Lateralization

• The corpus callosum is the biggest white matter tract between hemispheres and is made up of 200 to 250 million axons
• Anterior commissure


  White matter tract 1/10 the thickness of the corpus callosum between the two temporal lobes and conveys important limbic info like memories and emotion
• Hippocampal commissure


  One of the outputs of the HPC that connects the two and are points of reference in surgical dissection
• Myers and Sperry were curious about the communication between the two hemispheres, so they ran tests on cats, then on humans who had a corpus callostomy and Sperry eventually won a Nobel prize for his findings
• Corpus callostomy (commissurotomy)


  When the corpus callosum is severed to help with seizures in epileptic patients
• Interhemispheric transfer


  How information is passed between the hemispheres of the brain
• The Myers Sperry cat experiments had an experimental group (cut corpus collosum and optic chiasm) and 3 controls (no changes or one of each cut)
• Optic chiasm


  Nerve that moves visual information to the other hemisphere
• Box-selection behavioral test


  Myers Sperry test on cats. One box had food, one didn't. The cats learned which one did while wearing an eyepatch, and went from 50% success to 100% after they'd learned. In experimental cats, when the eyepatch was switched, they had to restart because the opposite hemisphere of the brain had no knowledge of the boxes
• Brain split patients


  Patients who've had their corpus callosums cut to mitigate their epilepsy
• Split brain patients who were shown a donut in their right hemisphere (left eye) could not verbalize what they were seeing because the left hemisphere is better at language. They had no issues with the opposite side
• When split brain patients had an apple placed in their right hands, they could easily find it in a box of other objects by feeling around with their right hand. However, they could not do that with their left hand, because the right hemisphere had no knowledge of the apple
• Agenesis of the corpus callosum (ACC)


  When a person is born without a corpus callosum. They sometimes develop atypically, and 1/4 have mental disabilities, but most are normally intelligent (might have some issues with social cues like in autism tho). Rain Man is based on a savant with this