NEUR2020 Quiz 2

What are the three functional categories of sensory systems?

exteroception, body sense, interoception

define exteroception

determine what's out in the world and decide on the best/most appropriate action or behaviour. ie. vision (mostly conscious)

Define body sense?

maintain balance, enable co-ordinated action, adjust for movement (mostly unconscious)

Define interception?

keep the body operating optimally - tied with motivations and emotions (conscious and unconscious)

What is the role of the auditory canal?

channel sound energy to the tympanic membrane

What is the role of the tympanic membrane (ear drum)?

vibrates in response to air pressure changes of sound waves, the ossicles are attached to the tympanic membrane (TM)

What is the role of the ossicles in the middle ear?

concentrate the vibrations of the tympanic membrane on a very small area on the oval window

T or F? pressure causes the basil membrane to vibrate

true

Auditory processing is t-

tonotopic

T or F? As the basilar membranes move up, hair cells move to the left. As the basila membranes move down, hair cells move to the right

false

What is the purpose of the basilar membrane?

mechanical analyser of frequency

T or F? the pitch we hear, depends on which of the outer hair cells vibrate

true

Where does localisation of sound sources occur?

subcortically at superior olives

What are the two detectable ways in which sound differs?

time and intensity

T or F? low frequencies wrap around head more easily than high frequencies.

true

T or F? the signal that goes to the lateral on the other side is excitation.

false - this is inhibition

What did teng et al. 2012 find?

human expert echo-locators (blind people) can discriminate target offsets of as little as 1.2 degrees

The Auitory cortex is both t- and c-?

tonotopic and columnar

What are the 3 broad classes of hearing loss?

conduction

sensorineural

central

What is conduction deafness?

damage to the tympanic membrane and ossicles

What is sensorineural deafness?

auditory nerve fibres are not stimulated properly

What is central deafness?

caused by brain lesions in the temporal cortex (rare)

What is the vestibular system?

in the inner ear; helps with movement and position of head, whole body and control of vision

What do the utricle and saccule otolith organs sense?

linear acceleration, horizontal movement and tilt

What do the 3 perpendicular canals sense?

rotations around the three principles axes

T or F? hair cells deform one way for depolarisation (excitation) other for hyperpolarisation (inhibition)

true

What can't the oitolith system distinguish between?

tilt and linear acceleration

What is a constant linear acceleration that we always experience?

gravity

What is the vestibulo-occular reflex?

head movements illicit compensatory eye movements to maintain fixation

What is oscillopsia?

loss of VOR causing bouncing vision as information about head movements is unavailable

What are three main types of touch receptors?

mechanoreceptors, temperature receptors, noiceptors

What are 5 types of exteroceptive receptors?

meissner corpuscles, pacinian corpuscles, merkel's disks, ruffini endings, free nerve endings

What is the patellar reflex?

knee jerk - stretches muscle spindle in quadricep

What is the purpose of interoception?

drive behaviour for survival: respiration, hunger, thirst, nausea (food aversion), arousal

What does the Dorsal Column-Medial Lemniscus do?

carries information about touch and proprioception

What does the Anterolateral system do?

carries information about pain and temperature

What are dermatomes?

afferent nerve fibres over a specific area of the body that converge on specific dorsal roots in the spinal cord

T or F? Dorsal Column-Medial Lemniscus is irpsilateral?

true

T or F? The Anterolateral system is contralateral?

true

What is the difference between post insula and ant insula?

post insula correalted with objective painful heat intensity, ant insula correlated with subject pain intensity

What are the traits of people who score highly on interoceptive sensitivity?

they are better able to utilize bodily signals to guide decision making, subliminal learning and implicit learning. Less susceptible to illusions of body ownership.

What are some examples of behaviour that kids who are hypersensitive to sensory input may exhibit?

eating more, going to the bathroom more

T or F, the cortical representation of pain is diffuse

true

What does Thunberg thermal grill explain?

if all bars are the same temperature (cool or warm) no pain occurs. When the bars alternate, it excited extreme pain to touch. Pain is constructed. The grill is somehow connected to the anterior cingulate.

What is the purpose of the peridaqueductal greay (PAG) area?

this is the place where inhibitory neurons are excited, endorphins modulate this area (reducing pain signal)

Explain the Craig et al. study (1996)

all conditions produced activity in mid/anterior insular cortex. Only did noxious cold/warm produce activity in anterior cingulate (emotional response to pain).

What is pain asymbolia?

A condition in which pain is perceived, but does not cause suffering (no emotional responses). This means a person is not bothered by pain.

What is congenital insensitivity to pain (CIP)?

do not feel pain. Mutation in a gene for the sodium channel. e.g Miss C

T or F? we can detect chemicals in the environment through our nose and out taste?

true

What is a volatile chemical?

An odor compound that can break off and travel to olfactory receptors

Where does synapse for smell project from?

olfactory tracts

What are olfactory receptors?

G- protein coupled receptors located on cilia on the olfactory receptor neurons dendrite

How many olfactory receptor neurons do humans have?

10 million

T or F? smell moved through the thalamus before going through the cortex

false

Describe the steps of the limbic olfactory tract? (the one responsible for motivational responses, autonomic, emotional)

ORNS
Olfactory Bulb
Amygdala
Hypothalamus

Olfactory Bulb

Amygdala

Hypothalamus

Describe the steps of the thalamic-orbitofrontal olfactory tract? (conscious perception of odours, memory, attention)

ORNS
Olfactory Bulb
primary cortex (primary olfactory)
thalamus
orbital frontal cortex

Olfactory Bulb

primary cortex (primary olfactory)

thalamus

orbital frontal cortex

What are the three kinds of Olfactory Dysfunction?

Anosmia
Parosmia
Phantosmia

Parosmia

Phantosmia

What are the 5 primary tastes?

salty, sweet, sour, bitter, umami

T or F? tastes is an indicator of of what kind of food is entering the stomach. ie. sweet tastes, prepares the digestive system for carbohydrates

Where are taste buds located?

small protuberances (papillae)

What are the non taste papillae?

secretory and somatosensory - mouthfeel, temperature, noiception

T or F? there are 33 gustatory receptor proteins - 1 unami, 30 sweet, 2 bitter

F - 30 bitter, 2 sweet - identifying poisonous food is extremely important

What are the 3 gustatory afferents?

glossopharyngeal nerve

facial never

vagus nerve

What do super tasters experience?

especially sensitive to bitter flavours and irritants. Due to a more densely packed paillae

What is ageusia?

The inability to taste, result of head trauma or oral surgery that diffuses afferent tracts

What is the working definition of attention?

1. processes that enable a person to recruit resources for processing selected aspects of the incoming sensory information more fully than non selected aspects

2. included allocating resources to relevant aspects of the environment

T or F? Attention is alertness and arousal

False - however if you are not aroused, you cannot attend

What is the reticular activating system (RAS)?

brain area that plays a key role in arousal. Has diffuse connection to the cortex, damage results in coma.

What are the two important properties of attention?

capacity and selectivity

What is capacity (in terms of attention)?

the amount of perceptual resources available for a task/process. Varies with the task and individual

What is selectivity (in terms of attention)?

the fixed perceptual resources being allocated to different subsets of information in a flexible way. What gets processed and what does not.

What is the cocktail party effect?

ability to attend to only one voice among many

What was the results of Cherry (1953) shadowing experiment?

an individuals own name is special, and cause for selectivity (salience).

What are the two theories for attention selectivity?

early and late selection

What are the counter arguments to early attention selection?

how to know what is important without processing at all

What are the counter arguments to late attention selection?

if everything is being processed - why both processing at all? (Most consistent)

What is distractor interference?

T or F? irrelevant informations slows responses to a target, especially if response needs to be inhibited by an opposite target.

false

T or F? distractor interference is due to obstruction

false - seen is ccades patterns, the distractor does not obstruct the pattern but the effect is still the same

What are the mechanisms we use to determine attention?

overt, shifting, topdown/bottom up, spotlight, zoom lens, parallel/serial search

What is the difference between covert and overt attention shifts?

overt = eye movement to shift attention

covert = move your attention but not your eyes

What are the three components of shifting attention?

disengagement

movement/shifting

engagement

T or F? damage to the parietal lobe (especially the right) results in loss of disengagement

true