Cerebral Laterality

1
Cerebral Laterality
2
(No Transcript)
3
Left Lateralized Skills

• Language
• e.g., Brocas area
• Critical Thinking

4
Right Lateralized Skills

• Attention
• Spatial processing
• Emotion

5
Corpus Callosum

• 200 million neurons
• Interconnect LH and RH
• Cell body in cortex of one hemisphere
• Myelinated axon projects to other hemisphere

6
(No Transcript)
7
Body
Splenium
Genu
8
(No Transcript)
9
History

• 1850 Fechner proposed that CC might interconnect
  two hemispheres
• Two hemispheres might contain two separate
  consciousnesses

10
Wagenen

• 1940s performed 1st callousectomy
• 12 patients
• Partial cuts
• Little effect on behavior

11
Sperry Meyers

• Used cats to determine role of CC
• Patched one eye and tested to see if a visual
  discrimination behavior transferred to the other
  eye
• Tested
• Normal cats
• Cats with a severed optic chiasm
• Cats with severed chiasm and CC

12
(No Transcript)
13
Bogen and Vogel

• Cut CC and anterior commisure
• Controlled seizures
• Little effect on normal everyday behavior

14
(No Transcript)
15
(No Transcript)
16
Patient NG

• If picture or word projected to LH could name it
• Same items to RH could not name
• Objects could be identified if NG was allowed to
  feel objects with left hand

17
Everyday behaviors

• Lack of dreaming
• Problems with geometry
• Face name association problems
• Occasional conflects

18
Cross-cueing
19
Language Controversy

• Zaidel questioned whether split-brain patients
  really indicate that RH is mute
• Z-lens

20
(No Transcript)
21
Imagery

• Farah used upper/lower case task
• Is the lower case version of B tall or short?
• Used pointing task in split patients
• Found that LH was better than RH
• Suggests that LH may be more involved in imagery

22
Corballis

• Used mental rotation task

23
(No Transcript)
24
(No Transcript)
25
Corballis

• RH gt LH
• So, different kinds of imagery depend on
  different hemispheres

26
Chimeric Faces
27
Learn names with faces
28
(No Transcript)
29
Naming
30
Pointing
31
Attention - cueing