Different spatio‐temporal electroencephalography features drive the successful decoding of binaural and monaural cues for sound localization

Abstract

The human ability to localize sound is essential for monitoring our environment and helps us to analyse complex auditory scenes. Although the acoustic cues mediating sound localization have been established, it remains unknown how these cues are represented in human cortex. In particular, it is still a point of contention whether binaural and monaural cues are processed by the same or distinct cortical networks. In this study, participants listened to a sequence of auditory stimuli from different spatial locations while we recorded their neural activity using electroencephalography (EEG). The stimuli were presented over a loudspeaker array, which allowed us to deliver realistic, free-field stimuli in both the horizontal and vertical planes. Using a multivariate classification approach, we showed that it is possible to decode sound source location from scalp-recorded EEG. Robust and consistent decoding was shown for stimuli that provide binaural cues (i.e. Left vs. Right stimuli). Decoding location when only monaural cues were available (i.e. Front vs. Rear and elevational stimuli) was successful for a subset of subjects and showed less consistency. Notably, the spatio-temporal pattern of EEG features that facilitated decoding differed based on the availability of binaural and monaural cues. In particular, we identified neural processing of binaural cues at around 120 ms post-stimulus and found that monaural cues are processed later between 150 and 200 ms. Furthermore, different spatial activation patterns emerged for binaural and monaural cue processing. These spatio-temporal dissimilarities suggest the involvement of separate cortical mechanisms in monaural and binaural acoustic cue processing.

Shared and modality-specific brain regions that mediate auditory and visual word comprehension

“…On a technical level, it is important to keep in mind that the insights derived from any classification analysis are limited by the quality of the overall classification performance. Classification performance was highly significant and reached about 10% above the respective chance level, a number that is in accordance with other neuroimaging studies on auditory pathways (Bednar, Boland, & Lalor, 2017;Correia, Jansma, Hausfeld, Kikkert, & Bonte, 2015). Yet, more refined classification techniques, or data obtained using significantly larger stimulus sets and more repetitions of individual target words may be able to provide even more refined insights.…”

Study of Correlation Between EEG Electrodes for the Analysis of Cortical Responses Related to Binaural Hearing

“…Based on the correlation study, the electrode locations Cz and Pz were selected for further analysis. The selection of electrode locations for AEP recording is in line with previous literature in which researchers selected the midline electrodes for the ERP analysis [73,100]. A high correlation in these regions shows that these electrodes are highly correlated.…”

“…This shows that the homophasic and antiphasic signals are weakly correlated and that there exists a significant difference between the observed responses to the antiphasic and homophasic signals. This supports the fact that the phase difference can serve as a binaural cue which is useful in the analysis of the binaural hearing in the brain [100][101][102]. Applying the technique of correlation analysis, we were able to identify the optimal EEG electrode location to be utilized in audiometric EEG in order to distinguish the EEG responses to different signals for the study of binaural hearing [103].…”

“…These frequency bands correspond to the Beta frequency range which may indicate conscious phase detection by the brain [37,125]. The selection of the stimuli used for the study, the investigation for the most suitable electrode locations [73,100] and frequency bands which can give an indication of the binaural interaction in the human brain [110,126] and makes our current research relevant. Based on the correlation study, the electrode locations Cz and Pz were selected for further analysis.…”

Mitochondrial disorders in multiple sclerosis

“…C. Rice и соавт. [9] сообщили о роли митохондриальных сиртуинов как терапевтического средства для репарации и защиты нервных волокон при РС. G. Campbell и соавт.…”