Lecture 14: Frontal Lobes Flashcards
Dorsolateral Prefrontal Cortex (dlPFC)
makes reciprocal connections with posterior parietal cortex and superior temporal sulcus
responsible for selecting behavior and movement with respect to temporal memory
Orbitofrontal Cortex (OFC)
gains input from all sensory modalities
projections influence autonomic nervous system physiological changes important for decision making related to emotion and reward
Ventromedial Prefrontal Cortex (vmPFC)
connects subcortically with structures capable of emotional behavior bodywide
responsible for selecting behavior with respect to context, based either on current circumstance or previous knowledge, including self-knowledge
Salience Network
correlated activity among the anterior cingulate cortex, supplementary motor cortex, and anterior insular cortex that operates to modulate other brain networks’ activities and is most active when a behavioral change is needed
Temporal Meaning
memory for the order of events in time
Executive Function
a term applied to the range of cognitive processes that feature elements of self-control, such as attentional control, planning, reasoning, working, memory, problem solving, abstract thinking and self-monitoring
generally associated with the frontal lobe, through also involving many other brain areas linked to the frontal lobe
Corollary Discharge
a signal from the frontal lobe to the parietal and temporal association cortex that preset the sensory system to anticipate a motor act
thus, the sensory system can interpret changes in the external world in light of information about voluntary movement
Reafference
confirmation by one part of the nervous system of the activity in another
Agrammatism
impairment in the ability to use verbs and to produce appropriate grammer
Convergent Thinking
a search for a single answer to a question (e.g., 2 + 2 = ?)
Divergent Thinking
a search for multiple solutions to a problem (e.g. how may ways to use a pen)
Delayed-Response Task
a behavioral task in which a subject observes a reward being placed under a plaque, in a well
the subject’s view is blocked for a few seconds, and then the subject is allowed to retrieve the reward
Pseudodepression
a personality change subsequent to frontal-lobe lesion in which apathy, indifference, and loss of initiative are apparent symptoms but are not accompanied by a patient’s sense of being dejected or dispirited
Pseudopsychopathy
a personality change subsequent to frontal-lobe lesion in which immature behavior, lack of tact, and restraint, and other behaviors symptomatic of psychopathology are apparent but are not accompanied by the equivalent mental or emotional components of psychopathology
Fluid Intelligence
the ability to see abstract relationships and draw logical inferences
Crystallized Intelligence
an ability to retain and use knowledge acquired through prior learning and experience
What is the anatomy of the frontal lobes?
constitutes 20% of neocortex
all regions anterior to central sulcus
What is the function of the frontal lobe?
persistence and ignoring distracting stimuli (attention, vigilance)
short-term, working, and temporal memory
executive functions or “cognitive control”: cognitive flexibility (not perseverating), planning & decision making (advance information), response inhibition, error correction & troubleshooting
emotion
What is the Wisconsin Card Sorting Task (WCST)?
after 10 correct trials: change rules
patients who perseverate cannot switch behavior to fit with new rule
even continue when they “know” they are not following the new rule
disconnection between thought and action
What is environmental dependency syndrome?
had a life where they engaged in certain behaviors or actions
certain cues trigger these behaviors, revert back to what’s familiar to him
“environmental cues” trigger perseveration
also relates to pre-morbid functioning
cannot inhibit responses - free will?
What is the experiment used to asses the advance information paradigm in the frontal lobes?
have to determine if “R” when rotated clockwise will be normal or backward
then have to match to cue to know if it’s correct
normal: faster on task two because they don’t have to do mental rotation
frontal lobe damage: show same results between conditions
What is the advance information paradigm?
frontal lobe patients have difficulty using advance information (i.e., cannot employ advance info for strategy formation)
alternative hypothesis: cannot maintain image in working memory, maybe they can’t keep info in working memory long enough
perseveration
What was the experiment on response inhibition conducted on neurologically intact individuals?
GO/NOGO task
presented green light; push button
don’t push button when presented with red light
“oddball task”: 80% green, 20% red
ACC: is active in both red and green trials
LH inferior frontal: role in response inhibition in NOGO trials, not active in GO trial
RH inferior frontal: same activation as LH
What is the orbitofrontal cortex?
reward and punishment
lesions: deficits in anticipating consequences, myopic for future, yet high intellect (patient case)
disinhibited - aggressive behavior
lack of empathy
What is the dorsolateral cortex?
acting on feelings (motivational states)
functional asymmetries in NI (fMRI)
approach - pleasant (LH)
withdrawal - aversive (RH)
What are catastrophic reactions?
caused by LH lesions
inappropriate sadness, anger, tearfulness
What is euphoric-indifference?
caused by RH lesions
inappropriate happiness, joy, humor
deficit in identifying subtle humor and emotional judgement
What is the relationship between the prefrontal cortex and depression?
Beck inventory used to measure depression: increased scores means increased levels of depression
patients with left anterior lesions had higher depression scores
levels of depression increase as lesions get further back in right side
What is the valence-arousal model of emotion?
Wendy Heller
neuropsych model: based on observational damage
valence dimension (frontal): if there is more LH activation than RH valence is positive, more RH activation means unpleasant valence
arousal dimension (right parietotemporal): right hemisphere plays role in arousal, determines emotion you experience within the valence
