Abstract

We assessed perceived angular self-location in a vestibular orientation task involving passive whole-body angular displacements in the dark, in 14 focal right hemisphere stroke patients. We report that self-location perception was impaired only in patients with lesions involving the Temporo-Parietal Junction (TPJ) and then only for leftward displacement. Self-motion (ie, vestibular) perception could not explain the deficit as this was preserved in all patients. We also found no correlation between the degree of hemi-spatial neglect and self-location perceptual performance. Critically however, in only those patients with a manifest spatial deficit, did we find a congruent and co-lateralised impairment of motion duration perception, suggesting but not confirming that self-location perception relies upon internal estimates of time. Thus, in a separate series of experiments, we show that healthy humans update their percept of motion duration when provided with erroneous self-position feedback, implying that self-position perception is indeed encoded as a function of time. We thus infer from our data that humans utilise an explicit measure of time in deriving their self-position perception from vestibular signals of self-motion and this perceptual neural integration occurs in the TPJ.