9 - Cortical Networks & Disconnection

Question 1

cortical networks

Answer 1

unique pathways of activity that control our complex cognitive processes

Question 2

association pathways

Answer 2

• long fiber bundles that connect distant neocortical areas & short fibers that connect adjacent areas
• 1 of 3 neural fiber pathways connecting neocortex

Question 3

projection pathways

Answer 3

• ascending fibers from lower brain to neocortex & descending fibers from neocortex to brainstem and spinal cord
• 1 of 3 neural fiber pathways connecting neocortex

Question 4

commissural pathways

Answer 4

• connect the 2 hemispheres; includes corpus callosum, anterior commissure, hippocampal commissures
• 1 of 3 neural fiber pathways connecting neocortex

Question 5

genu

Answer 5

• anterior part of corpus callosum
• contains fibers projecting from prefrontal cortex

Question 6

splenium

Answer 6

• posterior callosum
• fibers project from superior temporal, inferior temporal, & visual cortices

Question 7

anterior commissure

Answer 7

• connects parts of anterior temporal lobe, amygdala, & paralimbic cortex of temporal lobe

Question 8

commissurotomy

Answer 8

• treatment for epilepsy involving removal of interhemispheric fibers
• –> each hemisphere can only see opposite side of visual world; isolates speech in people with lateralized speech

Question 9

callosal agenesis

Answer 9

• people born with congenitally reduced/absent interhemispheric connections
• develop enhanced ability to use few projections, but still many deficits exist

Question 10

animal research

Answer 10

• disconnections performed to learn about symptoms, interhemispheric development, & model human symptoms

Question 11

anosmia

Answer 11

• loss of smell
• If anterior commissure is severed….cannot name odors presented to R. nostril b/c speaking L. hemisphere is disconnected from the information, but L. hand can pick out object emitting odor
• remember olfactory connections are NOT crossed