Visual experience supports haptic face recognition: Evidence from the early- and late-blind

In previous experiments, we provided further evidence that the haptic and visual systems both have the capacity to process faces, and that face information can be shared across sensory modalities [1]. Interestingly, we found this information transfer across modalities to be asymmetric and limited by haptic face processing. Visual face perception relies on specific processes that evolve with perceptual expertise, while we have little to no training in haptic face recognition throughout life. We, therefore, suggest that the observed asymmetry in visual and haptic face processing might be attributed to different levels of expertise. To test the importance of visual experience with faces also for haptic recognition we studied haptic face recognition in the early-blind (N=10), late-blind (N=9) and sighted (N=18). Participants performed an old/new recognition task for which sets of three faces were learned haptically, followed by three subsequent haptic test-blocks. We found that early-blind participants could recognize faces haptically, although recognition accuracy was low (d’= 0.83). More interestingly, however, recognition accuracy was significantly better in late-blind (d’=1.56) as well as sighted (d’=1.42) participants. Our results, therefore, suggest that behavioral benefits in haptic face recognition require visual experience with faces. A lack thereof cannot be compensated for by purely perceptual haptic expertise as the results for the early-blind show. These findings suggest that haptic face recognition can recruit specific visual processing mechanisms that are shaped by visual experience [2]