Phys Psych Smell, Taste, Vision, and Hearing

chemical

what kind of sense is smell?

a mixture of chemicals that is stored as a memory to be one distinct smell

what is an odor?

cranial nerve 1, olfactory

which cranial nerve is responsible for smell?

anosmia

what is the technical name for the loss of smell?

orthonasal olfaction

smells sniffed through nostrils

retronasal olfaction

chewing and swallowing food forces smells behind the palate to enter the nose from the back

papillae

where taste buds are located

taste buds

tiny clusters of cells buried in tissue of papillae

200+

how many taste buds are in each papillae?

50-100

how many taste receptors are in each taste bud?

taste receptor

chemoreceptor involved in the sense of taste specialized for different tastes

cranial nerve 7 (facial) and cranial nerve 9 (glossopharyngeal)

which cranial nerves are associated with taste?

anterior 2/3

what part of the tongue is taste in cranial nerve 7 responsible for?

posterior 1/3

what part of the tongue is taste in cranial nerve 9 responsible for?

newborns instinctively enjoy sweet and dislike bitter

how is taste affect hardwired?

over time, or with associated memories

how can tastes change?

olfactory bulb close to subcortical brain areas, like amygdala which controls how different smells are perceived

why is smell so closely tied to memory?

cornea, pupil, lens, vitreous humor, retina, rods/cones, bipolar cells, ganglion cells, optic nerve, thalamus, occipital lobe

what is the process that light travels through the eye?

light comes through, hits the rods and cones, bipolar cells tell ganglion cells whether or not to turn on, ganglion cells actually send information to the brain

what is the process of light going past the retina?

rods

detect low light, peripheral vision, movement

cones

detect color, acuity/detail, bright light

movement

what aspect of rod signal detection is prioritized?

densely packed around the fovea

where are cones located?

fovea

back of retina

contrast

what are cone signals largely based on?

rods>cones

more rods or cones?

visual information from the left visual field of both eyes crosses over at the optic chiasm and is sent to the right hemisphere of the brain, while information from the right visual field crosses over and is sent to the left hemisphere

how are the left and right visual fields of each eye are processed?

optic chiasm

allows for both visual fields to combine and then split off and go to be processed in the brain

nerve signals travel from bipolar cells, go to ganglion cells, then go to lateral geniculate nucleus in the thalamus, and then goes to the visual cortex

how is vision reconstructed in the brain?

v1

primary visual cortex

color, simple lines, orientation, a little motion

what does v1 do?

receives information from v1 at slightly higher levels of complexity

what does v2 do?

contributes to color and motion

what does v3 do?

color and object recognition

what does v4 do?

motion

what does v5 do?

dorsal stream

pathway for identifying where an object is

ventral stream

pathway for identifying what an object is

as information goes through the temporal lobe, the fusiform gyrus helps to identify the object

how does the ventral stream work?

fusiform gyrus

on the very edge of occipital lobe and part of the temporal lobe

pinna, auditory canal, tympanic membrane/eardrum

what makes up the outer ear?

pinna

visible outside part of ear

incus, malleus, stapes

what makes up the middle ear?

transmit vibrations from the tympanic membrane to the oval window of the cochlea

what do the incus, malleus, and stapes do?

cochlea, hair cells, basilar membrane, organ of corti

what makes up the inner ear?

convert sound into electrical signals that the auditory complex can process

what do hair cells of the cochlea do for hearing?

loudness

sound intensity, pressure close to eardrum

pitch

the faster the waveform repetition, the higher the pitch

timbre

everything that allows for sound differentiation even when it has the same loudness, pitch, and duration

frequency analysis

frequencies that make up complex sounds are broken down by the cochlea into constituent frequencies

spatial hearing

ability to locate sources in space domes from two sources of information, humans are NOT good at this

interaural timed differences

sound source on the left will generate a sound that hits the left before the right

interaural level differences

when a sound is in the left ear, the sound level is somewhat higher than the right

auditory scene analysis

multiple sound sources in an environment at any given time combine to form a single complex waveform which is then broken down by the auditory system

separating sounds into what they are the most like, but not based on computations/studies

what is a simpler way to think of auditory scene analysis?