Functional Areas of the Cerebral Cortex

Question 1

Describe the difference between primary, unimodal, and hetermodal areas of the cerebral cortex

Answer 1

Primary - simply receives/projects that modality
Unimodal - receives info from related from a primary area, does higher level processing of just that modality
Heteromodal - combines various modalities in the highest level of cognitive processing

Question 2

What are the main inputs to the Primary motor cortex

Answer 2

VA/VL of the thalamus (cerebellum/basal ganglia)
Somatosensory cortex
Premotor cortex

Question 3

What are the outputs from the Primary Motor Cortex

Answer 3

Corticospinal pathways
Corticopontocerebellar pathways
Corticobulbar pathways

Question 4

How is the body represented on the Primary motor and somatosensory cortices?

Answer 4

Tongue (lateral) to toe (medial)

Question 5

What does stimulation of the primary motor cortex do?

Answer 5

Leads to contralateral isolated movement of body and lower face

Bilateral movements of upper face, tongue, jaw, throat muscles

Question 6

What does lesion in the PMC cause?

Answer 6

Contralateral paresis (mostly in the distal limbs)

Apraxia (difficulty performing learned movements)

If the lesion causes overexcitment of PMC neurons than it can lead to convulsive epileptic seizures (Jacksonian seizures)

Question 7

What is the difference between Apraxia and Ataxia?

Answer 7

Apraxia = difficulty performing learned movements
Ataxia = uncoordinated movements usually due to cerebellar damage

Question 8

What is the function of the pre-motor cortex?

Is the premotor cortex primary, unimodal, or heteromodal?

Answer 8

Program the activity of the primary motor cortex

Unimodal

Question 9

What is the function of the supplementary motor area?

Is it primary, unimodal, or heteromodal?

Answer 9

Unimodal

Bimanual coordination, planning learned sequences of movements

Question 10

What is the function of the Frontal Eye Fields?

Answer 10

They have direct control over the superior colliculus, and they control horizontal saccades (voluntary scanning movements)

Question 11

What occurs with lesion to the Frontal Eye Fields?

Answer 11

Look toward the lesion

**Stimulation causes contralateral horizontal movement

Question 12

Is the prefrontal cortex primary, unimodal or heteromodal?

Answer 12

Heteromodal

Question 13

What are the impacts of frontal lobectomy/leukotomy?

Answer 13

Changes in personality, loss of social inhibition, lack in initiative - all lead to difficulty living independently

Question 14

Where does the primary somatosensory cortex receive inputs from?

Answer 14

VPM VPL of thalamus via posterior limb of internal capsule

Question 15

What do lesions in the primary somatosensory cortex lead to?

Answer 15

Poor localization of sensory stimulus, may lead to paresthesia

Question 16

Where is the somatosensory association cortex anatomically located?

Answer 16

Anterior part of supramarginal and superior parietal gyrus

Question 17

Function of somatosensory association area?

Answer 17

Sensory integration

Question 18

What can lesions to the somatosensory association area lead to?

Answer 18

Tactile agnosia - inability to recognize something that is in your hand (if you can’t see it)

Astereognosis - inability to combine sensory modalities to make sense of sensations

Question 19

Where does the occipital cortex receive projections from?

Answer 19

Lateral Geniculate Nucleus

Question 20

What do lesions to the primary visual cortex lead to?

Answer 20

Contralateral homonymous hemianopsia (depending if upper or lower, it can be quandrantic)

Question 21

What is the function of the visual association area?

Answer 21

Analysis of movement, colour and other properties of visual input

Question 22

What structure does the primary auditory cortex receive input from?

Answer 22

Medial Geniculate Nucleus of the Thalamus via internal capsule

Question 23

What would bilateral lesions to the primary auditory cortex lead to?

Answer 23

Cortical deafness

Question 24

What would a lesion to the superior temporal gyrus lead to?

Answer 24

Inability to interpret sounds

Question 25

What connects the Broca’s and Wernicke’s areas?

Answer 25

Arcuate Fasciculus

Question 26

What pathway is located where?

Answer 26

Occipital to temporal

Question 27

Where pathway is located where?

Answer 27

Occipital to Parietal