Influence of rhythmic contexts on perception: No behavioral and eye- tracker evidence for rhythmic entrainment

Attention fluctuates over time, throughout task performance, and with wax and wane throughout the day. Entrainment theories, such as the Dynamic Attending Theory, extend this idea by proposing that attention acts as an oscillatory system that alternates between moments of attentional enhancement and instants of attentional disengagement. Consequently, perceptual and response benefits have been reported in tasks with a rhythmic structure, presumably because regular external sequences would promote synchronization of attention with the phase of the relevant expected stimuli. In the present study, we report two preregistered auditory experiments attempting to replicate previous behavioral evidence supporting entrainment theories. In addition, we incorporated eye-tracker measures for their value in characterizing online cognitive processes. Both Experiment 1 (perceived duration task) and Experiment 2 (pitch discrimination task) showed the absence of a phase-specific benefit of rhythmic sequences compared to arrhythmic ones. Importantly, a tonic larger pupil size for arrhythmic conditions was observed irrespective of target phase, participants’ performance, and perceived task difficulty, suggesting higher processing demands imposed by a sustained uncertain context. Overall, the present results call into question that the perceptual benefits predicted by entrainment theories are generalizable across all experimental designs and paradigms. On the contrary, our findings join a large group of studies that have failed to replicate the foundational results of attentional entrainment, highlighting the need to determine the specific conditions under which entrainment effects may emerge. Moreover, they underscore the importance of eye-tracker measures as an online indicator of cognitive processes in rhythmic contexts.