Term
| What is an example of a common frontal lobe trauma? |
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Definition
| Car accident amnesia, as the forehead is impacted |
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Term
| Why do we no longer perform frontal lobotomies? |
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Definition
| The reduction in behavioral symptoms can easily be achieved through drugs and not cutting out the PFC |
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Term
| What are some general functions of the frontal lobe? |
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Definition
Speech (inferior frontal gyrus)
Movement (motor cortex)
Executive processing (attention, switching tasks, planning, working memory)
Social Behavior |
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Term
| Why is it so difficult to study frontal lobe activity in animals? |
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Definition
Most animals don't have a frontal lobe
most animals don't have sulci and gyri
Largest in humans, grew the most over evolution compared to others |
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Term
| What are the major structures in the frontal lobe? |
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Definition
Motor cortex (primary, premotor, supplementary)
Medial prefrontal cortex
Lateral Prefrontal cortex (ventrolateral and dorsolateral)
Orbital cortex
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Term
| What are the major structures in the prefrontal cortex? |
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Definition
Medial prefrontal cortex
Lateral Prefrontal cortex (ventrolateral and dorsolateral)
Orbital cortex
No Motor areas! |
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Term
| What are the two main sulci in a monkey? |
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Definition
Primary sulcus (goes sagitally ->)
Arcuate Sulcus (goes down sagitally) |
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Term
| What is a distingushing feature of monkey PFC compared to human PFC? |
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Definition
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Term
| What is the cytoarchitectonic structure of the human prefrontal cortex like? |
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Definition
very heterogeneous, wide range of variability compared across individuals.
We use the sulci to give us landmarks |
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Term
| What are some connections between the prefrontal cortex and the thalamus? |
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Definition
From Anterior, mediodorsal, ventral anterior, and pulvinar nuclei
Mediodorsal is the strongest, affects dorsolateral PFC |
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Term
| What are some connections between the PFC and the brainstem? Why is/are these pathway(s) associated with schizophrenia? |
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Definition
from Dopamine neurons in the Ventral Tegmental area, go to medial PFC
Implicated in schizophrenia, as dopamine antagonists are used to control symptoms |
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Term
| What are some connections between the PFC and the basal ganglia? |
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Definition
Cortico-Striatal projection from layer 5 to basal ganglia, processed in ganglia, and then loop through thalamus to the PFC
Deep brain stimulation studies on subthalamic nuclei show working memory deficits and decreased PFC activity |
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Term
| What are some connections between the superior colliculus and the PFC? |
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Definition
| Between the frontal eye fields and layer 5. |
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Term
| What are some connections between the hypothalamus and the PFC? Between the amygdala and the PFC? |
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Definition
hypothalamus -> orbital and medial frontal lobe areas (poor decision making)
Amygdala -> medial PFC (depression) |
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Term
| How do we think executive function is organized in PFC? |
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Definition
| Through it's heavily interconnected neurons. |
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Term
| What sort of connections are sent from other parts of cortex and received by frontal lobe areas? |
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Definition
Visual -> TE and TEO (inferior temporal cortex) go to orbitofrontal cortex and ventrolateral PFC
Somatosensory -> Somatosensory association cortex to Lateral and ventrolateral PFC
Parietal cortex -> large reciprocal connections between posterior parietal and dorsolateral PFC (spatial delay task)
Auditory -> rostral auditory to rostral and ventral PFC, caudal auditory to caudal and dorsolateral PFC
EVERYTHING IS NOT CONNECTED TO EVERYTHING else |
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Term
| What is Thurstone's Word Fluency test? |
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Definition
Name all the fruits you know
Tests broca's area (Inferior frontal gyrus) |
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Term
| What are some common language tests? |
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Definition
| Thurstone's word fluency, Verbal recall test, and story comprehension test |
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Term
| What is the 'n' -back test? |
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Definition
| fMRI task requiring you to push a button when x occurs n positions back from a stimuli, tests verbal memory updating in dorsolateral PFC, and verbal rehearsing in premotor cortex, broca's area |
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Term
| What areas in the PFC produce personality/social behavior and how do we test them? What areas affect mood? |
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Definition
Personality/social -> Ventromedial PFC, orbital cortex and frontal pole
Mood -> Medial PFC, cingulate area (DBS relief in the subgenual region) |
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Term
| What areas in PFC are associated with occulomotor tasks? |
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Definition
| Frontal eye fields, more than just movement, also attention |
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Term
| What is the tower of london task? |
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Definition
Subject tries to choose least moves to make a certain pattern appear.
affects many regions, but always dorsolateral PFC |
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Term
| What is the stroop task? What does it test? What does it activate? |
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Definition
Read words, say the color of the word, not the word itself
Tests response inhibition, fMRI
Cingulate cortex and dorsolateral PFC |
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Term
| What is the Wisconsin sort task? What does it test? What does it activate in the PFC? How do lesioned patients perform? |
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Definition
different number symbol and colored Cards are sorted into 4 piles, tester says right or wrong. After ten correct responses, rules are switched
Tests attention, or ability to switch
Lateral PFC primarily, but deficits can be caused by a number of lesions
Lesioned patients perseverate (keep doing the first rule set) |
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Term
| What test examines the ability to organize letters? What area of PFC does it activate? |
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Definition
Alphabetzing test
tests working memory and executive processing
Dorsolateral PFC |
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Term
| How do we test working memory? What areas of PFC are used in working memory? |
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Definition
Delayed response task, or delayed alternation task
In monkeys, primary sulci region is activated
Hard to do with PFC lesion |
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Term
| How did researchers separate out different functions of Dorsal PFC and ventral PFC? |
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Definition
Different perfomance on delayed response tests
DLPFC lesions disrupt spatial delayed alternation task
VLPFC lesions disrupt delayed matching to color task. |
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Term
| Describe Baddeley's model of working memory. What are its limitations? |
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Definition
A central executive regulates the distribution of attention and coordinates information in working memory, which can be sent to long term memory.
is the DLPFC the central executive? I don't think so...many brain areas are active during both master and slave tasks.
Visualspatial -> evision things
Episodic Buffer -> stores events
Phonological loop -> language |
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Term
| What did Fuster say about delay activity in neurons? |
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Definition
| It temporally links behaviorally relevant events. |
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Term
| What did Goldman-Rakic say was the response field of PFC? |
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Definition
a Memory field.
Integrates events separated in time, uses stored knowledge to guide a response |
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Term
| What did Goldman-Rakic hypothesize about schizophrenia and the PFC? |
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Definition
| Modulation of dopamine localized in the PFC has an effect on working memory. The overall ability of the PFC to use and hold information is it's primary function. |
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Term
| What are some problems associated with separating out a memory field in the PFC? |
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Definition
many neurons are memory-motor receptive field intertwined.
Used an Anti-saccade task to control for motor receptive fields. |
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Term
| What is the working hypothesis for how Delay activity comes about in the PFC? |
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Definition
| Delay activity is the result of a reverberating circuit between dorsolateral PFC and the posterior parietal cortex. |
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Term
| What happens when you inactivate DLPFC cortex and record from posterior parietal cortex? What happens if you do the reverse? |
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Definition
Delay activity increases.
Less Delay activity, more visual cue activity. |
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Term
| How do we know the spatial working memory of dorsolateral PFC is dependent on dopamine? |
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Definition
| A strong blockade of dopamine receptors can abolish delay activity, but a moderate amount can enhance it. There seems to be an optimal amount for working memory performance maximization . |
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Term
| What is the domain specificity hypothesis? |
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Definition
The prefrontal cortex can be dissociated by the type of information processed.
Science paper showed that different areas of the PFC were involved in interpreting different cues to give a saccade
dPFC spatial delay, visual stimuli
vPFC object type, color, no spatial tuning
dorsolateral PFC spatially dependent
ventrolateral PFC auditory tuning |
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Term
| Why is the domain specificity hypothesis controversial? |
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Definition
Patients examined with fMRI don't always have the same domains. There aren't discrete domains.
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Term
| What is Earl Miller's view on PFC activity? |
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Definition
PFC activity represents associations between events and actions, context and rules.
PFC is very plastic, responsive to task demands.
Assumes there are bias signals, guiding the flow of activity that allow for proper mapping of circuits to achieve a task. |
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Term
| What is a conditional response task? |
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Definition
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Term
| How did Miller argue that PFC activity is association based, using a conditional response task? |
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Definition
| PFC activity changes if the rules of the conditional response task change, even if the cues do not. |
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Term
| How did Millner show that the PFC is involved in flexible category learning? |
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Definition
| Showed that dorsolateral PFC neuron responded to a dog but not a cat, in weighted proprotion to the degree that the dog looked like a dog. |
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Term
| What kind of processing did Petrides say the dorsolateral PFC did? |
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Definition
Manipulation of information stored in working memory.
Activated when trying to repeat a phone number backwards |
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Term
| What kind of processing did Petrides say the ventrolateral PFC did? |
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Definition
rehearsal of information.
Reharsing a phone number you just learned activates this region. |
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Term
| What are some disorders of cognition associated with activity in the frontal lobe? |
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Definition
OCD -> hypofrontal activity
ADHD -> hypofrontal activity (lack of inhibitory control, poor executive function)
Autism -> hypofrontal (orbital frontal, medial PFC)
Depression (medial PFC)
Dyslexia (temporo-frontal)
Drug Addiction (orbitofrontal, medal PFC)
Alzheimers, Parkinsons (subthalamic nucleus) |
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Term
| What is the dopamine hypothesis of schizophrenia? |
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Definition
positive symptoms (hallucinations, extreme emotions, incoherent thought, delusions) caused by too much dopamine
Negative symptoms (flat affect, lack of social activity) caused by a lack of dopamine. |
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Term
| What is some evidence that supports the dopamine hypothesis of Schizophrenia? |
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Definition
Amphetamine use, up dopamine, up hallucinations
anti-psychotics block dopamine
D2 agonists can induce hallucinations
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