Pre-target neural oscillations predict variability in the detection of small pitch changes.

Esther Florin,Sylvain Baillet,Isabelle Peretz,Dominique Vuvan

doi:10.1371/journal.pone.0177836

Abstract

Pitch discrimination is important for language or music processing. Previous studies indicate that auditory perception depends on pre-target neural activity. However, so far the pre-target electrophysiological conditions which enable the detection of small pitch changes are not well studied, but might yield important insights into pitch-processing. We used magnetoencephalography (MEG) source imaging to reveal the pre-target effects of successful auditory detection of small pitch deviations from a sequence of standard tones. Participants heard a sequence of four pure tones and had to determine whether the last target tone was different or identical to the first three standard sounds. We found that successful pitch change detection could be predicted from the amplitude of theta (4–8 Hz) oscillatory activity in the right inferior frontal gyrus (IFG) as well as beta (12–30 Hz) oscillatory activity in the right auditory cortex. These findings confirm and extend evidence for the involvement of theta as well as beta-band activity in auditory perception.

Highlights

The ability to discriminate pitches underlies a number of important cognitive functions
For the hard deviant tone condition, participants detected between 0% and 99% correctly, implying that the broadest range of possible performances was covered for the hard deviant tones
Our results on pre-target activity show that the modulation of oscillatory activity from 5–20 Hz in both inferior frontal gyrus (IFG) were predictive of the successful detection of near-threshold pitch deviations

Summary

Introduction

The ability to discriminate pitches underlies a number of important cognitive functions. It is important for auditory scene analysis, where it facilitates stream segregation in the service of auditory object formation [1]. In the domain of music, the ability to detect small differences between pitches is necessary for the hierarchical organization of pitch known as key or tonality [3]. Unpacking the neural underpinnings of this seemingly basic ability of pitch discrimination has far-reaching consequences for the understanding of the auditory system and cognition. Electrophysiological investigations into pitch discrimination used an auditory oddball task to determine brain responses to changes in pitch frequency [4, 5].

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Results

Conclusion