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Study of timing processing by event-related potentials (ERPs)
Japanese Society of Clincal Neurophysiology / Clinical Neurophysiology 118 (2007) e203–e212
e211
30. Physiological findings
32. ERP
Cortical mapping of transcranial magnetic stimulation (TMS) related F-wave—S. Ishikawa 1, S. Etoh 1, R. Nakanishi 2, K. Kawahira 1, N. Tanaka 1 (1 Kagoshima university, Japan, 2 Kumamoto Kinoh hospital, Japan)
ERP differences in auditory processing of cross-language stimuli by adults of differing language backgrounds— S. Snyder 1,2, N. Tsuru 1 (1 Miyazaki Medical College, Japan, 2 Kyushu University of Health and Welfare, Japan)
Purpose: To detect cortico-spinal interaction by combining preceding TMS and F-wave. Subject and method: Five healthy subjects participated in this study. The TMS related F-waves (TRFs) were recorded on the first dorsal interosseus muscle. The preceding TMS with 5–300 ms (5, 10, 15, . . . , 300) inter-stimulus interval (ISI) from following electric stimulation on the ulner nerve at the wrist was given on contralateral hand motor cortex (HMC), 2.5, 5 cm anterior to HMC and 2.5 cm posteriol to HMC, and 2 cm lateral of each points by a eight-figured coil with the intensity of 120–130% resting threshold. Result: TRF by contralateral HMC stimulation showed obvious two peak facilitations. Early one was observed at shorter ISI than 20 ms ISI and late one was found on 150–250 ms ISI. TRF by contralateral prefrontal cortex showed undersized broadband facilitation. TRF by 2 cm lateral of each cortex showed no obvious facilitation. Conclusion: These results suggested that HMC and prefrontal cortex influence spinal excitability in 150–200 ms ISI and TRF is of use in understanding cortico-spinal interaction.
The present study sought to compare word and nonword processing by using non-repeated auditory stimuli. We obtained ERP readings of initial responses to nonword and real single-syllable word stimuli by matching word onsets and durations of stimuli. At question was the plasticity of the phonological systems of adults; specifically, whether increased familiarity with a nonnative language showed processing more similar to native speakers of the target language. This study also found significant differences in amplitude and latency in the ERPs between native speakers of Japanese and English languages and found evidence of changes in processing related to increased familiarity with the L2 language. In general, ERPs on L2 real word stimuli showed greater latency and lower amplitudes than did ERPs on L1 real word stimuli. Functionally fluent bilingual Japanese participants had average amplitudes on L2 real word stimuli between native speakers and naive participants. For the nonword stimuli the functionally fluent Japanese participants showed greater amplitudes for L2 nonword stimuli than did non-fluent participants. The finding that adult bilinguals showed a shift towards L2 standards supports the hypothesis that phonological processing retains plasticity in adults. The higher amplitude processing of L2 nonword stimuli suggests that greater phonological processing is being tapped in the naming task. This finding would implicate acquired phonological sensitivity to L2, rather than phonological memory capacity, as the source of difference in performance on the naming task.
doi:10.1016/j.clinph.2007.06.050
31. Physiological findings Interhemispheric interaction of bilateral motor and sensory cortices—H. Mochizuki 1,2, Y. Terao 1, S. Okabe 1, T. Furubayashi 1, N. Arai 1, N. Iwata 1, K. Kamakura 2, Y. Ugawa 1 (1 University of Tokyo, Japan, 2 National Defense Medical College, Japan) To study interaction between bilateral sensorimotor cortices, we tested effects of single pulses of TMS applied to the right hemisphere over either the hand sensory area, the hand motor area (M1), ventral premotor area (vPM), dorsolateral prefrontal cortex, or 10 cm away from head (sham stimulation) on MEPs elicited by single pulse TMS over the left M1 or the SEP elicited by an electrical stimulus to the right median nerve. The interstimulus intervals (ISIs) for MEP experiments were 50, 100, 150, 200, 300 and 400 ms, with those for SEP experiments being adjusted for the impulse conduction time from the wrist to the cortex. TMS over the right M1 reduced MEPs elicited by TMS of the left M1 at ISIs of 50–150 ms. TMS over M1 and vPM facilitated the contralateral cortical median nerve SEPs at an ISI of 100–200 ms. Based on these results, we conclude that at around 150 ms intervals, TMS over the motor areas (M1 and vPM) reduces the excitability of the contralateral motor area. This reduction has a secondary effect of enhancing the responsiveness of the sensory cortex through cortico-cortical connections. doi:10.1016/j.clinph.2007.06.051
doi:10.1016/j.clinph.2007.06.052
33. ERP Study of timing processing by event-related potentials (ERPs)—Y. Mochizuki 1, H. Tanaka 2, H. Masaki 1, N. Takasawa 3, K. Yamazaki 1 (1 Waseda University, Japan, 2 Obirin University, Japan, 3 National Research, Institute of Police Science, Japan) The present study used the contingent negative variation (CNV) paradigm (S1-S2-MR) to investigate timing processing by varying interstimulus interval (ISI:3s-fixed/random) and intertrial interval (ITI:3s/10s). The reaction time (RT) was delayed under ISI-random and ITI- 10s conditions. The amplitude of late CNV over Cz of ISI-3s-fixed conditions was larger than that of ISI-random conditions, and the larger amplitudes seemed to represent the prediction and motor preparation for S2. The amplitudes of the early and late CNV over Fz and Cz of ITI- 10s conditions were larger than those of ITI-3s conditions, and the larger amplitudes might represent the activities to retrieve the temporal information in each trial. N1 latency of ITI-10s conditions elicited by S1 was delayed than that of ITI-3s conditions, and N1 amplitude of ISI-random conditions elicited by S2 was larger than that of ISI-3s-fixed conditions. P3 latency and ampli-
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Japanese Society of Clincal Neurophysiology / Clinical Neurophysiology 118 (2007) e203–e212
tude of ITI-10s conditions elicited by S1 were delayed and larger than those of ITI-3s conditions, and those of the ISI-3s-fix/ITI-3s condition by S2 were shorter and smaller than those of other conditions. Our findings in the present study show that not only ISI but also ITI duration plays a crucial role in timing processing. doi:10.1016/j.clinph.2007.06.053
34. ERP Event-related potentials to the absence of anticipated action effects—H. Nittono (Hiroshima University, Japan) To examine brain electrical responses to unexpected action consequences, event-related potentials were recorded in 16 healthy young volunteers. Participants were asked to make a voluntary key press once per 1–2 s. Each key press triggered either an auditory or a visual stimulus in separate blocks. In some trials (p = 0.2), no stimulus followed after key press. When an anticipated auditory or visual action effect did not occur, a negativepositive missing stimulus potential complex was emitted within 150–500 ms. The negative potential was dominant at the right parieto-temporal sites, whereas the positive potential was dominant at the central sites. Although the eliciting event was identical (i.e., the absence of a stimulus), the peak latencies of the negative and positive waves were about 30 ms shorter in the auditory than in the visual modality. The amplitude of the negativity was larger in the visual than in the auditory modality, whereas no amplitude difference was found for the positivity. These negative and positive potentials probably reflect the failure to detect an anticipated action effect and the subsequent orientation of attention to such a deviant event, respectively. doi:10.1016/j.clinph.2007.06.054
35. Neuroimagings Activation of distinct brain areas caused by virtual visual stimulation in allodynia patients—T. Ushida, T. Ikemoto, S. Taniguchi, T. Tani, S. Tanaka, K. Morio, O. Zinchuk, W. Ueda (Kochi Medical School, Japan) Introduction: It is frequent clinical observation that in neuropathic pain patients pain anxiety can exacerbate pain sensation. We hypothesize that they may experience unpleasantness similar to that evoked by real mechanical painful stimuli when imagining painful experience from the past. Methods: Virtual visual tactile stimulation was employed to evoke experiences of tactile or painful sensations in the brain areas responsive to pain in 10 normal volunteers and 5 patients with allodynia. Examined subjects were shown a digital video demonstrating tactile palm stimulation by horse hair brush.
Results were analyzed using functional magneto-resonance imaging. Results: Normal subjects showed activation of Brodmann‘s areas (BA) 19, 39, 40 and fusiform gyrus. In allodynia patients virtual visual stimulation revealed activation of the superior frontal gyrus (BA 8-10), anterior cingulate cortex, primary somatosensory cortex (SI) and temporal lobe fusiform gyrus. Conclusion: These findings highlight differences in the perception of pain between normal volunteers and neuropathic pain patients with allodynia. Activation of frontal lobe and anterior cingulate, observed in patients with allodynia, might be indicative of a not yet described mechanism related to the activation of brain areas responsible for virtually evoked emotional discomfort and pain cognition. doi:10.1016/j.clinph.2007.06.055
36. Neuroimagings An event-related fMRI study of the Stroop task— T. Sasai 1, A. Hayakawa 1, M. Yamazaki 1, Y. Ikeda 1, M. Koeda 1, H. Takahashi 2, K. Oda 3, Y. Okubo 4 (1 Graduate School of Tokyo Medical and Dental University, Japan, 2 Asai Hospital, Japan, 3 Onda-daini, Hospital, Japan, 4 Nippon Medical School, Japan) Background: A number of neuroimaging studies have demonstrated that the anterior cingulate is activated by Stroop tasks. But some problems have been pointed out in Stroop tasks applied to neuroimaging studies. That is, neural activation progressively decreases by learning successive incongruent stimulus in boxdesign Stroop task. In color Stroop tasks, speaking produces head movements and matching buttons with color names requires undesired cognitive demands. Thus, we performed an eventrelated design fMRI study to investigate brain activation during a counting Stroop task. Methods: Eleven normal right-handed volunteers underwent fMRI while performing the task and they reported number of the characters by button-press. Incongruent trials contained number characters ( ) whose contents were incongruent with the number of characters while neutral trials contained animal characters ( ). Results: Behavioral data showed longer reaction times for incongruent trials than for neutral trials. Imaging data demonstrated significant activation in the medial prefrontal cortex when contrasting incongruent versus neutral conditions. Conclusions: Our study showed that the medial prefrontal cortex rather than the anterior cingulate cortex is involved in mediating response selection and allocating attentional resources under conflict conditions. doi:10.1016/j.clinph.2007.06.056
e211
30. Physiological findings
32. ERP
Cortical mapping of transcranial magnetic stimulation (TMS) related F-wave—S. Ishikawa 1, S. Etoh 1, R. Nakanishi 2, K. Kawahira 1, N. Tanaka 1 (1 Kagoshima university, Japan, 2 Kumamoto Kinoh hospital, Japan)
ERP differences in auditory processing of cross-language stimuli by adults of differing language backgrounds— S. Snyder 1,2, N. Tsuru 1 (1 Miyazaki Medical College, Japan, 2 Kyushu University of Health and Welfare, Japan)
Purpose: To detect cortico-spinal interaction by combining preceding TMS and F-wave. Subject and method: Five healthy subjects participated in this study. The TMS related F-waves (TRFs) were recorded on the first dorsal interosseus muscle. The preceding TMS with 5–300 ms (5, 10, 15, . . . , 300) inter-stimulus interval (ISI) from following electric stimulation on the ulner nerve at the wrist was given on contralateral hand motor cortex (HMC), 2.5, 5 cm anterior to HMC and 2.5 cm posteriol to HMC, and 2 cm lateral of each points by a eight-figured coil with the intensity of 120–130% resting threshold. Result: TRF by contralateral HMC stimulation showed obvious two peak facilitations. Early one was observed at shorter ISI than 20 ms ISI and late one was found on 150–250 ms ISI. TRF by contralateral prefrontal cortex showed undersized broadband facilitation. TRF by 2 cm lateral of each cortex showed no obvious facilitation. Conclusion: These results suggested that HMC and prefrontal cortex influence spinal excitability in 150–200 ms ISI and TRF is of use in understanding cortico-spinal interaction.
The present study sought to compare word and nonword processing by using non-repeated auditory stimuli. We obtained ERP readings of initial responses to nonword and real single-syllable word stimuli by matching word onsets and durations of stimuli. At question was the plasticity of the phonological systems of adults; specifically, whether increased familiarity with a nonnative language showed processing more similar to native speakers of the target language. This study also found significant differences in amplitude and latency in the ERPs between native speakers of Japanese and English languages and found evidence of changes in processing related to increased familiarity with the L2 language. In general, ERPs on L2 real word stimuli showed greater latency and lower amplitudes than did ERPs on L1 real word stimuli. Functionally fluent bilingual Japanese participants had average amplitudes on L2 real word stimuli between native speakers and naive participants. For the nonword stimuli the functionally fluent Japanese participants showed greater amplitudes for L2 nonword stimuli than did non-fluent participants. The finding that adult bilinguals showed a shift towards L2 standards supports the hypothesis that phonological processing retains plasticity in adults. The higher amplitude processing of L2 nonword stimuli suggests that greater phonological processing is being tapped in the naming task. This finding would implicate acquired phonological sensitivity to L2, rather than phonological memory capacity, as the source of difference in performance on the naming task.
doi:10.1016/j.clinph.2007.06.050
31. Physiological findings Interhemispheric interaction of bilateral motor and sensory cortices—H. Mochizuki 1,2, Y. Terao 1, S. Okabe 1, T. Furubayashi 1, N. Arai 1, N. Iwata 1, K. Kamakura 2, Y. Ugawa 1 (1 University of Tokyo, Japan, 2 National Defense Medical College, Japan) To study interaction between bilateral sensorimotor cortices, we tested effects of single pulses of TMS applied to the right hemisphere over either the hand sensory area, the hand motor area (M1), ventral premotor area (vPM), dorsolateral prefrontal cortex, or 10 cm away from head (sham stimulation) on MEPs elicited by single pulse TMS over the left M1 or the SEP elicited by an electrical stimulus to the right median nerve. The interstimulus intervals (ISIs) for MEP experiments were 50, 100, 150, 200, 300 and 400 ms, with those for SEP experiments being adjusted for the impulse conduction time from the wrist to the cortex. TMS over the right M1 reduced MEPs elicited by TMS of the left M1 at ISIs of 50–150 ms. TMS over M1 and vPM facilitated the contralateral cortical median nerve SEPs at an ISI of 100–200 ms. Based on these results, we conclude that at around 150 ms intervals, TMS over the motor areas (M1 and vPM) reduces the excitability of the contralateral motor area. This reduction has a secondary effect of enhancing the responsiveness of the sensory cortex through cortico-cortical connections. doi:10.1016/j.clinph.2007.06.051
doi:10.1016/j.clinph.2007.06.052
33. ERP Study of timing processing by event-related potentials (ERPs)—Y. Mochizuki 1, H. Tanaka 2, H. Masaki 1, N. Takasawa 3, K. Yamazaki 1 (1 Waseda University, Japan, 2 Obirin University, Japan, 3 National Research, Institute of Police Science, Japan) The present study used the contingent negative variation (CNV) paradigm (S1-S2-MR) to investigate timing processing by varying interstimulus interval (ISI:3s-fixed/random) and intertrial interval (ITI:3s/10s). The reaction time (RT) was delayed under ISI-random and ITI- 10s conditions. The amplitude of late CNV over Cz of ISI-3s-fixed conditions was larger than that of ISI-random conditions, and the larger amplitudes seemed to represent the prediction and motor preparation for S2. The amplitudes of the early and late CNV over Fz and Cz of ITI- 10s conditions were larger than those of ITI-3s conditions, and the larger amplitudes might represent the activities to retrieve the temporal information in each trial. N1 latency of ITI-10s conditions elicited by S1 was delayed than that of ITI-3s conditions, and N1 amplitude of ISI-random conditions elicited by S2 was larger than that of ISI-3s-fixed conditions. P3 latency and ampli-
e212
Japanese Society of Clincal Neurophysiology / Clinical Neurophysiology 118 (2007) e203–e212
tude of ITI-10s conditions elicited by S1 were delayed and larger than those of ITI-3s conditions, and those of the ISI-3s-fix/ITI-3s condition by S2 were shorter and smaller than those of other conditions. Our findings in the present study show that not only ISI but also ITI duration plays a crucial role in timing processing. doi:10.1016/j.clinph.2007.06.053
34. ERP Event-related potentials to the absence of anticipated action effects—H. Nittono (Hiroshima University, Japan) To examine brain electrical responses to unexpected action consequences, event-related potentials were recorded in 16 healthy young volunteers. Participants were asked to make a voluntary key press once per 1–2 s. Each key press triggered either an auditory or a visual stimulus in separate blocks. In some trials (p = 0.2), no stimulus followed after key press. When an anticipated auditory or visual action effect did not occur, a negativepositive missing stimulus potential complex was emitted within 150–500 ms. The negative potential was dominant at the right parieto-temporal sites, whereas the positive potential was dominant at the central sites. Although the eliciting event was identical (i.e., the absence of a stimulus), the peak latencies of the negative and positive waves were about 30 ms shorter in the auditory than in the visual modality. The amplitude of the negativity was larger in the visual than in the auditory modality, whereas no amplitude difference was found for the positivity. These negative and positive potentials probably reflect the failure to detect an anticipated action effect and the subsequent orientation of attention to such a deviant event, respectively. doi:10.1016/j.clinph.2007.06.054
35. Neuroimagings Activation of distinct brain areas caused by virtual visual stimulation in allodynia patients—T. Ushida, T. Ikemoto, S. Taniguchi, T. Tani, S. Tanaka, K. Morio, O. Zinchuk, W. Ueda (Kochi Medical School, Japan) Introduction: It is frequent clinical observation that in neuropathic pain patients pain anxiety can exacerbate pain sensation. We hypothesize that they may experience unpleasantness similar to that evoked by real mechanical painful stimuli when imagining painful experience from the past. Methods: Virtual visual tactile stimulation was employed to evoke experiences of tactile or painful sensations in the brain areas responsive to pain in 10 normal volunteers and 5 patients with allodynia. Examined subjects were shown a digital video demonstrating tactile palm stimulation by horse hair brush.
Results were analyzed using functional magneto-resonance imaging. Results: Normal subjects showed activation of Brodmann‘s areas (BA) 19, 39, 40 and fusiform gyrus. In allodynia patients virtual visual stimulation revealed activation of the superior frontal gyrus (BA 8-10), anterior cingulate cortex, primary somatosensory cortex (SI) and temporal lobe fusiform gyrus. Conclusion: These findings highlight differences in the perception of pain between normal volunteers and neuropathic pain patients with allodynia. Activation of frontal lobe and anterior cingulate, observed in patients with allodynia, might be indicative of a not yet described mechanism related to the activation of brain areas responsible for virtually evoked emotional discomfort and pain cognition. doi:10.1016/j.clinph.2007.06.055
36. Neuroimagings An event-related fMRI study of the Stroop task— T. Sasai 1, A. Hayakawa 1, M. Yamazaki 1, Y. Ikeda 1, M. Koeda 1, H. Takahashi 2, K. Oda 3, Y. Okubo 4 (1 Graduate School of Tokyo Medical and Dental University, Japan, 2 Asai Hospital, Japan, 3 Onda-daini, Hospital, Japan, 4 Nippon Medical School, Japan) Background: A number of neuroimaging studies have demonstrated that the anterior cingulate is activated by Stroop tasks. But some problems have been pointed out in Stroop tasks applied to neuroimaging studies. That is, neural activation progressively decreases by learning successive incongruent stimulus in boxdesign Stroop task. In color Stroop tasks, speaking produces head movements and matching buttons with color names requires undesired cognitive demands. Thus, we performed an eventrelated design fMRI study to investigate brain activation during a counting Stroop task. Methods: Eleven normal right-handed volunteers underwent fMRI while performing the task and they reported number of the characters by button-press. Incongruent trials contained number characters ( ) whose contents were incongruent with the number of characters while neutral trials contained animal characters ( ). Results: Behavioral data showed longer reaction times for incongruent trials than for neutral trials. Imaging data demonstrated significant activation in the medial prefrontal cortex when contrasting incongruent versus neutral conditions. Conclusions: Our study showed that the medial prefrontal cortex rather than the anterior cingulate cortex is involved in mediating response selection and allocating attentional resources under conflict conditions. doi:10.1016/j.clinph.2007.06.056