higher cortical function Flashcards
what type of neurones are mostly output from the cortex ?
Pyramidal
what are the types outputs from the cortex?
Projection fibres down brainstem
Commissural between hemispheres
Association fibres in the same hemisphere
where do inputs come from ?
thalamus
Reticular formation = consciousness
what can control memory, emotion and behaviour ?
interneurone connections
what would you expect in terms of motor function if frontal lobe damaged ?
contralateral weakness
what is the frontal lobe do for language ? what area is known for this?
expression of speech
broca’s area
usually left hemisphere
what is difference between Broca’s and wernicke’s aphasia
Broca = cannot express wernicke's = perception of language not understood = receptive
What behavioural problems arise due to frontal lobe damage ?
impulsivity, disinhibition
agression and sexual inappropriateness
what other problems may arises if the right frontal lobe is damaged ?
Complex problem solving
what controls quick eye movements ?
frontal eye fields in the frontal lobe
how can you tell lesion form frontal love or CN / Brainstem using eye movement ?
conjugate gaze = Frontal lobe
diplopia
where in the brain can cause incontinence ?
frontal lobe
what are the functions of the parietal lobe ?
sensory comprehension body image awareness of environment calculation and writing
what happens in terms of sensation in parietal lobe lesions ?
contralateral anaesthesia affecting all modalities (modalities
converge at the cortex)
what 3 things are needed for language pathway ? what hemisphere is dominant
Broca’s - inferior lateral frontal lobe
Wernicke’s - superior temporal lobe
Arcuate fasciculus
what hemisphere s known for body image and awareness ?
right parietal
damage = neglect
what optic radiation goes through parietal lobe ? what can happen if there is lesion there ?
Superior optic radiation
contralateral inferior
homonymous quadrantanopia
where is the primary auditory cortex ?
superior surface
of temporal lobe, near to Wernicke’s area
where is the primary olfactory cortex ?
inferomedial aspect of the temporal lobe
what part of the brain is especially responsible for memories ? if lesion present what can it lead to
hippocampus - declarative
amnesia
what system is partly in the temporal lobe ? what parts especially and what is the function of this system ?
Limbic
hippocampus and amygdala
emotions
what optic radiation goes through temporal lobe ? what can happen if there is lesion there ?
inferior optic radiation
contralateral superior
homonymous quadrantanopia
what is the left hemisphere dominant for ?
language and
mathematical/logical functions
what is the right hemisphere dominant for ?
body image,
visuospatial awareness, emotion and musical ability
what can cause alien hand syndrome ?
damage to corpus callosum
what can cause global aphasia ?
Large middle cerebral artery infarcts
= no verbal language
function
what happens if arcuate fasciculus is damaged ?
inability to
repeat heard words
why are memories stored everywhere in the brain ?
if damage to 1 area it is less likely to lose many memories
what are the types of memories ? where are they each stored
declarative (facts) = cerebral cortex
Nondeclarative (motor skills/emotion) = ubcortical structures (e.g. basal ganglia)
and cerebellum
where are short term memories stored ?
seconds to minutes as a ‘reverberation’ or ‘echo’ in
cortical circuits
where are long term memories stored ?
cerebral cortex, cerebellum
etc. (up to a lifetime) following consolidation
what is consolidation and what factors help it ?
short term to long term
emotional context
rehearsal
association
what helps consolidate declarative memories? where is it found ?
The hippocampus
deep in the temporal lobe
how does the hippocampus consolidate ?
multimodal inputs from many brain systems
facilitating consolidation of
memories in the cortex via its output pathways (primarily the
fornix mammillary bodies thalamuscortex)
what in terms of celluar mechanism helps memory consolidation
Long term potentiation (LTP)
increase in glutamate receptors in synapses leading to
synaptic strengthening
New physical connections can also form between neurones to
further strengthen connections (axonal sprouting)
