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Updated: Jun 19, 2026
Infant Auditory Processing and Event-related Brain Oscillations
Published on: July 1, 2015
Numerical discrimination in newborn infants as revealed by event-related potentials to tone sequences
Timo Ruusuvirta1, Minna Huotilainen, Vineta Fellman
1Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, Helsinki, Finland. timo.ruusuvirta@utu.fi
Insights
Newborn infants show early auditory numerical processing. This study reveals infants can detect significant numerical differences in sound sequences, suggesting nascent number discrimination abilities.
Area of Science:
- Cognitive Neuroscience
- Developmental Psychology
- Auditory Perception
Background:
- Human infants can discriminate numbers attentively from 6 months.
- The emergence of pre-attentive numerical processing in newborns is not well understood.
Purpose of the Study:
- To investigate the age at which pre-attentive auditory numerical processing emerges in human infants.
- To determine if newborns can detect numerical differences in auditory sequences at a pre-attentive level.
Main Methods:
- Event-related potentials (ERPs) were recorded from 3- to 5-day-old infants.
- Infants were passively exposed to sequences of tones with varying numerical ratios (2:2 standards, 3:1 or 4:0 deviants).
Main Results:
- A robust mismatch response was observed for 4:0 deviants, indicating detection of a larger numerical difference.
- No significant mismatch response was found for 3:1 deviants, suggesting a threshold for numerical discrimination.
Conclusions:
- Newborn infants possess neurophysiological abilities for pre-attentive auditory numerical discrimination.
- This suggests very early sensitivity to numerical information in the auditory domain during human infancy.
Abstract:
Humans are able to attentively discriminate number from 6 months of age. However, the age of the emergence of this ability at the pre-attentive stage of processing remains unclear. Event-related potentials (ERPs) were recorded in newborn human infants aged from 3 to 5 days. At 500-ms intervals, the infants were passively exposed to 200-ms sequences of four tones. Each tone could be either 1000 or 1500 Hz in frequency. In most sequences (standards), the ratio of the tones of one frequency to those of the other frequency in a sequence was 2 : 2. In the remaining sequences (deviants, P = 0.1), this ratio was either 3 : 1 or 4 : 0. The mismatch response of ERPs could not be found for 3 : 1 deviants, but it was a robust finding for 4 : 0 deviants, showing the neurophysiological ability of the infants to register the larger deviant-standard difference. The findings suggest very early sensitivity to auditory numerical information in infancy.
