Poster Session C, Sunday, March 24, 5:00 – 7:00 pm, Pacific Concourse
Native language affects visual processing by activating categorical template of objects via the modulation of alpha oscillations
Piermatteo Morucci1, Francesco Giannelli2, Nicola Molinaro1; 1Basque Center on Cognition Brain and Language, 2University of Barcelona
Linguistic labels are known to facilitate visual processing during object recognition, detection and discrimination tasks. These effects have usually been explained within a predictive framework, which emphasizes the role of prior knowledge in shaping sensory experience. Under this view, verbal labels preactivate top-down categorical representations of the cued object, that alter subsequent bottom-up visual processes. Despite studies showing this label advantage to occur very early during visual processing, direct evidence of object preactivation is scarce. The present work aimed at (i) testing whether words affect visual perception by altering pre-stimulus activity in sensory areas; (ii) investigating whether multilingual experience modulates the label advantage. Twenty-six Basque-Spanish proficient bilinguals performed a cue-picture matching task with cues presented in Basque (L1) or Spanish (L2), while their EEG were recorded. Results showed that only words in L1 affected early processing of target images by modulating early electrophysiological signals associated with bottom-up visual processes, specifically the N150 and the activity in theta (4-7Hz). Crucially, time-frequency analysis of the interval between the word and the target image showed that words in L1 led to an increase of oscillatory activity in the alpha-band (8–12 Hz). This pre-target activity is likely to reflect the neural fingerprint of the preactivated object. These results suggest that words affect visual processing by activating categorical template of cued objects via the modulation of alpha oscillations, providing strong evidence for a predictive view of language-perception interactions. Moreover, these findings suggest that early language exposure largely shapes the predictive mechanisms affecting visual perception.
Topic Area: LANGUAGE: Semantic