Lecture 16: Cerebral Cortex

Question 1

Describe the major functions of the lobes of the cortex

Answer 1

Frontal: logic, judgement, planning
Occipital: visual processing
Parietal lobe: sensory processing
Temporal lobe: auditory processing

Question 2

Explain the different stages of sleep in an EEG

Answer 2

stage 1: alpha: relaxed, eyes closed
beta: relaxed, eyes open
stage 2: theta waves
stage 3: sleep spindles, K complexes
stage 4: delta waves
stage 5: REM sleep - similar to when aroused

Question 3

Describe the parts of the brain responsible for understanding language and producing speech

Answer 3

understanding language: Broca’s area

producing speech: Wernicke’s area

Question 4

Describe 2 experiments related to interhemispheric transfer

Answer 4

With rats: teach them how to respond to stimulus when one eye is covered. If there is split in optic chiasm and corpus callosum, then there will be no learning between eyes (interocular transfer)

with humans: display word to monocular vision. This will not cross over to the contralateral side, so human can’t pick up correct object with the ipsilateral side as the visual cortex. (muscles control contralaterally)

Question 5

Describe the cerebral cortex layout

Answer 5

Has 3 layers: neocortex (90%) (6 layers), paleocortex (4-5 layers), archicortex (3 layers)

Afferents from thalamus to cortex go to layer 4
Efferents to other parts of the cortex originate in layer 2 and 3
efferents to the spinal cord/brain stem originate in layer 5
efferents to the thalamus originate in layer 6

Question 6

Describe the different layers of the neocortex

Answer 6

1) Molecular layer: axon terminals
2) External granular layer: stellate cells
3) External pyramidal layer: small pyramidal cells
4) Internal granular layer: stellate cells
5) Internal pyramidal layer: subcortical efferents
6) Multiform layer: pyramidal and fusiform cells, corticothalamic efferents

Question 7

Describe the structure of the hippocampus

Answer 7

has 3 layers: molecular, pyramidal, and polymorphic layer
composed of the hippocampus, dentate gyrus, and subiculum
part of memory and emotion (Papez’s circuit)

Question 8

Describe what happens with damage to the parietal lobe (posterior and non-dominant), hippocampus, frontal lobe

Answer 8

Parietal lobe: in general, loss of spatial awareness
posterior: can’t put self on map
posterior parietal: visual neglect/physical neglect on right side, can’t calculate or write on the left side

hippocampus: loss of memories, learning, short term memory

frontal lobe: loss of personality, dis-inhibition of behaviour, motor planning/initiation