chapter 3

Question 1

perception

Answer 1

understanding what is going on outside of the brain to know how to act to achieve goals

Question 2

the inverse problem

Answer 2

know how to determine the distal stimulus (world) from the proximal stimulus (sound, sight, touch)

Question 3

sources of information

Answer 3

genes, past experience, internal state, environmental context, proximal stimulus

Question 4

sensory receptors

Answer 4

cells to transduce (convert) external phenomena (light, sound, pressure etc) into neural signals

Question 5

neural pathway

Answer 5

from sensory receptors via thalamic nuclei to cerebral cortex

Question 6

hierarchy of stimulus

Answer 6

attempt to construct useful representation of distal stimulus

Question 7

photoreceptors

Answer 7

1 type of rod, 3 types of cones

Question 8

rods

Answer 8

more sensitive, work well in dark places

Question 9

cones

Answer 9

3 types, work well in lit areas, each cone has different sensitivity of light. S-cones (short, blue), M cones (medium, green), L cones (long, red/yellow)
large concentration at fovea

Question 10

primary visual field

Answer 10

partial crossover at optic chiasm, info from left visual field gets sent to the right side of brain

Question 11

sound

Answer 11

changes in air pressure

Question 12

ear drum

Answer 12

tympanum: converts changes in air pressure into mechanical vibrations

Question 13

sound vibration travel

Answer 13

vibrations travel through bones of middle ear to oval window of cochlea. hair cells in cochlea detect vibrations

Question 14

basilar membrane

Answer 14

location of maximal excitation along basilar membrane depends of sound frequency

Question 15

proprioception

Answer 15

mechanical forces on muscles, tendons and joints

Question 16

nocioception

Answer 16

harmful chemical, mechanical or thermal stimuli

Question 17

thermoception

Answer 17

hot and cold

Question 18

mechanoreception

Answer 18

pressure, vibration and distortion

Question 19

4 types of mechanoreceptors

Answer 19

some closer to surface (touch : messier corpuscle, merkel disc receptor), some deeper in dermis (weight : ruffini ending and pacinian corpuscle)

Question 20

webers law

Answer 20

just noticeable difference

delta I/I = K

Question 21

receptive field

Answer 21

are of sensory surface to which a neutron response, higher order neutrons have larger receptive field and response to more complex sensory stimuli

Question 22

receptor size

Answer 22

receptive field close to fovea are small, become larger in size on outer areas. receptor more likely to fire if photoreceptors in centre are stimulated, stimuli on surround makes receptor fire less (inhibited)

Question 23

auditory receptive field

Answer 23

frequency of sound

Question 24

somatosensory receptive field

Answer 24

area on skin. size and accuracy vary with location on body

Question 25

topography

Answer 25

spatial organization of sensory surface is generally preserved in primary sensory cortex

Question 26

cortical magnification

Answer 26

area of cortex is proportional to density of sensory receptors

Question 27

plasticity

Answer 27

changes in neural organization

Question 28

bottom-up

Answer 28

stimulus driven, feedforward connections

Question 29

top-down

Answer 29

driven by goals and expectations, feedback connections, depends on past experiences, environmental context