Chapter 7 Flashcards
exteroceptive sensory systems
the auditory (hearing), somatosensory (touch), olfactory (smell) and gustatory (taste) systems
primary sensory cortex
area of the sensory cortex that receives most of its input directly from the thalamic relay nuclei of that system
secondary sensory cortex
compromises the areas of the sensory cortex that receives most of their input from the primary sensory cortex of that system or from the other areas of the secondary cortex of the same system
Association cortex
any area of cortex that receives input from more than one sensory system
hierarchical organization
hierarchy is a system whose members can be assigned to specific levels or ranks in relation to one another
sensation
the process of detecting the presence of stimuli
perception
higher-order process of integrating, recognizing, and interpreting complete patterns of sensations
functional segregation
characterizes the organization of sensory system … each of the three levels of cerebral cortex in each sensory system contains functionally distinct areas that specializes in different kinds of analysis
functionally homogeneous
assumed that all areas of cortex at any given level of a sensory hierarchy acted together to perform the same function — false assumption
serial system
information of the sensory hierarchy flows among the components over just one pathway, like a string through a strand of beads – false assumption
parallel system
information flows through the components over multiple pathways
parallel processing
uses the parallel system… known as an simultaneous analysis of a signal in different ways by the multiple parallel pathways of a neural network … correct system
binding problem
how does the brain combine individual sensory attributes to produce integrated perceptions
amplitude frequency and pure tones
exist only in laboratories and sound recording studios
fourier analysis
the mathematical procedure for breaking down complex waves into their component sine waves
fundamental frequency
highest frequency of which the various component frequencies of a sound are multiples
missing fundamental
not relating the pitch of a complex sound to the frequency of any one of the sound’s components
tympanic membrane
the eardrum vibrates when hit by sound waves
ossicles
the small bones of the middle ear: the malleus (hammer), incus (the anvil), and the stapes (stirrup)
oval window
the membrane that transfers vibrations from the ossicles to the fluid of the cochlea
cochlea
long, coiled tube in the inner ear that is filled with fluid and contains the organ of Corti and its auditory receptors
organ of Corti
the auditory receptor organ, comprising the basilar membrane, the hair cells, and the tectorial membrane
hair cells
auditory receptors
basilar membrane
the membrane of the organ of Corti in which the hair cell receptors are embedded
tectorial membrane
the cochlear membrane that rests on the hair cells
auditory nerve
branch of auditory-vestibular nerve that carries auditory signals from the hair cells in the basilar membrane
tonotopic
organized, like the primary auditory cortex, according to the frequency of sound
semicircular canals
receptive organs of the vestibular system
vestibular system
the sensory system that detects changes in the direction and intensity of head movements and that contributes to the maintenance of balance through its outputs to the motor system
superior olives
medullary nuclei that play a role in sound localization
inferior colliculi
the structures of the tectum that receive auditory input from the superior olives
medial geniculate nuclei
the auditory thalamic nuclei that receive input from the inferior colliculi and project to primary auditory cortex
anterior auditory pathway
involved in identifying sounds “what”
posterior auditory pathway
involved in locating sounds “where”
conductive deafness
hearing impairment associated with damage to the ossicles
nerve deafness
hearing impairment associated with damage to the cochlea or auditory nerve
tinnitus
ringing of the ears
cochlear implants
bypass damage to the auditory hair cells by converting sounds picked up by a microphone on the patient’s ear to electrical signals, which are then carried to the cochlea by a bundle of electrodes
somatosensations
sensations from body
somatosensory system
three separate but interacting systems
exteroceptive system
senses external stimuli that are applied to the skin
proprioceptive system
monitors information about the position of the body that comes from receptors in the muscles, joints, and organs of balance
interoceptive system
provides general information about conditions within the body (e.g. temperature and blood pressure)
exteroceptive system
comprises three division: perceiving mechanical stimuli (touch), one for thermal stimuli ( temperature) and one for nociceptive stimuli (pain)
free nerve endings
neurons endings with no specialized structures on them… are particularly sensitive to temperature change and pain
pacinian corpuscles
largest and deepest cutaneous receptors…adapt rapidly, respond to sudden displacement of the skin but not to constant pressure
Merkel’s disk and Ruffini endings
adapt slowly and respond to gradual skin indentation and skin stretch
stereognosis
identification of objects by touch
dermatome
area of the body that is innervated by the left and right dorsal roots of a given segment of the spinal cord
dorsal-column medial-lemniscus system
tends to carry information about touch and proprioception
anterolateral system
tends to carry information about pain and temperature
somatotopic
organized according to a map of the body surface
somatosensory homunculus
the somatotopic map
astereognosia
inability to recognize objects by touch
asomatognosia
failure to recognize parts of one’s own body
anosognosia
failure of neuropsychological patients to recognize their own symptoms
contralateral neglect
the tendency not to respond to stimuli that are contralateral to a right-hemisphere injury
rubber hand illusion
the feelign that an extraneous object, in this case a rubber hand, is actually part of one’s own body
hemispherectomized
patients with one cerebral hemisphere removed
raphe nuclei
cluster of serotonergic nuclei in the core of the medulla
Neuropathic pain
severe chronic pain in the absence of a recognizable pain stimulus
pheromones
chemicals that influence the physiology and behavior of conspecifics (members of the same species)
olfactory mucosa
upper part of the nose which holds the olfactory receptors cells, embedded in a layer of mucus-covered tissue
olfactory bulbs
where the synapse on neurons that project via the olfactory tracts to the brain
olfactory glomeruli
axons of olfactory receptors terminate in the discrete clusters of neurons near the surface of the olfactory bulbs
chemotopic
organized, like the olfactory bulb, according to a map of various odors
taste buds
taste receptors cells found on the tongue and in parts of the oral cavity
solitary nucleus
the medullary relay nucleus of the gustatory system
anosmia
inability to smell
ageusia
inability to taste
selective attention
consciously perceive only a small subset of the many stimuli that excite our sensory organs at any one time and largely ignore the rest
endogenous attention
Attention focused on internal cognitive processes
exogenous attention
Attention focused on external events
cocktail-party phenomenon
the fact when we are in total focus in one conversation and totally unaware of the content around us the mentioning of our name in the external environment would obtain our attention
change blindness
subject is shown a photographic image on a computer screen and is asked to report any change in the image as soon as it is noticed
simultanagnosia
difficulty in attending visually to more than one object at a time
