Visual perception
the dorsal stream aka ambient system, “where” pathway that is responsible for producing our sense of spatial orientation,binocular fusion/depth perception, and the location,movement, movement direction and velocity of objects in space.
ventral stream aka focal system, “what” pathway that is responsible for recognizing objects and colors,reading text, and learning and remembering visual objects.
mTBI slows the acquisition and processing of visual information, so naturally certain areas of visual perception, especially timed tests , can be affected. Visual attention is another area that is affected in mTBI; therefore, visual discrimination and figure–ground can also
be affected.
ms TBI are usually more focal and more severe. Injury to the parietal lobe will cause more deficits in the where pathway and will affect visual-motor integration. Injury to the temporal lobe will cause more deficits in the what pathway and will affect visual closure and visual discrimination.
In most ways, a visual perceptual assessment on a TBI patient is no different than the one performed on a learning disabled patient of the same age.
reliable:
The test should give the same result if repeated on the same person.
The test should give the same result if repeated on the same person by a different examiner.
validity:
The test should measure what it purports to measure.
