[show abstract][hide abstract] ABSTRACT: The ability to understand events that happen to other people is a characteristic feature of the human mind. Here, we investigate whether the links between mental representation of one's own body and the bodies of other people could form the basis of human social representations. We studied interpersonal body representation (IBR) in a series of behavioural cueing experiments. Subjects responded to tactile events on their own body after a visual event was presented in either the corresponding anatomical location on a model's body, or in a non-corresponding location. We found that reactions were faster when the visual cue was in register with the tactile stimulation. This effect was absent when identical visual events were presented on a non-body control stimulus, suggesting a body specific mechanism for interpersonal registration of purely sensory events. Similar interpersonal systems have been demonstrated previously for the coding of action and emotion, but we believe that our results provide the first behavioural evidence for interpersonal body representation at the purely sensory level. We show that a sensory processing mechanism specific for bodies is automatically activated when viewing another person. Interpersonal body representation may be an important precursor to empathy and theory of mind. In our social world, we understand the percepts of others by registering them against the representations used to perceive our own body, and this mechanism involves an interpersonal somatotopic map.
[show abstract][hide abstract] ABSTRACT: We report a study on a patient (DW) with integrative visual agnosia and a category-specific recognition impairment for living things. We assessed DW's local and global processing and tested if his integrative agnosia could have led directly to his category-specific impairment. The main findings were: (i) DW was faster at identifying local compared to global letters. (ii) DW showed no local-to-global (or global-to-local) interference effects in selective attention tasks. (iii) DW showed a congruency effect in a divided attention task, suggesting that, when his attention was cued to both levels, he could process information simultaneously and integrate local and global information. (iv) Controls were poorer at naming nonliving compared to living things when presented with silhouettes. These data suggest that local and global information are differentially weighted in the visual recognition of living and nonliving things, and that an impairment in processing the overall shape of an object can lead to a category-specific deficit for living things. Crucially, this implies that category-specific impairments do not necessarily reflect damage to the semantic system, and models of semantic memory based on this assumption need to be revised.