Peter Kaposvari, Gergo Csete, Anna Bognara, Peter Csibri, Eszter Toth, Nikoletta Szabo, c, Laszlo Vecsei, Gyula Sary, Zsigmond Tamas Kincses
Abstract
Audio–visual integration has been shown to be present in a wide range of different conditions, some of which are processed through the dorsal, and others through the ventral visual pathway. Whereas neuroimaging studies have revealed integration-related activity in the brain, there has been no imaging study of the possible role of segregated visual streams in audio–visual integration. We set out to determine how the different visual pathways participate in this communication. We investigated how audio–visual integration can be supported through the dorsal and ventral visual pathways during the double flash illusion. Low-contrast and chromatic isoluminant stimuli were used to drive preferably the dorsal and ventral pathways, respectively. In order to identify the anatomical substrates of the audio–visual interaction in the two conditions, the psychophysical results were correlated with the white matter integrity as measured by diffusion tensor imaging.The psychophysiological data revealed a robust double flash illusion in both conditions. A correlation between the psychophysical results and local fractional anisotropy was found in the occipito-parietal white matter in the low-contrast condition, while a similar correlation was found in the infero-temporal white matter in the chromatic isoluminant condition. Our results indicate that both of the parallel visual pathways may play a role in the audio–visual interaction.
Source: CLICK HERE
Keywords:
MRI, DTI, TBSS, Multisensory, Doubleflash
