The impact of human language on perceptual categorization: electrophysiological insights.

Abstract

How does learning cultural systems like language impact cognition and perception? The last few years have seen increased interest into this topic, yet with little theoretical advance. One fundamental question concerns the nature of the neural mechanism through which language affects perceptual processes. Some accounts suggest that effects of language are ¿high-level¿, meaning that language does not affect early perceptual processes, but rather interact at later conceptual or decision-making stages. More recent proposals posit that language can alter perceptual processes at early sensory levels. This latter account is in line with current predictive processing theories of perception, which suggest that sensory processes are largely influenced by prior knowledge and expectation. The present thesis investigates whether and how language shapes perceptual processing. We focus on two specific types of language-perception interactions: (i) the effect of linguistic labels on the recognition of visual object categories; and (ii) the effect of linguistic knowledge on neural processing of rhythmic sounds. Using an interdisciplinary approach combining behavioral measures, human electrophysiology, and advanced statistical methods, we demonstrate that language can impact visual and auditory perception at early stages of processing, shaping how we perceive sensory events. This thesis also offers novel insights into the neurophysiological implementation of predictive processing in the human neocortex.