Some of the differences in processing in the dorsal and ventral visual pathways include that the ventral stream, (the What), originates in primary visual cortex and extends along the ventral surface into the temporal cortex. In contrast, the dorsal stream, (the Where) also arises in primary visual cortex but continues along the dorsal surface into parietal cortex (Hebart & Hesselmann, 2012). The ventral stream is sometimes nicknamed the “vision-for-perception” pathway. It is believed to mainly work towards recognition and discrimination of visual shapes and objects. The dorsal stream can be nicknamed the “vision-for-action” pathway, and has been primarily associated with “visually guided reaching and grasping based on the moment-to-moment analysis of the spatial location, shape, and orientation of objects” (Hebart & Hesselmann, 2012).
If I had a friend who had an injured dorsal visual pathway, that might manifest as optic ataxia, where there is a deficit in reaching and grasping objects. They may reach too far or too near from the object, or have difficulties climbing stairs. If this friend had an injured ventral visual pathway, that might look like an inability to visually identify and descriminate between objects (Van Polanen & Davare, 2015). Additionally, faces, facial expressions, and reading could all be daily challenges (Dutton, 2003, p. 298).
Deficits in their daily functioning from an injured ventral visual pathway would include an inability to label an item, such as a pencil, but be able to use the pencil as the ability to use “vision-for-action” is still intact. Contrastingly, deficits in their daily functioning from an injured dorsal visual pathway would include an inability to be spacially aware of the pencil, inhibiting the ability to use hand-eye coordination, but the ability to label the pencil would still be intact. Thanks for reading!