Assessing the Role of Stimulus Novelty in the Elicitation of the Pupillary Dilation Response to Irrelevant Sound

ABSTRACT

Introduction

Being exposed to an irrelevant sound that deviates from the auditory scene can disrupt performance on an ongoing task. This deviation effect is usually explained in terms of attention capture whereby the detection of an unexpected acoustical irregularity – or deviation – triggers an involuntary attentional diversion from ongoing mental activity. Recent studies showed that the pupillary dilation response (PDR) could index this attentional response. Yet, these studies almost exclusively used novel (i.e., recently unencountered) sounds as deviants. It is therefore unclear whether the PDR is specifically sensitive to stimulus novelty or to any form of acoustical irregularity. This study thus aimed at examining whether the PDR could be triggered by non-novel irrelevant deviant sounds. Methods. Participants performed visual serial recall while ignoring sequences of alternating spoken letters (BKBKB) in which a novel sound (BKBKX) or a deviant repetition (BKBKK) could be inserted. Results. The presentation of any deviant impaired recall and elicited a significant PDR. Yet, whereas the detrimental impact on performance was similar for the two types of deviant, the amplitude of the PDR was larger for the novelty deviant. Discussion. Results suggest that the PDR indexes attentional capture and that it is underpinned by relative, higher-order, expectancy-violation detection processes.

KEYWORDS:

• Auditory distraction
• attention capture
• stimulus novelty
• auditory deviation
• pupillary dilation response

Acknowledgments

We are grateful to Agathe Blanchette-Sarrasin, Hugo Fitzback-Fortin and Lysandre Provost for running the experiment.

Disclosure Statement

The authors declare that the research was conducted in the absence of any personal or financial relationships that could be construed as a potential conflict of interest.

Notes

1. For the Tobii TX-300, this refers only to the ‘0ʹ validity code, i.e., situations for which “the system is certain that it has recorded all relevant data for the particular eye, and that the data recorded belongs to the particular eye” (see Tobii Pro, 2019).

Additional information

Funding

This research was supported by a grant [418623-2013] from the Natural Sciences and Engineering Research Council of Canada (NSERC) awarded to François Vachon. Alessandro Pozzi was supported by an NSERC and an FRQNT scholarship. The data that support the findings of this study are available from the corresponding author upon reasonable request.