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Infant and adult pupil dilation in response to unexpected sounds
Nicole Wetzel1, David Buttelmann2, Andy Schieler2
1Institute of Psychology, University of Leipzig, Neumarkt 9-19, 04109, Leipzig, Germany. wetzel@uni-leipzig.de.
Insights
Deviant sounds capture infant attention, as shown by pupil size changes. This pupil dilation response (PDR) is a sensitive measure for auditory involuntary attention in preverbal children.
Area of Science:
- Auditory neuroscience
- Developmental psychology
- Cognitive science
Background:
- Unexpected sounds involuntarily capture attention.
- Pupil size changes reflect autonomic nervous system activity, including attention.
- Investigating auditory involuntary attention in infants is crucial for understanding cognitive development.
Purpose of the Study:
- To examine the impact of deviant sounds on pupil size in 14-month-old infants and adults.
- To assess pupil dilation response (PDR) as a marker of auditory involuntary attention.
- To explore age-related differences in responses to deviant auditory stimuli.
Main Methods:
- An oddball paradigm with standard and four types of deviant sounds was used.
- Pupil size was measured in 14-month-old infants and adults.
- Principal component analysis was applied to pupil dilation response data.
Main Results:
- Environmental and noise deviant sounds elicited significant PDR in both infants and adults.
- Moderate frequency deviants elicited PDR in adults but not infants.
- Age differences were observed in PDR components, suggesting distinct autonomic responses.
Conclusions:
- Pupil dilation response is a sensitive indicator of auditory involuntary attention in preverbal children.
- Deviant sounds with high arousal potential elicit age-specific autonomic responses.
- Findings highlight developmental changes in how the brain processes and attends to auditory stimuli.
Abstract:
Surprisingly occurring sounds outside the focus of attention can involuntarily capture attention. This study focuses on the impact of deviant sounds on the pupil size as a marker of auditory involuntary attention in infants. We presented an oddball paradigm including four types of deviant sounds within a sequence of repeated standard sounds to 14-month-old infants and to adults. Environmental and noise deviant sounds elicited a strong pupil dilation response (PDR) in both age groups. In contrast, moderate frequency deviants elicited a significant PDR in adults only. Moreover, a principal component analysis revealed two components underlying the PDR. Component scores differ, depending on deviant types, between age groups. Results indicate age effects of parasympathetic inhibition and sympathetic activation of the pupil size caused by deviant sounds with a high arousing potential. Results demonstrate that the PDR is a sensitive tool for the investigation of involuntary attention to sounds in preverbal children.
