I heard that coming: event-related potential evidence for stimulus-driven prediction in the auditory system

Abstract

The auditory system has been shown to detect predictability in a tone sequence, but does it use the extracted regularities for actually predicting the continuation of the sequence? The present study sought to find evidence for the generation of such predictions. Predictability was manipulated in an isochronous series of tones in which every other tone was a repetition of its predecessor. The existence of predictions was probed by occasionally omitting either the first (unpredictable) or the second (predictable) tone of a same-frequency tone pair. Event-related electrical brain activity elicited by the omission of an unpredictable tone differed from the response to the actual tone right from the tone onset. In contrast, early electrical brain activity elicited by the omission of a predictable tone was quite similar to the response to the actual tone. This suggests that the auditory system preactivates the neural circuits for expected input, using sequential predictions to specifically prepare for future acoustic events.

Figure 1.

Schematic illustration of the stimulus sequences in the three conditions. Top, Predictable condition; middle, restorable condition; bottom, control condition. Small black squares represent tones; arrows indicate the timing of the omissions.

Figure 2.

ERP responses. Group-average (N = 14) ERPs elicited by tones (top row) and omissions (middle row), and difference waveforms (bottom row) in the predictable (red line), restorable (green line), and control (black line) conditions. Difference waveforms are corrected for the position within the sequence (see Materials and Methods). The 0 time point is at the onset of the tones (“expected” onset in case of omissions).