Abstract
For material perception, audition also provides useful information as well as vision and haptics. A previous study showed that adults can judge an object's material by perceiving the visual appearance of one material is combined with the impact sound of the same material (Fujisaki et al., 2014). However, its development has been little understood. This study examined the brain activity in response to audiovisual material matching in fifteen 4-8 month-olds Japanese infants, using functional near infrared spectroscopy (fNIRS). We measured cerebral hemoglobin concentrations in bilateral temporal brain regions, included the superior temporal sulcus (STS) area which is known to be critical for supra-additive processing of auditory and visual information (e.g., Calvert et al., 2000). We used two materials (wood and metal, used in Fujisaki et al. (2014)) and set two consistency conditions; for example, a match stimulus of "wood" material is the impact sound of wood paired with the visual appearance of wood, while a mismatch stimulus of "wood" is the impact sound of wood paired with the visual appearance of metal. Our results showed that a cerebral activation in the right temporal region increased when infants observed match stimuli of "wood" material as compared to baseline. Furthermore, such activation in the right temporal region was also observed in 4 month-olds infants. On the other hand, for "metal" material, a cerebral activation in the right temporal region increased significantly only in 7 month-olds infants. These findings suggest that the right temporal region plays a role in the processing of audiovisual material matching. In addition, 4 month-olds infants developed the neural mechanism underlying material perception, but its development might depend on a material's familiarity.
Meeting abstract presented at VSS 2017