title: Optimal signal bandwidth for the recording of surface EMG activity of facial, jaw, oral, and neck muscles.
abstract: Spontaneous pericranial electromyographic (EMG) activity is generally small and is contaminated by strong low-frequency artifacts. High-pass filtering should suppress artifacts but affect EMG signal power only minimally. In 24 subjects who performed a warned simple reaction time task, the optimal high-pass cut-off frequency was examined for nine different pericranial muscles. From four experimental conditions (visual and auditory reaction signals combined with hand and foot responses), 1-min EMG recordings were selected (bandwidth: 0.4-512 Hz) and divided into 60 1-s data segments. These segments were high-pass filtered, the -3-dB cut-off frequency varying from 5 to 90 Hz, and subjected to power spectral analysis. Optimal high-pass filter frequencies were determined for the mean power spectra based on visual estimation or comparison with a theoretical spectrum of the artifact-free EMG signal. The optimal frequencies for the different muscles varied between 15 and 25 Hz and were not influenced by stimulus or response modality. For all muscles, a low-pass filter frequency between 400 and 500 Hz was appropriate.
authors.affiliation: Department of Psychology, Tilburg University, The Netherlands. a.vanboxtel@kub.nl
authors.forename: A
authors.initials: A
authors.lastname: van Boxtel
mesh_terms: D000328:Adult; D004576:Electromyography / Q000379:methods*; D005152:Facial Muscles / Q000502:physiology*; D005260:Female; D006801:Humans; D007568:Jaw / Q000502:physiology*; D008297:Male; D009055:Mouth / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009334:Neck Muscles / Q000502:physiology*