Santani Teng, PhD
Associate Scientist
Smith-Kettlewell Eye Research Institute
Biography
Santani Teng received his B.A. in psychology from the University of California, Davis and his Ph.D. in psychology from UC Berkeley in 2013. He then conducted postdoctoral work at the Massachusetts Institute of Technology before pursuing a fellowship at the Smith-Kettlewell Eye Research Institute in San Francisco in 2017. Since January 2020, Santani has been a PI at Smith-Kettlewell, where his lab investigates auditory and visual perception, neuroplasticity, haptics, echolocation, and assisted mobility in sighted and blind persons. His work uses a combination of psychophysical, neurophysiological, engineering, and computational tools to better understand how we perceive the world, especially when vision is unavailable.
Abstract
Functional networks are reorganized in blind individuals to engage typically visual cortical sensory areas in nonvisual tasks. Braille has served as a major model to investigate such crossmodal plasticity, but the underlying brain representations and spatiotemporal dynamics of these computations remain poorly understood. In this talk, I will discuss recent work in which visual and tactile (braille) alphabetic letters were presented to sighted and early-blind participants, respectively, while recording brain activity with magnetoencephalography (MEG). We analyzed the dynamics of brain responses using multivariate pattern analysis, then compared the results to models of low- and high-level stimulus coding using a representational similarity analysis (RSA) framework. The results indicate a robust progression from sensory-specific low-level features to abstract higher-level representations shared across groups, with a potential intermediate role for blind readers’ occipital cortex in the processing cascade. This work reveals spatiotemporally dissociable representations of individual letter processing, clarifies the role of early “visual” cortex in reorganized functional brain networks of blind readers, and paves the way for future studies of tactile and language processing in blind populations.