L11 - Brain Laterality

Question 1

Lateralised Functions:

Answer 1

• NO personalities linked to “Left Brain” or “Right Brain”
• Some cognitive functions rely more on one side of the brain than the other

Question 2

Left hemisphere:

Answer 2

• Language comprehension/reading (Right-handed = 95% of language in left hemisphere; Left-handed = 70%)
• Speech production (Broca’s)

Question 3

Right hemisphere:

Answer 3

• Tone of voice (prosody)
• Facial perception
• Perceptual grouping

Question 4

Contralateral (Crossed) Functions:

Answer 4

• Movement: Left hemisphere controls right side of body and vice-versa
• Sensation
• Vision: Left visual fields of both eyes go to right hemisphere; right fields of both go to left hemisphere

contralateral = opposite side

ipsilateral = same side

Question 5

Inter-Hemispheric Communication:

Answer 5

Corpus callosum: Nerve fibres (axons) from neurons of each hemisphere cross to contralaterally connect to the other

Question 6

Split brain experiments:

Answer 6

• Visual sensory information from the right visual fields enters the left hemisphere (responsible for language) where it can be verbally processed = Left hemisphere only
• Visual information from the left visual fields enters the right hemisphere BUT must then be communicated via the corpus callosum to the left hemisphere so that the object may be verbally processed = Both hemispheres
• Right hemisphere can still interpret and understand words so they can still draw/point to/identify the object with their left hand (right hemisphere)

Question 7

Independent hemisphere functioning:

Answer 7

• Left hemisphere can tell what it has seen
• Right hemisphere can only show it (via the left hand); Patient cannot say what their left hand is doing