Unconscious learning of auditory discrimination using mismatch negativity (MMN) neurofeedback

Abstract

Neurofeedback is a strong direct training method for brain function, wherein brain activity patterns are measured and displayed as feedback, and trainees try to stabilize the feedback signal onto certain desirable states to regulate their own mental states. Here, we introduce a novel neurofeedback method, using the mismatch negativity (MMN) responses elicited by similar sounds that cannot be consciously discriminated. Through neurofeedback training, without participants' attention to the auditory stimuli or awareness of what was to be learned, we found that the participants could unconsciously achieve a significant improvement in the auditory discrimination of the applied stimuli. Our method has great potential to provide effortless auditory perceptual training. Based on this method, participants do not need to make an effort to discriminate auditory stimuli, and can choose tasks of interest without boredom due to training. In particular, it could be used to train people to recognize speech sounds that do not exist in their native language and thereby facilitate foreign language learning.

Mechanisms of Neurofeedback: A Computation-theoretic Approach

“…Related to topic of subjective experiences is the notion that neurofeedback does not require consciousness at all (Birbaumer et al, 2013;Chang et al, 2014). Although the multistage theory allows for explicit processes to influence learning, the striatal-exploration stage is unconscious to extent that the actual response plan may not be amenable to introspection.…”

“…In fact, Birbaumer et al (2013) view neurofeedback learning as an implicit learning process that does not require consciousness (see also Chang et al, 2014). This, however, is inconsistent with the methods in animal studies of making the animals hungry or thirsty before training and the observation that humans are actively trying to find a suitable strategy.…”

Unconscious learning of speech sounds using mismatch negativity neurofeedback

“…However, after behavioral discrimination training, the MMN emerged in those participants who learned behaviorally to discriminate the stimulus changes. Our recent findings [3] indicate that behavioral auditory discrimination performance of pure tone can be improved only by enhancing brain activity without behavioral discrimination training. Similarly, improvements in discrimination of complex sounds at the word level were elicited by the same training framework in this study.…”

“…The participants are instructed to only focus on visual feedback rather than the sounds and to try to enlarge the visual feedback in the same way of neurofeedback that was used in our recent study [3]. The procedure is described in 'Training Procedure' section.…”

“…Request permissions from Permissions@acm.org. [3] indicated that participants could unconsciously achieve a significant improvement in the auditory discrimination of pure tones that could not be discriminated in advance; MMN was used as a measure of perceptual discriminability as visual feedback was presented to provide a continuous cue for learning. However, it is not known whether this method can be used to improve speech sound recognition in foreign language learning.…”