HiCortical Networks and Disconnection Sydromes Flashcards
Association Fibers
Fibers that connect distant and adjacent neocortical areas
Projection Fibers
Ascending fibers to and from neocortex
Comissural Fibers
Connect the two hemispheres
Conduction Aphasia
Predicted by Wernicke
Result of severing fiber connections between the anterior and posterior speech centers
Liepmann
Developed the theory of apraxia–> series of neocortical disconnections
Comissurotomy
Surgical severing of cerebral commissures
Treatment for epilepsy
Callosal Agenesis
Congenitally reduced or absent interhemispheric connections
When humans are born without a corpus callosum
Of all the senses which system connections are not crossed
The olfactory system
Anosmic
Lacking sense of smell
What happens when you sever the anterior commissure?
Inability of the right nostril to name odors
Where does visual stimuli in the right visual field travel?
To the left hemisphere
Where does visual stimuli in the left visual field travel?
To the right hemisphere
What happens to the vision system after a commissurotomy?
Info. is no longer shared
Where do sensations in the left hand travel to?
The right hemisphere
Where do sensations in the right hand travel to?
The left hemisphere
What happens to somatosensory functions after commissurotomy?
They become independent
Auditions
Has both cross and uncrossed sections
What happens to the left ear after hemispheric disconnection?
Input to this ear is suppressed
Movement
Largely crossed sections
What happens to the posterior transection after partial disconnection?
Disruption of visual transfer
Somatosensory transfer affected
What happens to the anterior transection after partial disconnection?
Motor Disturbance
When does apraxia of the left hand appear?
When it is disconnected from the left hemisphere
When does apraxia of the right hand appear?
When there is a disconnection between the verbal center in the left hemisphere and the motor cortex in the left hemisphere
Contralateral Neglect
Damage to the right parietotemporal junction
White matter damage
