Final Remaining Flashcards
Utilization behavior
exaggerated tendency for one’s behavior to be determined by the external environment
behavior automatically determined by salient stimuli in environment
damage to IFG (Inferior Frontal Gyrus)
Imitation Behavior
Copying environmental stimuli
Utilization behavior
Environmental Dependency Syndrome
Behaviors determined by environment as opposed to willful action
Damage to IFG (Inferior Frontal Gyrus)
Damage to Inferior Frontal Gyrus (IFG)
Inferior Frontal Gyrus
damage to IFG demonstrate utilization behavior
will spontaneously mimic actions
Dorsolateral Prefrontal Cortex
Brenda Milner identified dPFC role in cognitive control through Wisconsin Card Sorting Task (WCST)
perseverative error: error of inhibition
patient “can’t stop himself”
could verbalize proper response but couldn’t could not modify skeletomotor responses accordingly
recruit epilepsy patients pre/post unilateral cortical incision
perseverative error: error of inhibition
patient “can’t stop himself”
could verbalize proper response but couldn’t could not modify skeletomotor responses accordingly
Pavlovian Threat Conditioning
Classical conditioning
US, CS + NS pairing, CS alone elicits CR,
Amygdala plays role in learning fear response
Le Doux
Threat processing circuit
Lateral Nucleus = association formation
Central Nucleus = downstream response
plasticity in lateral nucleus is what allows it to encode and store the associations between the CS and US
Amygdala = structure = consists of several nuclei
The sensory information from the CS (all stimuli) goes to thalamus —> sent to lateral nucleus (labeled input nucleus of amygdala bc takes in all stimuli CS + US) —plasticity in lateral nucleus is what allows it to encode and store the associations between the CS and US; in this nucleus the association is being formed; if you lesion the LN only you will prevent fear conditioning —> associations then get transferred to central nucleus “referred to as output nucleus” bc takes info from LN and sends downstream to parts of brain responsible for fear response; you’re not preventing the association from being formed, you’re preventing the information from going downstream
Extinction
Originally thought to involve “unlearning” of the CS-US association; but evidence suggests original pathway remains intact; extinction learning–CS is actually associated with something neutral; active form of learning
EXTINCTION LEARNING IS AN IMPLICIT FORM OF EMOTION REGULATION
Current understanding of extinction posits that it involves new learning of a CS-No US association
COMPETES WITH PREVIOUSLY LEARNED CS-US ASSOCIATION
Reinstatement
Exposure to US -> Reinstatement
Reemergence of CR –> Original association between CS and US must remain intact following extinction
Renewal
Presentation of CS in new context -> Renewal
Reemergence of CR –> Original association between CS and US must remain intact following extinction
Spontaneous Recovery
Passage of time -> Spontaneous Recovery
Reemergence of CR –> Original association between CS and US must remain intact following extinction
Prelimbic Cortex
PL
in rats
crucial in fear expression
homologous to dorsal anterior cingulate cortex (dACC)
Dorsal Anterior Cingulate Cortex
dACC
in humans
crucial for fear expression
homologous to prelimbic cortex in rats
Infralimbic
IL
in rats
crucial in extinction
homologous to ventralmedial prefrontal cortex (vmPFC)
Ventromedial Prefrontal Cortex
vmPFC
in humans
crucial for extinction
Homologous structures in rodents and humans in fear conditioning and extinction
prelimbic cortex (rats) = dACC dorsal anterior cingulate c ==> promote fear expression, oppose extinction
infralimbic cortex (rats) = vmPFC ventromedial prefrontal c ==> inhibit fear expression, promote extinction
Quirk rodent experiment
lesioned IL in rodents (homologous to vmPFC in humans)
does not interfere with extinction on day 1
interferes with retrieval
on same day, you don’t see huge change; prominent differences show up on day 2; it’s as if they never learned extinction, only retained threat learning
Implications for extinction process
Functions as a memory…contains three steps
- acquisition
- consolidation
- retrieval
***retrieval of extinction memory impaired on day 2
Process Model of Emotional Regulation
Outline of the process of experiencing emotion according to appraisal theories
start with a situation that could elicit emotion if you attend to the aspects of the environment —> once you attend to something, it depends on the meaning/appraisal so place on something, that determines your emotion generation
What enables us to change the meaning that emotional stimuli have to us?
- situation selection
- situation modification
- attentional deployment
- cognitive change
Cognitive Reappraisal
down-regulating negative emotion
meta-analysis task –> bc volitional action, lateral regions more involved
Circadian Timing
- Operates over the 24 h light-dark cycle
- Drives metabolic and behavioral rhythms
- sleep
- wakefulness
- appetite
- metabolic and reproductive fitness
Millisecond Timing
Subsecond range
used for speech, music, motor control
Interval Timing
Seconds-to-minutes range
used for anticipating future events, organizing behavior, decision making
Verbal Time Estimation Task
(Participants verbally estimate duration of the square on screen)
Temporal Reproduction Task
Reproduce the duration themselves
Participants are required to press the spacebar once to initiate their time estimates and then press once again when they think that the presentation duration of the former square (e.g., 3 s) has elapsed
Duration Discrimination Task
2+ stimuli presented
subject may be asked to make a judgment as to whether the longer interval was the first or second
Behavioral Properties of Timing Ability
Accuracy - close to actual
Precision - close to each other
Accuracy
On average, we are highly accurate in our temporal judgments
Linear relationship between target durations and time estimates
Close to actual
Precision
Error in time estimates grow proportional to the timed interval
Trial-to-trial variability is constant within an individual
close to each other
Scalar Property of Timing
scalar time: errors vary linearly with estimated durations
Scalar property/Weber’s law: one of the hallmark signatures of interval timing that describes the linear relationship between target durations and the standard deviation of duration judgments, indicating that variability in timing behavior grows proportional to the mean of the interval being estimated. In this sense, duration discrimination is relative rather than absolute, that is time perception is like a rubber band in that it can be stretched to produce time-scale invariance across different durations
Factors Affecting Subjective Time Judgements
- Affective state - emotion-induced activation temporarily increases the speed of an internal clock (thereby leading to longer perceived durations)
- Age: older vs. younger adults (time passes more quickly for older adult)
- Health status: psychiatric disorders (e.g., depression, schizophrenia) and neurodegenerative conditions (e.g., Parkinson’s disease)
- Stimulus properties and context
- Cognitive load (e.g., increasing the number of timed intervals) accuracy of time estimation deteriorated with cognitive load; overestimation of time
- Dynamic vs. static stimuli
Neural and Physiological Substrates of Timing
Distributed neural network involved in forming and updating temporal expectations
dlPFC (dorsolateral prefrontal cortex)
anterior insula
vPM (ventral premotor area)
ACC (anterior cingulate cortex)
Cortico-striatal-cerebellar Circuit
?
Striatal Subpopulations
Striatal subpopulation dynamics predict duration judgments
- Trained rats to estimate and categorize the duration of time intervals as longer or shorter than 1.5 seconds
- When rats mistook shorter interval for a long one, population activity had traveled farther down path than would normally (and vice-versa)
- Suggests that variability in subjective estimates of the passage of time might arise from variability in the speed of striatal neuron’s changing patterns of activity
- Lesioning striatum impaired rat’s ability to classify interval durations altogether
- striatal ensembles drive subjects’ judgments of duration,
Individual neurons show significant short and long preferences
===> Striatal subpopulation dynamics predict duration judgments
___________
The striatum encodes reinforcement learning and procedural motion, and consequently is required to represent temporal information precisely, which then guides actions in proper sequence.
dorso-medial striatal neurons = time-relevant neurons
dlPFC (dorsolateral prefrontal cortex)
Time Cells in Hippocampus
Hippocampal neurons that fire at successive moments in temporally structured experiences
different striatal neurons are active at different time points
Hippocampal time cells fire at successive moments in temporally structured experiences.
Pupillary Indices of Temporal Expectation
Temporal expectations in the autonomous nervous system (ANS)
Human pupil size
Temporal prediction
- Letter discrimination task
- Delays to visual target presentations were manipulated
Pupillary response tracks temporal information
- Dilatory pupillary activity started earlier when the targets were expected to appear sooner after trial onset
- Time-based information processing in the ANS
Neural correlates of timing ability
No dedicated region associated with timing
Basal ganglia (BG) as the locus for the representation of temporal information
- Striatum, a main input area of the BG, has been implicated for timing supra-second intervals
Supra-second and sub-second intervals
Sub-second intervals are mainly processed by automatic timing, which does not require attentional modulation, whereas supra-second durations are under the control of higher cognitive functions such as attention and working memory
Mouse Duration Discrimination Task
time as encoded by striatal populations ran faster or slower when rats judged a duration as longer or shorter, respectively. These results demonstrate that the speed with which striatal population state changes supports the fundamental ability of animals to judge the passage of time
Mouse Duration Discrimination Task
time as encoded by striatal populations ran faster or slower when rats judged a duration as longer or shorter, respectively. These results demonstrate that the speed with which striatal population state changes supports the fundamental ability of animals to judge the passage of time
- Trained rats to estimate and categorize the duration of time intervals as longer or shorter than 1.5 seconds
- When rats mistook shorter interval for a long one, population activity had traveled farther down path than would normally (and vice-versa)
- Suggests that variability in subjective estimates of the passage of time might arise from variability in the speed of striatal neuron’s changing patterns of activity
- Lesioning striatum impaired rat’s ability to classify interval durations altogether
- striatal ensembles drive subjects’ judgments of duration
- Individual neurons show significant short and long preferences !!!
- Different striatal neurons are active at different time points
Mouse Duration Discrimination Task
time as encoded by striatal populations ran faster or slower when rats judged a duration as longer or shorter, respectively. These results demonstrate that the speed with which striatal population state changes supports the fundamental ability of animals to judge the passage of time
- Trained rats to estimate and categorize the duration of time intervals as longer or shorter than 1.5 seconds
- When rats mistook shorter interval for a long one, population activity had traveled farther down path than would normally (and vice-versa)
- Suggests that variability in subjective estimates of the passage of time might arise from variability in the speed of striatal neuron’s changing patterns of activity
- Lesioning striatum impaired rat’s ability to classify interval durations altogether
- striatal ensembles drive subjects’ judgments of duration
- Individual neurons show significant short and long preferences !!!
- Different striatal neurons are active at different time points
fMRI Timing Test
- Estimation of the time-of-arrival of a pendulum
- Make a key press when the pendulum reaches its maximum height
- Manipulation: Induce unpredictable changes in speed of the pendulum’s swing from one semi-period to the next
Periodic –predictable
Non-periodic -unpredictable - More extensive activation in non-periodic test trials
- Distributed neural network involved in forming and updating temporal expectations
dlPFC (dorsolateral prefrontal cortex)
anterior insula
vPM (ventral premotor area)
ACC (anterior cingulate cortex)
Gouvea Rat Timing
- Trained rats to estimate and categorize the duration of time intervals as longer or shorter than 1.5 seconds
- When rats mistook shorter interval for a long one, population activity had traveled farther down path than would normally (and vice-versa)
- Suggests that variability in subjective estimates of the passage of time might arise from variability in the speed of striatal neuron’s changing patterns of activity
- Lesioning striatum impaired rat’s ability to classify interval durations altogether
- striatal ensembles drive subjects’ judgments of duration,
Individual neurons show significant short and long preferences
===> Striatal subpopulation dynamics predict duration judgments
Neural correlates of timing
- There is no dedicated brain region that is associated with the timing function
- Distributed neural network subserving temporal cognition
There is no dedicated time-keeping mechanism in the brain
The involvement of very large and distributed neural networks
CNS + ANS (pupillary dilation)
Coma
state of unarousable consciousness
failure of ‘ascending reticular system
looks like someone is alseep but can’t wake them up; can’t respond to external stimuli
Vegetative State
state of arousal after coming out of coma
brain/physiological system is a little bit more ‘awake’ but no meaningful interaction
also referred to as Unresponsive Wakefulness Syndrome
Vegetative state: reticular activating system is INTACT; fiber tracts are intact; conclusion is that reticular activating system is necessary for consciousness but not sufficient for consciousness
Unresponsive Wakefulness Syndrome
aka vegetative state
state of arousal after coming out of coma
brain/physiological system is a little bit more ‘awake’ but no meaningful interaction
Minimally Conscious State
half the time in vegetative, half the time responsive (conscious)
Locked-In Syndrome
you are conscious, but cannot respond to external stimuli
Implication: patient is aware and intentional
REM Sleep
Rapid eye movement sleep
Reticulate system is active during REM
More of a conscious state
The body’s internal function is more active during REM sleep. Heart rate is faster and more irregular, blood pressure rises and breathing is quicker and more irregular
Dreams occur here
Non-REM Sleep
Unaware and unconscious
Brain waves are typically slow and of high voltage, the breathing and heart rate are slow and regular, the blood pressure is low, and the sleeper is relatively still
Recovery of Consciousness
Recovery of conscious awareness and cognitive function following severe brain injuries can occur over surprisingly long time intervals of months, years and rarely decade
Awareness
What determines the contents of our conscious
awareness at any given moment?
==ATTENTION
Knowledge or perception of a situation or fact
Change Blindness
Not consciously aware of the change
Visual Masking
If you put a visual white noise screen being presented, if it’s close enough in time you won’t have conscious experience of seeing the word
the mask is inhibiting your ability to notice the stimulus; has to be close in time
implicit memory for the word – repetition suppression: recall “note” faster if seen it before, even if don’t consciously remember seeing it
The fusiform gyrus= part of the temporal lobe and occipital lobe
drastically reduced during subliminal messaging
V1 test
Neuronal Correlates of Perception in Early Visual Cortex
Looking in V1 —> presented noise structures, some with grating in it, difficult to identify whether or not grating was present
Hit = yes grating, should activate V1 neurons (O) + conscious of that grating (S)
Correct Rejection = no grating, no V1 neuron activation (O) + no conscious recall (S)
Miss = yes grating, V1 neuron activation (O) + no conscious recall (S)
False Alarm = no grating, no V1 neuron activation (O) + conscious recall (S)
BOLD Activation –> much more activation in hits than in misses; V1 not telling you just what is in environment; hits and misses should be same if objective;
false alarms led to almost same level of activity as hits
V1 activity modulated by conscious experience
–> all about your interpretation of experience
Locked-In Owen experiment
Spoken speech —> temporal lobe (speech)
Ambiguous speech —> additional activation in frontal, indicating semantic processing [creek, beam, ceiling]
Imagine playing tennis —> motor cortex
Imagine walking through childhood home —> PPA, parietal (navigation)
Hearing what is being said and consciously responding to it
Attentional Blink
Attentional Blink Experiment
Presented with serial visual presentation
1. Identify the white stimulus?
2. Was there an x?
Percent correct as function in relation to relative serial position
Performance drops right after onset of T1, then returns to normative levels
—> A tiny temporal window after onset of target 1 in which you are unable to identify the second stimulus
Application: 100-400 after surprise
Parietal Cortex
R-Damage, L-Damage
Damage to R parietal lobe, neglect to left visual field – doesn’t make it into awareness, not conscious of left side of space – no reporting of conscious awareness
Right P cortex is typically damaged in cases of visual neglect
L parietal cortex is not important in consciousness of external world, but instead in internal consciousness; lack of self-awareness?
Right damage - hemispheric neglect
Left damage - lack of self-awareness?
Massimini Cortical Connectivity Study
Break down of Cortical Effective Connectivity
How the brain is physiologically different during awake and during non-REM sleep
Stimulating TMS over part of brain —> how brain reacts to stimulation
During wakefulness, you get activity in site of activation that then moves bilaterally to nearby areas [doesn’t stay localized in one area] ability of activation in one brain area to activate other regions is much greater during wakefulness than when sleeping
In non-REM sleep, same robust activation in stimulation site but doesn’t travel in brain (the brain is inhibited from cross-regional connectivity) —> local activity might be intact, but consciousness requires the areas to communicate with each other
LOCALIZED ACTIVITY IN SLEEP/UNCONSCIOUS vs. WIDESPREAD ACTIVITY WHEN AWAKE/CONSCIOUS
Neural Correlates of Consciousness
Global metabolism is not diagnostic about consciousness
The overall level of activity of a brain area doesn’t seem to be indicative of level of consciousness, except with reticular formation system (needed but still not enough)
Effective connectivity may be a more sensitive measure —> how distributed and long-range information is being integrated
Gorilla Video Implications
Too much environmental stimuli for us to process
Selecting from the over 2 million bits of auditory and visual stimuli that you can process at any given moment
Attention gives you spotlight to the world
Gorilla Video Implications
Too much environmental stimuli for us to process
Selecting from the over 2 million bits of auditory and visual stimuli that you can process at any given moment
Attention gives you spotlight to the world
Tong Paper
Both stimuli present in both situations (both faces and places)
Consciously aware of only one at a time
When aware of face, increased FFA activation; when aware of house, PPA activation
Evidence for Extinction Learning
Exposure to US -> Reinstatement
Presentation of CS in new context -> Renewal
Passage of time -> Spontaneous Recovery
Brenda Milner
Dorsolateral Prefrontal Cortex
Wisconsin Card Sorting Task
Perservative Error = error of inhibition
Brenda Milner Error
Perservative error = error of inhbitiion
