|
Dynamic properties of multisensory peripersonal space : an fMRI investigation| old_uid | 2295 |
|---|
| title | Dynamic properties of multisensory peripersonal space : an fMRI investigation |
|---|
| start_date | 2007/02/22 |
|---|
| schedule | 16h |
|---|
| online | no |
|---|
| summary | Multi-modal neurons in primates can encode tactile and visual information with spatially coinciding receptive fields. This suggests that visual space is encoded in relation to the body. We set out to find cortical areas in humans that represent visual information with respect to the position of the hand, using fMRI. We identified brain areas that showed preference (near space > far) to a visual stimulus when it was presented in perihand space. These areas were localised mainly along the contralateral intraparieatal sulcus (IPS) and in the lateral occipital complex. Interestingly, some of these areas showed a similar preference for a visual stimulus approaching a realistic looking dummy-hand, while the anterior IPS also showed a preference for the same stimulus approaching the subjects’ occluded hands.
Next, we used a similar paradigm to tackle the question whether peripersonal space can be dynamically extended by the use of tools upon objects which are out of reach. Our preliminary results show that the left anterior IPS showed changes in activation following a training period of tool-use, which is consistent with an extension of peripersonal space. This was not the case, following a control period of similar training, which did not include any tool-use.
In conclusion, these results parallel findings in monkeys, neuropsychological patients, and in behavioural studies which reveal the multisensory and dynamic properties of peripersonal space. |
|---|
| responsibles | Farnè |
|---|
| |
|