Two discrete components of the 20 Hz steady-state response are distinguished through the modulation of activation level

TY - JOUR

T1 - Two discrete components of the 20 Hz steady-state response are distinguished through the modulation of activation level

AU - Griskova, Inga

AU - Morup, Morten

AU - Parnas, Josef

AU - Ruksenas, Osvaldas

AU - Arnfred, Sidse M

AU - Griskova, Inga

AU - Morup, Morten

AU - Parnas, Josef

AU - Ruksenas, Osvaldas

AU - Arnfred, Sidse M

N1 - Keywords: Acoustic Stimulation; Adult; Auditory Perception; Brain Mapping; Cerebral Cortex; Electrodes; Electroencephalography; Evoked Potentials; Female; Humans; Male; Nerve Net; Neuropsychological Tests; Signal Processing, Computer-Assisted; Young Adult

PY - 2009

Y1 - 2009

N2 - OBJECTIVE: To investigate the modulation of amplitude and phase precision of the auditory steady-state response (SSR) to 20 Hz stimulation in two conditions varying in the level of activation. METHODS: Click stimuli (20 Hz) were applied while subjects were sitting upright silently reading a book of interest (high activation level) and while subjects were sitting in a reclined position with eyes closed and the lights turned off (low activation level). Sixty-one channel EEG data was wavelet transformed, the amplitude and phase precision measures extracted and decomposed by the multi-subject non-negative multi-way factorization (NMWF). RESULTS: The NMWF decomposition of amplitude and phase precision measures resulted in the observation of two distinct components: a component at the frequency of stimulation--20 Hz SSR and a component emerging at 40 Hz--20 Hz SSR-related 40 Hz activity. Modulation by the activation level was observed only for 20 Hz SSR-related 40 Hz activity as increased amplitude and phase precision during low activation level. No such effects were observed for 20 Hz SSR. CONCLUSION: The discrete components of the 20 Hz SSR are distinguished through modulation of activation level, 20 Hz SSR-related 40 Hz being higher in low activation state. SIGNIFICANCE: The biological modulation of 20 Hz SSR-related 40 Hz activity by the level of activation points to a physiological nature of this activity beyond a mere periodic effect in relation to the 20 Hz activity.

AB - OBJECTIVE: To investigate the modulation of amplitude and phase precision of the auditory steady-state response (SSR) to 20 Hz stimulation in two conditions varying in the level of activation. METHODS: Click stimuli (20 Hz) were applied while subjects were sitting upright silently reading a book of interest (high activation level) and while subjects were sitting in a reclined position with eyes closed and the lights turned off (low activation level). Sixty-one channel EEG data was wavelet transformed, the amplitude and phase precision measures extracted and decomposed by the multi-subject non-negative multi-way factorization (NMWF). RESULTS: The NMWF decomposition of amplitude and phase precision measures resulted in the observation of two distinct components: a component at the frequency of stimulation--20 Hz SSR and a component emerging at 40 Hz--20 Hz SSR-related 40 Hz activity. Modulation by the activation level was observed only for 20 Hz SSR-related 40 Hz activity as increased amplitude and phase precision during low activation level. No such effects were observed for 20 Hz SSR. CONCLUSION: The discrete components of the 20 Hz SSR are distinguished through modulation of activation level, 20 Hz SSR-related 40 Hz being higher in low activation state. SIGNIFICANCE: The biological modulation of 20 Hz SSR-related 40 Hz activity by the level of activation points to a physiological nature of this activity beyond a mere periodic effect in relation to the 20 Hz activity.

U2 - 10.1016/j.clinph.2009.02.175

DO - 10.1016/j.clinph.2009.02.175

M3 - Journal article

C2 - 19345612

SN - 1388-2457

VL - 120

SP - 904

EP - 909

JO - Clinical Neurophysiology

JF - Clinical Neurophysiology

IS - 5

ER -