Exam 3 Flashcards
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
true or false: attention increases our processing of some things and decreases our processing of other things
true
___ models of attention highlight our limited capacity to process information
cognitive models
attention is:
focusing on a subset of features that are somehow “relevant” and ignoring the “irrelevant”
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
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
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
example of goal-directed attention
where’s waldo?
-we search the area slowly and carefully until we find the target
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
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
can attention be defined simply by gaze location?
no
does attention operate independent or “above” simple visual input?
yes
asking subjects to pay attention to a location on a screen, while keeping fixation somewhere else
attending covertly
true or false: attending covertly leads to increased response speed and improved accuracy to a stimulus appearing at the attended location
true
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
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
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
___ elements in the unattended ear can “force through” the filter and “capture” our attention
salient
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
a revised model, which allows highly relevant information to pass through the ears
porous filter
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
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
where does early selection occur?
sensory cortex
where does late selection occur?
prefrontal 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)
___ shifts of attention are associated with activity in ventral network (TPJ and IFG)
exogenous
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
which FP network is mostly in charge?
dorsal
this FP network can be thought of as a “circuit breaker” or “interrupt mechanism” to cease focused attention
ventral FP network
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
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
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
in studies where attention is ‘captured’ by features like salience, or emotion, attention effects take longer, around ___ ms after the target
200 ms
___ 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”
by studying attention ___ stimuli, we reveal how attention works (and evolved) to solve ‘real world’ problems
naturalistic stimuli
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
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
is a naturalistic search performance faster or slower than expected
faster than expected
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
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)
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
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
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
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
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
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
both ___ and ___ of EEG appear to support network connections
frequency and phase
cortical neurons are constantly ___ (increasing and decreasing. inactivity)
oscillating
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
low frequency EEG = ___ signals
feedback
top-down =
alpha-beta
rhythms for cognition:
communication through coherence
V1 features 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
this phase representation locks itself to ___ somehow, so it only hears this V1 cluster
V4
true or false: V1 attended and V1 unattended both feed into V4
true
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 memory:
working memory and long-term memory
two components of long-term memory:
declarative (explicit memory) and nondeclarative (implicit memory)
declarative memory is referred to as ___ memory
explicit memory
nondeclarative memory is referred to as ___ memory
implicit
two components of declarative (explicit memory)
episodic memory (events) and semantic memory (facts)
3 components of nondeclarative (implicit) memory
priming, skill learning, and conditioning
is memory formation understood well? or poorly understood?
poorly understood
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
true or false: minor concussions typically erase memory of recent events
true
can severe concussions eliminate memory of the entire day, week, or more?
yes
what must occur over an extended period of time for the memory of an event to last
the brain must be allowed to “consolidate”
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
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
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
3 flavors of implicit memory:
priming, skill learning, and conditioning
how are implicit memories formed?
automatically, by mere exposure or by simple association
are implicit memories easy or difficult to describe?
difficult
this flavor of implicit memory only works if it happens implicitly (outside our awareness)
priming
___ 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
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
___ is one of the best understood sorts of memory, from a neuro standpoint
associative conditioning
learning that a neutral cue produces an aversive (or appetitive) outcome
classical 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
implicit learning activates this part of the brain
amygdala
explicit learning activates this part of the brain, indicating declarative learning
hippocampus
3 basic components of declarative memory:
encoding, storage, and retrieval
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
this working hypothesis of declarative memory function considers the HC as an ‘index’ - a map of memory elements
the hippocampal “index model”
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
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
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
during retrieval of word memories that were formed in combination with sound stimuli, the ___ cortex is reactivated
auditory cortex
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
memory encoding: we see greater IFG activity during ___ (deep) compared to ___ (shallow) strategy use
semantic (deep) ; phonological (shallow)
more left IFG activity during ___ vs. ___ memory encoding
semantic vs. sound
true or false: L IFG activity is weaker during memory retrieval
false ; stronger
correctly remembered word trials showed much more ___ activity
L IFG
clearly recalled items are associated with more ___ parietal activity
ventral parietal
low-confidence items are associated with more ___ parietal activity
dorsal parietal
encoding has been linked to
left IFG
retrieval has been linked to
left IFG and posterior parietal cortex
both retrieval and encoding are somehow connected with the ___, which stores the “index” of an event
hippocampus
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
memory consolidation has been shown to involve ___ and ___ scales that vary widely
spatial and temporal
both ___ (receptors, dendrites) and ___ processes (large cortical networks) are involved in memory consolidation
subcellular and systemic processes
one likely component to consolidation
sleep
selectively interrupting different stages of sleep reveals that stage 4 “___” sleep is especially critical to memory retention the following day
“slow-wave”
learned spatial associations that were ___ during slow wave sleep were remembered better in human trials
re-cued
how do we determine which things to remember and which to forget?
it’s unclear
true or false: the information that ultimately remains available for retrieval may tend to be that which is reactivated during sleep
true
neurocognitive processing during sleep can benefit memory storage when memories are covertly cued via ___ and ___ stimulation
auditory and olfactory
memories are gradually altered over time through ___
reconsolidation
the stored memory is stable; the “original” copy is read out at retrieval
classic view of reconsolidation
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
ex. of reconsolidation
memories that are repeatedly recounted tend to put the narrator in a better light
