Cortex; a journal devoted to the study of the nervous system and behavior
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The visual system is able to represent and integrate large amounts of information as we move our gaze across a scene. This process, called spatial remapping, enables the construction of a stable representation of our visual environment despite constantly changing retinal images. Converging evidence implicates the parietal lobes in this process, with the right hemisphere having a dominant role. ⋯ The results were consistent with an impairment in spatial remapping for left visual field targets following adaptation to leftward-shifting prisms. These results suggest that temporarily realigning spatial representations using sensory-motor adaptation alters right-hemisphere remapping processes in healthy individuals. The implications for the possible mechanisms of the amelioration of hemispatial neglect after prism adaptation are discussed.
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For individuals with vision-touch synaesthesia, the sight of touch on another person elicits synaesthetic tactile sensation on the observer's own body. Here we used the traditional rubber hand paradigm (Botvinick and Cohen, 1998) and a no-touch rubber hand paradigm to investigate and to authenticate synaesthetic tactile sensation. In the traditional rubber hand paradigm, the participant views a prosthetic hand being touched by the Examiner while the participant's hand - hidden from view - is also touched by the Examiner. ⋯ Thus, synaesthetic tactile sensation on the (untouched) hidden hand was referred to the prosthetic hand. These individuals also demonstrated proprioceptive drift (a change, from baseline, in proprioceptively perceived position) of the hidden hand towards the location of the prosthetic hand, and a pattern of increased proprioceptive drift with increased trial duration (60 sec, 180 sec, 300 sec). The no-touch rubber hand paradigm was an excellent method to authenticate vision-touch synaesthesia because participants were naïve about the rubber hand illusion, and they could not have known how they were expected to perform on either the traditional or the no-touch rubber hand paradigm.