Modality independent coding of 3d layout: fMRI evidence for PPA involvement of haptic and visual scenes by sighted and blind participants

Citation: 
Giudice, N.A., Wutte, M., Klatzky, R.L., Loomis, J.M., and Wolbers, T. (2009). Modality independent coding of 3d layout: fMRI evidence for PPA involvement of haptic and visual scenes by sighted and blind participants. 50th Annual Psychonomics Society Meeting. Boston, MA.
Abstract: 
The Parahippocampal Place Area (PPA) has been established as a brain area crucial for extracting the visuospatial structure of 3D scenes. However, previous research has only been carried out with visual stimuli. We propose that the PPA is recruited for spatial computation of 3-D geometric configuration, independent of encoding modality. To test this prediction, we used fMRI and compared PPA involvement for scenes apprehended from touch or vision. In experiment 1, sighted participants showed similar PPA activation for visual and tactile exploration of LEGO scenes but not objects. These effects were not related to visual recoding, given that we observed the same pattern of results in blind participants during haptic conditions in Experiment 2. Taken together, our findings strongly suggest that the PPA is an amodal (or supramodal) spatial processing region, which indicates that the human brain may represent space in a more abstract fashion than was previously thought.