PSYC1002 Lecture Notes - Lecture 11: Expressive Aphasia, Frontal Lobe, Thalamus
19 May 2018
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Right hemisphere - receives sensory input from left, controls motor response on left side
of body
○
Left hemisphere - receives sensory input from right, controls motor response on right
side of body
○
Differences between 2 cerebral hemispheres
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2 hemispheres NOT perfect mirror images on one another
○
E.g most of us have hand-preference, indicates superiority of one hemisphere for
manual control
▪
Several "higher" functions are laterialised, so one side is more important/dominant
○
In most of us, left hemisphere controls speech and better at comprehension
▪
Stroke in left brain often causes aphasia (problem with production and
comprehension of speech)
□
Brain imaging: left hem is more active when person speaks or listens to
speech
□
Dichotic listening task - people understand word faster if presented to right
ear
□
Lateralisation of language - evidence
▪
Of all cognitive or behavioural functions, language is most lateralised
○
Hemispheric dominance
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Damage causes speech difficulties, but can understand speech (expressive
aphasia)
▪
Broca's aphasia not just a motor problem, patients can often sing
▪
Problems with writing but not drawing
▪
Deaf singers with damage can lose ability to sign
▪
Broca's area - lower posterior region of left frontal lobe
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Damage causes problems with speech comprehension (receptive aphasia)
▪
Cannot read
▪
Produce fluent but meaningless speech (fluent aphasia)
▪
Wernicke's area - posterior region of left temporal lobe
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Speech areas
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Hemispheric laterialisation
Lateralisation of function not normally evidence because info is shared between
The split brain
L6 - laterialisation of function and split brains, memory
Saturday, 4 November 2017
3:42 PM
Neuroscience Page 1
Document Summary
L6 - laterialisation of function and split brains, memory. Right hemisphere - receives sensory input from left, controls motor response on left side of body. Left hemisphere - receives sensory input from right, controls motor response on right side of body. 2 hemispheres not perfect mirror images on one another. Several higher functions are laterialised, so one side is more important/dominant. E. g most of us have hand-preference, indicates superiority of one hemisphere for manual control. Of all cognitive or behavioural functions, language is most lateralised. In most of us, left hemisphere controls speech and better at comprehension. Stroke in left brain often causes aphasia (problem with production and comprehension of speech) Brain imaging: left hem is more active when person speaks or listens to speech. Dichotic listening task - people understand word faster if presented to right ear. Broca"s area - lower posterior region of left frontal lobe. Damage causes speech difficulties, but can understand speech (expressive aphasia)
