The time course of within and between-language interference in bilinguals

Abstract

Purpose: Recent research has provided support for linguistic coactivation, the view that the two languages of a bilingual are simultaneously active. Importantly, even if the system is fundamentally nonselective, the two languages of a bilingual can be activated to different degrees. The main contribution of the present paper is to empirically test what “different degrees of activation” really means. Differences could emerge in the timing or the magnitude of language activation. Methodology: Most of the research to date has been based on experiments using reaction times. In the present experiment participants responded to a bilingual Stroop task using a computer mouse. We argue that mouse tracking can provide new insights into the temporal dynamics of cognitive processes. Data and analysis: We used a series of t-tests to analyze participants’ mouse trajectories ( n = 20). We compared the x-coordinates over time for each of the four experimental conditions (Congruent-Within, Congruent-Between, Incongruent-Within, Incongruent-Between) with the x-coordinates over time for the control trajectory. Findings: Differences in the timing, but not the magnitude, of interference are at the root of the differential effects within and between languages. Within-language interference emerged 80 ms earlier than between-language interference. Originality: To our knowledge, the current experiment is the first to use the dynamic mouse-tracking paradigm to compare the time course of the two languages of a bilingual participant. Implications: The mouse-tracking paradigm can help to distinguish between the timing and the magnitude of interference, informing current theories of the bilingual mind.