Transcript Ascending Visual Pathway

Ascending Visual Pathway
• Geniculostriate pathway
– form and detail
• Tectopulvinar pathway
– motion and location
• Both pathways start with the optic nerve leaving the
eye
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Both Pathways Go To The Optic Chiasm
Nasal
retina
Occipital lobe
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Optic Chiasm
• At the optic chiasm
– fibers from the nasal hemiretinas cross to the opposite
hemisphere
– fibers from the temporal hemiretinas continue to the
same hemisphere
• Retinotopic mapping
– the spatial relationships on the retina are preserved in
cortex
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Lateral View Of Visual Pathways
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Subdivisions Of The Occipital Lobe
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Geniculostriate Pathway
• Optic chiasm
– cross over
• LGN
– selective attention
• Occipital areas
– 17 - simple cells
– 18 - complex cells
– 19 hypercomplex cells
• Temporal lobe
– object identification
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Tectopulvinar pathway
• Optic chiasm (cross over)
• Superior colliculus
– location mapping
• Occipital lobe
– 18 - motion
– 19 - complex motion
• Temporal lobe
– combine visual information
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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Two Ascending Visual Pathways
Sensation and Perception -ascendvis.ppt
© 2001 Dr. Laura Snodgrass, Ph.D.
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