Amplitude and phase dynamics associated with acoustically paced finger tapping.
To gain insight into the brain activity associated with the performance of an acoustically paced synchronization task, we analyzed the amplitude and phase dynamics inherent in magnetoencephalographic (MEG) signals across frequency bands in order to discriminate between evoked and induced responses. MEG signals were averaged with respect to motor and auditory events (tap and tone onsets). Principal component analysis was used to compare amplitude and phase changes during listening and during paced and unpaced tapping, allowing a separation of brain activity related to motor and auditory processes, respectively. Motor performance was accompanied by phasic amplitude changes and increased phase locking in the beta band. Auditory processing of acoustic stimuli resulted in a simultaneous increase of amplitude and phase locking in the theta and alpha band. The temporal overlap of auditory-related amplitude changes and phase locking indicated an evoked response, in accordance with previous studies on auditory perception. The temporal difference of movement-related amplitude and phase dynamics in the beta band, on the other hand, suggested a change in ongoing brain activity, i.e., an induced response supporting previous results on motor-related brain dynamics in the beta band.
Boonstra
T W
TW
Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands. t.boonstra@fbw.vu.nl
Daffertshofer
A
A
Peper
C E
CE
Beek
P J
PJ
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D017711:Nonlinear Dynamics; D011597:Psychomotor Performance / Q000502:physiology*; D013997:Time Factors; D013998:Time Perception / Q000502:physiology*