Evidence for ventral and dorsal neural pathways for visuo-haptic object recognition

Sunah Kim, Daniel Eylath, Ryan Andrew Stevenson, Thomas Wellington James
Poster
Last modified: 2008-05-15

Abstract


There is ample evidence that the primate visual system comprises two visual pathways: a ventral pathway for the identification of objects and a dorsal pathway for visually-guided action and/or spatial processing of objects. A few behavioral and neuroimaging studies have shown that there also exist separate ventral and dorsal processing pathways in human somatosensory system. In the current functional magnetic resonance imaging (fMRI) study, visuo-haptic object-selective brain regions that responded more to both visual and haptic objects than textures were defined in seven participants. We specifically analyzed three bimodal regions of interest, the left lateral occipital tactile-visual area (LOtv) and the anterior aspect of the left fusiform gyrus (FG) in the ventral pathway, and the left anterior intraparietal sulcus (aIPS) in the dorsal pathway. Patterns of BOLD (Blood Oxygen Level-Dependent) activation in these bimodal regions were analyzed for evidence of multisensory integration by presenting unimodal and bimodal visual and haptic stimuli at two levels of saliency. Results showed different patterns of BOLD activation in the ventral and dorsal pathways, suggesting that the two pathways integrate visual and haptic sensory inputs using different mechanisms.

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