Electrophysiological evidence for a Whorfian double dissociation of categorical perception across two languages

Languages vary considerably in how they group objects into categories. For example, the word taza in Spanish can refer to either cup or mug in English, whereas glass can refer to either copa or vaso – two different types of glasses –, in Spanish. It is still debated whether such language distinctions cause differences in early perceptual processing between speakers of different languages. Here, for the first time, we test the effects of terminology on pre-attentive indices of categorical perception symmetrically across two languages. In a visual mismatch negativity (vMMN) paradigm, native speakers of English or Spanish were flashed with different exemplars from four object categories: cup, mug, copa, and vaso. We measured the vMMN elicited by language-dependent within- and cross-category changes in the peripheral visual field. Results showed significant vMMN modulations for categorical contrasts distinguished by participants’ native language, but not for objects grouped under the same label. P3a modulations showed the reverse pattern, with significant modulations only for those categorical contrast unmarked in the native language. These results provide the strongest evidence to date that native language labels influence categorical perception of objects at pre-attentive stages of perceptual encoding. In addition, they show that non-verbally encoded categorical dissociations also reorient attention but at a later stage and in a more controlled fashion. Therefore, we conclude that perceptual encoding is shaped by one’s language.