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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.


Motor-evoked potential (MEP) amplitude. Group means (±SE) of MEP amplitudes during the go/stop task with contralateral (upper) and ipsilateral (lower) TMS at -500 and 0 ms. Error bars show standard error (SE). *p < 0.05; significant difference in post hoc multiple comparisons with Bonferroni corrected paired t-tests.
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Figure 3: Motor-evoked potential (MEP) amplitude. Group means (±SE) of MEP amplitudes during the go/stop task with contralateral (upper) and ipsilateral (lower) TMS at -500 and 0 ms. Error bars show standard error (SE). *p < 0.05; significant difference in post hoc multiple comparisons with Bonferroni corrected paired t-tests.

Mentions: Mean MEP amplitudes increased only in the go trials with the contralateral TMS at 0 ms, and there were not much differences in the mean MEP amplitudes in the other seven conditions (Figure 3). The mixed factorial ANOVA of the mean MEP amplitudes revealed significant within-participant effects of trial [F(1, 10) = 17.7, p < 0.01] and TMS time [F(1, 10) = 11.4, p < 0.01] and their significant interaction [F(1, 10) = 17.4, p < 0.01]. There were no significant between-participants effects of TMS side, while there were significant TMS side × TMS time [F(1, 10) = 10.4, p < 0.01], TMS side × trial [F(1, 10) = 12.4, p < 0.01], and TMS side × TMS time × trial [F(1, 10) = 12.8, p < 0.01] interactions. Therefore, post hoc multiple comparisons were conducted for all six pairs among 2 TMS time × 2 trial conditions separately for each TMS side. There were significant differences of mean MEP amplitudes in three pairs between go trial with TMS at 0 ms and the other three conditions for the contralateral TMS condition, while there was no significant difference of mean MEP amplitudes in all six pairs for the ipsilateral TMS condition. These results indicated that MEP enlarged only in go trials with the contralateral TMS at 0 ms.


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

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

Motor-evoked potential (MEP) amplitude. Group means (±SE) of MEP amplitudes during the go/stop task with contralateral (upper) and ipsilateral (lower) TMS at -500 and 0 ms. Error bars show standard error (SE). *p < 0.05; significant difference in post hoc multiple comparisons with Bonferroni corrected paired t-tests.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Motor-evoked potential (MEP) amplitude. Group means (±SE) of MEP amplitudes during the go/stop task with contralateral (upper) and ipsilateral (lower) TMS at -500 and 0 ms. Error bars show standard error (SE). *p < 0.05; significant difference in post hoc multiple comparisons with Bonferroni corrected paired t-tests.
Mentions: Mean MEP amplitudes increased only in the go trials with the contralateral TMS at 0 ms, and there were not much differences in the mean MEP amplitudes in the other seven conditions (Figure 3). The mixed factorial ANOVA of the mean MEP amplitudes revealed significant within-participant effects of trial [F(1, 10) = 17.7, p < 0.01] and TMS time [F(1, 10) = 11.4, p < 0.01] and their significant interaction [F(1, 10) = 17.4, p < 0.01]. There were no significant between-participants effects of TMS side, while there were significant TMS side × TMS time [F(1, 10) = 10.4, p < 0.01], TMS side × trial [F(1, 10) = 12.4, p < 0.01], and TMS side × TMS time × trial [F(1, 10) = 12.8, p < 0.01] interactions. Therefore, post hoc multiple comparisons were conducted for all six pairs among 2 TMS time × 2 trial conditions separately for each TMS side. There were significant differences of mean MEP amplitudes in three pairs between go trial with TMS at 0 ms and the other three conditions for the contralateral TMS condition, while there was no significant difference of mean MEP amplitudes in all six pairs for the ipsilateral TMS condition. These results indicated that MEP enlarged only in go trials with the contralateral TMS at 0 ms.

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.