parietal lobes (touch) (e3) Flashcards
what are the two functional zones of the parietal lobes?
the anterior zone
- somatosensory cortex
the posterior zone
- posterior parietal cortex (PE, PF, PG)
anterior = own body
posterior = outside body
what is the organization of the somatosensory cortex?
it is organized into maps
- adjacent areas of the skin project to adjacent areas in the brain
- some areas on the skin are represented by a disproportionately large area of the brain
how can representations of a specific area of the body become larger?
with experience
- i.e., violin player have a greater cortical representation for fingers on their left hand
what are the body maps called?
homunculus
what is the phantom limb experience?
- even though there is nothing there, you feel a pain sensation in the amputated limb
- when a body part is amputated, it doesn’t get anymore input, so the body-image map is reorganized and invades other representations (reorganization)
three pathways leaving the posterior parietal region and traveling to:
premotor: “how” pathway
prefrontal: visuospatial working memory
medial temporal regions: spatial navigation
anosognosia
unawareness of illness
Balint’s syndrome
simultagnosia and optic ataxia (pertains to where pathway)
neglect syndrome
problem with consciousness (neglect)
the Gerstmann syndrome
dysgraphia, dyscalculia, problems with right-left discrimination
apraxia
loss of a skill movement not caused by weakness
problems with sensoriomotor transformation (posterial parietal region)
when we integrate movements of various body parts with sensory feedback of what movements are actually being made (the efference copy - corollary discharge) and the plans to make movements
corollary discharge
efference copy of an action command that inhibits sensory responses so that those don’t interfere with the execution of the motor task
example of the efference copy
tickling yourself
