Food words distract the hungry: Evidence of involuntary semantic processing of task-irrelevant but biologically-relevant unexpected auditory words.

Fabrice B. R. Parmentier,Antonia P. Pacheco-Unguetti,Sara Valero,Manuel S. Malmierca

doi:10.1371/journal.pone.0190644

Fabrice B. R. Parmentier, Antonia P. Pacheco-Unguetti + Show 2 more

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https://doi.org/10.1371/journal.pone.0190644

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Abstract

Rare changes in a stream of otherwise repeated task-irrelevant sounds break through selective attention and disrupt performance in an unrelated visual task by triggering shifts of attention to and from the deviant sound (deviance distraction). Evidence indicates that the involuntary orientation of attention to unexpected sounds is followed by their semantic processing. However, past demonstrations relied on tasks in which the meaning of the deviant sounds overlapped with features of the primary task. Here we examine whether such processing is observed when no such overlap is present but sounds carry some relevance to the participants’ biological need to eat when hungry. We report the results of an experiment in which hungry and satiated participants partook in a cross-modal oddball task in which they categorized visual digits (odd/even) while ignoring task-irrelevant sounds. On most trials the irrelevant sound was a sinewave tone (standard sound). On the remaining trials, deviant sounds consisted of spoken words related to food (food deviants) or control words (control deviants). Questionnaire data confirmed state (but not trait) differences between the two groups with respect to food craving, as well as a greater desire to eat the food corresponding to the food-related words in the hungry relative to the satiated participants. The results of the oddball task revealed that food deviants produced greater distraction (longer response times) than control deviants in hungry participants while the reverse effect was observed in satiated participants. This effect was observed in the first block of trials but disappeared thereafter, reflecting semantic saturation. Our results suggest that (1) the semantic content of deviant sounds is involuntarily processed even when sharing no feature with the primary task; and that (2) distraction by deviant sounds can be modulated by the participants’ biological needs.

Highlights

Efficient functioning often requires the ability to focus on a task while filtering out irrelevant stimuli
Past work showed that the distractive effect of deviant words presented in the context of an ongoing visual categorization task is partially due to the incongruity between the involuntary semantic processing of the deviant sounds and the voluntary semantic processing of the visual target stimuli
Past demonstrations relied on tasks in which the characteristics of the deviant sounds overlapped with aspects of the primary task demands

Summary

Introduction

Efficient functioning often requires the ability to focus on a task while filtering out irrelevant stimuli. Deviant sounds delay (and sometimes reduce the accuracy of) responses to target stimuli [24], whether presented in purely auditory [3,25,26,27], visual [26,28,29], or in cross-modal oddball tasks where irrelevant and target stimuli are presented in distinct sensory modalities: auditory-visual [28,30,31,32,33,34,35,36,37,38,39,40,41,42] or tactile-visual [43,44] This distraction effect reflects the deviant sound’s violation of predictions rather than its low frequency of occurrence per se [8,10,12,13], and results from the shift of attention to the deviant sound and reorientation to the target stimulus [2,3], and from the temporary suspension and resetting of action plans [45,46]

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