Abstract
The lateral occipital temporal cortex (LOTC) shows spatially overlapping responses for viewing hands and tools. This overlap is particularly interesting given that the two are functionally linked in object manipulation, giving rise to potential explanations based on connectivity constraints linking shape properties to motor affordances and action. Here we investigated the role of motor experience in driving the organization of this region, by studying five individuals born without developed hands (dysmelic subjects), who use tools with their feet. In an fMRI experiment we presented pictures of tools, non manipulable artifacts, hands and feet to the dysmelic subjects and to typically developed controls. We found that some dysmelic subjects, like the majority of the controls, showed an overlap between hand- and tool-selective responses in LOTC, refuting an explanation based solely on visuo-motor representations of actions. Instead, this suggests the region's overlap may develop based on object co-occurrence in visual experience alone. However, since both body and object responses were also observed in LOTC in people born blind, the current findings add support to a modality-independent organization model, based on connectivity constraints, without reliance on any specific sensory or motor experience. Of interest is the additional finding that some dysplasic subjects also had an overlap of foot- and tool-selective responses in LOTC, suggesting a certain level of plasticity to this principle, based on one's own sensory and motor experience.
Meeting abstract presented at VSS 2016