Neurofeedback training of auditory selective attention enhances speech-in-noise understanding

Abstract

Speech-in-noise (SiN) understanding involves multiple cortical processes including feature extraction, grouping, and selective attention. Among those processes, we aimed to investigate the causal relationship between auditory selective attention and SiN performance. Selective attention enhances the strength of cortical neural responses to attended sounds while suppresses the neural responses to ignored sounds, which forms an evidence of sensory gain control theory. We hypothesized that the cortical response-guided neurofeedback could strengthen the sensory gain control, which in turn will improve selective attention performance and may result in better SiN understanding. With a single-blinded, between-subjects design including a placebo group, subjects were asked to attend to one of two simultaneous but asynchronous streams. For the participants assigned to the experimental group, a visual feedback was provided after each trial to demonstrate whether their attention was correctly decoded using their single-trial EEG response. The experimental group participants with four weeks of this neurofeedback training exhibited amplified cortical evoked responses to target speech as well as improved SiN understanding, while the placebo group participants did not show consistent improvement. To our best knowledge, this is the first report of selective-attention training enhancing SiN performance.