Perceptual Learning of Acoustic Noise Generates Memory-Evoked Potentials

Abstract

Experience continuously imprints on the brain at all stages of life. The traces it leaves behind can produce perceptual learning [1], which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure [2]. Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show that the perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever a memory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) [3], triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices [7], suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics.

Long Term Memory for Noise: Evidence of Robust Encoding of Very Short Temporal Acoustic Patterns

“…Further support for the claim that short acoustic features are rapidly (Andrillon et al, 2015) and robustly (our results) stored, comes from Spike time dependent plasticity (STDP) models that demonstrate how neurons can learn repeating spatiotemporal patterns in noise (Masquelier et al, 2008, 2009). The model used random Poisson activity in 2000 afferents with variable instantaneous firing rates at baseline.…”

“…Recently, the neural correlates of memory for meaningless sounds were investigated in a study where participants were presented with 200- or 500-ms patterns that repeated every 500 ms (Andrillon et al, 2015). These patterns were embedded randomly in 8 min of continuous noise while participants detected changes in amplitude modulations.…”

A psychoengineering paradigm for the neurocognitive mechanisms of biofeedback and neurofeedback

“…There is no consensus yet on these three models. However, a recent study demonstrated that noise learning is accompanied by rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns within sensory regions (Andrillon, Kouider, Agus, & Pressnitzer, 2015). This is the first experimental confirmation that schemata bridge the gap between sensory and memory processes, and a validation of Cowan's hypotheses.…”

Temporal Organization of Sound Information in Auditory Memory

“…The neural correlates of the white noise learning have also been examined using MEG or EEG on human subjects recently (Keceli et al, 2012; Luo et al, 2013; Andrillon et al, 2015). By employing the same experimental paradigm and white noise stimuli, a recent MEG experiment demonstrates that the establishment of a reliable neuronal phase pattern in low-frequency (3–8 Hz) auditory cortical responses mirrors the noise memory formation process.…”