Prefrontal Cortex - Lecture Capture[]'; Flashcards
Where is the prefrontal cortex located and what major gyri does it include?
Anterior to the motor areas
Includes superior frontal gyri, cingulate gyrus medially and the superior, middle, and inferior frontal gyri dorsolaterally
Where does the prefrontal cortex receive info from?
Visual: about object/form and spatial, motion, depth, also faces
Olfactory
Affective pain and rewards
What is sustained attention?
Maintaining focus and effort on one task, it is related to general allerness
What regions is sustained attention dependent on?
Prefrontal/orbitofrontal cortex
What is selective attention?
Ability to tune out irrelevant stimuli and enhance detection and processing of relevant stimuli
What regions is selective attention dependent on?
Prefrontal/orbitofrontal cortex and parietal for spatial info and temporal for object info
Like “where’s waldo?” or listening to one instrument in a song
What is attentional set shifting?
Shift in where selective attention is focused
Ex. adult -> child voice at dinner table
What regions is attentional set shifting dependent on?
Prefrontal/orbitofrontal cortex
What area regulates visual spatial attention?
Superior parietal lobule (regulates activity in primary or 2ndary visual cortex)
What area regulates visual object attention?
Temporal visual association cortex (regulates activity in primary or 2ndary visual cortex)
General principle/path of selective attention
Sensory association cortex -> primary sensory cortex to filter irrelevant info
Finding the X in a sea of + is a quantitative test of
Selective attention
Can also tell subject where it is and measure time difference between two trials
Stroop test (colors and names) is a test for
Selective attention and attentional set shifting
Dependent on dorsolateral prefrontal cortex and anterior cingulate cortex (damage impairs ability)
Switching from a word name to the color of the word in the stroop test is dependent on
Orbitofrontal cortex
May impair set shifting but pt may be able to maintain focus on initial test
What is short-term (working) memory?
Ability to hold information in the mind during use for seconds to minutes
What is delay-dependent memory?
Memory in which accuracy decreases as delay length increases
What is delay dependent and working memory mediated by?
Prefrontal cortex, mostly dorsolateral Lateral convexity (S/M/I frontal gyri)
Examples of working memory tests?
Delayed non-match (or match) to sample, N-back
When are working memory tests important?
As a baseline measurement in contact sports - can be used to determine if a patient has a concussion
Locus coeruleus (LC)
Major ascending norepinephrine system, promotes alertness, sustained and selective attention
Lies lateral to 4th V and cerebral aqueduct
Ventral Tegmental Area (VTA)
Dopaminergic, promotes selective attention to relevant (especially rewarding) stimuli
Located medial to substantia nigra
How to ritalin and adderol work?
Increase action of norepinephrine and dopamine (either increase release or inhibit reuptake)
Cholinergic (acetylcholine) neurons function how?
Have widespread projections targeting cerebral cortex and limbic regions, enhance both sustained and selective attention
What are the major functions of the orbitofrontal region?
Motivational level exhibited towards tasks, impulse control, social interaction, emotional stability and self-regulation, and prefrontal regulation of fear/stress via interactions with limbic and other regions
Also cognitive function of decision making (rewarding vs. aversive, consequences of decisions)
READ OVER CASE OF PHINEAS GAGE
READ OVER CASE OF PHINEAS GAGE
Cognitive deficits of clinical prefrontal syndrome
Attention, set-shifting, working memory, executive function
Emotional deficits of clinical prefrontal syndrome
Emotional volatility, loss of control, impaired motivation
Social deficits of clinical prefrontal syndrome
Impaired attention to and interaction with others, impaired empathy
Frontal lobe release phenomenon is described by what deficits/patient presentations?
Disinhibited and inappropriate behavior, inappropriate use of objects (like putting on someone else glasses), infantile reflexes like grasping and suckling, repeating same words or responses, inability to change from one correct answer to another
Akinetic mutism
Patient doesn’t respond due to lack of motivation
Abulia
Lack of enthusiasm/energy, lack of spontaneous behavior, delayed motor/verbal response
Extreme cases = catatonic state
Prefrontal cortex gradually matures until what age?
20s
Impaired prefrontal development causes what conditions
Autism and schizophrenia
Impaired (but treatable) prefrontal conditions include
Schizophrenia, depression, PTSD, drug addiction
