The influence of face-ethnicity on word recognition: a cognitive pupillometry study

Ethnicity plays a substantial role in shaping the way faces are perceived. At the same time, several social factors seem to influence word recognition. However, there is currently a lack of research investigating whether word recognition is influenced by the ethnicity of concomitant facial stimuli. In a lexical-decision task, 48 Italian participants were presented with words and non-words along with Caucasian (ingroup) or Asian (outgroup) faces. Participants saw a face for 2000ms, followed by a linguistic-stimulus and decided whether the string of letters represented a word or a non-word in their native language (Italian). Reaction times were faster for words with respect to non-words (lexicality-effect), and for high-frequency with respect to low-frequency words (frequency-effect). Results also showed greater pupil dilation indicating increased attentional engagement towards outgroup-faces compared to ingroup-faces. Then, when the linguistic stimulus was presented, a first interaction was observed showing that pupil dilation was greater for words with respect to non-words when presented with an ingroup-face. The opposite emerged by presenting an outgroup-face. In addition, a substantial interaction was observed showing greater pupil dilation for high-frequency with respect to low-frequency words, only for outgroup-face. We interpreted these interactions as an indication that word-recognition processes (words and high-frequency words) can be dramatically affected by face-ethnicity. Our results allow us to interpret the cognitive pupillary-response as an index of word recognition influenced by the ethnicity of the face. The data from this study provides early support for the idea that social cues influence an automatic process such as word recognition.