exam one (central vision system) Flashcards
what is the pathway of vision from the retina
optic nerve, optic chiasm, optic tract, LGN, primary visual cortex (striate cortex)
is information from both eyes shared at the level of the optic nerve
no
is information from both eyes shared at the level of the optic tract
yes
axons from the ____ retina cross over to opposite side of the brain, while axons from ____ retina remain
nasal, temporal
_____ field is what one eye receives
receptive
____ field is a region of the visual world
visual
what happens if you cut the optic nerve of the left eye
lost vision in left eye but only in peripheral (right eye covers the nasal portion)
what happens if you cut the left optic track
lose right visual field (half of your world vision)
what would happen if you cut at optic chiasm
peripheral vision is lost in both left and right
info from left visual hemi field goes to ___ LGN
right
in the LGN layers 1 and 2 have what cell type
magnocellular
the nonM-nonP are ___ to each principal layer
ventral
in the LGN layers 3-6, what is the cell tye
parvocellular
_____ provides 80% of the excitatory synaptic input to the LGN
Primary visual cortex
neuron in this structure provides modulatory influence on neuronal activity in the LGN
brain stem
what two structures project to LGN not from the retina
brain stem and PVC
a ___ point of light in the retina activates many cells in the striate cortex to overlapping receptive fields
discrete
the area of the central retina is ______ in the striate cortex
overrepresented
what layers of the striate cortex do you find pyramidal cells
III, IVB, V, VI
what layers of the striate cortex do you find spiny stellate cells (make local-vertical connections)
IVC
where do the magnocellular LGN neurons project within the striate cortex
IVC alpha
where do the parvocellular LGN neurons project within the striate cortex
IVC beta
where do the koniocellular LGN axons project within the striate cortex
make synapses in layers II and III
where are horizontal connections made
layer III
even in layer III, there will be _____ dominance of one eye in certain columns
ocular
each ____ centered on an ocular dominance in layer IV
blob
the blobs receive mostly ____ inputs from LGN
koniocellular
what layers have projections that go out of the striate cortex
II, III, IVB
what layer of the striate cortex project to the superior colliculus and pons
V
what layer of the striate cortex project back to the LGN
VI
V1 neurons (outside of IVC) are _____ selective
orientation
some V1 neurons are complex cells, which are binocular and have ON and OFF responses, but with no distinct _____ regions
on-off
striate cortex
cortical neurons above layer IV and centered on the interblob region exhibit ____ and _____ selectivity
binocularity and orientation
cortical neurons superficial to IVC and centers on blobs which generally exhibit _____ and ______ sensitivity (no orientation or direction selectively)
monocularity and wavelength
the magno cellular pathway for visual processing is thought to be
motion specific
the Parvo-interblob pathway for visual processing is thought to be
shape specific
the blob pathway (koniocellular) for visual processing is thought to be
color specific
from the striate cortex the visual information takes two pathways; what are they?
dorsal and ventral
where does the dorsal stream go (the “how” pathway”
parietal lobe
where does the ventral stream go (the “what” pathway)
temporal lobe
the parietal lobe houses the
primary motor cortex
the temporal lobe is mostly
auditory
the dorsal stream is analysis of visual ____ and the visual control of action
motion
the ventral stream is ___ of the visual world and ___ of objects
perception and recognition
the dorsal stream goes from V1 (in the striate cortex) to V2, V3, and then to __ or the ___ ____ and finally to __ ___
V5 or middle temporal, medial superior temporal
dorsal stream
the Area MT is ___ ____ and respond more to the motion of objects rather than their shape
direction-selective
dorsal stream
the area MST is for what?
navigation and directing eye movements
the ventral stream takes what pathway from V1 (striate cortex)
V1, V2, V3, V4, IT
the area V4 of the ventral stream does
processing of color and shape (achromatopsia can come from damage to this area)
ventral stream
major output of V4 and the receptive fields respond to a wide variety of colors and abstract shapes, what is this area?
IT (inferior temporal lobe)
The ___ is another part of area IT which allows us to recognize faces
fusiform face area
the registration of physical stimuli from the environment by the sensory organs
sensation
