Cortical pt 2 Flashcards
What are the 3 motor association areas found in the frontal lobe
Primary
Supplementary
Premotor area
see diagram
What is the function of the primary motor area
Control fine, discrete, precise voluntary movements and to provide descending signals to execute movements
What is the function of the supplementary area
Involved in planning complex movements eg ( internally cued movements ie speech)
What is the function of the premotor area
Planning movements that are externally cued ie lifting a glass
What are the 2 association areas found in the parietal lobe
Primary somatosensory
Somatosensory association
What is the function of the primary somatosensory cortex
note where is it found
Processes somatic sensations arousing from receptors in the body ( fine touch ,vibration , two point discrimination , proprioception , pain and temperature )
parietal lobe
What is the function of the somatosensory association cortex and where is it found
Interpret significance of sensory information ie recognising an object placed in the hand + awareness of self and personal space
Parietal lobe
What are the 2 association areas found in the occipital lobe and what are their functions
Primary visual –> process visual stimuli
Visual association –> give meaning and interpretation of visual input
see notes for picture
What are the two association areas found in the occipital lobe and what is their function
Primary auditory –> Processes auditory stimuli
Auditory association –> gives meaning and interprets auditory input
see note for picture
What is an association area
an area of the cerebral cortex that functions in linking and coordinating the sensory and motor areas
Name 3 other association areas of the brain and their functions
Broca’s area –> usually in L side of brain. contains motor cortices associated with the production of language ( legion = loss of speech)
Wernicke’s area –> usually in L side of brain. Important for language processing and understanding language. ( legion = not understanding language)
Prefrontal cortex –> attention , adjusting social behaviour, planning , personality expression , decision making ( degeneration often seen in dementia + causes symptoms ie personality shift + loss of inhibitions+ inappropriate behaviour)
what are symptoms of frontal lobe lesions
Changes in personality
Inappropriate behaviour
what are some symptoms of parietal lobe lesions
Contralateral neglect –> lack of awareness of self and of extra personal space on side of body opposite side of brain where legion occurred. Ie legion in right hemisphere causes person to be unable to dress properly on left side or unable to draw see objects on their left
symptoms of temporal lobe lesions
damage to lateral and medial parts can lead to agnosia ( inability to recognise objects and ppl) . damage to medial part can also lead to anterograde amnesia ( inability to form new memories)
What connects the broca’s and wernicke’s areas
Arcuate fasciculus
see white matter tracts
symptoms of legion to broca’s area
Expressive aphasia ( poor production of speech but comprehension intact) ( motor defect)
this is different to legion in wernicke’s area
Symptoms of legion to wernicke’s area
Receptive aphasia ( poor comprehension of speech but production is fine)
( sensory defect)
this is different to legion in broca’s area
Symptoms of legion to primary visual cortex
Blindness in corresponding part of visual field
Symptoms of legion to visual association area
Defects in interpretation of visual info ( ie Prosopagnosia –> inability to recognise familiar faces or learn new faces aka face blindness)
What imaging techniques can be used to assess cortical function
( remember there are a few ways we do this
1) Measure brain activity in healthy ppl then compare to lesioned ppl
2) Measure brain activity throughout the day / night
3) Measure brain activity while doing a particular activity
1) PET scans –> measures blood flow directly to a brain regions by measuring uptake of radioactive glucose at different areas
2) functional MRI –> measures2 amount of blood O2 in brain
3) EEG–> measures electrical signals produced by brain ( useful for sleep and epilepsy)
4) MEG –> measures magnetic signals prod by brain ( new)
note both EEG and MEG are measured by event related potentials / evoked potentials
How to use encephalography ?
place electrodes on head then look at graph produced by event related potentials evoked potentials
if different electrodes are placed at different parts of the body can get a series of waves that reflect sequential activation of neurons along somatosensory pathways and can tell where a problem occurs in the body
( see docs)
How do you stimulate the brain to assess cortical function
Assess function of neural circuits –> used electromagnetic induction to stimulate neurons ( TMS / transcranial magnetic stimulation)
What is brain stimulation used for
1) investigate neurons controlling movements after a spinal cord injury
2) investigate whether a specific brain area is responsible for a function ie speech
What is Transcranial direct current stimulation (tDCS)
Using low direct current over the scalp to increase or decrease neuronal firing rates . can be used to treat epilepsy
describe 2 imaging techniques of the brain
Diffusion tensor imaging (DTI) based on diffusion of water molecules
DTI with tractography ( 3d reconstruction to assess neural tracts)
