name: regions of frontal lobe (4)
- primary motor cortex
⤷ precentral gyrus (post central = primary somatosensory) - premotor cortex
⤷ sends info to precentral gyrus - prefrontal cortex
⤷ collects all connections + involved in attention + higher order - anterior cingulate cortex
⤷ anterior part of cingulate cortex (connects all the lobes)
name: function of primary motor cortex (location?)
- movement selection
- fine movements
- motor strength
- direction of movement
**located in precentral gyrus
name: pre-motor areas
- premotor cortex
⤷ has supplementary area - frontal eye field
⤷ has supplementary eye field - Broca’s area
⤷ bc mvt. assoc. w/ lang.
name: function of pre motor areas
- movement programming
- corollary discharge
⤷ world stays stable despite eye mvt. - motor strength
- mirror neurons
⤷ mirrors motor activity of others - eye mvt.
name: projections of motor + premotor areas
MOTOR
- spinal neurons (spinal cord) + cranial nerves
- basal ganglia + red nucleus (tegmentum of midbrain)
PREMOTOR
- spinal cord
- motor cortex
name: receiving connections to pre motor areas
PREMOTOR CORTEX
- parietal areas PE, PG, PF
- dorsolateral prefrontal area
EYEFIELDS
- parietal area PG
- superior colliculus
name: symptoms of frontal lobe lesions
- disturbances of motor function (damage to primary motor)
⤷ loss of fine movements, speed, strength - loss of mvt. programming (damage to premotor)
- changes in voluntary gaze (damage to eye fields)
name: parts of pre frontal cortex
- dorsolateral PFC
- orbitofrontal PFC
- ventromedial PFC
⤷ part of cingulate cortex
explain: connections to prefrontal areas
- dorsolateral and orbitofrontal PFC connect to everything
⤷ all of the above
**vision is also in PFC through the orbitofrontal PFC
name: functions of the PFC
- control cognitive processes
⤷ ensures appropriate behaviours are selected at the right times - internal + external cues
- context cues
⤷ social interactions (orbitofrontal) - autonoetic awareness
⤷ self knowledge collected over a lifetime of exp. - executive functions
explain: internal cues (PFC)
- info that originates from w/in an indiv. mind/body
- thoughts, memories, emo.
- temporal memory = info collected from dorsal + ventral streams
⤷ order of events = vis. info. + timing/seq.
explain: external cues (PFC)
- sensory stim. that come from external envrt.
- visual, aud., tactile
define: autonoetic awareness
- self knowledge collected over a lifetime of exp.
- binding awareness of oneself as continuous through time
- knowing yourself + how you behave
- controlled by PFC
name: executive functions of frontal lobe
- planning + selection
- persistence + ignoring distractions
- memory (long term)
- responding to internal + external + context cues
explain: asymmetry of frontal lobes
- L = language
⤷ encoding memories - R = retrieving memories
⤷ non verbal movements
⤷ facial expressions
explain: convergent vs divergent thinking
- convergent = only 1 answer to the question
- divergent = questions that can have many responses
question: do frontal lobe lesions cause issues with convergent or divergent thinking?
- divergent
- loss of behavioural spontaneity
- decreased verbal + design fluency (lots of similar designs)
name: symptoms of frontal lobe lesions
- increased perseveration
- inability to form a strategy
⤷ worse when completing new tasks - loss of response inhibition
⤷ wisconsin card sorting task
⤷ stroop task - impaired social and sexual behaviour
- changes in personality
explain: wisconsin card sorting
- ask patient to sort cards into categories (shape, colour, number)
- invigilator can give feedback on the sorting but no further instruction
⤷ can also change the categories to see if person will adapt and change strategies - normal patient = trial and error to get invigilator to say “yes”/correct category
- frontal lesion patient = bad at forming strategy
⤷ also poor response inhibition for the categories
explain: stroop test
- ask patient to read the colour of the word, not the word itself
- tests response inhibition
⤷ frontal lobe lesion
explain: changes in personality as a symptom of frontal lobe lesions
- pseudodepression
⤷ lesions in L frontal lobe
⤷ apathy, indifference, loss of initiative - pseudopsychopathy
⤷ lesions in R frontal lobe
⤷ immature bhea. lack of tact and restraint
⤷ sexual beha.
⤷ coarse lang.
⤷ lack of social graces
explain: schizophrenia
- affects all brain
- abnormality in mesocortical dopaminergic projection
⤷ neural path
⤷ from dopamine prod. neurons in midbrain (ventral tegmental area)
⤷ projects to many cortex regions - decrease blood flow to the frontal lobes + frontal lobe atrophy
- symptoms include aud. + vis. hallucinations
explain: parkinson’s disease (cause)
- loss of dopamine cells in substantia nigra that project to PFC
explain: korsakoff’s syndrome (cause)
- alcohol induced
- damage to dorsomedial thalamus
- deficiency in frontal lobe catecholamines
⤷ ex. dopa.
