Cortical organisation and function Flashcards
What are the functions of the frontal lobe?
- regulating and initiating motor function
- language
- cognitive functions e.g. planning
- attention
- memory
What are the functions of the parietal lobe?
- sensation: touch, pain
- sensory aspects of language
- spatial orientation and self-perception
What is the function of the occipital lobe?
- processing visual information
What are the functions of the temporal lobe?
- processing auditory information
- emotions
- memory
What structures make up the limbic lobe?
- amygdala
- hippocampus
- mammillary body
- cingulate gyrus
What are functions of the limbic lobe?
- learning
- memory
- emotion
- motivation and reward
Where is the insular cortex found?
deep within lateral tissue (between frontal and temporal lobe)
What are the functions of the insular cortex?
- visceral sensations
- autonomic control
- interoception
- auditory processing
- visual-vestibular integration
What is grey matter?
neuronal cell bodies and glial cells
What is white matter?
myelinated neuronal axons arranged in tracts
What are association fibres?
white matter tracts that connect areas within SAME hemisphere
–> short fibres and long fibres (superior longitudinal fasciculus, arcuate fasciculus, inferior longitudinal fasciculus and uncinate fasciculus)
What are commissural fibres?
white matter tracts that connect similar structures in the left and right hemispheres
e.g. corpus callosum, anterior commissure
What are projection fibres?
white matter tracts that connect the cortex w/ lower brain structures e.g. thalamus, brainstem, spinal cord
(corona radiata, internal capsule)
What are the differences between primary and secondary/association cortices?
- 1y= predictable function, whereas 2y less predictable
- 1y organised topographically, but 2y not
- 1y has symmetry between left and right, whereas weak/absent symmetry in 2y cortices (some only found on one hemisphere)
What are the motor areas in the frontal lobe?
- primary motor cortex: somatotopic, fine/precise voluntary movements
- supplementary area: planning movements (INternally cued)
- premotor area: planning complex movements (EXternally cued)
What is the difference between the primary somatosensory cortex and the somatosensory association cortex?
- 1y processes somatic sensations arising from receptors in body (e.g. fine touch, vibration etc…)
- association cortex interprets significance of sensory info (e.g. recognising object placed in hand)
What is the difference between the primary visual cortex and the visual association cortex?
- primary visual processes visual stimuli
- visual association gives meaning and interpretation fo visual input
What is the difference between the primary auditory cortex and the auditory association cortex?
- primary auditory processes auditory stimuli
- auditory association gives meaning and interpretation of auditory input
What is the prefrontal cortex?
- attention
- adjusting social behaviour
- planning
- personality
- decision making
What is the Broca’s area and what would occur if there was a lesion here?
- association area in left (usually) frontal lobe
- involved in PRODUCTION of language
- N.B. if lesion, expressive aphasia- poor production of speech, but comprehension intact
What is the Wernicke’s area and what would occur if there was a lesion here?
- association area in left temporal lobe
- involved in the COMPREHENSION of language
- N.B. if lesion, receptive aphasia- poor comprehension of speech, but production is fine
What are classic symptoms of a parietal lobe lesion?
- contralateral neglect
- lack of awareness of self on contralateral side
- lack of awareness of extra personal space on contralateral side
What are classic symptoms of a temporal lobe lesion?
- agnosia (inability to recognise)
- anterograde amnesia (inability to form new memories)
What is prosopagnosia?
inability to recognise familiar faces or learn new faces (face blindness)
What does a PET scan indicate when it lights up?
blood flow directly to that brain region
What does fMRI assess?
amount of blood oxygen in an area of the brain
What does EEG measure?
electrical signals produced by the brain
What does MEG measure?
magnetic signals produced by the brain
What is transcranial magnetic stimulation (TMS)?
- uses electromagnetic induction to stimulate neurons (with a coil outside the head)
- assesses functional integrity of neural circuits
- can also be used as a therapeutic intervention
What is transcranial direct current stimulation (tDCS)?
- uses low direct current over the scalp to increase or decrease neuronal firing rates
- potential therapy
What is diffusion tensor imaging (DTI)?
- brain imaging based on diffusion of water molecules
- gives insight into connections within brain
