Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
297 Cards in this Set
- Front
- Back
|
What is memory for?
|
• Learning facts and keeping track
Information about the world … about objects … about situations … about language Information about ourselves … who we are … what we have experienced |
|
|
-can't make new memories
-remembers old stuff |
anterograde memory
|
|
|
-can learn now
-can't remember old stuff |
retrograde memory
|
|
|
what was the key point of karl lashley's work
|
worked with rats. trained them to do maze. removed small portion of brains. rats did fine. didn't matter where in brain.
*no localization of memories* |
|
|
what was the key point of penfields work
|
*storage of memories not localized in the brain
*stored across the cortex (Penfield thought temporal region was important bc of woman who heard music when this part of her brain was stimulated....wrong) |
|
|
medial temporal lobe (includes portions of hippocampus and other regions...) is important for
|
memory, amnesia
|
|
|
HM suffered intratable __ perhaps due to a bike accident at age 7.
|
epilepsy
|
|
|
in 1953, dr. scovile localized HM's epilepsy to __ and suggested surgical resection
|
MTL
|
|
|
Scoville removed parts of HM's MTL on both sides of his brain. HM lost__.
|
approximately two-thirds of his hippocampus, parahippocampal gyrus (and
all his entorhinal cortex) was destroyed, and amygdala. |
|
|
His hippocampus appears entirely nonfunctional because the remaining 2
cm of hippocampal tissue is atrophic and because the entire _________ (forming the major sensory input to the hippocampus) was destroyed. |
entorhinal
|
|
|
After the surgery he suffered from severe __amnesia: although
his short-term memory was intact, he could not commit new events to longterm memory. |
anterograde
|
|
|
HM also suffered moderate ______amnesia, and could
not remember most events in the 3-4 day period before surgery, and some events up to 11 years before. |
retrograde
|
|
|
However, his ability to form ___was still intact; thus he could, as an example, learn
new ____, despite not being able to remember learning them. |
long-term procedural memories
motor skills |
|
|
The selective nature of HM’s
disorder. Almost entirely restricted to _____. |
memory
|
|
|
He has _____damage restricted to the _____.
Such surgeries have never again been done in humans |
bilateral
MTL |
|
|
HM’s perceptual, motor and
cognitive functions are _____. |
intact
|
|
|
HM performs ________on tests of visual acuity
|
normally
|
|
|
HM can ____and _____objects
|
recognize
name |
|
|
HM had ___than average IQ before operation and IQ
___slightly afterward |
higher
rose |
|
|
HM's language capacities largely ___.
|
intact
|
|
|
HM's sense of humor ______
• Spatial capacities not depending on memory are _____. • ________ for most types of new learning |
intact
mixed Almost no capacity |
|
|
Overall: very pronounced memory problems beyond
|
short-term (working) memory
|
|
|
• In HM Childhood memories, including memory for English
language ______ • Some_______ for the period just before the surgery • Immediate or short-term memory ____ • Memory deficit immediately apparent after _________. |
intact
retrograde loss intact short-term period elapses |
|
|
Exceptions to new learning
problems: __________ • Intact mirror drawing learning, despite not being able to recall taking the test • This was a revelation in the field of memory research (aka Lashley hypothesis) • This is acquisition of a skill |
mirror drawing
|
|
|
Exceptions to new learning
problems: ___________ • The serial reaction time task measures learning in terms of Reaction time (RT) to respond to a sequence of flashes • When flashes are really random, no RT speeding with practice • When flashes obey “hidden” sequences then the subject becomes sensitive to this and shows speeding of RT • This represents the acquisition of a skill |
sequence learning
|
|
|
Exceptions to new learning
problems: __________ • Weather Prediction Paradigm • On each trial, subject is shown 1 to 3 cards • Must indicate if cards predict rain or sunshine • Outcome is shown • Outcome is probabilistically related to cards • This makes it too difficult to learn using “explicit awareness” • You learn it procedurally, as a skill, see later lectures Intact procedural but impaired declarative memory • Amnesics learn to predict the weather almost as well as controls! • And much better than Parkinson’s patients (with basal ganglia damage) • But amnesics remember almost no facts about the testing episode Weather Prediction Facts about episode |
procedural learning
|
|
|
Intact procedural but impaired
______ • Amnesics learn to predict the weather almost as well as controls! • And much better than Parkinson’s patients (with basal ganglia damage) • But amnesics remember almost no facts about the testing episode |
declarative memory
|
|
|
Against Lashley’s view that cognition (and memory) is well
distributed throughout the brain, research on HM showed that it can be _____, and that all sorts of dissociations amongst memory systems are possible |
localized
|
|
|
the brain's ability to change as reult of experience
|
plasticity
|
|
|
memory for info currently held "in mind" has limited capacity
|
STM
|
|
|
memory for info that is stored but need not be consciously accessible; has an essentially unlimited capacity
|
longer term memory
|
|
|
silently mouthing words while performing some other task (typically memeory task)
|
articulatory suppression
|
|
|
a system for the temporary storage and manipulation of info
|
working memory
|
|
|
memories that can be consciously accessed
|
declarative memory
|
|
|
memories that cannot be consciously accessed (eg procedural memory)
|
non-declarative memory
|
|
|
explicit memory=
|
declartive memory
|
|
|
implicit memory
|
=nondeclarative memory
|
|
|
memory for skills such as riding a bike
|
proceduaral memory
|
|
|
conceptually based knowledge about he world, including knowledge of people, places the meaning of objects and words
|
semantic memory
|
|
|
memory of specific events in one's own life
|
episodic memory
|
|
|
memory for events that have occured after brain damage
|
anterograde memory
|
|
|
memory for events that occured before brain damage
|
retrograde memory
|
|
|
amnesia arising from long term alcoholism
|
korakoff's syndrome
|
|
|
the process by which moment to moment changes in brain activity are translated into permaneent structural changes in the brain
|
consolidation
|
|
|
an increase in the long term responsiveness of a postsynaptic neuron in response to stimulation of a persynaptic neuron
|
long term potentiation (LTP)
|
|
|
the observation that memories from early in life tend to be preserved in amnesia
|
ribot's law
|
|
|
a memory test in which participants must decide whether a stimulus was/was not shown on a particular occasion
|
recognition memory
|
|
|
participants must produce previously seen stimuli without a full prompt being given (compare recognition memory)
|
recall
|
|
|
context free memory in which the recognized item just feels familar
|
familiarity
|
|
|
context dependent memory that involves remembering specific info from the study episode
|
recollection
|
|
|
info that is processed semantically is more likely to be remembered than info that is processed perceptually
|
levels of processing account
|
|
|
retrieval of a memory causes active inhibition of similar competing memories
|
retrieval induced forgetting
|
|
|
forgetting arising bc of a deliberate intention to forget
|
directed forgetting
|
|
|
the act of remembering consturcted in terms of making interferences about the past based on what is currently known and accessible
|
constructive memory
|
|
|
the process by which retrieved memorie are attributed to their original context
|
source monitoring
|
|
|
a memory that is either partly or wholly inaccurate but is accpted as areal memory by the person doing the remembering
|
false memory
|
|
|
a memory that is false and sometimes self-contradictory without an intention of a lie
|
confabulation
|
|
|
______relates to vocab facts naming faces
takes ____ usually known to depend son the ____: Amnesics very impaired -this relates to higher level of of object recognition |
semantic memory
multiple exposures MTL |
|
|
____ is memory for events
-usually 1 shot kind of memory -known to depend on ___ -can be thought of as a ___ tying together items in your ____ memory relates to emotion eg. ____ memories |
episodic
one shot kind of memory MTL map flashbulb |
|
|
amnesia has a problem with ______
|
consolidation
|
|
|
how moment to moment changes in brain activity are translated into permanent structural changes in the brain
-this relates to how new memories are formed but also can be used to account for ______ if consolidation takes days, wks, even years to achieve brain damage will affect events prior to the injury too -this could aslo explain effects seen with _________ |
consolidation
retrograde memory loss electro convulsive shock (ECT) |
|
|
make holes in memory (recent)
shock brain used to treat serious depression whatever memories are made of takes time |
ECT
|
|
|
recall of events shows a
|
temporal gradient
|
|
|
memories from earlier in life are easier to recall than those from later in life
|
ribot's law
|
|
|
ribot's law can be explained by...
|
consolidation?
also.. -older memories mayb ebecome more like stories and less like episodes -each time an old event is rehearsed a new memory is made, so more resilient |
|
|
cellular mechanisms of consolidation
|
Long term potentiation
|
|
|
can the synapses btw neurons in the hippocampus store information?
-input nerve cell was stimulated electronically -found that high frequency tetanus produced an increase in synaptic strength in hippocampus lasting hours -manifest in increased EPSP |
LTP
|
|
|
2 types of consolidation
|
-fast synaptic consolidation... anywhere in nervous system
-slower system consolidation... esp for hippocampus and declarative memory |
|
|
adding new memory to cortex immediately would produce...
-in this model _____ learns quickly then integrates this info gradually elsewhere without disrupting existing memory |
catastrophic interference
hippocampus |
|
|
How memories may be made:
|
pathways into and out of the MTL
|
|
|
for information in
parietal (P) and temporal (TE) areas, which are influenced by the frontal cortex (FC), to develop into stable longterm memory: |
- neural activity must occur at the
time of learning along projections from these areas to the MTL - first to parahipp, perirhinal cortex and entorhinal cortex - then through several states of hippocampus and back to Parietal and Temporal areas |
|
|
Role of MTL in encoding new
information confirmed with fMRI STUDY: Scan people while they learn new material (e.g. complex color photographs) ...this study showed... |
Activation at time
of scanning predicts what is subsequently remembered |
|
|
Skills and habits=
|
procedural memory
|
|
|
The Weather Prediction paradigm
engages a different kind of memory system: |
the Basal Ganglia (see lectures
on movement) |
|
|
• This is because facts and episodes
aren’t relevant to learning to predict the weather from cards • Instead, it is brain-as-statisticalprocessor; picking up associations between stimuli and responses • This is___________ |
nondeclarative, procedural,
implicit learning - acquiring a skill or habit. |
|
|
an fMRI
experiment feedback baseline baseline feedback 30secs |
Procedural learning
|
|
|
• “Boosting” ___________
led to more response strategy • “Boosting” _________led to even more place strategy This experiement was ______ |
caudate
hippocampus double diss |
|
|
Two types of declarative memory
|
Facts and episodes
|
|
|
MTL as
|
“gatekeeper”
|
|
|
two explicit tests of memory
|
1. tests of recognition
2. tests of recall |
|
|
in ____ memory diff tasks tax diff systems
|
explicit memory
|
|
|
_____ is easier than recall
|
recognition
|
|
|
subjects shown a list of words and then at test:
1. was given word previously preented on the list? (single probe recognition) 2. which of the two words shown togetherwas previously presented? (forced choice recogition) |
tests of recognition
|
|
|
subjects shown a list of words and they recall them in
1. any order (free ___) 2. order given (serial ___) 3. given a prompt (cued ___) |
tests of recall
|
|
|
are subregions of MTL specialized for recognition vs. familiarity?
|
-contentious issue
-fmri data suggest yes -others have argued recollection is just a more vivid form of familiarity |
|
|
fmri study of familiarity vs recollection
|
-subjects shown stream of words
-make animacy (living or nonliving) or size judgement depending on color of the word -after scan subjects make recognition judgement depending on color of the word -after scan , subjects make recognition judgement(1. def new...6. def old) and source memory (red or green) -results: mean proportion of studied ('old') vs unstudied ('new') items endorsed at each confidence level |
|
|
familiarity=
|
rhinal cortex
|
|
|
recollection=
|
1. posterior hippocampus
2. posterior parahippocampal cortex show strong effects |
|
|
familiarity and recollection are ...
|
two diff processes
|
|
|
this study suggests a a _____ btw regions for familiarity (______) and regions for recollection (______)
|
dissociation
rhinal hippocampal parahippocampal |
|
|
why do we forget?
|
forgetting may be important for efficient memory
it is desirable to forget where you parked your car on a particular (previous) day when you parked it in a diff place every day -new info needs to be consolidated -permanent memories take months to lay down -watch tv...calms brain down...drinking alchol...better recall when you drink (moderation...) |
|
|
levels of processing account for forgetting
-info that is prcocessed ____ is more likely to be remembered than info processed ____. |
semantically
perceptually |
|
|
how would you remember better?
house-> big house-> mouse |
1st way
better recall when you process more deeply and give meaning to word |
|
|
forgetting: a prob with encoding or retrieval?
-_______refers to what happens at the time of the stimulus -______ refers to the time of trying to recall or recognize stimulus -difficult to distinguish experimentally...eg you may access a memory right now but you might in the future -it would be wrong to conclude that you hadn't encoded it correctly and it would be wrong to conclude that retrieval as such was the problem -also whether or not people can successfully retrieve a memory also depends subtly on the way they are tested |
encoding
retrieval |
|
|
-memories might fade away _____ (eg weakening of synaptic connection)
-or there might be ___ mechanisms such as strategic contrl via inhibition |
passively
active |
|
|
active, controlled, inhibitory mechanisms are
|
contentious
|
|
|
automatic side effect of act of retrieval is that other items get inhibited
|
retrieval induced forgetting
|
|
|
memories are voluntarily inhibited eg. think/no think paradigm
|
retrieval induced forgetting
|
|
|
memories are volutarily inhibited
|
directed forgetting
|
|
|
Train all cue-target
pairs to 50% performance at test Learn which are suppression cues If green ->Think If red ->Nothink Try to recall all target words, including those for pairs not include in phase 3 |
The Think/no-think paradigm
|
|
|
Results: think/no think
|
recall for NoThink targets
worse than for Think targets • These results are interesting but contentious • Kind of like Freudian repression … • Could suggest that active control mechanism literally inhibits the memory representation of the target word • Perhaps the frontal cortex “stamps” in MTL or other representations …? • This is an example of cognitive (or executive) control - we’ll revisit in later lectures. |
|
|
•False recall of related words
|
False memories
|
|
|
False recall: why?
|
• False recall/recognition may occur because the non-presented
item has features whose memory trace is “reactivated” when the features are primed by other other concepts |
|
|
• Activity in ________has been observed for false recall
|
hippocampus
|
|
|
patients provide memories and information that
is false and even self-contradictory, without intending to lie |
Confabulation:
|
|
|
______have different memory problems from amnesics
• They don’t just forget the story, they embellish |
Confabulators
|
|
|
Confabulation is associated with damage to
|
orbital frontal and
ventromedial frontal cortex rather than MTL |
|
|
Why confabulation?
(3 expl) |
• Failure of retrieval?
• Failure of source monitoring? • Failure of executive control? |
|
|
• Failure of retrieval?
|
– Episodic memories (as opposed to semantic ones) may be
retrieved using a strategy – Damage to OFC will affect the retrieval operation - so inappropriate fragments emerge for the current context |
|
|
• Failure of source monitoring?
|
– Source monitoring refers to attributing memories to their
original context – Requires an evaluation of the context in which the memory was made (was it heard or seen? Was it internally imagined or an external event?) – But usually associated with lateral PFC, not OFC |
|
|
• Failure of executive control?
|
– See later lectures on Executive Control
– Concerns control processes during task performance – But usually associated with lateral PFC, not OFC |
|
|
Frontal cortex is important for memory....
|
retrieval, and interacts with MTL
|
|
|
Recognizing (_____) is different from remembering/knowing
(_____) -It may depend on different sectors of ____ |
familiarity
recall MTL |
|
|
Forgetting is an important aspect of memory
-It could _____ or _____ |
passive
active |
|
|
False memories could be generated through ______
-Could lead to ____representation being activated |
semantic priming
MTL |
|
|
...is something that occurs after frontal damage
|
Confabulation
|
|
|
The_______plays an important role in encoding and retrieval
of memory |
frontal cortex
|
|
|
What is working memory?
• Short-term memory or working memory is memory for information currently held “in mind” - i.e. it’s information that is ______ rather than _____ • Remember: HM has intact memory for immediate items, but as soon as time elapses or he does something else, it’s gone • George Miller famously argued that working memory span is for ___ • It seems possible that this could be true for _____ chunks rather than items • As we’ll see, ___is very important for working memory - in concert with other regions |
active
7 +/- 2 items 7 +/- 2 lateral prefrontal cortex |
|
|
What is working memory? … more
• Baddeley posited that working memory consists of 3 components: |
– Central executive does the encoding and
retrieval – Two slave systems - Phonological buffer, refreshed via the articulatory loop - The visuo-spatial scratch-pad for nonlinguistic information |
|
|
• In reality for working memory there are probably...
|
multiple multiple
“slave” systems; and the relation between these and the “Central Executive” is still unclear |
|
|
Certainly, working memory (or
short term memory) is an important way station between _______ and _______, as we have seen |
sensory information
longterm memory |
|
|
Lateral prefrontal cortex
• An important division is the ________ • Above is the _____ • Below is the ______ • Anterior is______ • There are many more areas in PFC - e.g. Brodmann Areas (defined cytoarchitectonically) • There may or may not be homologous areas in the monkey |
inferior frontal sulcus
dorsolateral PFC (DLPFC) ventrolateral PFC (VLPFC) the anterior PFC (APFC) |
|
|
___________ - goal driven, topdown
attention • The cue designates a location in space, but working memory is needed to keep this ‘online’ for a few seconds |
Endogenous
|
|
|
______ or top-down attention engages
a ___________(both hemispheres) • Demonstrated by many fMRI studies |
Endogenous
dorsal frontoparietal network |
|
|
typically associated with
working memory • Connected to ______via white matter tract |
Dorsolateral PFC
Superior parietal lobe |
|
|
Role of the dorsolateral PFC:
Lesion study in monkeys ______ condition • Monkey displaces one object of 3 to get to food well • At test: one between one of the prior nonchosen objects and the prior chosen one; monkey must choose previously non-chosen object to get reward (must monitor prior choice across time) _______condition • Monkey displaces one object of 3 to get to food well • At test: chosen object is presented along with new one; monkey must select the chosen one (doesn’t require monitoring, just recognition) |
Recognition
Monitoring |
|
|
Dorsolateral PFC important for
_____not ________. |
monitoring
recognition |
|
|
• affect monitoring but not
recognition |
MDL - mid-dorsolateral PFC
lesions |
|
|
• have no
effect, and there is no effect on NC (normal control) animals |
PA - periarcuate lesions (more
ventral and posterior) |
|
|
• ______ is
important for monitoring/maintenance but not for recognition |
dorsolateral PFC
|
|
|
______is probably important for
recognition |
MTL
|
|
|
In ________ Subject sorts cards according to number, color or
object rule • After some time, experimenter says “wrong” and subject must stop sorting with that rule and find the new one • Lesions to_______ produce many persevative errors after the change of rule - the subject keeps sorting according to the previously correct (but currently incorrect) rule • Part of the problem probably relates to poor _____- but things are more complicated as we’ll see in lectures on Executive Function |
Wisconsin Card Sort Test
dorsolateral PFC working memory |
|
|
• Monkey remembers where food is across
a delay period • Neuron in DLPFC fires strongly during delay period |
Single unit recording in monkeys:
delayed recall |
|
|
Neural responses do
occur at stimulus presentation and at response and at reset, but they are strongly sustained throughout the delay period |
Single unit recording: Oculomotor
delayed response |
|
|
How does working memory work?
|
Prefrontal cortex may be temporary
repository for “active” material • May communicate with posterior sensory areas to retrieve, rehearse and maintain information • Consistent with extensive connectivity with posterior sensory areas |
|
|
fMRI study with the N-back task
|
• The authors compare 0-back with
1-back with 2-back with 3-back • On each trial there are several fMRI scans to get a measure of the stimulus, response and delay periods • The design allows one to examine the effect of time and of working memory load • Brain regions that “care” about working memory maintenance should show sustained activation across time; those that “care” about visual and response aspects should change with time |
|
|
Dorsolateral PFC maintains activity
|
• The authors perform two
analyses: – 1. Which regions show an increase of fMRI signal with increasing load? – 2. Which regions show increased signal for scans 2 and 3 vs. 1 and 4? |
|
|
Visual and other cortical areas
showed an effect of _____- i.e. they were sensitive to the stimulus • DLFPC and SMG (parietal) showed an effect of ____- I.e. they are relate to holding memory information in mind across time |
time
load |
|
|
________
showed an effect of load - I.e. they are relate to holding memory information in mind across time |
DLFPC and SMG (parietal)
|
|
|
A similar study: DLPFC activity
________with _______memory load |
increases
increasing |
|
|
in terms of awareness, ownership, plan as to what you want to do
|
action (vs. movement)
|
|
|
-tons of ways to pick up your keys
-potentially infinite number of solutions -you can calculate and action from scratch each time |
degrees of freedom problem
|
|
|
-specification or pattern of muscles
-higher level script for motor commands (single muscle program) -eg. handwriting does not change when you use an effector |
motor programs
|
|
|
handwriting does not change when you use _________...use other hand, still looks like your handwriting
|
effector
|
|
|
actions are directed towards
|
objects
|
|
|
-can't act in a vacuum (need objects)
-need visuomotor or sensory motor integration -incorporate ____ and ____ visual system pathways |
what
where |
|
|
what pathway
|
ventral
|
|
|
where pathway
|
dorsal
|
|
|
incoporate where your body parts are
|
proprioception
|
|
|
bringing together of sensory and motor info for action
|
sensory motor transformation
|
|
|
frontal lobe=
|
primary motor
|
|
|
-antieror to primary somatosensory cortex and posterior to premotor cortex
|
primary motor cortex
|
|
|
-there is a homunculus in the ________ for control of body parts, just as there is in _________
|
motor cortex
somatosensory cortex |
|
|
In the primary motor cortex
-areas such as the ___ have larger representation bc of fine control |
hand
|
|
|
In the primary motor cortex
___ controls right side of the body and vice versa |
Left M1
|
|
|
damage to one side of the brain affecting M1 thus produces ____ (paralyzed on 2 side of the body)
|
hemiplegia
|
|
|
motor cortex contains _________ for specififying voluntary movements of body parts.
projects down the ______ |
motor programs
corticospinal tract |
|
|
motor programs are collections of lots of neurons which encode *specific movements* via
|
patterns of muscle activation
|
|
|
eyes are unusual- are controlled by _________ in laeteral superior frontal gyrus (avove superior frontal sulcus) and not by M1
|
frontal eye fields
|
|
|
Axons in M1 project down the white matter tract bundles into
|
1. pons (jaw and face)
2. cervical level of the spinal cord (hand) 3. lumbar level (legs, feet, trunk) |
|
|
Brain machine interface in
|
M1
|
|
|
neural signals in ____ may be sufficient to control simple prosthetic devices
|
M1
-arms plugged into primary motor cortex (implant into primary motor cortex) -moves arms by thinking |
|
|
Anterior to M1 is the premotor cortex which has two major divisions
|
1. lateral permotor cortex
2. medial premotor (supplementary motor area= SMA) |
|
|
role of lateral premotor cortex
|
Lateral premotor: acts with objects in
the environment (reaching for pen): more externalised |
|
|
– Lateral premotor cortex has _____than the motor
programs of M1 - not just muscle representation but set of movements (e.g. grasp) |
motor plans at a higher level
|
|
|
role of SMA:
|
deals with spontaneous welllearned
actions, more internalised |
|
|
TMS shows _________ in function
for SMA vs M1 |
dissociation
|
|
|
• TMS delivered over SMA and M1 in 3
conditions: – “simple” button press – “scale” buttons presses – “complex” - playing a prelearned musical piece • TMS over SMA disrupted complex only • TMS over M1 disrupted simple and scale Conclusion=??? |
• Conclusion: SMA has critical role in
organizing forthcoming movements in complex motor sequences that are rehearsed from memory (i.,e. internal plans) |
|
|
Prefrontal cortex (PFC) lies ______to premotor cortex
|
anterior
|
|
|
PFC regions are involved in _____ cognition rather than action
specifically |
“higher”
|
|
|
Premotor regions prepare actions (to ________ triggered
events) |
internally or externally
|
|
|
Prefrontal cortex mediates their selection and
|
working memory
maintenance |
|
|
Prefrontal cortex and motor
planning Frontal lobe damage does not impair movement or execution of actions per se • Instead, ... Symptoms of frontal damage: 1. 2. |
the actions become
poorly organized - do not necessarily reflect the goals of the subject (“frontal apraxia”) • Symptoms of frontal damage: – Perseveration – Utilization behavior |
|
|
Goal driven action: the supervisory
attention system (SAS) • Key distinction: actions performed ________ vs those that require some ________ |
automatically
online control |
|
|
Driving a car can be very automatic:
changing gear, stopping, going, turning are presumably driven by ______ - without the need for much awareness • But parking in a narrow space requires an interruption of automatic behavior, and setting up of a novel sequence -> _________ |
motor schemas
control |
|
|
The SAS model describes the
relationship between automatic schemas, the control system and motor output in terms of ________ |
contention scheduling
|
|
|
Goal driven action=
|
the supervisory
attention system (SAS) |
|
|
The Supervisory Attentional System likely
has its home |
in the frontal cortex
|
|
|
The frontal cortex exerts “executive
control” over: (4) |
– Premotor cortex (motor plans),
– primary motor cortex (motor programs), – posterior cortex (e.g. parietal and temporal representations) – Subcortical regions (e.g. basal ganglia) |
|
|
________ is:
(Miller and Cohen, 2001) The optimization, by prefrontal cortex, of cognitive, sensory or motor processing in posterior cortical and subcortical modules |
Executive Control
|
|
|
The SAS model accounts for ______ after brain damage
|
action impairments
|
|
|
Damage to frontal cortex produces symptoms of
_______ behavior by damaging the putative Supervisory Attentional System • Partly could relate to working memory problems, but … • Automatic schemas or habits or routines run wild without .... |
Perseveration and Utilization
...appropriate contention scheduling and SAS monitoring |
|
|
• Subjects sits in front of a oscilloscope timer with a rotating dot. EEG electrodes on scalp.
• Subject presses a button (or moves wrist) within a certain time frame. • No limits placed on # times subject could perform the action within this period. • During the experiment, the subject noted the position of the dot on the oscilloscope timer when "he/she was first aware of the wish or urge to act" • Pressing the button records position of dot on the oscillator, electronically. • By comparing the marked time of the button's pushing and the subject's conscious decision to act, researchers were able to calculate the total time of the trial from the subject's initial volition through to the resultant action. • On average, approximately ____ elapsed between the first appearance of conscious will to press the button and the act of pressing it. • Brain activity involved in the initiation of the action, primarily centered in the SMA, occurred, on average, around ____ before the trial ended with the pushing of the button. • So, researchers recorded mounting brain activity related to the resultant action as many as ___before subject reported first awareness of conscious will to act. • So, apparently conscious decisions to act were preceded by an unconscious buildup of electrical charge within the brain - ______________ |
200ms
500ms 300ms the Bereitschaftspotential or readiness potential. |
|
|
– ______is at the apex
in terms of conceptual cognitive plans – It organizes, selects, controls lower-level motor plans and programs, e.g. in premotor cortex – ______generates plan for motor programs – Activation of arm and other effectors occurs via _______ |
prefrontal
Premotor primary motor cortex |
|
|
- higher plans and
working memory |
Prefrontal
|
|
|
internally generated
actions |
SMA
|
|
|
externally
generated actions |
• Lateral premotor
|
|
|
motor programs and
movement execution |
M1
|
|
|
semantic
memory for object names and concepts |
Hippocampus
|
|
|
where, how and visuomotor integration
|
Parietal cortex
|
|
|
e.g. V5 - motion area
|
Occipital regions,
|
|
|
fine timing
|
Cerebelleum
|
|
|
Why is it impossible to tickle
yourself? |
A sense of ownership over one!s actions
could be maintained by predicting the sensory outcomes of our actions |
|
|
This can happen via a ______
• A representation of the motor command ("efference copy!) is used to predict the sensory consequences of action • This could explain why tickling yourself doesn!t work - you sensory system gets a copy of the motor command before it occurs! |
forward model
|
|
|
Our actions vs others’ actions
• Mimicry vs imitation • Humans may reproduce (and understand?) the actions of others by imitation, i.e. by representing the goal state. • An important finding in neuroscience relevant to our understanding of the goal state and action is the discovery of _____ • An important finding was that neurons within region F5 of the monkey brain ___ as well as the _________ show increased activity for goal-directed action • Both when monkey performs a goal-directed action or when it views a human or another monkey performing a goal-directed action • It is not certain what is the corresponding region in the human brain, but it may include ventral premotor cortex as well Broca!s region (or Brodmann area 44) |
mirror neurons, or the mirror
system. (ventral lateral premotor cortex) parietal lobe |
|
|
An important finding was that
neurons within region F5 of the monkey brain (ventral lateral premotor cortex) as well as the parietal lobe show increased activity for _________ |
goal-directed action
|
|
|
Both when monkey performs a
goal-directed action or when it views a human or another monkey performing a___________ |
goal-directed action
|
|
|
It is not certain what is the
corresponding region in the human brain, but it may include |
ventral
premotor cortex as well Broca!s region (or Brodmann area 44) |
|
|
• A mirror neuron in F5
responds strongly when the human movement is a _______ - i.e. to grasp the object • The neuron also responds strongly when the monkey makes the _____ Monkey observing human action • A mirror neuron in F5 responds strongly when the human movement is a goaldriven action - i.e. to grasp the object • When there is no object the neuron hardly cares. • The neuron does care about goal-driven action even when the final destination is obscured by a screen - as long as monkey saw the object there beforehand • Neuron does not care about the reach if there is no object |
goaldriven action
goal-directed movement too |
|
|
What vs. where/how
• The _______ has been characterized as “Where”, but it can also be characterized as “How” if we emphasize output (action) rather than input (perception) • Remember: damage to visual stream causes apperceptive agnosia - this is a problem with ________ • Damage to dorsal stream (parietal lobe) produces _______ but also severe problems with acting towards objects (especially under visual guidance) - optic ataxia • This is a probem with __________ |
dorsal visual pathway
object recognition attentional neglect sensory-motor integration |
|
|
Typically, left parietal
damage affects _______ and vice-versa The deficit is not purely motoric (“bad” hand functions ok in “good part” side of space ) and not purely visual (“good” hand functions poorly in “bad side” of space). Instead, such patients have profound problems ________ sensory input (visual) with the motor system |
right hand
integrating |
|
|
• 3D structural description of the object
(tool) is computed based on grouping of parts (edges, form, depth, etc.) • The representation is probably in the typical (normalized) view and it probably located in ______ • The tool will have access to semantic representations (e.g. what to do with it) and have a name - probably a function of the medial temporal lobe • But tools are different from other objects in that they have specific gestures associated with them - likely stored in _________ - perhaps because most people are right handed |
infero-temporal cortex - ventral
visual stream left inferior parietal lobe |
|
|
Left inferior parietal cortex and ideomotor apraxia
• Subjects had to generate either an action or a name in response to an object, OR they had to generate an action or a name in response to an action • Generating an action to an object (pantomiming) activated ________ • Patients who cannot produce an appropriate action on command or to a visual object (or picture of an object) have ______ |
left inferior parietal cortex
ideomotor apraxia |
|
|
Basal ganglia anatomy
5 key structures: |
• Caudate
• Putamen • Globus Pallidus • Subthalamic Nucleus • Substanta Nigra |
|
|
Basal ganglia circuitry
• There are excitatory and inhibitory connections • Cortex send projection to striatum (glutamate) • Striatum sends _________ projections to Gpe and Gpi (GABA) • Gpe and Gpi send _____ connections on to thalamus • Thalamus sends ________ connection on to cortex |
excitatory
inhibitory inhibitory excitatory |
|
|
Movements are selected by means
of the |
direct pathway
|
|
|
Striatum inhibits Gpi, thus removing
inhibition on thalamus, and increasing |
thalamocortical drive
|
|
|
Movements can be inhibited by the
|
indirect pathway
|
|
|
Striatum inhibits Gpe, thus removing
inhibition on Gpi, thus increasing inhibition on thalamus, and decreasing |
thalamocortical drive
|
|
|
• Single gene, genetic disorder
• Autosomal dominant • 5 to 10 per 100 000 • Leads to massive striatal cell loss (and cortical loss too) • Choreic movements |
HD
|
|
|
- classic HD symptom
- involuntary ‘writhing’ |
Choreic movements
|
|
|
______relates to loss of striatal
projection neurons to pallidum |
Chorea
|
|
|
_______ lead to
loss of projection neurons to globus pallidus (especially Gpe) • This affects the _______ • Means the “braking” of movements is weak - so motor commands are disinhibited - i.e. chorea |
Loss of striatal cells
indirect pathway |
|
|
• Affects 0.15% of the population
• Rigidity, dystonia, bradykinesia • Aetiology uncertain - multiple factors • Neuropathology now well understood - partly because of MPTP • These people developed ..after ingesting the drug • Leads, like ..., to loss of dopamine cells from substantia nigra pars compacta - which project to striatum |
Parkinsons D
|
|
|
_____ caused by loss of dopamine
neurons projecting to striatum |
PD
|
|
|
• Loss of enervation of striatum
leads to abnormal ability for subjects to initiate movements via cortical-striatal circuits • Direct pathway drive is too weak • Gpi is not inhibited enough • Gpi output to thalamus too strong • Thalamocortical output weak |
Direct pathway is too weak
|
|
|
Why the basal ganglia?
• Most movements are executed via M1 • So why are the basal ganglia needed? |
• Answer: They allow complex
interchanges between cognitive, motor, emotional, and motivational information • All this kind of processing is brought to bear to determine the best response |
|
|
They let through the response that is most “active” in
terms of best fitting goals, emotion, and motivation (think dam) |
Basal ganglia act as a response
selection device |
|
|
PFC reaches largest relative
size in ______ • Comprises 1/3 of cortex |
humans
|
|
|
Increase in PFC must relate
to (and parallel) |
language,
abstract representation, planning and thinking |
|
|
We do these things so much
better than the great apes and we have a much ____ • PFC damage affects these functions, but not much else |
bigger
PFC |
|
|
Major Sulci of PFC
|
• Precentral
• Superior frontal • Inferior frontal • Sylvian |
|
|
Major Gyri of PFC
|
• Superior frontal gyrus
• Middle frontal gyrus • Inferior frontal gyrus |
|
|
• The pattern of direct connectivity, via white matter
association and projection pathways is complex • Two examples we’ve already seen concern: - prefrontal to striatum connections - prefrontal to parietal connections • PFC has other extensive connections with other brain regions, and there is an extensive pattern of connectivity within PFC, but that is beyond this course. |
Connectivity of PFC to other
brain regions |
|
|
DLPFC and VLPFC connect to
parietal lobe • _____for stimulus-driven attention • ________ for top-down attention |
Ventral fronto-parietal
connection Dorsal fronto-parietal connection |
|
|
So what does the PFC do?
|
• We have already seen that it’s important for:
– Spatial attention (e.g. top-down attention) – Working memory maintenance across delay – Short-term (working) memory to facilitate encoding and retrieval of material via MTL and cortical networks • Higher-level representations of action plans and schemas to enable movement and behavior |
|
|
• Another, similar, way of thinking about
executive functions is in terms of automatic vs controlled • As we saw before, this is how the Supervisory Attentional System is supposed to work: • Sensory information can automatically trigger associated motor programs, leading to movement, but when there’s a conflict, or unusual situation, the SAS kicks in and does contention scheduling • We could regard the SAS as a set of executive functions |
Automatic/habitual vs controlled
|
|
|
1. Situations involving planning and decision making
2. Situations involving error correction and trouble shooting 3. Situations where responses are not well-learned or contain novel sequences 4. Situations judged dangerous or technically difficult 5. Situations requiring overcoming strong habitual responses or resisting temptation |
Executive functions in practice
• There are a few real world scenarios where control over automatic tendencies is needed: |
|
|
• The “Stockings of
Cambridge” • Subjects inspects the display • This is a 3-move problem • Subjects decides (in head) exactly which moves to get yellow ball into right hand pocket |
Tasks of planning and decision making
|
|
|
• The Wisconsin Card Sort Test requires subject to
sort a new card on each trial according to 3 possible rules – Number, Color or Shape • Experimenter says, “correct”, “correct”, “correct”, but suddenly, “wrong” • Subject has to register the error, control the tendency to sort on the previously correct rule, remember what she previously did, remember the currently relevant rules, choose a new one • The experimenter could say “correct” or “wrong” on the next trial • Depending, the subject has to process this new |
Tasks of error-correction and
trouble shooting |
|
|
• Requires subject to develop a strategy to deal with a
novel situation • E.g. the F-A-S test • Subject asked to produce as many words as possible beginning with a given letter, e.g. “F” • Do not use proper names • Do not repeat words • Do not repeat related words such as “fast” and “fasting” |
Novel situations
|
|
|
• Driving car vs parking car in tight spot
• Danger is typically associated with arousal and emotion • Emotional/arousing signals may engage the ______ and feed into VLPFC and DLPFC to generate response control • In this way, automatic or habitual responding could be overriden |
Dangerous or difficult situations
ventromedial/orbital |
|
|
Overcoming habitual responses
• This can be tested in many ways: |
- Stroop paradigm
- Eriksen Flanker task - Go/NoGo or Stop signal |
|
|
• Subject responds to central letter in
display, here it “S” • Central letter can be flanked with congruent letters, i.e Ss or incongruent ones, i.e. Hs • Reaction Time and error rate is longer for incongruent compared to congruent condition • In incongruent condition, there is _________ and control is needed to ensure the correct response |
The Eriksen Flanker Test
response interference |
|
|
DLFPC and
|
memory maintenance/monitoring
|
|
|
Dorsomedial and
|
conflict monitoring
|
|
|
Orbital (ventromedial)
and |
decision-making
|
|
|
Ventrolateral and
|
inhibition
|
|
|
Anterior frontal and
|
higher-level goals
|
|
|
Dorsolateral PFC and
monitoring/maintenance of memory • DLPFC is BAs 46 and 9 • We’ve seen in prior lectures that DLPFC is important for working memory ______- i.e. what are the rules of the task? What am I doing now? Which object was the relevant one? |
maintenance
|
|
|
• Monkey displaces one object of 3
to get to food well • At test: one between one of the prior nonchosen objects and the prior chosen one; monkey must choose previously non-chosen object to get reward (must monitor prior choice across time) |
Monitoring condition
|
|
|
• Monkey displaces one object
of 3 to get to food well • At test: chosen object is presented along with new one; monkey must select the chosen one (doesn’t require monitoring, just recognition) |
Recognition condition
|
|
|
Dorsolateral PFC important for
monitoring not |
recognition
|
|
|
• _________ PFC lesions
affect monitoring but not recognition • ______ have no effect, and there is no effect on NC (normal control) animals • Thus ________ is important for monitoring/maintenance but not for recognition • ___is probably important for recognition |
MDL - mid-dorsolateral
PA - periarcuate lesions (more ventral and posterior) dorsolateral PFC MTL |
|
|
• Monitoring is a variant
of working memory maintenance • Although some have argued that monitoring and maintenance are different functions (see your book) • Neural responses in monkey DLFPC strongly maintained across the memory delay |
Single unit recording: Oculomotor
delayed response |
|
|
DLPFC activity increases with
increasing |
memory load
|
|
|
___damage affects
Wisconsin Card Sort • Human subjects with ______ lesions are impaired at shifting their response to a new rule after negative feedback • Trouble maintaining task rules? • Trouble monitoring self and environment? |
DLPFC DLPFC
|
|
|
• ____frontal cortex
comprises: – BA 24/32 (aka Anterior Cingulate aka ACC) and – pre-Supplementary motor area (aka, preSMA, aka medial premotor, BA 6) |
Dorsomedial
|
|
|
Dorsomedial frontal cortex and
|
“conflict monitoring”
|
|
|
The dorsomedial frontal cortex is
typically activated for ___ • In the Stroop task incongruent trials are contrasted with congruent trials • RT is slower on incongruent trials • fMRI signal is increased in preSMA and ACC |
“conflict”
|
|
|
measures
voltage at surface of skull • Raw time-course at dozens of electrodes is voltage across time (relative to a reference electrode on back of neck) |
EEG
|
|
|
• EEG signal is really noisy
(treat as 1 trial) • ______is event-related potential • You get it by averaging trials • 10, less noisy • 100 averaged trials starts to have a typical pattern of positive and negative peaks |
ERP
|
|
|
Many ERP studies have shown an
“error” or “conflict” response over |
dorsomedial PFC
|
|
|
• In Stroop and other conflict
tasks you average, e.g. 100 incongruent trials and e.g. 100 congruent trials • Large _____ negativity (on incongruent trials with mistake) found over dorsomedial electrodes • This is a form of conflict signal |
“error-related”
|
|
|
• Stimuli consist of face plus name
• Sometimes incongruent, sometimes congruent • Face activates …. - fusiform face area! • Word activates …. - gotcha! -word form area |
fMRI experiment investigates
how conflict may generate control |
|
|
How conflict-monitoring *may*
generate control • These results are a cartoon …. • On a high-conflict trial (incongruent), ACC is activated • Supposedly recruits DLPFC which sends ____ to FFA or to Word Area to ______the processing Hence …. Dorso-medial frontal cortex |
topdown signals to
increase |
|
|
Problems with this study
|
• Not clear that how DLPFC is
connected to FFA and Word Area • Not clear that ACC signals conflict and then recruits DLPFC, as opposed to other way round • Not clear exactly what is role of DLFPC -working memory for tasks - top down signals (how?) |
|
|
_______
cortex corresponds to BA 11 • Phineas Gage is the famous case in history • Selective damage to orbital frontal cortex left him with profound problems with decision-making, especially involving risk and social situations • But remainder of |
• Orbital (or ventromedial) frontal
|
|
|
• ______is intimately wired up with the limbic (emotion
processing) areas of the brain - see later lectures • It may send an “emotional” input into the deliberative process |
OFC
|
|
|
• Emotion processing can be
measured autonomically, e.g. via the galvanic skin response (GSR) • Voltage at skin changes with more sweating • It is reported that patients with OFC damage show less (or no) GSR response to emotional stimuli • Hence - their decision-making may be impaired because they don’t get the “body markers” |
The “somatic marker hypothesis”
|
|
|
there are potentially infininite number of motor solutions for acting on object
|
degrees of freedom problem
|
|
|
there are potentially an infinite number of motor solutions for acting on an object
|
degrees of freedom problem
|
|
|
a stored routine that specifies certain mtor parameters of an action (eg. relative time of strokes)
|
motor program
|
|
|
a cluster of perceptual processes that relate to the skin and body and includes touch pain theraml sensation and limb postion
|
somatosensation
|
|
|
knowledge of the position of the limbs in psace
|
proprioception
|
|
|
linking together of perceputual knowledge of objects in space and knowledge of the position of one's body to enable objects to be acted on
|
sensory motor transformation
|
|
|
the problem of explaining volitional acts without assuming a cognitive processt hat is itself volitional ("a man within a man")
|
homuculus problem
|
|
|
responsible for execution of voluntary movements of the body
|
primary motor cortex
|
|
|
damage to one side of the primary motor cortex results in a failure ot voluntarily move the other sid eof the body
|
hemiplegia
|
|
|
responsible for voluntary movement of the eyes
|
frontal eye fields
|
|
|
the lateral area is important for the linking action with objects int he enviornment the medial area is known as the supplementary motor area and deals with well learned actions and action sequences
|
premotor cortex
|
|
|
deals iwth well-learned actions particularly action sequences that do not place strong demands on monitoring the enviornment
|
supplementary motor area (SMA)
|
|
|
repeatng an action that has already been performed and is no longer relevant
|
perservation
|
|
|
impulsively acting on irrelevant objects in the enviornment
|
utilization behavior
|
|
|
an organized set of stored info (eg familiar action routines)
|
schema
|
|
|
the mechanism that selelcts on particular schema to be enacted form a host of competing schemas
|
contention scheduling
|
|
|
failure in tasks of routine activity that involve setting up and maintaining diff subgoals but with no basic deficits in object recognition or gesturing the use of isolated objects (also called action disorganization syndrome)
|
frontal apraxia
|
|
|
a representiation of the motor command (a so-called "efference copy") is used to predict the sensory consequences of a n action
|
forward model
|
|
|
the ability to reproduce the behavior of another through obervation
|
imitation
|
|
|
a neuron that responds to goal directed actions performed by oneself or by others
|
mirror neuron
|
|
|
an impairment of visually guided reaching
|
optic ataxia
|
|
|
a sensation that amputated or paralysed limb is still present
|
phantom limb
|
|
|
an object that affords certain actions for specific goals
|
tool
|
|
|
an in ability to produce appropriate gestures on command given either an obect, a word, or a command
|
ideomotor apraxia
|
|
|
certain structural properties of objects imply certain usages
|
affordances
|
|
|
a disease associated iwth basal ganglia and characteried by a lacck o self initiated movement
|
parkinson's disease
|
|
|
a test of exectutive functions involving rule induction and rule use
|
wisconsin card sorting
|
|
|
response interference from naming the ink colour of written color name (eg word blue is printed in red ink and participants asked to say ink color ie red)
|
stroop test
|
|
|
a model of executive functions that assumes that controlled behavior arises through selection and implementation of schemas
|
supervisory system model
|
|
|
remembering to do things in the future (eg to deliver sthing or take meds)
|
prospective memory
|
|
|
the prcoess of relating info currently held in mind back to the task requirements
|
monitoring
|
|
|
retaining focus on the task requirements over a period of time
|
sustained attention
|
|
|
a working memory task; the participant must decide whether the currently presented sitmulus is the same as the one persented immediately before (1back) or two items ibefore (2back) or three items before (3back)
|
N-back task
|
|
|
carrying out several tasks in sucession; requires both task switching and maintaing future goals while current goals are being dealt with
|
multitasking
|
|
|
an electrical potential (error potential) that can be detected a the scalp when an error is made
|
error related negativity
|
|
|
a situation in which a perpotent incorrect response needs to be overcome to perform a task successfully (as in stroop color naming)
|
response conflict
|
|
|
discarding a pervious schema and establishing a new one
|
task switching
|
