Eye blinking, musical processing, and subjective states—A methods account

Affective sciences often make use of self-reports to assess subjective states. Seeking a more implicit measure for states and emotions, our study explored spontaneous eye blinking during music listening. However, blinking is understudied in the context of research on subjective states. Therefore, a second goal was to explore different ways of analyzing blink activity recorded from infra-red eye trackers, using two additional data sets from earlier studies differing in blinking and viewing instructions. We first replicate the effect of increased blink rates during music listening in comparison with silence and show that the effect is not related to changes in self-reported valence, arousal, or to specific musical features. Interestingly, but in contrast, felt absorption reduced participants' blinking. The instruction to inhibit blinking did not change results. From a methodological perspective, we make suggestions about how to define blinks from data loss periods recorded by eye trackers and report a data-driven outlier rejection procedure and its efficiency for subject-mean analyses, as well as trial-based analyses. We ran a variety of mixed effects models that differed in how trials without blinking were treated. The main results largely converged across accounts. The broad consistency of results across different experiments, outlier treatments, and statistical models demonstrates the reliability of the reported effects. As recordings of data loss periods come for free when interested in eye movements or pupillometry, we encourage researchers to pay attention to blink activity and contribute to the further understanding of the relation between blinking, subjective states, and cognitive processing.