Association cortices

Question 1

What is an association cortex?

Answer 1

Anything not in the primary sensory or motor areas (so most of the cortex, the fucking morons, this whole deck is shit dont bother)

Question 2

What is the cytoarchitecture of the neocortex and rough functions of each layer?

Answer 2

1 - pyramidal - input/output to other cortical areas, ipsilateral (usually sensory) but also contralateral (corpus callosum + anterior commisure)
2 - pyramidal - as above
3 - pyramidal - as above
4 - stellate cells - input layer = thalamus (esp primary sensory) , other cortical sites and brainstem modulatory systems (also feedd to every other layer)
5 - big apical branching neurons… output = basal ganglia
6 - as with 5, output = thalamus

White matter

Question 3

What are paleo- and archicortex?

Answer 3

Paleo = 3 layers, ventral surface of hemispheres

Archi - 4 layers, hippocampus

Question 4

How did Brodmann sort out his areas?

Answer 4

Using cytoarchitecture - different in cell densities between layers

Question 5

What is the function of the parietal lobe?

Answer 5

Right hemisphere dominance - controls visual attention for the whole visual field so right lesion is worse; left only attends to the right (as left hemisphere specialised for language)

Damage = visuospatial neglect - draw a house, bisect the line etc

Question 6

What is the function of the temporal cortex?

Answer 6

Contains the fusiform face area - active when presented with faces; inferior temporal lesions = prosopagnosia

Regions also represent bodies, scenes, objects, visually presented words, other peoples beliefs

Deficits agnosias - right = typically faces/objects; left = language material

Processing is reliant on graded signals carried by a population of neurons rather than individual cells for specific things

Similar regions present in macaques

Question 7

What is the function of the frontal cortex?

Answer 7

Phineas Gage + evidence from psychosurgery frontal lobotomies for schizophrenia :(

'Personality'
Executive functions - planning, rule following, logic, task switching, inhibition, reward processing (ventromedial)
Memory retrieval (dorsolateral) 

Failures on Wisconsin card sort, tower of Hanoi etc

Question 8

What are the subcortical structures responsible for input and what are their neurotransmitters?

Answer 8

Midbrain - dopaminergic nuclei

Brainstem - noradrenergic and serotonergic nuclei

Brainstem and basal forebrain - cholinergic nuclei

Contribute to learning, motivation, arousal etc

Dysfunctions in behavioural and psychiatric disorders; drug treatments treat chemical imbalances (no shit)

Question 9

What is diffusor tensor imaging?

Answer 9

DTI - identifies large bundles of axons connecting brain areas in living brains

Human connectome project = mapping all connections in human brain

Question 10

What has single unit electrophysiology taught us?

Answer 10

Can chronically implant electrodes in awake behaving primates, restrain them and train them to do various things for juice…

Posterior parietal cortex - visual attention (we knew this..)

Inferior temporal cortex - cells respond to monkey faces, less so to human faces, some more to monkey faces side on/at certain angles, less so with scrambled faces or parts hidden, less so to hands (we can do this with fMRI…)

Dorsolateral prefrontal cortex - reference memory ie delayed matching to sample task (food hidden under cover, screen comes down then back up, monkey finds food) - neurons may contain a representation of hidden food (again, fMRI and patients ffs why u cage the monkey?)