b&b ch6: hearing, mechanical and chemical sense

periodic compressions of air, water, or other media varying in amplitude and frequency

sound waves

intensity of a sound wave

amplitude

number of compressions or cycles per second measured in Hz cyclers per second

frequency

related to the aspect of perception, sounds higher in frequency are higher in this

pitch

represented by height of each wave

amplitude

measured by the number of waves per second

frequency

tone quality of complexity dependent on the harmonics of the tone

timbre

conveying emotional information by tone of voice

prosody

outer ear structure of flesh and cartilage that sticks out from each side of the head

pinna

alters the reflection of sound waves and helps us locate the source of a sound

pinna

sound waves passing through the auditory canal enter here, evolved ti amplify sound vibrations

middle ear

eardrum that vibrates in the middle ear and connects to three tiny bones (ossicles)

tympanic membrane

membrane of the inner ear that ossicles transmit vibrations to

oval window

structure of the inner ear containing auditory receptors set into motion the fluid by the oval window

cochlea

auditory receptors that lie along the basilar membrane in the cochlea abd stimulate the auditory nerve

hair cells

basilar membrane vibrates in synchrony with sound waves, causing auditory nerve axons to produce action potentials in the same frequency (50hz = 50 action potentions per second)

frequency theory

what is the caveat of frequency theory

refractory period limits the maximum firing rate of any neuronto about 1000hz, far short of the highest frequencies we hear

basilar membrane varies from stiff at its base from stiff at its base where the stirrup meets the cochlea, to floppy at the other end of the cochlea, the apex

place theory

pitch perception depends on which part of the inner ear has cells with the greatest activity level ; the point at which it peaks identifies the frequency of the sound

place theory

area in the superior temporal cortex in which cells respond best to tones of a particular frequency

primary auditory cortex (A1)

where do axons cross over to enable each hemisphere of the forebrain to get most of its input but not all from the opposite ear

the midbrain

this pathway in A1 combines input from the auditory system and the visual system, and it connects to systems for memory and decision making

what pathways

this pathway in A1 localizes sound sources and guides actions toward or away from them

where or how

processes the experience you have of a sound source moving from one place to another, connected to area MT for visual motion and combines visual and auditory information to locate something accurately

planum temporale

damage to this area causes motion deafness, one can hear the sound but can not detect that the sound source is moving

planum temporale

responds to imagined sound and becomes active when people view silent videos that suggest sound

A1

people with damage here have trouble with speech and music but identify and localize single sounds reasonably well

primary auditory cortex

cells from the primary auditory cortex that have a preferred tone and differ in detail from one to another

tonotopic map of sounds

surrounds the primary auditory cortex and responds mainly to meaningful sounds such as animal calls, birdsong,machinery noises, music, and speech

secondary auditory cortex

sound localization and comparing intensity of sound at the two ears, useful up to 2k-3k hz; moreso localize high frequencies

sound shadow

sound localization and sound originates to the side of the head and the sound wave strikes the two ears out of phase , useful up to 1500hz; moreso localize low frequencies

phase difference

cant tell if someone is singing off key and do not detect a wrong note in a melody, but have trouble gauging peoples mood from tone of voice; tone deafness

amusia

people with this have fewer than average connects to the fronal cortex and differences in memory and attention to pitch

amusia

hearing loss that occurs if the bones of the middle ear fail to transmit sound waves properly to the cochlea

conductive/middle ear deafness

can be corrected by surgery or hearing aids have normal cochlea and auditory nerve

conductive/middle ear deafness

damage to the cochlea, hair cells, or auditory nerve, confined to one part of the cochlea and impairs hearing only of certain frequencies

nerve/inner ear deafness

frequent or constant ringing in the ears and can resemble phantom limb in some cases

tinnitus

these senses respond the pressure, bending, or other distortions

mechanical senses

adjacent to the cochlea and monitors movements and directs compensatory movements of your eyes

vestibular organs

sensations from here detect the tilit of the head and the heads acceleration, used to guide eye movement and maintain balance, people with damage here wiggle and fall

vestibular organs

oriented in perpendicular planes filled with a fluid and line that move when the head is accelerated at any angle and sensitive to directional tilit, like on a roller coaster

semicircular canals

calcium carbonate particles that lie next to hair cells, push against hair cells and excite them when your head tilts, tell brain which direction you are moviing. like reading a book when ur moving ur head

otoliths

what does the vestibular organ consist of

saccule, utricle, and three semiciruclar canals

sensory network that monitors the surface of the body and its movements including touch, deep pressure, pain, and temperature

somatosensory system

these detect vibrations or sudden displacements on the skin

pacinian corpuscle

chemical found in hot peppers that produces a painful burning sensation

capsaicin

responds to discrimitive touch and vibration

meissners corpuscles

responds to light touch

merkels disks

responds to skin stretch and roughness

ruffini endings

quickly adapting receptors

pacinian and meissner corpuscles

small receptive fields

meissner corpuscles and merkels disks

large receptive field and slowly adapting receptor

ruffini endings

where does information from touch receptors in the head enter

the central nervous system through cranial nerves

area of the body connected to a particular spinal nerve

dermatome

essential for touch experiences

primary somatosensory cortex, S1

where does information from skin sensations go to , responds to pleasantness or unpleasantness of the sensation

anterior cingulate cortex and insular cortex

what does damage to S1 (somatosensory cortex) do

impairs body perception

in S1, what do unmyelinated axons do

produce emotional aspect of touch, but not conscious sensation of it

guessing the location of a touch while insistinf that they did not feel it, inactivity in S1

numbsense

where do pain and temperature pathway cross

immediately from the receptors to a tract on the contralateral side of the spinal cord

where does touch information cross

travels up the ipsilateral side of the spinal cord to the medulla, then crosses to the contralateral side

what conveys sharp pain

thicker and faster axons

what conveys dull pain

thinner axons

what does mild pain release

glutamate

what does strong pain release

glutamate, neuropeptides, substance P, and CGRP

what part of the brain is active and responsive to emotional aspects of pain

the cingulate cortex and sensory areas responsive to physical pain

the brain puts the brakes on prolonged pain by__, systems that respond to opiate drugs and similar chemicals

opioid mechanisms

area of the brainstem that is rich in endorphin synapses; opiates bind to receptors here and in the spinal cord

periaqueductal gray area

what do opiates act on

the nervous system

nervous systems own opiate type chemicals , transmitters that attach to the same receptors as morphine

endorphins

spinal cord neurons receive messages from pain receptors also receive input from other inputs that can close the pathway for the pain messages

gate theory

relieve certain kinds of pain and act on the periphery of the body as well as the CNS

cannabinoids

condition of chronic pain that lasts long after original cause of pain has ended, can be treated with cannabinoids

neuropathic pain

what causes neuropathic pain

damaged tissues release, histamine, NGF, but also magnify response of nearby heat and pain receptors

what is Nav1.7

sodium voltage gate 7 important for axons conveying pain and olfactory sensations

receptors on the tongue that detect certain chemicals

taste buds

structures on a tongues surface that contain taste buds

papillae

contains the protein miraculin and modifies sweet receptors, enabling acids to stimulate them

miracle berry

decreased response to a stimulus as a result of recent exposure to it

adaptation

reduced response to one taste after exposure to another

cross adaptation

what are the 5 taste receptors

sweet, salty, sour, bitter, umami

this taste receptor permits sodium ions on the tongue to cross its membrane, thereby detects the presense of sodium

salty

this receptor detects the presence of acids

sour

these receptors resemble metabotropic synpases , binding to them activates a G protein that releases a second messenger within the cell

sweetness, bitterness, and umami

how do we detect taste partly by

timing pattern of neuron responses

anything that excites a pain axon reaches the brain as a pain sensation

labelned line

what coding does color vision require

across fiber pattern or combinatorial coding

taste information reaches cells here and can respond also to odors hunger and emotions

insula in the cortex

people with a higher than average number of tastebuds

supertasters

response to chemicals that contact the membranes inside the nose

olfaction

neurons responsible for smell, located on the olfactory epithelium in the rear of the nasal air passages

olfactory cells

receptors on the olfactory cells cilia that extend into the mucous surface of the nasal passage and detect the chemicals of the air you inhale

orthonasal olfaction

receportors on the olfactory cells cilia that extend into the mucous surface of the nasal passage and detect chemicals given off by food in your mouth

retronasal olfaction

in olfactory coding, receptors sensitive to a particular chemical or combination of chemicals connect to a single cluster in the olfactory bulb

glomerulus

the experience some people have in which stimulation of one sense evokes a perception of that sense and another one also , some have increased gray matter and alterned connections

synethesia

where do illusions, or misperceived stimulus occur

in the cerebral cortex