10.1184/R1/12275450.v1 Erez Freud Erez Freud Marlene Behrmann Marlene Behrmann Fred_Behrmann_final_version Carnegie Mellon University 2020 preprint visual agnosia 2020-05-11 22:39:08 Preprint https://kilthub.cmu.edu/articles/preprint/Fred_Behrmann_final_version/12275450 <div>preprint of the paper. abstract:</div><div>Recent findings suggest that both dorsal and ventral visual pathways process shape information.<br>Nevertheless, a lesion to the ventral pathway alone can result in visual agnosia, an impairment in<br>shape perception. Here, we explored the neural basis of shape processing in a patient with visual<br>agnosia following a circumscribed right hemisphere ventral lesion and evaluated longitudinal<br>changes in the neural profile of shape representations. The results revealed a reduction of shape<br>sensitivity slopes along the patient’s right ventral pathway and a similar reduction in the<br>contralesional left ventral pathway. Remarkably, posterior parts of the dorsal pathway bilaterally<br>also evinced a reduction in shape sensitivity. These findings were similar over a two-year<br>interval, revealing that a focal cortical lesion can lead to persistent large-scale alterations of the<br>two visual pathways. These alterations are consistent with the view that a distributed network of<br>regions contributes to shape perception.<br></div>