Final Exam - Cumulative Flashcards
most executive functions have been associated with which part of the brain?
prefrontal cortex
are the boundaries of the prefrontal cortex within the frontal well or poorly defined?
poorly defined
miller and cohen suggest that the PFC serves to enforce rules that are ___ to a given situation
-ex. it’s ok to wipe food off your child’s mouth, but not your uber driver’s mouth
appropriate
the PFC also manages ____ to the rules
-ex. it’s ok (heroic even) to grab a stranger’s arm and yank them (if they’re about to step in front of a bus)
exceptions
relative positions of regions within the PFC:
___ = toward midline
medial
relative positions of regions within the PFC:
___ = away from midline
lateral
relative positions of regions within the PFC:
___ = toward back (or top of head)
dorsal
relative positions of regions within the PFC:
___ = toward belly (or jaw of head)
ventral
connectivity tracing studies reveal distinct ___ and ___ PFC networks, along with overlapping regions of shared connectivity
lateral and medial
___ PFC networks support: “general purpose peerceptual-motor preparatory, goal monitoring”
lateral PFC networks
___ PFC networks support: “emotion/memory integration, physical awareness”
medial PFC networks
true or false: both PFC networks depend on “motor control, conflict monitoring”
true
brain lesion data links ___ PFC damage with a lack of action, initiative, and planning
lateral
patients respond OK to questions, show normal-ish IQ, but fail to prepare for the future, stick to a task, or maintain attention for longer than a few moments. if left alone, they sit down and don’t initiate any action at all
dysexecutive syndrome
___ PFC damage is linked with excessive, impulsive action, without self awareness
medial PFC damage
people with damage to the medial aspects of the PFC typically show ___ syndrome
disinhibition syndrome
deficits in controlling aspects of behavior
-they have problems integrating emotional information into decision making processes
-they are unaware of their inappropriate behavior, and appear manic, impulsive, and disorganized
disinhibition syndrome
____ medial PFC lesions can lead to bizarre behavior that is overly influenced by contextual cues
-these “environmental dependency” patients primarily react to whatever is around them, without any appreciation of social rulees
anterior medial PFC
ex. of anterior medial PFC lesions
walking into a room in which there is a picture leaning against the wall, along with a hammer and some nails - the person will immediately start hanging up the photo
a common method of evoking rule conflict in the lab
stroop task
true or false: relating and resolving conflicting rules is associated with a well functioning dorsomedial PFC
true
the ___ PFC is strongly linked to working memory, which involves the maintenance and manipulation of relevant information, along with the exclusion of irrelevant information
dorsolateral PFC (DLPFC)
do we see little or lots of evidence for DLPFC activity in working memory tasks in fMRI studies?
lots of
an alternative model by Cowan suggests that working memory is just the subset of ___ long term memory items (and conceptually associated items) that have been used in the last few minutes
genetic
alternative model proposed by Cowan: this smaller subset of all items in working memory are capable of being manipulated by the “central executive” - or ___
consciousness
the ___ also contributes to working memory
basal ganglia
a series of paired objects are presented, and your task is to decide if one of them matches the last set
dynamic working memory task
is the basal ganglia enhanced or hindered by difficult working memory trials?
enhanced
is rule learning handled solely in the prefrontal cortex?
no ; the basal ganglia makes a real contribution
is there evidence for distinct PFC-basal-ganglia-thalamic networks that support “executive” functions within motor, cognitive, and emotional domains?
yes
motor loop (3 components)
- primary motor
- premotor
- supplementary motor cortex
prefrontal loop
dorsolateral prefrontal cortex
affective loop (2 components)
anterior cingulate and orbitofrontal cortex
language is most strongly associated with which two areas of the brain?
left IFG (broca’s area) and L posterior auditory association cortex (wernicke’s area)
broca’s area
left IFG
wernicke’s area
L posterior auditory association cortex
relationship between broca’s area and wernicke’s area
densely interconnected, but independently support different aspects of language processing
damage to broca’s area
production deficits
damage to wernicke’s area
comprehension deficits
aprosodia (“robotic speech”) results from ___ hemisphere damage
right hemisphere
efficient language processing is strongly dependent on ___ we generate about upcoming words within a sentence
-this greatly speeds our ability to process language
expectations
if we present folks with a series of words, we can see an ERP that appears after a word that doesn’t meet these expectations, an ____
-this is distinct from the P300 ERP
N400
only ___ based violations trigger the N400
meaning-based
____ deviance (ex. a different font, or spoken by a different person) evoke a P300-like ERP
non-semantic
the bigger the deviation, the larger the ___
N400
any given language is made up of just ___ to ___ phones (or speech sounds)
30-100
there are only around ___ phones in all languages
200
infants lose the ability to distinguish phones outside their native language by ~___ years of age
~2
what is perceived when someone hears a phone
phoneme
language is not just auditory. we use both the sound and the sight of someone speaking to decipher language. when the sight doesn’t match the sound, we often perceive a third phoneme, not actually present in either modality
the mcgurk effect
when did language emerge in human evolution?
one popular model suggests that our refined speech ability may be due in part to a genetic mutation (____) that happened after humans split from other primates, ~7 million years ago
-we share this gene with all mammals, but ours contain two copies, and this distinction may partially underly our language abilities
FOXP2
in humans without a second FOXP2 copy, is language ability seriously (and specifically) enhanced or compromised?
compromised
darwin’s model of evolved traits is based on ___ - the slow, continuous refinement of traits, with each tweak providing a fitness benefit
gradualism
in contrast, darwin considered human language to have emerged ___, as a result of coincidental genetic mutations in vocal and brain anatomy
suddenly
ghazanfar and others review data suggesting that language could have evolved more gradually (maybe other primates’ language is better than we think)
-specifically, he presents evidence for three features:
- its audiovisual nature (it involves facial cues)
- its rhythmicity (speech timing, meter)
- its turntaking pattern (conversation coordination)
the audiovisual nature of speech:
both humans and macaques respond faster to ___ audio-visual “speech” stimuli than audio or video alone
combined
the rhythmicity of speech:
macaque and human vocalizations have a very similar (and rapid) ___, around 5 per second (HZ)
tempo
a typical speech interaction among people consists of vocal exchanges, gaps of silence, and minimal interruptions
-correspondence in back-and-forth timing between human speech and marmoset vocal ‘conversations’
turn taking pattern of speech
lots of research shows that just two dimensions describe most of people’s conscious response to emotional things
pleasure and arousal
LPP
late positive potential
one of the most reliable effects in human emotion neuroscience is the strong enhancement of a long-lasting ERP called the ___ during emotional scene perception
LPP
the LPP is strongly correlated (~0.95) with the ___ ratings of a scene (not pleasantness)
arousal ratings
EPN
early posterior negativity
the EPN effect is strongest for emotional scenes, but can be evoked by emotional hand gestures, faces, and even emotional ___ (a little)
words
separate from emotion, the EPN is enhanced by ‘simple’ scenes
-the more complicated the scene, the ___ the EPN
weaker
the EPN is often larger for ___ compared to unpleasant scenes, but not the reverse
larger for pleasant
the ___ still showed a ‘pleasure’ bias, where the LPP did not
EPN
victory scenes modulated the EPN well, but nothing like erotica
-we can’t conclude that the EPN shows a pleasure bias
-this suggests a ___-specific enhancement of the EPN
sex-specific
was thee EEPN larger or smaller for nudists than erotica?
larger
EPN modulation: a body part bias?
it appears that the scenes showing the most recognizable, upright bodies tend to drive the ___ EPNs
strongest
the EPN effect replicated
-the largest EPN was evoked by ___ scenes, followed by ___
-this order ___ for the LPP ; largest for erotica, followed by nudists, then mutilations/anim threat
nudist ; erotica ; flips
___ reflects emotion, complexity, and the presence of upright bodies
-our visual systems may be tuned to quickly identify obvious signs of people around us
-may actually include multiple overlapping processees
EPN
___ reflects the intensity of our conscious emotional response to whatever is around us
-it does not reflect complexity, body parts, etc. (only that it’s emotional)
LPP
what brain mechanisms drive these ERP arousal effects?
-work in rats and primates suggests that this enhancement may be driven by feedback from the ___
amygdala
the density of structural connectivity between amygdala and ventral visual cortex reveals heavy ___ connections from amygdala to visual cortex (feedforward path)
feedback
we argue that the ventral visual pathway is a ___ and ___ interactive occipitotemporal network linking early visual areas and the anterior IT cortex (aIT) along multiple routes through which visual information is processed
recurrent and highly interactive
the amygdala ___ back to almost every area in the occipitotemporal network…
-the precise nature of the modulatory signals arising from the amygdala remains unknown, but such diffusely distributed signals are likely to direct attentional resources to the processing of visual stimuli signaling potential danger or other emotionally intense events
projects back
in monkeys and humans, the amygdala shows a burst of emotion-linked activity ~___ms after the presentation of visual emotional cue
-the timing of this amygdala reactivity strongly suggests that it registers emotion before or after visual cortical processing is complete?
~150 ms ; after
using standard fMRI, we found that activity in amygdala and late-stage visual fusiform gyrus (IT) are ___ correlated (0.95)
strongly
the time point at which brain activity is reliably enhanced for emotional scenes is ___ seconds
3.9 seconds
emotional scenes enhanced activity in late-stage ventral visual cortex and amygdala ~___ second earlier than mid-stage visual cortex
~1 second
FP network discriminates emotional scenes before or after amygdala and FG?
after
Granger analyses showed that the amygdala, OFC, and FG are all influencing each other ___ in ___ directions
equally ; both
the entire visual system (outside V1) is enhanced by ___ stimuli
emotional
rapid fMRI data suggests that amygdala and FG ___ this emotional discrimination
initiate
other emotion-sensitive regions (like FP network, OFC) may be “___” of the emotional quality of stimuli from amygdala and FG
“informed”
fMRI work on emotional perception supports a “___ feedback” model of emotional perception
“reentrant feedback”
initial discrimination (first feedback wave) = ___ shift
EPN
second discrimination is more consistent with ___
LPP
a major goal of cognitive neuroscience is to define the relationships between ___
brain structure, brain function, and “consciousness”
brain structure pertains to:
distinct units (how they’re connected)
brain function pertains to:
how the units of the brain operate in real time
consciousness refers to:
an emergent property of brain function
what does EEG stand for?
electroencephalography
electroencephalography (EEG) provides excellent ____ resolution, but poor ____ resolution
temporal ; spatial (when but not exactly where)
millisecond time resolution is characteristic of which noninvasive method?
electroencephalography (EEG)
what does fMRI stand for?
functional magnetic resonance imaging
fMRI provides excellent ___ resolution, but poor ___ resolution
spatial ; temporal (where, but not exactly when)
cognitive neuroscience was born from the combination of three related fields of research on the brain and behavior:
cognitive psychology, neurology, and neurophysiology/neuroimaging
how the brain works in healthy folks
cognitive psychology
cognitive psychology data was explicitly ___ based
behavior (avoids brain)
how brain damage affects behavior in clinical patients
neurology
neurology data was ___ based
deficit (brain-behavior linked)
how healthy brains work in animal models, later including humans with the development of noninvasive brain recording methods
neurophysiology/neuroimaging
true or false: despite lots of investigation, there is little agreement about what consciousness is, and how it might be studied
true
over the last ~2 million years, the human cortex has nearly ____ in size
tripled
cortex = ___
cerebral cortex
the cortex consists of mostly ____ tissue
homogeneous
the cortex is greatly ____ in primates and is critical to (but not sufficient for) “____” cognition
expanded ; “higher-order”
“subcortex” refers to
everything else in the brain
cerebellum, thalamus, basal ganglia, amygdala, hippocampus, midbrain, brainstem, etc
subcortex
the subcortex is ___ in size and internal structure
variable
the subcortex is similar in ____ and ____ with other mammals
structure and function
is the subcortex also essential to higher order cognition?
yes
what are the three main components of the cortical surface?
gyrus, sulcus, and fissure
rounded protrusion of surface cortex (“mountain”)
gyrus
depression in surface cortex (“valley”)
sulcus
a particularly deep sulcus
fissure
___/___ of cortical surface is hidden in sulci and fissures (sulci within sulci)
2/3
cortical folding refers to cortical “___”
cortical “packaging”
cortical folding allows _____, and (maybe) speeds cortical processing time by keeping all brain regions relatively close together
lots of tissue in a small space
4 cortical lobes:
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
the boundary region between cortical and subcortical structures located between the frontal lobe and temporal lobe
insula
the ____ cortex is where the first stage of cortical processing occurs
the “primary sensory” cortex
V1 =
primary visual cortex
V2 =
primary auditory corteex
S1 =
sensory
M1 =
motor
this view states that the thalamus relays sensory and motor signals up to the cortical processing areas, and downstream to the brainstem (except smell)
classic view
recent work has identified that the structure of the thalamus is mostly (~80%) connections from one region of the cortex to another region of the cortex
modern view
the thalamus is heavily involved in ___ connections
cortico-cortical
rather than primarily carrying sensory input to cortex, and motor signals out to the body (“first order” connections”), the thalamus is instead heavily involved in cortico-cortical connections, which are referred to as ____
“higher order” connections
firing modes appear to enhance (____) or inhibit (____) the ‘quality of a connection between brain regions
burst ; tonic
the firing mode is changed by relatively long periods of ___ or ___ input from brain stem and cortex
excitatory ; inhibitory
two divisions of the nervous system
peripheral and central
the autonomic nervous system is part of the ___ nervous system
peripheral
two components of the autonomic nervous system
sympathetic and parasympathetic nervous systems
the ____ nervous system controls self-regulated action of internal organs and glands
autonomic
the ____ nervous system controls AROUSING for non-digestive organ systems
sympathetic
the ____ nervous system controls CALMING for non-digestive organ systems
parasympathetic
the ___ is mostly concerned with housekeeping of the body, but can show strong effects of mental state, such as anticipation or threat reactivity
autonomic nervous system
the ___ branch tends to prepare the body for intense action ; ‘fight or flight’
sympathetic branch
the ____ branch tends to maintain homeostasis and repair ; ‘rest and digest’
parasympathetic branch
our brains make up ____% of our body weight, but consume ____% of our metabolic resources
2% ; 20%
functional imaging is dependent on ___ to track brain activity
blood flow
____ were historically considered “support” cells for neurons
glial cells
we think that there is approximately ___ glial cell for each neuron in the brain
one
excitatory and inhibitory from other neurons
neuronal input
neuronal summation occurs at the ____
axon hillock
how does neuronal output travel
down the axon to synapse with next neuron
the ____ neuron releases neurotransmitter (NT) into the synapse, which modulates activity of the ____ neuron, depending on the neurotransmitter and the receptor type
presynaptic ; postsynaptic
basal forebrain constellation of cholinergic neurons, including basal nucleus of meynert ; dorsolateral pontine tegmental constellation of cholinergic neurons
acetylcholine
is acetylcholine more widespread or more limited?
widespread
is serotonin more widespread or more limited?
widespread
is dopamine more widespread or more limited?
more limited
the function of this neurotransmitter is to enable muscle action, learning, and memory
acetylcholine
with alzheimer’s disease, ACh-producing neurons ____
deteriorate
the function of this neurotransmitter is to influence movement, learning, attention, and emotion
dopamine
excess dopamine receptor activity is linked to ___
schizophrenia
starved of dopamine, the brain produces the tremors and decreased mobility of ____
parkinson’s disease
the function of this neurotransmitter is to affect mood, hunger, sleep, and arousal
serotonin
undersupply of serotonin is linked to ___
depression
____ and some other antidepressant drugs raise serotonin levels
prozac
the function of this neurotransmitter is to help control alertness and arousal
norepinephrine
undersupply of this neurotransmitter can depress mood
norepinephrine
___ is a major inhibitory neurotransmitter
GABA (gamma-aminobutyric acid)
undersupply of this neurotransmitter is linked to seizures, tremors, and insomnia
GABA
____ is a major excitatory neurotransmitter; involved in memory
glutamate
oversupply of this neurotransmitter can overstimulate the brain, producing migraines or seizures (which is why some people avoid MSG in food)
glutamate
“___” and “___” signals (from other neurons) flow through dendrites and cell body to the axon hillock where these signals are averaged together across the cell and over a short period of time (“___”)
“go” and “stop” ; (“summation”)
if ‘go’ signals win, the action potential is the ___ response
all or none
neurons fire at a ___ intensity
fixed
continuous ‘go’ input can increase the firing rate to the limit of the refractory period, perhaps up to ____ times per second
1000
(EEG) records the electrical activity of the ____ in real time
cortex
___ brain activity is missing from EEG
non-cortical
pyramidal neurons in the cortex are oriented in ____
columns
as these neurons sum input from other neurons, their electrical charge becomes more _____ near the outside surface of the cortex
voltage-negative
real time or “____” EEG is useful for tracking long-lasting ‘____’ mental states, like alertness or sleep
“raw” ; ‘tonic’
repeated averaging enhances the small but consistent ‘hidden’ signal
event-related potential (ERP)
true or false: brains will respond pretty much the same on trial one as they do on trial one-thousand
true
true or false: different people’s brains respond differently
false ; they respond similarly
averaging reveals the small, consistent EERP from the noisy EEG background, sort of like averaging the single pictures of a movie - the ____ elements remain
consistent
things that do not change appear ____, while things that do change ____ together
bolder ; blend
with ERP, ____ increases, and ____ decreases
signal ; noise
what does ERP stand for?
event-related potential
early ERP components (~100 ms after stimulus onset) are mostly driven by basic ____ features, like intensity
stimulus
early ERP components are sometimes called ____ components, because they are determined outside the body
exogenous
later ERP components (~250+ ms after stimulus onset) are mostly driven by _____ meaning of stimuli
psychological meaning
later ERP components are sometimes called the _____ components, because they are determined inside the body
endogenous
the first ERP component related to a psychological process was the ____
P300
a big ERP shift ~300 ms after a ‘rare’ event
the P300
the P300 was (and is) a hot area of study because it revealed brain reactivity to all sorts of ‘psychological events,’ including ____ events
missing
the P3 is not a sensory response - the P3 can also reflect a ____
broken expectation
____ is not recognized in the P3 (it often falls into the background) whereas ____ is noticed immediately
consistently ; change
a major problem with ERP
source localization
because the brain is ____, not all parts of the brain are perpendicular to the scalp
folded
the ____ the activity is from the scalp, the ____ the signal (known as volume conduction)
farther ; weaker
as the signal travels, it spreads out, and loses strength (relationship between depth and strength)
volume conduction
true or false: strong EEG voltage could represent weak activity close to the scalp OR strong activity from deeper in the brain
true
EEG/ERP source localization limitation: electrical activity ____ or _____ among folded sections of cortex
combines or cancels
EEG/ERP source localization limitation: source ____ is difficult to distinguish from source depth
strength
EEG/ERP source localization limitation: the exact ____ of sources is unknown
number
EEG/ERP source localization limitation: each person’s head _____ is slightly different
anatomy
what does MEG stand for?
magnetoencephalography
MEG looks for the ____ field that accompanies the voltage field
magnetic
MEG has the same ____ resolution as ERPs, but better ____ resolution than ERPs
temporal ; spatial
what does SQUIDS stand for?
superconducting quantum interference devices
do magnetic fields spread out like electric fields as they pass through the brain and skull?
no
without the smearing effect of volume conduction, MEG is only limited by the ____ and ____ of SQUIDS
size and number
MEG loses sensitivity sharply about ____ cm from the SQUID
5 cm
MEG is effectively blind to ___ brain structures
deep
MEG is really great for ____ cortical tissue, but has no sensitivity to deep cortical stuff
surface
what does fMRI stand for?
functional magnetic resonance imaging
fMRI yields colorful images that represent the ____ of brain activity with good precision, in a way that is easy to grasp
location
3 elements of MRI:
- strong, fixed magnet
- radio emitter and receiver
- weak, variable magnets
magnetic hydrogen protons (in water) align with the field, and spin at a known rate (128 MHz for a 3T scanner)
strong, fixed magnet
resonance radio wave energy at 128 MHz will “resonate with H protons and tilt them away from the main field
radio emitter and receiver
imaging smaller fields are added to across the area to be scanned, which allow a 2D image to be constructed
weak, variable magnets
this imaging method essentially detects the density of ____ in tissue, produces a stack of sharp images in about 15 minutes
structural MRI
this imaging method involves repeated, lower-resolution imaging of the brain, showing interest in image intensity as it CHANGES OVER TIME)
functional MRI (fMRI)
instead of focusing on water concentration, fMRI focuses on the small changes in signal intensity that accompany changes in local ____ oxygenation (BOLD contrast)
blood oxygenation
what does BOLD contrast stand for?
blood oxygen level dependent
high activity states trigger local increases in blood flow and volume (via astrocytes)
the “resupply” exceeds demand by about ____%
30%
this 30% excess of oxygenated blood ____ MRI signal intensity, because oxygenated blood contains slightly ____ iron than deoxygenated blood
increases ; less
how does iron affect magnetic fields?
it perturbs magnetic fields and causes signal intensity to sharply drop
because BOLD tracks the blood flow change, and not the neural activity that triggered it, BOLD signal onset is ____ and lasts for several seconds after scene offset
delayed
fMRI’s biggest weakness:
the typical fMRI sampling rate is far slower than the speed of the brain
true or false: consciousness is defined as correlated activity across at least 75% of the brain
false; there is little agreement about what consciousness is
true or false: consciousness is defined as the electrochemical activity of the brain oscillating above ~15 Hz
false; there is little agreement about what consciousness is
human skull volume has ____ over the last 2 million years
tripled
human skull volume has ____ over the last 5,000 years
a. remained stable
b. increased slightly
c. doubled
d. tripled
a. remained stable
human cortex shows unique structural features, such as:
a. homogeneous tissue organized in columns and layers
b. dense convolutions, including gyri and sulci
c. left-right symmetry in structure
d. all of the above
d. all of the above
true or false: the fissures of the cortex are unique to all individuals
false
true or false: subcortical structures operate independently from the cortex
false
true or false: the cerebral cortex contains primarily neurons, while subcortical structures are primarily glial cells
false
true or false: the autonomic nervous system is part of the central nervous system
false ; part of the peripheral nervous system
true or false: psychological states can strongly influence the autonomic nervous system
true
what autonomic branch would be expected to be more active after eating a large meal?
parasympathetic
the thalamus may be critical to consciousness because of its:
a. broad structural connectivity with cortex and brainstem
b. high proportion of cortical - cortical connections
c. capability to switch between “burst” and “tonic” modes of transmission
d. all of the above
d. all of the above
a neuron is more likely to fire when:
a. excitatory input arrives on the cell body, vs. a dendrite
b. multiple excitatory inputs arrive simultaneously, vs. over time
c. excitatory input at the hillock follows multiple inhibitory inputs on the dendrites
d. all of the above
d. all of the above
neurons fire at a ___ intensity
fixed
a neuron is more likely to fire when:
a. excitatory input arrives on the cell body, vs. a dendrite
b. multiple excitatory inputs arrive simultaneously, vs. over time
c. inhibitory input at the hillock follows multiple inhibitory inputs on the dendrites
d. all of the above
b. multiple excitatory inputs arrive simultaneously, vs. over time
perception = ___ + ___
sensation + prediction based on experience
our visual systems quickly and efficiently represent the world with limited ___ by making use of lots of past ___
limited information ; past experience
what we perceive is a ___ of what comes into our senses, guided (or biased) by what we have seen most often in our lifetime
construction
we have so much experience viewing ___ that our visual systems can sometimes lead us to perceive anything with many face-like features as being a face, at least momentarily
faces
the visual system develops over ___ to become efficient at classifying things commonly around you
childhood
photoreceptors that are sensitive to brightness
rods
photoreceptors that are sensitive to color
cones
the ___ is concentrated with cones
fovea
central fixation of the fovea
0 degrees
rods dominate ___
peripheral vision
pathway to cortex:
- retinal input
- ‘crosses over’ at the chiasm
- left or right visual field is processed in the opposite lateral geniculate nucleus (LGN) of the thalamus and occipital cortex
a “first order” thalamic nucleus
lateral geniculate nucleus (LGN)
the right visual field is processed solely in the ___ primary visual cortex (V1), and vice versa
right visual field - left primary visual cortex
left visual field - right primary visual cortex
the lateral geniculate nucleus (LGN) is a component of which part of the brain?
thalamus
the LGN of the thalamus transfers retinal input to ___ in successive stages
V1
when transferring retinal input from the LGN to V1, first, a coarse “gist” of the scene is sent, followed by the fine details over the next ~___ms
~10 ms
slow, detailed (“specific”)
parvo
fast, coarse (“global”)
magno
the primary visual cortex (V1) is located along the ___ fissure
calcarine fissure
the primary visual cortex (V1) receives retinal input according to the ___ of the stimulus in the visual field
location
the ___ half of your visual field is routed to right V1
left
the ___ field areas are routed to the inferior back of V1
upper field areas
the ___ fixation point is routed to posterior V1
central fixation point
___ areas route to anterior V1
peripheral areas
for every degree of the visual field, separate clusters of V1 neurons are sensitive to different ___ (edges, contrast, brightness) of objects in that location
visual features
despite considerable differences in our left and right eye’s visual field, we see ___ image
one unified image
the mystery of binocular vision: each of our eyes sees a different view, yet the image we see is uniform
how is this “convergence” accomplished?
we haven’t figured it out exactly
why do we have two eyes? there is a consistent difference across prey/predator species in ___ vs. ___ processing
peripheral vs. depth processing
___ overlap in visual field (both eyes facing ___) gives a much better account of our distance to the object
wide overlap ; both eyes facing forward
prey eyes vs. predator eyes
prey eyes - stronger peripheral vision
lateral geniculate nucleus (LGN) directs left and right visual input to V1, but keeps track of which eye the retinal input came from in layer ___
layer 4
if we present conflicting information into each eye, our perception switches back and forth between the two
binocular rivalry
according to binocular rivalry, there must be some ___ and ___ between left and right eye input, reflecting ‘higher order’ (late visual cortex and prefrontal cortex) processes that bias our perception toward one stimulus
competition and choice
binocular rivalry task: when presented a happy face, a neutral face, or an unhappy face, people have a slightly greater likelihood of reporting an __ face than a ___ face
emotional face ; neutral face
the visual system converts the light at the retina into the basic properties of visual perception including: (5 components)
- lightness
- color
- depth
- size
- motion
___ qualities can be different from the physical properties of visual stimuli as measured by purely objective methods (ex. was the dress white and gold or blue and black?)
perceived
lightness is a ___ quality, while luminance is a ___ property of an object
perceived quality ; physical property
the ___ of an object is not directly related to the ___ of an object
lightness ; luminance
lightness could be described as a ___ value, dependent upon local ___ and prior ___
calculated value ; local context ; prior experience
our visual systems have not evolved to determine the “___” nature of stimuli, only what we need to manage
“true”
through infancy and early childhood (by ___ and ___) we learn what visual features are “correct” and use this information to interpret future scenes
trial and error
around what age do we learn what visual features are correct?
around age 3 or 4
a global distinction can be made between “___” and “___” visual pathways, although recent data suggests the streams are more mixed
“what” and “where” pathways
two pathways within the primary and extrastriate visual cortex:
where pathway and what pathway
where pathway - ___ stream
dorsal stream
analysis of motion and spatial relations within this pathway
where pathway
what pathway - ___ stream
ventral stream
analysis of form and color within this pathway
what pathway
ventral visual cortex: early vs. late stage:
a rough distinction can be made between early visual (“___”) and later visual (“____”) processing regions
(“simple”) and (“complex categorical”)
which part of the brain is utilized during late stage?
inferior temporal (IT) visual cortex)
which part of the brain is utilized during early/mid stage?
occipital visual cortex (V1, V2, V3…)
visual cortex - general locations:
this part of the brain is medial inferior temporal
parahippocampal gyrus
visual cortex - general locations:
this part of the brain is lateral inferior temporal
fusiform gyrus
visual cortex - general locations:
this part of the brain is referred to as the “transition area”
lateral occipital
visual cortex - general locations:
this area of the brain is middle temporal
area MT
early/mid stage of visual processing occurs within:
V1, V2, V3, V3a
‘early stage’ :
‘late stage’ :
‘early stage’ : V1, V2, V3
‘late stage’ : everything else
PPA refers to:
parahippocampal “place area”
FFA refers to:
fusiform “face area”
lots of fMRI and invasive data reveals that there are multiple ventral visual regions dedicated to the processing of ___ of things like faces, body parts, words, and others
categories
where is color perceived?
lesion data suggests that color perception depends on regions of ___ visual cortex, a late stage of visual processing
ventral visual cortex
patients with damage in the ventral visual cortex (stroke, tumor) often report a ___ loss of color vision, while other visual abilities remain intact
specific
___ cues can even evoke activation in deeper regions of V1 that represent the peripheral visual field (larger objects)
depth cues
V1 activity at central fixation, representing a small object activates:
only V1 and V2
V1 activity at central fixation and periphery, representing a large object activates:
V1-5
the illusory effect in V1 depends on feedback from ___ brain regions
because fMRI reflects average activity over seconds of time, we can see this ___ effect in V1
later brain regions ; context effect
in the ___ (a type of monkey), the organization and timing of visual processing stages is relatively well known
macaque
visual information is integrated and resolved along the ventral pathway until task-driven decisions can be made in PFC around ~___ ms
~150 ms
the first stage of visual processing in V1 is purely ___ driven (“___”)
stimulus driven ; (“bottom up”)
the first stage of visual processing in V1 occurs up to around ~___ ms after cue onset
~50 ms
later V1 activity also reflects ___ from other brain regions (“___”), such as late visual cortex and prefrontal cortex
feedback ; (“top-down”)
later V1 activity occurs ~___ ms after onset
~100 ms
feedback biases perception:
~50 ms =
~50 ms = pure sensory
feedback biases perception:
~120 ms =
~120 ms = biased
perceptual priming:
one model of this process focuses on visual context, which has been shown to churn information in a repeating cycle of ___ and ___ waves
feedforward and feedback waves
…we argue that the ventral pathway is a ___ and highly ___ occipitotemporal network linking early visual areas and the anterior IT cortex (aIT) along multiple routes through which visual information is processed
recurrent and highly interactive
the ventral visual pathway is ___, ___
reentrant, nonlinear
“…anatomical evidence indicates that the ventral pathway is actually a complex network of feedforward and feedback projections, some of which are unidirectional (ex. non-reciprocal) feedback connections and others of which ___ intermediate areas, allowing direct communication between putative early and late stages of the hierarchy”
bypass
“visual information from ‘early’ stages of the central route can be transmitted to the most rostral temporal areas or ‘final’ visual processing stages without passing through the ___ areas of the central route”
intermediate
a reentrant, nonlinear explanation of the ventral visual pathway might explain how late-stage visual cortex could rapidly ___ early visual cortex
bias
visual cues for ___ and object ___ are so convincing because feedback from late-stage visual cortex seems to activate regions of V1 that represent larger objects (the peripheral visual field)
depth and object size
because fMRI reflects average activity over seconds of time, we can see this biasing effect in V1, ___ after the feedback has arrived
long after
the feedback to V1 is limited to basic features that V1 processes, like ___ and ___
luminance and size
explicit, clear awareness of a face is most strongly tied to ___ activity
FFA (fusiform face area)
is the FFA only specific to faces?
no ; the FFA shows plenty of activity for non-face stimuli too
in some studies, the FG is the ___ selective visual area
least
according to gauthier’s ‘greeble’ study, FFA = ___, and is not a genetic module for faces
FFA = experience
auditory information, including speech and music, can be quite powerful
true or false: science has come up with a reasonable evolutionary purpose for music
false; despite lots of trying, science hasn’t come up with a reasonable evolutionary purpose for music
the ventromedial prefrontal cortex and nucleus accumbens are referred to as the ___
reward circuit
the reward circuit runs on ___
dopamine
olds and milner (1954) demonstrated (accidentally) that a rat given the ability to self-stimulate the nucleus accumbens (NAcc) would continue to do so until ___ from thirst
death
what does NAcc stand for?
nucleus accumbens
in human fMRI studies, ___ rewards (ex. chocolate, cocaine) and ___ rewards (money) will drive reward circuit activity, including subcortical nucleus accumbens (NAcc) and ventromedial prefrontal cortex (mPFC)
primary rewards and secondary rewards
___ is a powerful driver of NAcc activity
methamphetamine (as well as all drugs of abuse and gambling)
___ music activates nucleus accumbens (vs. neutral)
pleasant (your favorite)
___ binding = more dopamine release
less binding
are pure tones rare or common in the real world?
rare (most natural sounds are combinations of many different frequencies)
a recent meta-analysis of 47 fMRI studies of music (n=997) found that pleasant music enhances activity in reward (NAcc) and basic emotion regions (amygdala), along with increases in auditory cortex
is it clear how music became linked to this basic reward system?
no; how music became linked to this basic reward system is unclear
instruments produce sounds that contain multiple ___ (or timbre) which we use to help us discriminate between different sound sources, like a piano vs. a flute
harmonics
the upper harmonics are a doubling of the ___ (___) frequency
fundamental (lowest) frequency
with each harmonic, the energy is ___, until it dies out around the ___th or so
reduced ; 10th
fundamental frequency is always the same: ___ Hz
440 Hz
does the strength of upper harmonics remain the same or vary?
varies widely
our auditory systems keep track of all of these simultaneous frequencies by converting sound pressure variation to neuronal input via the ___
cochlea
this device contains ~48 artificial excitation points in cochlea can be enough for people to decipher speech and other complex sounds
cochlear implant
the auditory system enables selective filtering of input at the level of the ___, allowing us to focus on frequencies of interest in the moment
cochlea
from the cochlea, frequencies are sent to the ___
primary auditory cortex (A1)
sounds are ordered by ___ within A1 (like a piano)
frequency
our auditory system is hyper-sensitive in the ___-___ range
2-5k range
specialization of the auditory system may have evolved recently, adding sensitivity about ~___KHz
~3.5 KHz
the auditory system includes two subcortical circuits to ___ low (<3 Hz) and high (>3 Hz) frequency sounds
localize
is our ability to localize sound good?
no
are humans more dependent on visual or auditory input?
visual
how does the somatosensory system work? is it clear or unclear?
unclear ; we know the parts involved, but not how they really work together in real time
located along the back edge of the frontal lobe (M1) and the front edge of the parietal lobe (S1), separated by the central sulcus
location of the primary somatosensory and primary motor cortex
The ___ of SS cortex involved depends on the need for fine control and sensitivity
volume
do your eyelids occupy about the same volume of the SS cortex as do your legs? more or less?
about the same
the primary sensory cortex (S1) includes three subtypes of physical sensation from the body:
- touch
- temperature/pain
- joint/muscle position sense
different types of sensory information are channeled through three parallel pathways in the ___ and ___, ultimately feeding into the same section of S1 representing that body part
spinal cord and brainstem
the first modality of the touch subtype of the primary sensory cortex (S1)
discriminative touch (DT)
discriminative touch includes 3 categories:
touch, pressure, and vibration perception
free nerve endings =
pain
meissner corpuscles =
slow vibration
ruffini endings =
compression
pacinian corpuscles =
rapid vibration
temperature/pain includes the sensation of ___ and ___ across the body
itch and tickle
___ nerve stimulation from pepper, ammonia, tear gas also falls under this group
trigeminal
___ stimulation in mouth, nose, and eyes = pain
noxious
when you put hot sauce in your food, you are not adding taste or improving the flavor, you are adding ___, as you are stimulating the trigeminal nerve
pain
___ and ___ are critical for tickle
intensity and duration
joint muscle position sense is described by
proprioception
joint muscle position sense (proprioception) includes receptors for muscle ___, joint ___, and tendon ___
muscle stretch, joint position, and tendon tension
this modality (joint muscle position sense - proprioception) feeds into the ___, which processes real-time feedback regarding the orientation of the body
cerebellum
___ is susceptible to alcohol
proprioception
somatosensory representation in the cortex is ___ (it expands and contracts with experience)
dynamic
throughout childhood, our common actions became ‘packaged’ into functional units in ___
M1 (primary motor cortex)
in an animal model, complex multi-joint movements can be evoked by stimulation at a ___ location on primary motor cortex
single location
M1 codes ___, not single muscles
actions
many of our common motor behaviors are “___”
-we combine motor scheme so we can walk, look at our phone, and eat at the same time
automated
example of a motor expectation
walking into the kitchen to put the milk and cereal box away (you know the general direction to walk into the kitchen, but you put the cereal in the fridge, and the milk in the pantry)
locomotor behaviors are even more ___
-once begun, major transitions in locomotion pattern can be managed outside of our awareness
packaged
does awareness make major transitions in locomotion pattern better or worse?
worse
animal research shows that the ___ alone can manage transitions in locomotor behaviors via what has been called ___ (CPG) without any input from the brain
spinal cord ; central pattern generators
does controlled motor behavior require little or enormous preparation and on/off timing before M1 becomes involved to execute the action?
enormous
this part of the brain manages the preparation for action in response to external cuees
premotor cortex
premotor cortex activity ___ primary motor cortex activity
precede
premotor cortex activity ___ when overt movement begins (or is aborted)
ceases
in superior medial frontal cortex, and feeds into premotor cortex
supplementary motor cortex
does the supplementary motor cortex manage well-learned movements, with or without need for explicit sensory cues?
without
does an action actually have to happen to evoke supplementary motor area (SMA) activity?
no; simply imagining that you are riding a bike will evoke SMA activity (the action does not have to actually happen)
SMA (and cerebellum) is strongly active during ___ actions, even when action is clearly impossible
-___ feedback is unnecessary
imagined ; sensory feedback
motor preparation occupies a large chunk of cortex, mostly located on surface ___
gyri
___ exploit this large premotor signal to communicate with “locked in” patients
brain-computer interfaces
to finely control the exact onset and offset of a movement, the ___ serves as a “gate” between premotor and motor cortex
basal ganglia
this part of the brain prepares and plans motor behavior
premotor cortex
the start and stop of motor behavior (“gating”)
basal ganglia
the execution of the motor behavior occurs in which part of the brain?
primary motor cortex
which part of the brain ensures that the action goes “according to plan”
cerebellum
cerebellum: movement “___” in real time
“tuning”
the cerebellum serves to ___ and ___ the balance of sensory-motor integration during a movement
coordinate and refine
cerebellum makes up ___% of total brain volume, but makes up almost ___% of neurons in the brain
10% ; 50%
this part of the brain is thought to be a huge ‘data processor’ crunching numbers to adjust motor output based on sensory feedback, thus enabling precise motor control in changing contexts
cerebellum
true or false: human brains have an oversized cortex
true; other mammals have nearly equivalent sized cortex and cerebellum
a quick neurological test of cerebellar integrity
moving your finger directly between your nose and a fixed point in space
the ___ pathways of the cerebellum are well defined, but real-time function is not
structural
the cerebellum receives huge amounts of input from the cortex (frontal, parietal), spinal cord, and midbrain, and then some sort of comparison is made between ___ and ___ action
planned and actual
after a comparison is made between planned and actual action, ___ signals are sent from the cerebellum to motor thalamus to refine movement in almost real time
error correction signals
error correction signals are sent from the ___ to motor ___
cerebellum to motor thalamus
the cerebellum is also active during many ___ tasks, which was often ignored as “noise” in early fMRI studies
non-motor
true or false: inhibiting the cerebellum (but not other areas of the brain) slows down our ability to make predictable choices
true
which 3 behavior domains appear to be associated with the largest clusters of cerebellum activity?
language, music, and working memory
one idea about the cerebellum’s contribution to no motor tasks is that its huge processing power may have been “repurposed” to ___ what might happen in future behaviors
predict
dynamic behaviors (language, music, working memory) involve the most significant ___ and ___ as the behavior takes place
prediction and adjustment
the nature of body ownership is ___
constructive
which study illustrated the flexible nature of body ownership?
the rubber hand illusion
-when a semi-realistic false hand was placed within the subject’s view (with their real hand out of view) and both hands were stimulated, most subjects soon reported feeling ownership of the false hand, reacting defensively if the false hand was threatened
notice taken of someone or something; the regarding of someone or something as interesting or important
attention
is attention a limited or unlimited resource?
limited
___ models of attention highlight our limited capacity to process information
cognitive models
true or false: attention increases our processing of some things and decreases our processing of other things
true
attention is:
focusing on a subset of features that are somehow “relevant” and ignoring the “irrelevant”
what kind of stimuli do we process a bit more readily during this “blink” of attention?
emotional stimuli
this form of attention is called endogenous, or “top-down” attention
-the “top” is the goal state coming from inside (endo) the person
-we are searching for a specific target
goal-directed attention
how does the filtering process for attention work? where and how do we process some things more fully than others, and how do we choose which things are “relevant” ?
it’s not completely clear
example of goal-directed attention
where’s waldo?
-we search the area slowly and carefully until we find the target
true or false: too much or too little attention can be dangerous
true
even when we are trying our best, our attention is ___
imperfect
this task asks folks to attend to 2 letters presented in a rapid series. processing the first letter (T1) absorbs most of folks’ attention, revealing a “blink,” or lapse of attention for the second letter (T2), strongest around 200 ms after T1
“attentional blink” task
searching for one particular thing through a mixture of multiple target features
conjunction search
true or false: multiple target features (conjunction search) does NOT increase search time along with the number of background distractors
false ; does increase search time
the ___ of a target extends reaction time significantly
absence
does reaction time extend or shorten as the number of distractors increases?
extends
this form of attention is called exogenous, or “bottom-up” attention
-the “bottom” is the sensory features that ‘pop-out’ or grab our attention from outside the body (exo)
automatic capture of attention (“captured” attention)
example of “captured” attention
a loud noise or a flash of lightning
-these features interrupt and grab our attention, without any intention on our part
-we can’t ignore it, these stimuli are processed even if we don’t want to
do endogenous and exogenous attention features function together or separately in search tasks?
together
if search features “pop-out” strongly, task performance is ___
-in this scenario, does the number of distractors matter?
fast ; does not matter
can attention be defined simply by gaze location?
no
does attention operate independent or “above” simple visual input?
yes
true or false: attending covertly leads to increased response speed and improved accuracy to a stimulus appearing at the attended location
true
asking subjects to pay attention to a location on a screen, while keeping fixation somewhere else
attending covertly
early visual ___ show evidence of a ‘covert’ attention advantage
-visual areas seem to be “warmed up” ahead of time by ___ attention
early visual ERPs ; endogenous attention
covert attention enhances visual cortical fMRI BOLD signal before or after the target appears?
before
first: locate ___ areas that respond to upper left and right patches
-subtracting BOLD signal recorded as subjects wait for left vs. right cue to appear shows a huge ___ increase in cortical activation due to attention
V1 ; preparatory increase
true or false: attending to the left ‘warms up’ left visual hemisphere areas
false ; attending to the left ‘warms up’ right visual hemisphere areas
___ elements in the unattended ear can “force through” the filter and “capture” our attention
salient
selective attention effect is mostly consistent with an old hypothesis of Helmholtz (1860s), suggesting that attention operates by filtering (“gating out”) unattended input at the early sensory stage
-this filter of attention is not perfect - ___ (or personally ‘salient’) stimuli break through the filter
exogenous
this also works for auditory input, by asking folks to wear headphones playing two different recordings, and asking them to alternate their attention toward one ear or the other
-in this “dichotomous listening” task, memory is much better for the content played to the ___ ear
attended ear
neuroscience studies of attention show that selection can modulate brain reactivity at all stages of the process. what are the two kinds of selection?
early selection and late selection
example: if an ‘ignored’ speaker sneezes, laughs, curses, or says your full name, this ability to register ‘relevant’ details in the ignored ear argues against a strict early selection model of attention
-why does this sort of feature make evolutionary sense?
we should never be able to completely ignore explicit threats
recent data demonstrates that the porous filter works in one or both directions? inhibiting processing of ignored cues, and enhancing processing of attended cues
both directions
a revised model, which allows highly relevant information to pass through the ears
porous filter
where does late selection occur?
prefrontal cortex
where does early selection occur?
sensory cortex
searching through a messy desk drawer for a highlighter is an example of which selection?
early selection
searching through a crowded bar for your roommate is an example of which selection?
late selection
if you are searching through a crowded bar for your roommate, and you happen to know that your roommate is wearing red, this is an example of which kind of selection?
early and late selection
how is selection managed in the brain?
folks are still working on it
this theory by treisman suggests that we have “feature maps” in our visual systems that allow us to quickly and efficiently recognize basic characteristics (color, shape, etc.) that enables exogenous “pop-out” attention
feature integration theory
if we need to locate something we ‘bind’ these multiple features together, using ___ attention.
-do we know much about the brain mechanisms supporting this process? or is this where research is in progress
endogenous ; where research is in progress
almost any sort of visual attention task evokes activity in two bilateral brain regions:
- the premotor frontal eye fields (FEF)
- dorsal parietal intraparietal sulcus (IPS)
this region of the brain is tied to eye movement and preparation
frontal eye fields (FEF)
this region of the brain is involved in 3D spatial awareness of stimuli around you
intraparietal sulcus (IPS)
the ___ network appears to swerve the needs of endogenous attention - anything that we need or want to look at engages the network
frontoparietal network
true or false: frontoparietal network (FP) network activity is limited to eye movements only
false ; FP network activity is independent of eye movement
does covert attention shifts also drive FEF/IPS activity?
yes
studies of exogenous shifts of attention find activity in a parallel attention network now called the ___
ventral FP (frontoparietal) network
the ventral FP network consists of two components:
- inferior frontal gyrus (IFG)
- temporoparietal junction (TPJ)
the dorsal network consists of two components:
FEF (frontal eye fields) and IPS (intraparietal sulcus)
___ shifts of attention are associated with activity in dorsal network (FEF and IPS)
endogenous
this type of attention is characterized by endogenous shifts of attention are associated with activity in dorsal network (FEF and IPS)
voluntary attention
ventral network is composed of two components in the brain:
temporoparietal junction (TPJ) and inferior frontal gyrus (IFG)
imagine sitting and watching TV; the ___ FP network manages your visual attention to the screen and limits sensitivity to anything else
dorsal
a timer goes off in the kitchen, the ___ FP network breaks your attention toward the TV. Then, the ___ FP engages as you make your way to get your dinner
ventral ; dorsal
this FP network can be thought of as a “circuit breaker” or “interrupt mechanism” to cease focused attention
ventral FP network
which FP network is mostly in charge?
dorsal
___ shifts of attention are associated with activity in ventral network (TPJ and IFG)
exogenous
in studies where attention is ‘captured’ by features like salience, or emotion, attention effects take longer, around ___ ms after the target
200 ms
The basic idea of selective attention is that some region of PFC (and probably other areas) ___ and ___ the search goal. The current goal appears to inform the FP network to scan the environment, locate the target, and fixate gaze to that point
chooses and maintains
___ designs in visual search are simplistic
-when searching for a target with one basic feature (ex. a red bar), we are able to rapidly search a large array, using exogenous attention
“classic”
most attention studies use ___ tasks, where the subject is “prepared and waiting” for a specific target
endogenous tasks
with endogenous tasks, attention effects are evident soon after the target appears, around ___ ms
100 ms
is a naturalistic search performance faster or slower than expected
faster than expected
by studying attention ___ stimuli, we reveal how attention works (and evolved) to solve ‘real world’ problems
naturalistic stimuli
find a notre dame fan in the crowd of a UGA football game: complex but familiar, and ecologically valid
example of a naturalistic (real world) search
when asked to decide if a scene contains an animal, people can correctly identify animals ___% of the time, even when the scene is presented for only ___ ms
94% ; 20 ms
find a horizontal red line in a picture of red and green lines, tilted at different angles: Simple, but also unfamiliar, and ecologically sterile, foreign
example of a naturalistic (real world) search
familiar contexts ___ search times
- we locate objects (ex. a coffee maker) ___ when they are placed in a natural setting, relative to a simple array, even though the natural setting is much more visually complex
reduce ; faster
naturalistic search: why so fast?
this early ERP effect is just as fast as hillyard’s left vs. right visual attention, or left vs. right ear attention. but the task is much more ___ (cars vs. trees, or faces vs. buildings)
complex
why is a naturalistic search so fast?
target objects and distractors are familiar ; it is easy for us to search for an animal in a natural environment (we’ve been training for this sort of task our whole lives)
true or false: scene context hinders gaze location
false ; scene context aids gaze location
-fixations demonstrate that people know where to look for an object in a photograph from past experience
does attention modulate only early or early and late visual cortex activity up and down?
both early and late
if we change the target category every trial, we can see the ___ ventral visual cortex ‘warm up’ and “cool down” the category-sensitive regions ahead of time (just like early visual cortex)
late ventral visual cortex
naturalistic search: limitations
-attention can bias visual processing of broad target categories (ex. cars vs. trees) but cannot focus on ___ subtypes (ex. BMWs vs. Fords, cats vs. dogs)
detailed
how does attention modulate brain reactivity?
models of selective attention propose that target stimuli are “tagged” or “gated through” in some way for enhanced processing, but the exact mechanism is unknown
the enhancement of familiar target categories is enacted in parallel across part of or the entire visual field, much like basic features such as color?
-we can’t limit our categorical attention to one location around us
the entire visual field
this type of attention is characterized by exogenous shifts of attention are associated with activity in a ventral network including temporoparietal junction (TPD) and inferior frontal gyrus (IFG)
attention reorienting
do the dorsal and ventral networks work in unison or opposition?
opposition
true or false: when one FP network is active, the other is inhibited
true
recently, a research group were able to identify multiple V1 clusters that responded to different line orientations, but all fed into a single ___ cluster
V4
both ___ and ___ of EEG appear to support network connections
frequency and phase
cortical neurons are constantly ___ (increasing and decreasing. inactivity)
oscillating
comparing the way cortical signals between V1 and V4 neurons changed when the same stimulus was attended or ignored focuses on 2 components:
frequency and phase of EEG signals between V1 and V4
activity is greatest at the ___ point of an oscillation. it sends and receives signals best at this point in time
high point
if two or more regions are connected, and oscillating at the same frequency, they are often part of a ___ network
functional network
for A and B to communicate best, A should send a signal to B so that it ___ when B is at a high point of activity
arrives
this process manages region A so that its signal is sent to A’s high point, and so it arrives when region B is at its high point
phase shift
higher oscillation frequencies represent ___ signals, while slower frequencies represent ___ signals
feedforward ; feedback
high frequency EEG = ___ signals
feedforward
bottom-up =
gamma
rhythms for cognition:
communication through coherence
V1 clusters feed into target cluster in ___
V4
V1 sends its signal as a perfect ___, so that it is heard much more loudly by V4 target than competing stimuli
phase representation
low frequency EEG = ___ signals
feedback
top-down =
alpha-beta
this phase representation locks itself to ___ somehow, so it only hears this V1 cluster
V4
two components of memory:
working memory and long-term memory
attended information is transmitted into V4 and its highest ___ point (its peak), while ignored information is transmitted into V4 at its ___ point
excitation ; inhibition
what manages phase tuning?
true or false: slow-frequency “top-down” feedback signals from later stages of visual cortex (or PFC) is involved
true
two components of long-term memory:
declarative (explicit memory) and nondeclarative (implicit memory
two components of declarative (explicit memory)
episodic memory (events) and semantic memory (facts)
nondeclarative memory is referred to as ___ memory
implicit memory
declarative memory is referred to as ___ memory
explicit
is memory formation understood well? or poorly understood?
poorly understood
3 components of nondeclarative (implicit) memory
priming, skill learning, and conditioning
true or false: minor concussions typically erase memory of recent events
true
what must occur over an extended period of time for the memory of an event to last
the brain must be allowed tp “consolidate”
can severe concussions eliminate memory of the entire day, week, or more?
yes
a rare condition in which a temporary loss of memory function occurs with no apparent cause, lasting 1-24 hours
-all other brain functions are intact, and CT, MRI, PET scans look normal
transient global amnesia
are novel memories formed instantly? or does it actually take quite a while for memories to become permanent?
it actually takes quite a while for memories to become permanent
with transient global amnesia, immediate recall (~1 min) is normal, along with term memories (longer than ~1 year), but everything in between is temporarily ___
-patients can’t understand what’s happening, and often ask the same series of questions in a “repeating loop”
temporarily lost
3 flavors of implicit memory:
priming, skill learning, and conditioning
this flavor of implicit memory only works if it happens implicitly (outside our awareness)
priming
how are implicit memories formed?
automatically, by mere exposure or by simple association
___ involves the implicit presentation of information/cues that have the effect of increasing the probability that a person will respond with a target stimulus (word, object, etc.)
priming
how long after a transient global amnesia episode does memory function gradually recover?
can new memories be formed again?
are memories of the TGA event itself permanent, or are they lost?
~24 hours ; yes ; lost
are implicit memories easy or difficult to describe?
difficult
true or false: V1 attended and V1 unattended both feed into V4
true
true or false: priming must remain ‘under the radar’ to work
true
personal practice and experience that leads to ‘motor learning’ that is highly resistant to decay - a ‘permanent memory’
ex. you never forget how to catch a ball, or ride a bike
skill learning
___ is highly implicit. it is impossible to explain to someone how to swim or ride a bike. they need to learn for themselves
skill learning
motor plasticity is revealed through ___
ex. riding a bike is a complicated motor task. many variables must be balanced to manage it well. once you ‘get it,’ it generally stays with you forever, BUT, if you change one part of the process, and try to adapt, strange things happen
(ex. backwards bicycle video)
reprogramming
learning that a neutral cue produces an aversive (or appetitive) outcome
classical conditioning
___ is one of the best understood sorts of memory, from a neuro standpoint
associative conditioning
skin conductance responses (sympathetic) reveal reveal the creation of the new memory association. SC will often show learning effects before or after the subject is able to verbally report the association, demonstrating ‘implicit’ learning?
before
classical conditioning depends on intact ___
amygdala
“fear potentiation” of the startle reflex is dependent on an intact central nucleus of the subcortical ___. without this part of the brain, fear associations are poorly learned
amygdala
the what, where, when, and how of an event (active clusters of activity in visual, auditory, and premotor cortex, etc.) are linked through connections with the HC
-after many years of use, can these clusters gain independence from HC index and develop direct links?
yes
in healthy folks, what brain structures are needed to recall an event
- the parts of the cortex that were active during the original event (sight, smell, sound, feelings, etc.)
- hippocampus to provide the list of all these elements, so that they can be reactivated when you bring the memory back online
explicit learning activates this part of the brain, indicating declarative learning
hippocampus
3 basic components of declarative memory:
encoding, storage, and retrieval
consistent with the index model, fMRI studies have shown visual cortex reactivation during retrieval of word memories that were formed in combination with ___ stimuli
-thus the text cue evokes the ___ associate in memory
picture ; visual
repeated recall of a past event strengthens the direct connections between those parts of the cortex, and eventually the hippocampus is not necessary. how long does this process take?
~6-12 months
implicit learning activates this part of the brain
amygdala
this working hypothesis of declarative memory function considers the HC as an ‘index’ - a map of memory elements
the hippocampal “index model”
why does head trauma affect memory more than other brain functions?
it is not clear, but it could be that memory depends on structures located in the middle of the brain, where shearing, twisting forces concentrate (medial temporal lobe structures)
HM’s declarative deficits were linked primarily to the loss of the ___
hippocampus
both retrieval and encoding are somehow connected with the ___, which stores the “index” of an event
hippocampus
during retrieval of word memories that were formed in combination with sound stimuli, the ___ cortex is reactivated
auditory cortex
true or false: L IFG activity is weaker during memory retrieval
false ; stronger
memory encoding: we see greater IFG activity during ___ (deep) compared to ___ (shallow) strategy use
semantic (deep) ; phonological (shallow)
encoding has been linked to
left IFG
from behavioral memory research, we know that greater ___ improves performance. in other words, the more deeply we think about an item, the more likely we are to remember it later
depth processing
deep thinking engages left inferior frontal cortex, or ___, known to be involved in language processing
broca’s area
more left IFG activity during ___ vs. ___ memory encoding
semantic vs. sound
clearly recalled items are associated with more ___ parietal activity
ventral parietal
correctly remembered word trials showed much more ___ activity
L IFG
low-confidence items are associated with more ___ parietal activity
dorsal parietal
retrieval has been linked to
left IFG and posterior parietal cortex
both ___ (receptors, dendrites) and ___ processes (large cortical networks) are involved in memory consolidation
subcellular and systemic processes
selectively interrupting different stages of sleep reveals that stage 4 “___” sleep is especially critical to memory retention the following day
“slow-wave”
how do we determine which things to remember and which to forget?
it’s unclear
one likely component to consolidation
sleep
memory consolidation has been shown to involve ___ and ___ scales that vary widely
spatial and temporal
neurocognitive processing during sleep can benefit memory storage when memories are covertly cued via ___ and ___ stimulation
auditory and olfactory
learned spatial associations that were ___ during slow wave sleep were remembered better in human trials
re-cued
true or false: the information that ultimately remains available for retrieval may tend to be that which is reactivated during sleep
true
this view of reconsolidation states that the stored memory is stable; the “original” copy is read out at retrieval
classic view of reconsolidation
memories are gradually altered over time through ___
reconsolidation
ex. of reconsolidation
memories that are repeatedly recounted tend to put the narrator in a better light
this view of reconsolidation states that the stored memory is malleable; the “most recently” accessed copy is read out at retrieval
modern view of reconsolidation
reconsolidation has been used in ___ patients to weaken the persistent emotional associations typically evoked by traumatic memories
PTSD
over time, the hippocampal index becomes less important in memory recall. how long?
~1 year
a set of processes that transfer hippocampus-mediated to direct cortical connections
consolidation
is memory consolidation well understood?
no ; poorly understood
