no information can be received (the brain fills in this blindspot)

Question 26

trichromatic theory

Answer 26

three types of cone cells (red, blue, and green) work together to produce perception of colour

Question 27

Ganglion cells

Answer 27

cells in the retina that receive input from cones (organized in pairs that respond to opposing colours)