What goes up must come down: EEG phase modulates auditory perception in both directions

Rufin Vanrullen,Douglas Mclelland

doi:10.3389/fpsyg.2013.00016

Abstract

What goes up must come down: EEG phase modulates auditory perception in both directions

Highlights

While the primary finding of a periodic modulation of auditory perception by EEG oscillations is a major novel result that we would not wish to contest, there is another conclusion of the study by Ng et al (2012) that merits elaborating: the EEG phase modulation they reported was higher for misses than for hits
Based on these unexpected results they proposed a “precluding” model of phase modulation, in which the “duty cycle” of phase modulation would be significantly longer than 50%
How could Ng et al (2012) observe a larger effect for misses than for hits? We suggest that this happened because these authors based their calculations on the relative number of hits and misses observed around each phase value, without taking into account the fact that all phase values were not sampled in their paradigm (Figure 1)

Summary

Introduction

Recent years have seen mounting evidence that the phase of low-frequency EEG oscillations— in the theta (4–8 Hz) and alpha (8–13 Hz) frequency ranges—is closely related to visual perception (Busch et al, 2009; Mathewson et al, 2009; Busch and VanRullen, 2010; Drewes and VanRullen, 2011; Dugue et al, 2011; VanRullen et al, 2011; Chakravarthi and VanRullen, 2012; Hamm et al, 2012; Romei et al, 2012; Schyns et al, 2012). While the primary finding of a periodic modulation of auditory perception by EEG oscillations is a major novel result that we would not wish to contest, there is another conclusion of the study by Ng et al (2012) that merits elaborating: the EEG phase modulation they reported was higher for misses (trials in which the auditory target was present but undetected) than for hits (detected targets).

Results

Conclusion