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Long-latency TMS-evoked potentials during motor execution and inhibition.

Yamanaka K, Kadota H, Nozaki D - Front Hum Neurosci (2013)

Bottom Line: Transcranial magnetic stimulation (TMS) has often been used in conjunction with electroencephalography (EEG), which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs).However, it remains unclear what pattern is associated with the inhibition of a planned motor response.TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Human Life Sciences, Showa Women's University Tokyo, Japan.

ABSTRACT
Transcranial magnetic stimulation (TMS) has often been used in conjunction with electroencephalography (EEG), which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs). However, it remains unclear what pattern is associated with the inhibition of a planned motor response. Therefore, we performed TMS-EEG recording during a go/stop task, in which participants were instructed to click a computer mouse with a right index finger when an indicator that was moving with a constant velocity reached a target (go trial) or to avoid the click when the indicator randomly stopped just before it reached the target (stop trial). Single-pulse TMS to the left (contralateral) or right (ipsilateral) motor cortex was applied 500 ms before or just at the target time. TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS. As a result, in TEPs induced by both contralateral and ipsilateral TMS, small oscillations were followed by a prominent negative deflection around the TMS site peaking at approximately 100 ms post-TMS (N100), and a less pronounced later positive component (LPC) over the broad areas that was centered at the midline-central site in both go and stop trials. However, compared to the pattern in go and stop trials with TMS at 500 ms before the target time, N100 and LPC were differently modulated in the go and stop trials with TMS just at the target time. The amplitudes of both N100 and LPC decreased in go trials, while the amplitude of LPC decreased and the latency of LPC was delayed in both go and stop trials. These results suggested that TMS-induced neuronal reactions in the motor cortex and subsequent their propagation to surrounding cortical areas might change functionally according to task demand when executing and inhibiting a motor response.

No MeSH data available.


Averaged electroencephalography (EEG) data in no-TMS trials. (A) Averaged EEG waveforms in no-TMS trials during a go/stop task for six participants in a contralateral-TMS session (left two panels) and for six participants in an ipsilateral-TMS session (right two panels). For stop trials, only the waveforms in stop trials with a stop time of -200 ms [stop(-200) trials] are displayed. The waveforms of all 61 sites are shown as thin black lines. The vertical thin lines represent indicator onset, the vertical dashed lines represent target time for the go task, and the vertical thick lines represent stop-signal onset. Time scales relative to target are displayed at the bottom. (B) Scalp topographies of averaged EEGs in the go and stop(-200) trials for six participants in a contralateral-TMS session (left 2 × 4 arrays) and for six participants in an ipsilateral-TMS session (right 2 × 4 arrays). The topographies are displayed only at -200, 0, 100, and 200 ms relative to target.
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Figure 4: Averaged electroencephalography (EEG) data in no-TMS trials. (A) Averaged EEG waveforms in no-TMS trials during a go/stop task for six participants in a contralateral-TMS session (left two panels) and for six participants in an ipsilateral-TMS session (right two panels). For stop trials, only the waveforms in stop trials with a stop time of -200 ms [stop(-200) trials] are displayed. The waveforms of all 61 sites are shown as thin black lines. The vertical thin lines represent indicator onset, the vertical dashed lines represent target time for the go task, and the vertical thick lines represent stop-signal onset. Time scales relative to target are displayed at the bottom. (B) Scalp topographies of averaged EEGs in the go and stop(-200) trials for six participants in a contralateral-TMS session (left 2 × 4 arrays) and for six participants in an ipsilateral-TMS session (right 2 × 4 arrays). The topographies are displayed only at -200, 0, 100, and 200 ms relative to target.

Mentions: In the grand-mean-averaged EEG waveforms in no-TMS trials (Figure 4), gradual negative deflections over the fronto-central sites were observed as the target time approached in both go and stop trials. After the stop signal onset of -200 ms, the grand-mean-averaged EEG waveforms clearly differentiated between go and stop trials. Distinct negative–positive peaks over the frontocentral sites appeared around and after the target time in stop trials, while a mild positive peak over the centroparietal sites appeared after the target time in go trials. These waveforms in the no-TMS trials have been typically shown in the go and stop trials of the go/stop (or stop-signal) task (De Jong et al., 1990; Schmajuk et al., 2006).


Long-latency TMS-evoked potentials during motor execution and inhibition.

Yamanaka K, Kadota H, Nozaki D - Front Hum Neurosci (2013)

Averaged electroencephalography (EEG) data in no-TMS trials. (A) Averaged EEG waveforms in no-TMS trials during a go/stop task for six participants in a contralateral-TMS session (left two panels) and for six participants in an ipsilateral-TMS session (right two panels). For stop trials, only the waveforms in stop trials with a stop time of -200 ms [stop(-200) trials] are displayed. The waveforms of all 61 sites are shown as thin black lines. The vertical thin lines represent indicator onset, the vertical dashed lines represent target time for the go task, and the vertical thick lines represent stop-signal onset. Time scales relative to target are displayed at the bottom. (B) Scalp topographies of averaged EEGs in the go and stop(-200) trials for six participants in a contralateral-TMS session (left 2 × 4 arrays) and for six participants in an ipsilateral-TMS session (right 2 × 4 arrays). The topographies are displayed only at -200, 0, 100, and 200 ms relative to target.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824362&req=5

Figure 4: Averaged electroencephalography (EEG) data in no-TMS trials. (A) Averaged EEG waveforms in no-TMS trials during a go/stop task for six participants in a contralateral-TMS session (left two panels) and for six participants in an ipsilateral-TMS session (right two panels). For stop trials, only the waveforms in stop trials with a stop time of -200 ms [stop(-200) trials] are displayed. The waveforms of all 61 sites are shown as thin black lines. The vertical thin lines represent indicator onset, the vertical dashed lines represent target time for the go task, and the vertical thick lines represent stop-signal onset. Time scales relative to target are displayed at the bottom. (B) Scalp topographies of averaged EEGs in the go and stop(-200) trials for six participants in a contralateral-TMS session (left 2 × 4 arrays) and for six participants in an ipsilateral-TMS session (right 2 × 4 arrays). The topographies are displayed only at -200, 0, 100, and 200 ms relative to target.
Mentions: In the grand-mean-averaged EEG waveforms in no-TMS trials (Figure 4), gradual negative deflections over the fronto-central sites were observed as the target time approached in both go and stop trials. After the stop signal onset of -200 ms, the grand-mean-averaged EEG waveforms clearly differentiated between go and stop trials. Distinct negative–positive peaks over the frontocentral sites appeared around and after the target time in stop trials, while a mild positive peak over the centroparietal sites appeared after the target time in go trials. These waveforms in the no-TMS trials have been typically shown in the go and stop trials of the go/stop (or stop-signal) task (De Jong et al., 1990; Schmajuk et al., 2006).

Bottom Line: Transcranial magnetic stimulation (TMS) has often been used in conjunction with electroencephalography (EEG), which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs).However, it remains unclear what pattern is associated with the inhibition of a planned motor response.TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Human Life Sciences, Showa Women's University Tokyo, Japan.

ABSTRACT
Transcranial magnetic stimulation (TMS) has often been used in conjunction with electroencephalography (EEG), which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs). However, it remains unclear what pattern is associated with the inhibition of a planned motor response. Therefore, we performed TMS-EEG recording during a go/stop task, in which participants were instructed to click a computer mouse with a right index finger when an indicator that was moving with a constant velocity reached a target (go trial) or to avoid the click when the indicator randomly stopped just before it reached the target (stop trial). Single-pulse TMS to the left (contralateral) or right (ipsilateral) motor cortex was applied 500 ms before or just at the target time. TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS. As a result, in TEPs induced by both contralateral and ipsilateral TMS, small oscillations were followed by a prominent negative deflection around the TMS site peaking at approximately 100 ms post-TMS (N100), and a less pronounced later positive component (LPC) over the broad areas that was centered at the midline-central site in both go and stop trials. However, compared to the pattern in go and stop trials with TMS at 500 ms before the target time, N100 and LPC were differently modulated in the go and stop trials with TMS just at the target time. The amplitudes of both N100 and LPC decreased in go trials, while the amplitude of LPC decreased and the latency of LPC was delayed in both go and stop trials. These results suggested that TMS-induced neuronal reactions in the motor cortex and subsequent their propagation to surrounding cortical areas might change functionally according to task demand when executing and inhibiting a motor response.

No MeSH data available.