Lesions of the Medial Occipito-Temporal cortex affect spatial binding of sensory and memory data

Occipito-temporal cortex is parcellated, with medial regions having a greater representation of the visual periphery than regions along the lateral aspect. Imaging studies have suggested disparate functions for medial regions. These proposals do not generally account for the dramatic impairments of attention and memory displayed by patients with strokes in medial Occipito- Temporal cortex. We examined a middle-aged man, who had suffered bilateral posterior circulation strokes involving the medial Occipito-Temporal cortex. The patient showed impaired recognition of compound objects, when constituent parts were rearranged, but not, for example, when their shape was changed. The patient was impaired when recalling the color of an object from visual working memory, only when the object was identified by its location, rather than shape. He showed a specific liability to long recall delays, with an increase in spatial binding errors. The patient had no difficulty discriminating large and small objects, or performing a facial discrimination task, as long as the task did not require the appraisal of fine spatial relations between facial features. We conclude that medial Occipito–Temporal Cortex is crucial for spatial binding of perceptual and memory information, in part because of its role in maintaining stable spatial representations over time.