module 5 Flashcards
what is sensation
detection/representation of info through sensory receptor (bottom up)
what is perception
organization and interpretation in the brain (top down)
what is vision?
eyes transferring light energy into electrical energy
wavelength: colour
amplitude: brightness
what is the iris
coloured muscles that controls diameter of pupil
what is the pupil?
the hole in iris for light to enter
what is the lens
bends light to focus on retina accommodations
what is the ciliary muscles
contract to change lens shape
what is your retina
photoeceptors to transduce light to neural impulse
what is your optic nerve
transmits signals to visual cortex
optic disc
blind spot caused by blood vessels
In what order does this happen within your retina
1. bipolar cells activate ganglion cells, the axons of which converge to form optic nerve. This nerve transmits info to the visual cortex.
2.Light enters eye triggering photochemical reaction rods and cones at back of retina
3. chemical reaction in turn activates bipolar cells
2,3,1
are cones located in the center or the peripheral of retina?
center
are rods located in the center or the peripheral of retina?
peripheral
how man rods do we have? how many cones?
130 million. 6 million
125 million; 6 million
6 million;125 million
6 million; 130 million
125 million; 6 million
do cones like bright light or dim light? good acuity (direct line to optic nerve) or poor acuity (shared line to optic nerve)?
bright lights, good acuity (direct line to optic nerve)
do you see rods in colour or black and white
black and white
what color does red or green shoes look for someone with red/green color blindness
yellow
what are the three colours our cones use to see light?
red/blue/green
3 opponent processes in retina and thalamus
red/green, blue/yellow,
white/black
* Some cells are turned on
by each colour in the
pair, others are turned
of
certain areas of the brain recognize types of stimuli which recognizes faces?
Fusiform face area/fuisform gyrus
how does hearing work?
Sound waves enter the
ear and cause
vibrations. These get
transformed into neural
(electrical) signals.
Amplitude: loudness
- measured in decibels
Frequency: pitch
(high/low
steps on how we hear
Sound → vibrates tympanic
membrane → vibrates
ossicles → vibrates oval
window → vibrates fluid in
cochlea → bends hair cells
on basilar membrane→
transmits impulses to
cochlear nerve → thalamus
→ auditory cortex
Loudness coding perception
– Number of activated hair cells
* Louder = more cells
pitch coding perception
Place theory: location on basilar membrane that
codes frequency
* High: beginning; Low: end (sort of)
– Frequency theory: brain codes frequency (rate) of
impulses coming up auditory nerve
* Works for low frequency sounds but neurons can’t fire that
fast in succession for high frequency sounds (so they trade
off with one another
how do we localize sound
Sound must travel farther to reach right ear as
opposed to left ear. Difference in time of arrival gives a cue to localization
what happens when sounds doesn’t originate from behind you
we turn our heads
what cause hearing loss
Sensorineural (hair cells, auditory nerve,
cortex)
Loud noises
* Don’t listen to your music on max!!
Conductive
– Age, ear infection, ruptured ear drum, wax build-u
is taste electrical or chemical? How often do our taste buds reproduce?
Reproduce every 7-14 days
why do humans have enhanced taste?
to help with hunger cues
sensitivity allows for better nutrition and toxin avoidance
to taste if food is healthy
sensitivity allows for better nutrition and toxin avoidance
why do we have preferences
Preferences result of genetic and environmental factors
Taste nerve pathways
Hypothalamus (emotions)
Amygdala (conscious perception)
Hippocampus (hunger)
Frontal cortex, somatosensory cortex
(memory)
– Hypothalamus (hunger)
– Amygdala (emotions)
– Hippocampus (memory)
– Frontal cortex, somatosensory cortex
(conscious perception)
Taste and expectations
Top-down control
– ‘Have a drink of milk’ (OJ)
– Wrapping on chocolates
– Price of wine
* Label on wine study
for smell Pathway links to
– Frontal cortex (hunger,
basic drives)
– Amygdala (emotions)
– Hypothalamus (conscious
perception)
– Hippocampus (memory)
– Frontal cortex (conscious
perception)
– Amygdala (emotions)
– Hypothalamus (hunger,
basic drives)
– Hippocampus (memory)
smell
Olfactory bulb
* Size of a postage stamp
* Old, chemical sense
– Cells respond to chemicals
dissolved in mucous
Smell and taste interact
Sense of taste worse with a cold or with your
nose plugged
