Chapter 14:
Lateralization and Language
What is Lateralization?
1.
What does ‘lateral’ mean in the CNS?
2.
What do you know about the organization
of the brain that might speak to this issue?
Let’s talk about connection…
1.
2.
The two hemispheres are connected by a
band of axons
There are three other commissures where
some hemispheric communication occurs
Problems with the Corpus Callosum
Surgical severing
1.
•
Split-brain video
2.
Maturation
3.
No corpus callosum
Physical Evidence of Lateralization
1.
Handedness
2.
Footedness
How important are hemispheric
distinctions?
1.
In the 80’s this was a very hot area of ‘study’
in pop-psychology
2.
As I’m sure you can imagine, there are NO
real-world experiences that use only one
hemisphere
Functional Differences: Spatial
Relationships
1.
Right hemisphere
2.
People with damage on the right side of the
brain would have a hard time getting around
the Mount
3.
Which hand would split-brain patients be
better able to put a puzzle together with?
Functional Differences: Emotion
1.
The right hemisphere is dominant for
understanding emotion
2.
There is some research that indicates that
the left side is better at understanding
happiness, the right is better at anger/fear
Functional Differences:
Language
1.
In most people, the language centers of the
brain reside in the left hemisphere


2.
Broca’s area
Wernicke’s area
The right hemisphere does seem to have some
very basic semantic (word naming) knowledge
Evolution of Language
1.
Humans have unique language abilities

2.
Productivity
Non-human primates also have language
skills, but not with the same level of
productivity
Can chimps talk?
1.
Common chimps do communicate orally, but
their calls don’t resemble human speech
2.
They can be taught very basic sign-language
& to use other symbolic representations to
indicate requests, etc.
3.
But they don’t use these gestures and
symbols to make unique communications
Bonobo video
Chomsky & Theory of
Language Aquisition
1.
‘Language Acquisition Device’
•
LAD is required for language to develop
Critical Period?
1.
If we aren’t exposed to language during
childhood, will we ever be able to learn it?
Aphasias


Broca’s aphasia – non-fluent aphasia
•
Broca's video
Wernicke’s aphasia – fluent aphasia
•
Wernicke's video