Language induced changes of mind: shifts in categorical colour perception after a short language learning experience

This study investigated the reorganization of perceptual categories following a short language learning experience. A first goal was to investigate the interaction of previous labels with learning and potential language-induced effects on categorical perception. A second goal was to determine whether language learning might make similar colours more distinctly perceived (within category separation) and/or more dissimilar colours less distinctly perceived (between category compression). A third goal was to assess whether potential effects would be persistent, indicating authentic learning and reorganization of the semantic space. In two experiments, native French participants were asked to learn new labels for two nuances of each of four hues. Across participants, we manipulated whether the colours had a previous robust label (ETN colours) or not (HTN colours). Linguistic similarity of labels for different nuances and hues was manipulated within participants. Speakers then had to rate the perceived similarity of colour pairs. Results showed that colours that had a previous robust label were persistently rated as more similar if they had similar new labels. These findings highlight 1) a key role of spreading activation and lexico-semantic strengthening induced by competition as a drive of second language learning, and 2) an impressive malleability of the human perception-based interpretation of the world.