This study evaluated a time-restricted region-suppressed event-related synthetic aperture magnetoencephalography (TRRS-ER-SAM) beamformer algorithm against equivalent current dipole (ECD), and event-related synthetic aperture magnetoencephalography (ER-SAM) post-processing methods for magnetoencephalography data. This evaluation was done numerically and with auditory evoked field (AEF) data elicited by binaurally presented 500 Hz tones. The TRRS-ER-SAM beamformer demonstrated robustness to noise, and the ability to handle coherent sources. The TRRS-ER-SAM algorithm was then applied to a study of N1m AEFs in 8 subjects aged 12-25 years. The study examined the effects of age, stimulus frequency, and right-sided monaural versus binaural stimulation on the N1m location, amplitude, and latency. It was found that age affected the N1m latency; stimulus frequency affected the N1m location, amplitude, and latency; and monaural versus binaural stimulation affected the N1m amplitude. In the context of these effects, the auditory pathway structure and neurophysiological changes due to maturation were discussed.

This study evaluated a time-restricted region-suppressed event-related synthetic aperture magnetoencephalography (TRRS-ER-SAM) beamformer algorithm against equivalent current dipole (ECD), and event-related synthetic aperture magnetoencephalography (ER-SAM) post-processing methods for magnetoencephalography data. This evaluation was done numerically and with auditory evoked field (AEF) data elicited by binaurally presented 500 Hz tones. The TRRS-ER-SAM beamformer demonstrated robustness to noise, and the ability to handle coherent sources. The TRRS-ER-SAM algorithm was then applied to a study of N1m AEFs in 8 subjects aged 12-25 years. The study examined the effects of age, stimulus frequency, and right-sided monaural versus binaural stimulation on the N1m location, amplitude, and latency. It was found that age affected the N1m latency; stimulus frequency affected the N1m location, amplitude, and latency; and monaural versus binaural stimulation affected the N1m amplitude. In the context of these effects, the auditory pathway structure and neurophysiological changes due to maturation were discussed.

This study investigated the neuroplastic changes that accompany speech identification training using magnetoencephalography (MEG). Participants completed three practice sessions over two consecutive days. In the morning group, practice occurred in the morning and evening of the first day, and in the morning of the next day; whereas, in the evening group, practice occured in the evening of the first day, and in the morning and evening of the second day. In both groups, behavioural improvement between the first session and last session was comparable. Neuromagnetic data showed practice-related changes in N1m amplitude between the first and last sessions. A time-of-day (TOD) of practice effect was found for P2m mean amplitude. In both groups, P2m-related changes with practice were greater when consecutive sessions occurred between days than within a day. The results are consistent with the proposal that task-related changes in the P2m wave are an index of perceptual learning.

This study investigated the neuroplastic changes that accompany speech identification training using magnetoencephalography (MEG). Participants completed three practice sessions over two consecutive days. In the morning group, practice occurred in the morning and evening of the first day, and in the morning of the next day; whereas, in the evening group, practice occured in the evening of the first day, and in the morning and evening of the second day. In both groups, behavioural improvement between the first session and last session was comparable. Neuromagnetic data showed practice-related changes in N1m amplitude between the first and last sessions. A time-of-day (TOD) of practice effect was found for P2m mean amplitude. In both groups, P2m-related changes with practice were greater when consecutive sessions occurred between days than within a day. The results are consistent with the proposal that task-related changes in the P2m wave are an index of perceptual learning.