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Exam 1
Introduction - Spatial Cognition
314
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Post-Graduate
10/05/2020

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Term
Are human & monkey cerebral hemispheres a lot alike or very different?
Definition
a lot alike
Term
Are there a lot or few cortical areas?
Definition
a lot
Term
Why do we use old world monkeys to understand human cognition?
Definition
they are remarkably close to us cognitively
Term
old world monkeys vs. new world monkeys
Definition
old world monkeys are more sorted for cognitive studies compared to new world monkeys because they are "smarter"
Term
ways in which rhesus macaques are like us/unlike us
Definition
about the size of a large dog, like us in regards that they have an opposable thumb, unlike us because they walk on all fours & have very sharp canines
Term
why are rhesus macaques suitable for studies in cognitive neuroscience?
Definition
they are by no means threatened!
Term
macaques & human brains look similar - although _____
Definition
mass of brain relative to body is greater in humans
Term
which rodents have very convoluted brains?
Definition
capybara (by contrast to rats which have no folds!)
Term
why does brain get more convoluted as it gets larger?
Definition
conserve the surface-to-volume ratio
Term
two ways you could scale gray to white matter system up to a larger brain (BUT neither of these is what nature does!)
Definition
1. conserve the ratio of gray matter volume to white matter volume
2. conserve cortical thickness
Term
how does nature scale gray to white matter in larger brains?
Definition
convoluted/folds allows nature to conserve the ratio of gray to white matter but also conserves cortical thickness
Term
are lobes about equivalent in macaque & human brains?
Definition
yes
Term
4 lobes in the brain
Definition
1. frontal
2. parietal
3. occipital
4. temporal
Term
how are lobes functionally distinguished?
Definition
damage to a certain lobe tends to cause a certain kind of impairment
Term
human brain vs. macaque: complexity of sulcal morphology
Definition
human brain has a much more complex & variable pattern at sulcal morphology
Term
cytoarchitecture
Definition
anatomy of the cells that make up the cortex
Term
how were the first dyes used for staining neurons discovered?
Definition
came from the fashion craze for purple dresses!
Term
why do dyes work to stain neural bodies?
Definition
they had strong affinity for endoplasmic reticulum (which cell bodies are full of) & are basophilic
Term
what kind of cells are densely packed in layer 4 of primary visual cortex?
Definition
granule cells
Term
layer 5 of primary motor cortex contains what kind of cells?
Definition
huge pyramidal cells
Term
average cell body is _____ microns in diameter
Definition
20
Term
neuroanatomists working in late 1800s discovered that the distribution of cells going down layers of cortex is not consistent --> allowed ______
Definition
allowed the cortex to be divided into layers
Term
cortex layer 1 contains ______
Definition
neuropil (extraordinarily little cell bodies)
Term
cortex layer 2 contains ______
Definition
small pyramidal cells
Term
cortex layer 3 contains _____
Definition
larger pyramidal cells
Term
cortex layer 4 contains ______
Definition
granule cells
Term
cortex layer 5 contains ______
Definition
pyramidal cells again
Term
cortex layer 6 contains _____
Definition
groups of pyramidal cells separated by fibers running through the cortex
Term
do different parts of cortex look the same?
Definition
not necessarily!
Term
Brodmann mapped the hemisphere into areas (about 50) that are distinguished by ______
Definition
patterns of cytoarchitecture
Term
do areas in Brodmann & von Economo systems coincide?
Definition
sometimes but not always
Term
why is studying inter-areal connectivity in the cerebral hemisphere important?
Definition
if we can understand how information is transmitted from area to area (connectional anatomy), this will greatly help us understand how the brain works
Term
original work to trace axons wanted to use a _______ method
Definition
degeneration; killing a cell body would cause axons to change/degenerate
Term
are corresponding loci in the left & right hemispheres interconnected?
Definition
yes
Term
how are ascending connections from subcortical regions to cortex used for identifying cortical regions?
Definition
there are certain regions of cortex that are identifiable by connections with subcortical regions with a known function
Term
cortical connections are often organized _______
Definition
hierarchically
Term
3 main brain regions for vision
Definition
1. retina
2. lateral geniculate nucleus
3. primary visual cortex
Term
6 main brain regions for hearing
Definition
1. cochlea
2. cochlear nucleus
3. superior olive
4. inferior colliculus
5. medial geniculate nucleus
6. primary auditory cortex
Term
4 main brain regions for touch
Definition
1. spinal ganglion
2. dorsal column nuclei
3. ventrolateral nucleus
4. primary somesthetic cortex
Term
6 main brain regions for movement
Definition
1. spinal cord
2. cerebellum
3. various brainstem nuclei
4. ventrolateral nucleus
5. basal ganglia
6. motor cortex
Term
8 main brain regions for viscero-homeostatic function
Definition
1. visceral sensory ganglia
2. visceral sensory nuclei
3. hypothalamus
4. autonomic ganglia
5. blood
6. visceral motor nuclei
7. amygdala
8. orbitofrontal cortex
Term
why are association cortices called "association"?
Definition
they put together information from the surrounding areas with neatly specified functions to form associations with what is going on in different areas
Term
how is the limbic system situated in the brain?
Definition
kind of surrounds other cortices if you take a flattened-out view of the brain
Term
how are well-defined cortices (visual, auditory, somato, motor) arranged relative to association cortices?
Definition
they kind of sit "within a sea" of association cortices if you take a flattened-out view of the brain
Term
what is important about prefrontal cortex projecting back out to motor cortex but also getting input from orbitofrontal cortex?
Definition
allow emotion to have a role in motor output
Term
what differentiates human brains from monkey brains?
Definition
humans have much more vast association domains!
Term
how do lower order areas compare to higher order areas in terms of composition of brain hemisphere in humans?
Definition
exceedingly small part
Term
2 regions that exhibit the greatest degree of expansion in humans
Definition
1. parietotemporal association cortex
2. frontal association cortex
Term
what was the inspiration for the Barber's Diamond illusion?
Definition
illusion created by old fashioned barber's poles where the stripes rotate & look like they can go either up or down
Term
Barber's Diamond illusion
Definition
stripes moving to the left in a diamond are moving straight, uniformly to the left; depending on the depth perception of the diamonds around the center striped diamond make the stripes look either like they are moving up & to the left or down & to the left
Term
waterfall illusion
Definition
if you stand looking at a waterfall for a period of minutes & then you look at a rock, the flecks in the granite will look like they appear to drift up (opposite actual movement of the waterfall)
Term
what is important to keep in mind when looking at flattened-out views of the cortex?
Definition
the cortex has an intrinsic curvature, so if you flatten it out you do lose some information in how things are spatially connected
Term
receptive field of neurons in area V1
Definition
each neuron has a small receptive field (a degree or at most a couple of degrees in diameter) --> it responds to visual events only in a tiny part of the visual field
Term
how do receptive fields change as you move farther out from V1 in visual field hierarchy?
Definition
the mapping of the visual field becomes cruder & cruder (receptive fields become larger & larger)
Term
Ungerleider's discovery regarding V1 streams of information
Definition
there was not only an anatomical split between dorsal & ventral streams, but they serve distinct functions too!
Term
MT gets input from ______ & projects out to ______
Definition
primary visual areas (V1-V4); parietal cortex association areas
Term
MT was discovered in the 1970s via _______
Definition
mapping studies in monkeys
Term
"Where" pathway
Definition
dorsal stream, parietal lobe
Term
"what" pathway
Definition
ventral stream, temporal lobe
Term
motion vision depends on ______
Definition
area MT (MT is housed in the dorsal stream)
Term
3 symptoms of a woman with problems in area MT
Definition
1. unable to perceive the movement in a cup when the fluid rose
2. could not see the movements of the mouth of the speaker
3. unable to cross the street because she could not judge a car's velocity
Term
examples of visual functions that are normal following temporal lobe injury
Definition
visual ability, stereopsis, color vision, recognition, reading, saccadic localization, tactile motion
Term
3 visual things that can be impaired following temporal lobe injury
Definition
1. motion detection
2. direction discrimination
3. motion aftereffect
Term
akinetopsia
Definition
specific issues with motion vision while other vision is preserved (observed in a patient with damage to middle temporal gyrus)
Term
color/direction selectivity in areas MT vs. V4/TE
Definition
MT = direction but basically no color information

V4/TE = color but basically no direction information
Term
ventral stream vs. dorsal stream in terms of sensitivity to color & motion
Definition
ventral stream areas (V4 & TE) are sensitive to color whereas dorsal stream area (MT) is sensitive to motion; fits with the idea that they serve recognition & spatial vision
Term
what can be gained by having stimuli presented in different positions?
Definition
allowed authors to discover receptive fields of specific neurons
Term
2 important thins to remember when doing a recording study
Definition
1. neurons have spontaneous activity!
2. neurons fire stochastically
Term
if a neuron is directionally selective, how will its firing change throughout stimulus presentation?
Definition
you will see/hear it firing strongest for a specific direction, no change from baseline for others, & on others still go completely silent (often this is the case for opposite direction from preferred direction)
Term
Barlow & Levick 1965
Definition
described neurons in rabbit retina selective for direction of motion & proposed a simple model to account for the phenotype
Term
model describing direction selectivity in retina
Definition
if you have point A that has a 4 ms delay to neuron X & point B that has a 1 ms delay to neuron X --> when something moves from point A to point B, neuron X will get those two signals simultaneously & respond to movement in that direction!
Term
who first demonstrated the relationship between neural activity in MT & motion vision?
Definition
Newsome (using monkeys)
Term
Newsome's task for studying motion vision
Definition
while the monkey looks at a fixation point, a moving dot display with some degree of coherence is presented in the neuron's receptive field; the monkey must make an eye movement to the target toward which he thinks the motion flowed

motion of the dots could flow with 100% coherence OR there could be various degrees of noise (random moving dots)
Term
Newsome motion vision task results
Definition
monkey performance resulted in a psychometric curve for the % coherence necessary to reach a certain percent correct
Term
how do MT neurons in monkey compare to performance in terms of indicating direction of motion when viewing a stimulus?
Definition
MT neurons in the monkey are similar with regards to how their performance degrades as coherence degrades (just like behavior performance degrades as coherence degrades)
Term
results of Newsome's experiment studying correlation between MT neural activity & behavior performance of motion dot moving stimuli
Definition
there is a correlation between MT firing & choice; example: when there is no correlated motion & the monkey must guess, neuronal activity in MT is correlated with his guesses
Term
Newsome experiment to demonstrate the sufficiency of MT firing for direction choice results
Definition
electrical stimulation of a site in MT where neurons respond to motion in a certain direction sways the monkey's perception towards that direction
Term
Newsome experiment to demonstrate the sufficiency of MT firing for direction choice
Definition
he would have the motion going towards one point & stimulate MT neurons for a separate point --> monkey would end up making a saccade to a point in the middle between the two
Term
is MT stimulation sufficient to drive motion perception by the monkey?
Definition
yes (particularly at low coherence)
Term
lesions of area MT in the monkey produce an impairment of ______
Definition
motion perception
Term
comparison of coherence threshold required to determine dot movement in control monkeys vs. monkeys with lesioned MT
Definition
significantly increased coherence threshold required in lesioned monkeys!
Term
does lesion of area MT in monkeys affect other information about shapes (besides motion)?
Definition
no!
Term
interesting result of Newsome's MT lesion experiments regarding impaired motion vision
Definition
effects were not persistent --> if he waited weeks & then re-tested the monkey, they would get better at the task
Term
how do neurons in area MT relate to our perception of the Barber's diamond illusion?
Definition
neuron representing bars moving to the right can shift their firing as context changes to be stronger for either up & to the right or down & to the right (just like how our perception of the stripes changes as the background around the middle diamond changes)
Term
conclusions made from studying if MT neurons experience barber's diamond illusion like how we perceive it
Definition
neurons in MT experience the barber's diamond illusion EVEN THOUGH the context information that change our perception are outside of the receptive field of the neuron
Term
how was the study done to determine if MT neurons experience barber's diamond illusion like how we perceive it?
Definition
recording from cells in monkeys
Term
how was the study done to determine if MT neurons experience the motion aftereffect illusion like how we perceive it?
Definition
fMRI in humans
Term
Tootell et al study regarding MT neurons experiencing motion aftereffect illusion conclusion
Definition
the BOLD response to a moving stimulus greatly exceeds the response to a stationary stimulus in MT but not V1 of humans
Term
how was it determined that MT neurons experience motion aftereffect illusion like how we perceive it?
Definition
the BOLD "after signal" in MT closely parallels, in the time course of its fall-off, the decay of the motion aftereffect as measured in psychophysical experiments
Term
what disorder allows patients to look at an image & copy it, but if they are asked what it is, they cannot name the object?
Definition
visual object agnosia
Term
visual object agnosia results in impaired _______
Definition
recognition (however there is no indication of issues with visual competence)
Term
examples of impairments in prosopagnosia
Definition
recognize acquaintances or family members, recognize themselves in mirrors, recognize famous individuals in photographs, etc.
Term
prosopagnosia
Definition
a deficit of facial recognition specifically
Term
how can patients with prosopagnosia compensate?
Definition
recognize people from their voices, recognize people from distinctive hairstyles/glasses/etc.
Term
is prosopagnosia congenital?
Definition
yes
Term
visual object agnosia typically arises from bilateral damage to ______ & ______
Definition
fusiform & lingual
Term
prosopagnosia typically arises from right hemisphere damage to ______
Definition
fusiform
Term
fMRI data has demonstrated that visual object recognition "lights up" the _______ & ______ gyri; facial recognition "lights up" the _______
Definition
fusiform & lingual; fusiform
Term
damage to parahippocampal gyrus, fusiform gyrus, lingual gyrus typically involves _______
Definition
recognition
Term
damage to parahippocampal place area (PPA) (near parahippocampal gyrus) results in _______
Definition
topographic amnesia (inability to recognize places)
Term
damage to visual word form area (VWFA) (near fusiform gyrus in left hemisphere) results in ______
Definition
pure alexia (reading printed words is affected but spelling/writing are not)
Term
activation of area LO vs. area V1
Definition
area LO was more strongly activated when objects/faces were shown to the individuals compared to area V1 which was more strongly activated when textures were shown
Term
other name for fusiform gyrus
Definition
fusiform face area
Term
what area is more strongly activated by faces compared to common objects (especially in the right hemisphere!)
Definition
fusiform face area
Term
Holmes & Gross experiment to demonstrate importance of IT in visual object agnosia
Definition
monkeys had to learn between two objects which represented "good" to get a reward; monkeys without IT were unable to perform the task
Term
results of Holmes & Gross experiment studying role of IT in visual object agnosia...could monkeys re-learn a "good" vs. a "bad" object?
Definition
following the lesions, monkeys could re-learn the task with new objects, but it took a lot longer compared to control monkeys
Term
how do the responses to IT neurons that respond to hands change for actual hands vs. drawn outlines of hands?
Definition
responded the most strongly for actual hands & less strongly for just drawn outlines of hands
Term
All IT neurons have some form of ______ selectivity in their responses
Definition
image; each one will respond to a certain set of images & not to others
Term
IT neurons respond selectively to complex images with a degree of _______ invariance
Definition
viewpoint
Term
how was it discovered that IT neurons have location invariance?
Definition
authors presented images in various locations (center, left, right, upper, lower) & you could see some location selectivity, but for the most part, the object that elicited the greatest response would elicit the greatest response compared to other objects regardless of the location
Term
how is scale invariance represented in IT neurons?
Definition
ideal object does not change compared to other objects regardless of the size of that object
Term
results of authors presenting an ideal image to the IT neurons in different orientations
Definition
found that the other orientations elicited essentially no response from IT neurons that like it in the original orientation!
Term
Tanaka et al study finding the minimal combination of features required for driving an IT neuron
Definition
would show a monkey various objects until he found one that elicited a good response for the neuron of interest --> would simplify the object down to a 2D drawing representation & try to find a 2D representation that still elicited a strong response from the cell --> keep simplifying the image down until there was no more response from the cell
Term
conclusion from Tanaka et al study to find the minimal combination of features required for driving an IT neuron
Definition
neuron sin IT represent complex attributes of images (NOT specific objects!) so that any given object can contain attributes that excite multiple neurons
Term
how is the representation of images in IT distributed & continuous?
Definition
if each IT neuron represents a partial feature potentially present in many images (as suggested by Tanaka) & if each neuron fires in proportion to how closely the content of the current image matches its partial feature, then the representation of images in IT is distributed (each image is represented by the activity of a great many neurons) & continuous (it matters not which neurons are active but how much each neuron is active)
Term
how are images in the same category (i.e. "face" or "car") represented in IT neuronal activation space?
Definition
due to similarities in activation patterns, similar things cluster together!
Term
"disentanglement" (Jim DeCarlo)
Definition
as one goes up the ventral stream hierarchy, the points representing the objects in different categories move farther & farther apart so they become linearly dissociable
Term
oddball search study (Sripati & Olson)
Definition
the ability of monkey IT neurons to tell two images apart (measured as the average, across a large neuronal population, of the difference in firing rate elicited by the two images) is strongly correlated with the ability of humans to tell the images apart (measured as the speed with which they can find one embedded in a field of the others)
Term
how are images that are hard to tell apart for each other by humans related in IT activation space?
Definition
close together
Term
Agrawal, Hari, Arun study about learning a script & oddball search
Definition
if you can read a language, you can more easily distinguish between two similar letters & perform the oddball search more quickly AND they moved apart in activation space in IT neurons
Term
binocular rivalry, when subjects "fuse" two images together (one seen through the right & one through the left eye) --> you see ______
Definition
alternating representations of the two different images
Term
if I put a microelectrode in "face cortex" & I electrically stimulate those neurons --> ?
Definition
I can get a monkey to "perceive" faces & report that this is what he is seeing
Term
Afraz et al study: in monkeys performing a task requiring them to report with an eye movement (rightward or leftward) whether a foveally presented image represented a face or non-face object, electrical stimulation of patches of face cells in IT --> ?
Definition
induced a bias to report that the image represented a face
Term
how does sound work?
Definition
travelling pressure waves through a medium
Term
humans' sensitivity to oscillations in range ______ Hz (sound) (Hz = cycles per second)
Definition
10-20,000
Term
how can beating sinusoids reinforce or cancel sound depending on instantaneous values?
Definition
if sounds are happening that are close in frequency, they can sum together to cause a new waveform

if the two sound waves are out of sync, then they can sum to 0 & the wave will flatten out
Term
beating (sound)
Definition
interactions between the wave forms
Term
larger the difference between the frequencies of two sounds --> summing together sounds ______
Definition
less like a pure tone (with amplitude modulation) & sounds kind of fluttery --> even more different you hear a chord!
Term
different parts of the cochlea respond to different ______
Definition
frequencies
Term
sound first hits the outer ear --> gets into the ______
Definition
ear canal
Term
_____ vibrates with response to sound
Definition
tympanic membrane (ear drum)
Term
3 tiny bones that get the sound into the cochlea
Definition
1. middle ear stapes
2. incus
3. malleus
Term
cochlea itself is embedded in ______
Definition
temporal lobe
Term
coils at the top of cochlea are part of ______ system
Definition
vestibular balance (operate separately from hearing system)
Term
where does electrical activity for hearing really start happening?
Definition
a bundle of nerves that come out of the cochlea (auditory nerve)
Term
5 steps for transduction of sound
Definition
1. sound hits the outer ear
2. propagates through the inner ear to the tympanic membrane
3. oscillates to cause the stapes to oscillate
4. oscillates the cochlea
5. gets transduced into sounds
Term
what is the implication of hair cells being in an environment so full of potassium?
Definition
any time it gets stimulated it can depolarize
Term
what causes hair cells to fire?
Definition
movement of stereo-cilia causes opening of hair cells
Term
oscillation of basilar membrane --> ?
Definition
causes shearing movement on stereocilia of hair cells
Term
we have ______ rows of outer hair cells
Definition
3
Term
we have _______ rows of inner hair cells
Definition
1
Term
do all rows of hair cells have stereocilia?
Definition
yes
Term
______ opens potassium channels in stereocilia
Definition
stress on links
Term
how is motion important for hair cell electrochemistry?
Definition
motion in one direction opens ion gates; motion in other direction closes ion gates
Term
______ opens & shuts ion channels on hair cells
Definition
mechanical stretch
Term
how many neurons are in the human auditory nerve (8th nerve)?
Definition
30,000
Term
is the human auditory nerve primarily afferent or efferent?
Definition
afferent (ascending)
Term
do IHCs & OHCs project to the same or different places?
Definition
different
Term
ascending information for hearing is primarily conveyed by ______
Definition
the inner hair cells
Term
descending information: where it hits IHC vs. OHC
Definition
IHC: descending information connects onto its afferent connections to brain

OHC: descending information connects directly onto OHC body
Term
is efferent information for hearing more connected to OHCs or IHCs?
Definition
OHCs
Term
where are high vs. low frequencies affecting the BM displacement in the cochlea?
Definition
high frequencies more basal (oval window)

low frequencies apical (helicotrema)
Term
cochlear mechanics are primarily dependent upon ______
Definition
frequency
Term
how does sound travel through the cochlea?
Definition
get a wave that travels from base to apex
Term
some clues that cochlear amplification is an active process
Definition
responses nonlinear, tuning too sharp to be passive, Von Bekesy found broad peaks in cadavers, later researchers found sharper peaks, tuning at AN sharp, damaged OHCs results in flat tuning, drugs can induce flatter tuning, OHCs change shape with activity, otoacoustic emissions, etc.
Term
OHC or IHC changes length/width with electrochemical stimulation?
Definition
OHC
Term
PRESTIN (found in OHC [but not inner])
Definition
protein that allows for the motility of outer hair cells
Term
firing rate of the 8th nerve is intricately linked with ______
Definition
hyperpolarization & depolarization of hair cells
Term
depolarization of hair cells --> what change in firing rate of the 8th nerve?
Definition
increase
Term
hyperpolarization of hair cells --> what change in firing rate of the 8th nerve?
Definition
decrease
Term
3 things that cell polarization & thus auditory nerve firing pattern depend on
Definition
1. place along cochlea (cochlear mechanics perform Fourier analysis)
2. amount of acoustic energy (nonlinear, compressive growth response)
3. frequency of stimulation (AC/DC components)
Term
neurons have ______ dB dynamic range
Definition
20-30
Term
AVDL
Definition
the dB level at which the firing rate of an auditory nerve begins to change
Term
do different nerve fibers have the same or different shapes of tuning curves?
Definition
different!
Term
to hear high intensity sound levels/fluctuations --> more important to have high or medium/low spontaneous firing rate nerve fibers?
Definition
medium/low
Term
hearing low intensity sound levels/fluctuations --> more important to have high or medium/low spontaneous firing rate nerve fibers?
Definition
high
Term
noise exposure preferentially damages ______ spontaneous firing rate fibers
Definition
low & medium
Term
what do you do to solve mechanical transduction loss (destruction of middle ear bones)?
Definition
amplify the sound levels that get into the inner ear (easy to fix!)
Term
what happens if there is damage to the OHCs?
Definition
you lose amplification that you would normally get at higher frequency sounds
Term
if OHCs are damaged that are specific for a certain frequency --> ?
Definition
you can lose hearing at that frequency specifically
Term
does a lot or a little auditory processing happen before getting to cortex?
Definition
a lot!
Term
are ascending or descending auditory pathways better understood?
Definition
ascending
Term
what is the main role for descending auditory pathways?
Definition
automatic gain control of middle ear
Term
in the auditory nerve, parallel fibers convey ______ information
Definition
frequency-specific
Term
is there a tonotopic gradient of tuning at the cochlear nucleus?
Definition
yes
Term
3 distinct regions that have distinct processing in cochlear nucleus (CN)
Definition
1. dorsal
2. anteroventral
3. posteroventral
Term
2 typical approaches to classification of CN neurons
Definition
1. anatomy
2. physiology
Term
main cell type in dorsal CN
Definition
fusiform
Term
3 main cell types in posteroventral CN
Definition
1. octopus
2. stellate
3. bushy
Term
2 main cell types in anteroventral CN
Definition
1. bushy
2. stellate
Term
______ tend to get inputs that are very localized in the frequency areas that they like
Definition
bushy cells
Term
________ traverse a huge number of frequency regions
Definition
octopus cells
Term
_______ have extraordinarily complex local circuit connection that interact with all sorts of other cells in that region
Definition
fusiform cells
Term
function of octopus cells found in PVCN
Definition
onset detection across frequency
Term
physiology of octopus cells found in PVCN
Definition
respond to broadband inputs well, not narrowband; respond at onset (or on each cycle)
Term
do octopus cells have broad or sharp tuning curves?
Definition
broad (esp. at threshold), often flat about 2 kHz
Term
do octopus cells like broadband or narrowband input?
Definition
broadband
Term
when to octopus cells fire?
Definition
only at onset to tones (single spikes)
Term
function of spherical & globular bushy cells in the AVCN
Definition
fine timing & phase locking
Term
physiology of spherical & globular bushy cells in the AVCN
Definition
extremely high precise phase locking --> better than ANF; frequency tuning like ANF
Term
specializations of spherical & globular bushy cells in the AVCN
Definition
multiple inputs, none extraordinarily strong
Term
despite having remarkably similar neural dynamics, how are the inputs to octopus vs. bushy cells different?
Definition
octopus = across frequencies; bushy = within frequency
Term
function of fusiform cells in DCN
Definition
spectral processing
Term
describe the primary output cell of the DCN circuit model
Definition
excited by a narrow range of frequencies; is inhibited by a cell that is tuned to a slightly different frequency
Term
3 steps in ascending auditory pathway
Definition
1. cochlea
2. CN
3. contralateral & ipsilateral superior olivary complex
Term
3 places spherical bushy cells project to
Definition
1. ipsilateral MSO
2. contralateral MSO
3. ipsilateral LSO
Term
projection of globular bushy cells
Definition
contralateral MNTB (medium nucleus of the trapezoid body) --> large synapse to LSO
Term
are bushy cells temporally precise?
Definition
yes!
Term
LSO output is driven by relative input from ______
Definition
two ears
Term
Jeffress model of MSO coincidence detection
Definition
cells respond when they get input from left & right at the same time
Term
______ are good for interaural time difference temporal coincidence detector cells
Definition
MSOs
Term
2 ways LSO is different from MSO
Definition
1. inverted input
2. response to envelope rather than fine-time, cycle-by-cycle phase
Term
2 inputs to LSO
Definition
1. excitation from ipsilateral bushy cell
2. inhibition from the MNTB (which is innervated by contralateral bushy cell)
Term
what is the first thing to go with hearing issues?
Definition
selective hearing (think: cocktail party problem!)
Term
is selective attention harder for auditory system or vision?
Definition
auditory system
Term
does the brain store the content of unattended sounds?
Definition
no!
Term
are distinct features of auditory information processed in the same or different areas of the temporal lobe?
Definition
different
Term
Brodbeck et al experiment regarding the attention effect with hearing
Definition
overlapping voices cause both acoustic information to be taken in (i.e. a male or female voice) BUT the parts of the temporal lobe that encode content information only light up for the voice to which you were paying attention
Term
Posner task
Definition
subjects maintain fixation on a spot on a screen while a cue & then a target is presented --> target is difficult to see & when it appears the subject must press a lever indicating direction

in 70-85% of trials, the cue indicates the side of the screen on which the target will appear; in 150-30% of the trials, the cue does not indicate the side of the screen on which the target will appear
Term
the Posner paradigm has been widely used for studies of ______
Definition
covert orienting of attention
Term
results of the Posner task
Definition
valid cues --> decreased reaction times

invalid cues --> increased reaction times
Term
Cheal & Lynn adaptation of the Posner task
Definition
on some trials, the cues were in the location of the "T"; on other trials, the cue was an arrow in the middle pointing to the side of the screen to which the "T" would appear
Term
results of the Cheal & Lynn adaptation of the Posner task
Definition
the performance following the presentation of a cue in the position of the "T" was very fast; the performance following the presentation of the arrow cue was not as rapid but we saw a greater difference between first block of trials to last block of trials
Term
Juola et al adaptation of the Posner task: asking how performance depends on whether the arrow cue was valid and/or the peripheral onset cue was valid
Definition
on every trial there were two cues: a central arrow & a peripheral onset cue

on any given trial, both cues could be valid/only arrow could be valid/only peripheral onset cue could be valid/neither could be valid
Term
why did Juola et al include a probability factor in how often a periphery or arrow cue was correct in any given scenario on their task?
Definition
made it probabilistic because the individual would have to decide to pay attention to one of the factors (it was decision because it was still not a 100% given)
Term
Juola et al results: "neither" scenario (arrow correct 25%; periphery correct 25%)
Definition
slight improvement of reaction time when both arrow & periphery were correct & also when onset was correct
Term
Juola et al results: "onset" scenario (arrow correct 25%; periphery correct 75%)
Definition
huge improvement of reaction time when onset alone was correct & when both were correct; arrow cue alone being correct is just as long of a RT as when neither correct
Term
Juola et al results: "arrow" scenario (arrow correct 75%; periphery correct 25%)
Definition
either onset cue or arrow cue being valid is just about equal in terms of how they decrease RT (both are reduced from when neither are valid)
Term
Juola et al results: "both" scenario (arrow correct 75%; periphery correct 75%)
Definition
only the onset cue appears to be helpful!
Term
overall conclusion of Juola et al Posner task adaptation (arrow & periphery cue)
Definition
it is possible for cues indicating where a stimulus is going to appear to control attention to that stimulus with consequent improvement in performance in either detection or discrimination
Term
does attention have an effect on visual responsiveness in visual cortex?
Definition
yes!
Term
De Yon et al study results: used a stimulus in which gratings of various orientations moving in various directions appear in entire visual field but subject was instructed about the area to which they should attend
Definition
under these circumstances (visual stimulation constant but attention shifting), they saw that as attention moved, the zone of strongest activation moved
Term
conclusion from De Yon et al study of V1
Definition
V1 shows both visual retinotopy & attentional retinotopy
Term
Mansell et al results: had monkey maintain fixation after having plotted out receptive fields of neurons in MT --> stimulated with dots moving in two opposite directions simultaneously --> monkey was instructed to attend to either left dot or right dot
Definition
if a monkey was attending to left dot (for example): a neuron may fire much more strongly during time 1 (dot moving down) compared to time 2 (dot moving up)

saw the reverse when the monkey was instructed to attend to the right dot (up during time 1 & down during time 2) --> saw the reverse pattern of activation!
Term
in MT when multiple stimuli are present in the visual field & monkey attends to one of them, the firing of the neuron goes along with ______
Definition
the motion of the stimulus being attended to
Term
Chelazzi et al results (monkey maintains fixation --> a sample image appears at fixation point --> goes back to fixation dot --> two images appear in the periphery (one matches sample & the other doesn't) --> monkey must saccade to image that matched the one that initially appeared (all of this one while recording form IT!)): at initial showing of sample
Definition
neuron would respond more strongly to its preferred image (i.e. if it preferred a flower over a coffee cup)
Term
Chelazzi et al results (monkey maintains fixation --> a sample image appears at fixation point --> goes back to fixation dot --> two images appear in the periphery (one matches sample & the other doesn't) --> monkey must saccade to image that matched the one that initially appeared (all of this one while recording form IT!)): when back to fixation point
Definition
a neuron's baseline would be a little higher if its preferred image was previously shown
Term
Chelazzi et al results (monkey maintains fixation --> a sample image appears at fixation point --> goes back to fixation dot --> two images appear in the periphery (one matches sample & the other doesn't) --> monkey must saccade to image that matched the one that initially appeared (all of this one while recording form IT!)): when two images pop up
Definition
firing overall IT neurons shoot up & stays high (or may increase) when monkey is making a movement to that preferred object
Term
Chelazzi et al results (monkey maintains fixation --> a sample image appears at fixation point --> goes back to fixation dot --> two images appear in the periphery (one matches sample & the other doesn't) --> monkey must saccade to image that matched the one that initially appeared (all of this one while recording form IT!)): conclusion overall
Definition
images to which the monkey is paying attention dominates the activity of neurons by eliciting a strong response (firing rate effect!)
Term
Cohen et al results regarding attention & noise correlation in V4
Definition
attention reduces noise correlation --> when neurons are task-engaged, they become less susceptible to generalized noise signals
Term
Desimone et al results: recording from V4 for spike rates/LFP when monkey is attending outside of receptive field
Definition
little periodicity in LFP, little periodicity in spikes fired by neurons
Term
Desimone et al results: recording from V4 for spike rates/LFP when monkey is attending inside of receptive field
Definition
you see periodicity in LFP & the spiking of the neurons
Term
in the Desimone et al study on visual attention, do they use the same or different stimuli?
Definition
STIMULI ARE THE SAME! the only thing that changes is the monkey's attention
Term
why might performance benefit from the spiking/LFP periodicity seen when attention is payed to something in the neural receptive field
Definition
if neurons in V4 are responding to stimulus in attended location fire in frequency at gamma frequency --> spikes will hit neurons downstream in target cortices more strongly/keep the postsynaptic responses in line
Term
Corbetta study that gave rise to the premotor theory of attention
Definition
studying human brain scans when they either made eye movements or underwent covert attention (not making eye movements) --> there was a large degree of overlap in eye movement & attention-related zones in parietal & frontal cortices
Term
Russo & Bruce: how did the eye's starting point affect the direction/amplitude of the saccade caused by stimulation of FEF?
Definition
the direction & amplitude of the saccade tend to be constant at a given site regardless of the eye's starting point
Term
Thompson et al MGS task
Definition
monkey fixates on center of screen --> cue appears in periphery --> delay period during which monkey must fixate on center --> monkey then makes eye movement to location where the cue was present to get reward
Term
Thompson et al lever-search task
Definition
recorded from FEF neurons while monkeys maintain central fixation --> array of 8 images appears in a circle around center point in periphery --> 7 are "O" & 1 is a "C" --> monkey must move a lever to indicate which direction the gap in the "C" is facing WITHOUT making an eye movement
Term
Robinson et al results (trained monkeys to perform a Posner task with peripheral cues & also with central symbolic arrow cues --> on any given trial, one of the two cues would appear --> a target would be presented after a brief delay)
Definition
monkey showed clear benefit in finding target after valid cues even when they were prevented from making eye movements to that area
Term
when monkeys shift attention covertly, they also program ______
Definition
eye movements to the attended location
Term
Moore et al results (electrically stimulated the monkey FEF at currents so low that they did not elicit eye movements)
Definition
attention still shifted in the direction the eyes would have moved as reflected by a decrease in brightness threshold for detection of a small spot flashed in a field of distractors
Term
clinical test for neglect: cancellation task
Definition
patient is given a piece of paper with a bunch of symbols & asked to circle symbols of a given type
Term
clinical test for neglect: line bisection
Definition
patient is given a piece of paper & a pencil; on the paper is drawn a line with the left & right edges mark; patient is asked to draw a line that bisects the line through its center
Term
clinical test for neglect: copying
Definition
patient is asked to draw copies of images (e.g. clock, house, flower, etc.)
Term
the locus most often associated with neglect in humans is the _______
Definition
inferior parietal cortex (BA 39,40) of the right hemisphere
Term
right-sided lesion of inferior parietal cortex --> ?
Definition
left-sided neglect
Term
take a bunch of patients with left hemi-spatial neglect & superimpose their lesions, what is common of their lesions?
Definition
lateral parietal territory
Term
why right hemisphere more than left hemisphere for neglect?
Definition
probably because language is typically lateralized to the left hemisphere in humans & attentional functions have been displaced into the right hemisphere as language-related processes took residence in the left hemisphere
Term
study: took a cohort of left-handed people, in some of whom language was lateralized to the right hemisphere & in some of whom language was lateralized to the left hemisphere --> had these people perform a covert spatial attention task
Definition
in those with left hemisphere language functions, activation of right parietal cortex was stronger than activation of left parietal cortex (the opposite was true for those with right hemisphere language lateralization)
Term
is hemispatial neglect limited to visual functions?
Definition
no!
Term
4 similar symptoms that often accompany neglect
Definition
1. allesthesia
2. asomatognosia
3. anosognosia
4. extinction
Term
is neglect a problem with processing sensory input?
Definition
no! involves an unawareness of even the existence of the left half of space
Term
Ramachandran et al neglect task
Definition
tested neglect patients by holding up a mirror on their right & an object (in easy reaching distance of right hand) on left hemifield of patient so patient could see it by looking in the mirror --> asked the patient to reach for the object
Term
could patients who were blind to the left half of space (unilateral damage to V1 causing homonymous hemianopia) do the Ramachandran neglect task?
Definition
yes!
Term
difference in neglect patients vs. homonymous hemianopia patients asked to scan a scene (ex. "Where's Waldo?")
Definition
neglect --> patient will only look at right half of the display (as measured by tracking their gaze)

homonymous hemianopia --> patients looked across both sides
Term
how do neglect patients perform on the Posner task?
Definition
almost like cue in left ("bad") hemi-field does not affect performance because valid right is only slightly faster than invalid right

invalid left (cue in good right hemi-field, target in bad left hemi-field) we see a HUGE increase in RT
Term
Posner's theory for why neglect patients are particularly slow to response to a contralateral target preceded by an ipsilateral cue
Definition
patients are having problems disengaging from right "good side" cue (even when it was invalid) to left "bad side" target
Term
Kinebourne's "opponent processor" model of neglect
Definition
cross-inhibition between right & left hemisphere pools of attention
Term
Cohen et al model to show that it was possible to account for Posner's neglect results without positing a special "disengage" mechanism
Definition
cue appearing in right --> activates right perception unit --> activates right attention pool --> inhibits left attention pool

recurrent activity keeps these attention units in this state until target appears
Term
how Cohen et al model represents neglect for Posner's neglect patients
Definition
takes out a few "neurons" in the left attention pool --> already the left attention pool has reduced activity possible because "lesion" prevents large amounts of recurrent activity --> allows for profound inhibition of the left by excitation of the right attention pool
Term
Cohen et al model results vs. Posner neglect patient results
Definition
identical!
Term
study done to show that patients with left hemispatial neglect are not altogether neglectful of content of left half of an image
Definition
authors presented the patient with two pictures, both of houses, one with smoke coming out on the left & patient was asked what they were looking at

patients would say they were both houses & could not describe differences between the two, but when asked which house they would want to live in, they nearly always chose the house without smoke coming out of the window
Term
conclusion from the "smoking house" neglect study
Definition
the patients are not conscious of what is in the picture on the left side, but some sort of processing is going on because patients get a "bad feeling" about the house with the smoke
Term
task: patients with left hemispatial neglect arising from right parietal damage were required to report, in response to each visual display, whether it contained an item on the right, an item on the left, or items on both sides & to name each present item (ring, flower, or spider)

results when emotional stimulus (spider) was shown in bilateral displays on the left
Definition
robustly escaped extinction
Term
conclusion from bilateral display of ring/flower/spider with patients with neglect
Definition
potent image content, although neglected, may be processed to a stage at which it acquires salience sufficient to counteract extinction
Term
two spatial reference frames with respect to which neglect may be defined
Definition
egocentric or allocentric
Term
a patient with neglect copying a picture of two flowers next to each other will draw ______
Definition
the right half of each flower
Term
Arguin & Bub measured the RT for a patient with left-sided neglect to name a letter presented in an array in which the other 3 elements were just filled circles

results?
Definition
patients had faster RTs for relative positioning of the letter in the array regardless of literal position in space
Term
Alex Pouget's explanation for Arguin & Bub's array-centered demonstration of neglect
Definition
the firing rate of the neuron for the letter doesn't change whether it is leftmost or rightmost BUT it will be the highest relative to the firing rate of the other neurons being excited because the farther left something is, the lower its firing rate will be
Term
do neurons with object-centered spatial selectivity exist in the cerebral cortex of the monkey?
Definition
yes
Term
how do neglect patients perform on an experiment where a pair of stimuli are either identical or differ with respect with what is on the right or the left
Definition
patients with let brain damage are really bad at identifying pairs that differ with respect to what is on the left; patients with right brain damage are really bad at identifying pairs that differ with respect to what is on the right
Term
what is important about the experiment with neglect patients in which the stimuli were presented one at a time in succession by passing behind a narrow slit?
Definition
neglect effects not only processing of the left or right half of the display but rather the processing of information of the right or left half of the mental image formed from the display
Term
Bigiach & Luzzatti neglect experiment
Definition
neglect patients in Milan had to tell authors about aspects of the Piazza; sometimes from POV standing at palace facing the Duomo or vice versa --> patient could report landmarks from his POV "current" right compared to "current" left
Term
big conclusion from Bigiach & Luzzatti neglect experiment
Definition
neglect can affect even mental representations of scenes
Term
ventral stream - to temporal cortex --> for ______
Definition
object vision (pattern recognition)
Term
dorsal: ______ pathway
Definition
where
Term
who first came up with the "stream" idea of visual processing?
Definition
Desimone & Ungerleider
Term
dorsal stream of visual processing is also referred to as controlling _____ functions
Definition
"how"
Term
parietal cortex controls both ______ & _____ visual functions (but it may be regionalized within the parietal cortex)
Definition
where & how
Term
3 places with which parietal cortex has bidirectional connections
Definition
1. visual system
2. somatosensory system
3. premotor/prefrontal cortex
Term
______ is ideally suited to mediate spatial processes that are related to converging sensory signals from multiple modalities into motor outputs
Definition
parietal cortex
Term
is parietal cortex involved in homogenous or heterogenous functions?
Definition
extremely heterogeneous
Term
big overall pattern of parietal cortex function
Definition
there is a general distinction between functions of medial intraparietal sulcus (superior lobule) (related to representation of the body/control of the body; use of "how" functions) vs. lateral intraparietal sulcus (inferior lobule) (related to vision & spatial cognition)
Term
injury to superior lobule --> ?
Definition
tactile agnosia, disorders of body image, optic ataxia
Term
injury to inferior lobule --> ?
Definition
contralateral neglect, impairment of attention, constructional apraxia, disorders of drawing
Term
symptoms of optic ataxia
Definition
disorder of reaching for things under visual control, trouble reaching for things on the left (even though seen perfectly), reaching under visual guidance (no trouble with reaching in general!)
Term
Milner experiment of optic ataxia
Definition
asking a patient to put their hand through a slot in a large board in front of them
Term
what is meant by "inaccurate preshaping" of hand to object in optic ataxia?
Definition
"good" hand --> hand forms a pre-grasping shape with the digits to grasp a ball

you do not see this preshaping in the "bad" hand
Term
constructional apraxia is a common result of ______ injury
Definition
parietal lobe
Term
constructional apraxia experiment: patients are given matchsticks & asked to make a star shape with them
Definition
results: they cannot make accurate star shapes!
Term
constructional apraxia experiment: patient is asked to recreate a shape with painted tiles
Definition
results: the tiles will end up just almost randomly scattered about with no image being made when you put them together
Term
constructional apraxia experiment: asking patients to copy shapes
Definition
more complicated shapes ("3D" cubes, those involving multiple shapes) gave more issues compared to simple shapes (just drawing a circle or triangle)
Term
results of constructional apraxia patient asked to freely draw something like a "bicycle" or "face"
Definition
you may be able to pull out individual parts in the drawing (e.g. the wheels, handlebars, nose, mouth, etc.) BUT their relations to each other will not be correct so overall it looks like a scribble
Term
can constructional apraxia patients recognize things when they see them?
Definition
yes but cannot imagine them to draw them
Term
why the mingling of motor guidance (how) with spatial cognitive (where) functions?
Definition
over the course of evolution, mechanisms for representing where things are relative to the body (in the service of motor guidance) may have ramified into mechanisms for representing where things are relative to each other (in the service of spatial cognition)
Term
Brodmann areas: is human parietal cortex the same or different from monkey cortex?
Definition
quite different
Term
as we go from medial --> lateral in monkey intraparietal sulcus, we see functions changing from _____ --> ______
Definition
sensing/controlling body --> visual systems
Term
area LIP was first discovered in ______
Definition
anesthetized monkeys by recording in response to flashed stimulus
Term
memory guided saccade task
Definition
monkey has to wait, after seeing a stimulus, before making an eye movement to its location

neurons in area LIP fire in response to the stimulus, during the delay period, & at the time of the movement
Term
results of MGS task & recordings from area LIP
Definition
LIP has sensory responses, carries motor information, & activity related to attention/planning eye movements/holding a location in working memory
Term
Andersen et al study of the angle-of-gaze effects in LIP taught us ______
Definition
neurons in area LIP have visual receptive fields that are fixed with respect to retina
Term
Zipser & Andersen model for the gaze gradient in LIP neurons: inputs
Definition
where in the visual field the retinal input layer was for the stimulus & the gaze of angle of the monkey
Term
Zipser & Andersen model for the gaze gradient in LIP neurons: output
Definition
signal representing where the image was relative to the head
Term
Zipser & Andersen model for the gaze gradient in LIP neurons: conclusion
Definition
LIP neurons may represent a processing state between V1 early stage (neurons signaling where the retinal image is) & a later stage in which neurons represent where things are relative to the head
Term
neurons in VIP have transitional properties that relate to ______
Definition
transition from areas related to vision/attention to functions related to sensing/controlling the body
Term
2 things VIP neurons respond to
Definition
1. somatosensory stimuli
2. visual stimuli
Term
Duhamel et al study for VIP neural receptive fields
Definition
some neurons in area VIP respond to both cutaneous & visual stimulation & have matching bimodal receptive fields defined with respect to the body
Term
what does it mean that in VIP neurons "congruence is maintained as gaze shifts"?
Definition
visual receptive field shifts on the retina to maintain receptive fields with the cutaneous receptive field
Term
Snyder et al addition to the MGS task
Definition
interloped with trials in which the monkey had to make memory-guided saccades were trials in which the monkey had to make memory-guided reaches
Term
Snyder et al MGS task + reaches results
Definition
neurons in MIP responded to cues but only maintained sustained delay-period activity only on trials in which the monkey was instructed to execute a reach
Term
goal of Andersen study where he had monkey have both a starting fixation point for eyes & a separate starting point for holding hand in reach to target task
Definition
ask what factors neurons were sensitive to regarding their differential firing for different reaches
Term
conclusion from Andersen reach to target task
Definition
what differentiates conditions to where firing was strong was the reach direction as defined by where the monkey was looking!
Term
How did Sakata et al discover that neurons in area AIP fire during grasping of specific objects or in conjunction with seeing them or both?
Definition
recording from AIP while monkey manipulated different objects that required different kinds of grasps
Term
AIP appears to be the area that connects ______ input & _____ output for objects we will grasp
Definition
visual; motor
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