Frontal lobes Flashcards
According to Luria, why due frontal lobe patients have difficulty with problem solving?
The can access fragmentary operations but cannot combine them into an overall schema
How do lesions to the prefrontal areas affect attention?
Tilt emphasis away from internal mental processes toward stimulus-bound behavior
Orbitofrontal circuit
Mediation of emotional & social responses
Lesions to the frontal eye fields result in
Impaired exploratory eye movements even when spot eye movements are intact
Witzelsucht
Tendency to joke inappropriately
Lesions to the motor association areas anterior to M1 lead to
Complex deficits of mvmt in absence of weakness, dystonia, dysmetria, or hyperreflexia; reflect a disconnection between cognition & action
Stuss & Benson divided the functions of the frontal lobes into what 2 groups?
1st concerned with sequencing behaviors, forming mental sets, & integrating various behaviors 2nd concerned with more primitive processes such as drive, motivation, will
The frontal eye fields project to
Superior colliculus, caudate nucleus, PPRF
Mesulam describes 2 general types of frontal lobe syndromes. What are they?
Frontal abulia (lesions to heteromodal cortex) Frontal disinhibition (lesions to paralimbic cortex)
Manifestations of frontal lobe syndromes can result from
Lesions in the head of the caudate or MD of thalamus, multifocal WM disease, metabolic encephalopathy, multifocal parietal lesions
Personality changes is the hallmark of dysfunction in what frontal lobe circuit?
Orbitofrontal
Role of Broca’s speech area
Translating neural word forms into articulatory sequence, sequencing words/endings into utterances that have meaning (appropriate syntactic structure)
Dorsolateral prefrontal syndrome
Poor problem solving, poor organizational strategies, impaired set-shifting, perseveration, impersistence, memory may be disrupted, apathy & psychomotor slowing, poor motivation/abulia, decreased emotional range
Frontal release signs
Reflexes (e.g., grasp, snout, glabellar) that are usually inhibited by the frontal lobes
Fuster’s temporal processing model
Prefrontal cortex is principally involved with representing the ‘temporal structure of behavior’; to encode temporal aspects of behaviors, the prefrontal cortex must be involved in the formation of ‘cross-temporal contingencies’
