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P8-6 Multichannel NIRS revealed frontal cortex activation associated with speeded processing of visuospatial working memory
S148
Posters
significant activity only in association to passive listening of bi-syllabic words. Particularly, they were found activated channels located on left superior temporal gyrus (p = 0.008), left supramarginal gyrus (p = 0.007) and left posterior inferior parietal lobe (p = 0.007). No significant HbO2 variations were observed in association to syllables listening. In a sample of right handed, adult Italian native speakers, we found a significant activation in the left hemisphere during passive listening of bi-syllabic words in areas already known to be involved in speech comprehension. OT proved to be a promising alternative to Wada test for a noninvasive assessment of hemispheric language lateralization. This may be particularly relevant since it was obtained with a testing procedure, requiring minimal subject involvement, designed for future applications with less cooperative subjects (young children or patients with cognitive deficits, mental retardation or behavioural disorders). P8-4 Changes in task-associated cerebral blood induced by Role lettering: Measurement by multichannel near-infrared spectroscopy 1
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Y. Okamoto , K. Morita , A. Yamamoto , Y. Shoji , N. Haruguchi 1 Cognitive and Molecular Research Institute of Brain Diseases, Kurume University, Fukuoka, Japan, 2 Department of Neuropsychiatry, Kurume University, Japan, 3 Cognitive and Molecular Research Institute of Brain Diseases, Kurume University, Fukuoka, Japan, 4 Oita Yuai Hospital, Japan Objective: Role lettering shows promise as an effective treatment for problems resulting from psychological defenses and resistance, because it addresses patients’ paradoxical desires for self-disclosure and confidentiality in the therapy sessions, and this therapeutic exercise is useful in promoting objective self-assessment and personal security by relating oneself to others and others to oneself. Using optical topography (near-infrared spectroscopy: NIRS), relative changes in oxidized hemoglobin (oxy-Hb) were measured before and after the introduction of Role lettering. Methods: Subjects included 16 junior high school students (age, 12.1±0.8; boys, 13; girls, 3). No subject had a psychiatric illness or a motor system disease. The subject wrote the mukashi banashi (‘once a upon a time . . . ’) as a resting state, and ‘from me to five kind of persons’ (friend, mother, father, teacher, special friend) as antegrade, and ‘from five kind of persons to me’ as retrograde tasks with 30-second resting intervals, respectively. The averaged waveforms in the 5 tasks were measured, changes from the resting-state. The ethics committee of Kurume University approved the present study. Results: With the antegrade writing task, no significant difference was observed throughout the study; with the retrograde writing task, oxyHb level decreased significantly in right lateral ROI after 6 months; the decrease persisted at 1 year. The number of words produced after Role lettering increased significantly in both antegrade and retrograde writing tasks at 1 year. Conclusions: Oxy-Hb decreased significantly only in right recording regions, suggesting that subjects became more able to an objectively observe and describe themselves while thinking about themselves as viewed by other person as they practiced Role lettering. By training and continuation, people become able to readily think and perform the task, suggesting that plasticity of the cortical network for emotionally related imaging may contribute to adaptations leading to Role lettering practice. P8-5 Amplitudes of rTMS-evoked NIRS responses correlate with changes in heart rate aki1,2 , K. Kotilahti1,2 , I. Nissil¨ a1 , R.J. Ilmoniemi1 T. N¨ asi1,2 , H. M¨ 1 Department of Biomedical Engineering and Computational Science (BECS), Finland, 2 BioMag Laboratory, HUSLAB, Helsinki University Central Hospital, Helsinki, Finland Objective: Near-infrared spectroscopy (NIRS) can be used to measure concentration changes of total hemoglobin (HbT) due to repetitive transcranial magnetic stimulation (rTMS). In previous studies, TMS-evoked NIRS responses are thought to reflect brain activity. However, NIRS signals are also affected by changes in global hemodynamics. To address this issue, we studied similarities in rTMS-evoked HbT amplitudes and heart rate changes. Methods: We delivered rTMS trains to the left primary motor cortex of eight healthy subjects and recorded corresponding HbT responses over
the stimulation site and measured the heart rate with a pulse oximeter attached to the subject’s finger. The 8-s rTMS trains had an intensity of 75% of the resting motor threshold of the right abductor pollicis brevis, pulse frequencies of 0.5, 1, and 2 Hz in randomized order, and a randomized 20 30 s rest period between them. The NIRS grid had four short (1.3 cm), four intermediate (2.8 cm) and six long (3.8 cm) sourceto-detector (SD) distances. The HbT responses and changes in heart rate were averaged time-locked to the rTMS train onsets. Results: The rTMS produced HbT decreases at all SD distances and heart rate increases. The HbT responses to 0.5- and 2-Hz rTMS had larger amplitudes than the responses to 1-Hz rTMS. The HbT decreases of the subjects correlated with their increases in heart rate. Conclusions: HbT responses evoked by rTMS and changes in the heart rate of subjects are related. Thus, changes in global hemodynamics should be taken into account when analyzing and interpreting TMS-evoked NIRS responses. P8-6 Multichannel NIRS revealed frontal cortex activation associated with speeded processing of visuospatial working memory T. Nakahachi1 , R. Ishii1 , M. Iwase1 , L. Canuet1 , H. Takahashi1 , R. Kurimoto1 , K. Ikezawa1 , M. Azechi1 , Y. Aoki1 , O. Kajimoto2,3 , M. Takeda1 1 Department of Psychiatry, Osaka University Graduate School of Medicine, Japan, 2 Department of Biomarker and Molecular Biophysics, Osaka City University Graduate School of Medicine, Japan, 3 Soiken Incorporated, Japan Objective: Visuospatial working memory (VSWM) is commonly used during speeded and rather unconscious memory processing in daily life. The purpose of this study is to measure frontal cortex activation in a style mimicking VSWM performance in daily life activities using multichannel near-infrared spectroscopy (NIRS). Methods: Twenty-six healthy volunteers were enrolled in this study. We measured relative changes in concentration of oxygenated hemoglobin ([oxy-Hb]) by NIRS, as index of frontal activation, during a VSWM task, namely the Advanced Trail Making Test (ATMT). This task consists of Task R and Task F: the former is believed to measure motor factors only, and the latter is thought to measure motor and cognitive factors, which are involved in speeded and rather unconscious VSWM operations. Results: Changes in [oxy-Hb] during the ATMT were determined in fifty-two measurement points (channels) on the frontal area. Activated channels during Task F performance were distributed bilaterally over the dorsolateral and ventrolateral prefrontal cortices. This cortical activation might reflect central executive function of working memory. On the other hand, the channels activated by Task R were observed only over the left ventrolateral prefrontal cortex which was also activated during Task F performance and presumably represents subvocal articulatory rehearsal or task-related motor factors activation. Conclusions: It was confirmed that application of multichannel NIRS during ATMT performance is feasible to measure VSWM-induced cortical activation in a similar way that VSWM is used in daily activities. P8-7 Effects of aging on activity of the prefrontal cortex during shiritori task A. Yamamoto1 , K. Morita1 , Y. Shoji1,2 , Y. Nakashima1 , Y. Okamoto1 , N. Uchimura2 1 Cognitive and Molecular Research Institute of Brain Diseases, Fukuoka, Japan, 2 Department of Neuropsychiatry Kurume University School of Medicine, Fukuoka, Japan Changes in oxy-Hb during performing a shiritori (Japanese word-chain game) task were compared among generations in healthy subjects using optic topography (NIRS). The subjects were junior high school students (age: 12.9±0.67 years), adults (age: 30.7±11.32 years), and elderly persons (age: 70.7±3.03 years). They alternately performed control (6 times) and shiritori (5 times) tasks every 30 seconds, and the total number of words produced during the shiritori task was regarded as the result. Changes in oxy-Hb during performing the task were measured via a 44 channel set on the bilateral sides using an NIRS system (ETG4000, Hitachi). The task result was not significantly different among the 3 generation groups, but significant differences in oxy-Hb changes were noted in the left measurement region during performing the shiritori task between the junior high school student and adult groups and between the
Posters
significant activity only in association to passive listening of bi-syllabic words. Particularly, they were found activated channels located on left superior temporal gyrus (p = 0.008), left supramarginal gyrus (p = 0.007) and left posterior inferior parietal lobe (p = 0.007). No significant HbO2 variations were observed in association to syllables listening. In a sample of right handed, adult Italian native speakers, we found a significant activation in the left hemisphere during passive listening of bi-syllabic words in areas already known to be involved in speech comprehension. OT proved to be a promising alternative to Wada test for a noninvasive assessment of hemispheric language lateralization. This may be particularly relevant since it was obtained with a testing procedure, requiring minimal subject involvement, designed for future applications with less cooperative subjects (young children or patients with cognitive deficits, mental retardation or behavioural disorders). P8-4 Changes in task-associated cerebral blood induced by Role lettering: Measurement by multichannel near-infrared spectroscopy 1
1,2
3
2
4
Y. Okamoto , K. Morita , A. Yamamoto , Y. Shoji , N. Haruguchi 1 Cognitive and Molecular Research Institute of Brain Diseases, Kurume University, Fukuoka, Japan, 2 Department of Neuropsychiatry, Kurume University, Japan, 3 Cognitive and Molecular Research Institute of Brain Diseases, Kurume University, Fukuoka, Japan, 4 Oita Yuai Hospital, Japan Objective: Role lettering shows promise as an effective treatment for problems resulting from psychological defenses and resistance, because it addresses patients’ paradoxical desires for self-disclosure and confidentiality in the therapy sessions, and this therapeutic exercise is useful in promoting objective self-assessment and personal security by relating oneself to others and others to oneself. Using optical topography (near-infrared spectroscopy: NIRS), relative changes in oxidized hemoglobin (oxy-Hb) were measured before and after the introduction of Role lettering. Methods: Subjects included 16 junior high school students (age, 12.1±0.8; boys, 13; girls, 3). No subject had a psychiatric illness or a motor system disease. The subject wrote the mukashi banashi (‘once a upon a time . . . ’) as a resting state, and ‘from me to five kind of persons’ (friend, mother, father, teacher, special friend) as antegrade, and ‘from five kind of persons to me’ as retrograde tasks with 30-second resting intervals, respectively. The averaged waveforms in the 5 tasks were measured, changes from the resting-state. The ethics committee of Kurume University approved the present study. Results: With the antegrade writing task, no significant difference was observed throughout the study; with the retrograde writing task, oxyHb level decreased significantly in right lateral ROI after 6 months; the decrease persisted at 1 year. The number of words produced after Role lettering increased significantly in both antegrade and retrograde writing tasks at 1 year. Conclusions: Oxy-Hb decreased significantly only in right recording regions, suggesting that subjects became more able to an objectively observe and describe themselves while thinking about themselves as viewed by other person as they practiced Role lettering. By training and continuation, people become able to readily think and perform the task, suggesting that plasticity of the cortical network for emotionally related imaging may contribute to adaptations leading to Role lettering practice. P8-5 Amplitudes of rTMS-evoked NIRS responses correlate with changes in heart rate aki1,2 , K. Kotilahti1,2 , I. Nissil¨ a1 , R.J. Ilmoniemi1 T. N¨ asi1,2 , H. M¨ 1 Department of Biomedical Engineering and Computational Science (BECS), Finland, 2 BioMag Laboratory, HUSLAB, Helsinki University Central Hospital, Helsinki, Finland Objective: Near-infrared spectroscopy (NIRS) can be used to measure concentration changes of total hemoglobin (HbT) due to repetitive transcranial magnetic stimulation (rTMS). In previous studies, TMS-evoked NIRS responses are thought to reflect brain activity. However, NIRS signals are also affected by changes in global hemodynamics. To address this issue, we studied similarities in rTMS-evoked HbT amplitudes and heart rate changes. Methods: We delivered rTMS trains to the left primary motor cortex of eight healthy subjects and recorded corresponding HbT responses over
the stimulation site and measured the heart rate with a pulse oximeter attached to the subject’s finger. The 8-s rTMS trains had an intensity of 75% of the resting motor threshold of the right abductor pollicis brevis, pulse frequencies of 0.5, 1, and 2 Hz in randomized order, and a randomized 20 30 s rest period between them. The NIRS grid had four short (1.3 cm), four intermediate (2.8 cm) and six long (3.8 cm) sourceto-detector (SD) distances. The HbT responses and changes in heart rate were averaged time-locked to the rTMS train onsets. Results: The rTMS produced HbT decreases at all SD distances and heart rate increases. The HbT responses to 0.5- and 2-Hz rTMS had larger amplitudes than the responses to 1-Hz rTMS. The HbT decreases of the subjects correlated with their increases in heart rate. Conclusions: HbT responses evoked by rTMS and changes in the heart rate of subjects are related. Thus, changes in global hemodynamics should be taken into account when analyzing and interpreting TMS-evoked NIRS responses. P8-6 Multichannel NIRS revealed frontal cortex activation associated with speeded processing of visuospatial working memory T. Nakahachi1 , R. Ishii1 , M. Iwase1 , L. Canuet1 , H. Takahashi1 , R. Kurimoto1 , K. Ikezawa1 , M. Azechi1 , Y. Aoki1 , O. Kajimoto2,3 , M. Takeda1 1 Department of Psychiatry, Osaka University Graduate School of Medicine, Japan, 2 Department of Biomarker and Molecular Biophysics, Osaka City University Graduate School of Medicine, Japan, 3 Soiken Incorporated, Japan Objective: Visuospatial working memory (VSWM) is commonly used during speeded and rather unconscious memory processing in daily life. The purpose of this study is to measure frontal cortex activation in a style mimicking VSWM performance in daily life activities using multichannel near-infrared spectroscopy (NIRS). Methods: Twenty-six healthy volunteers were enrolled in this study. We measured relative changes in concentration of oxygenated hemoglobin ([oxy-Hb]) by NIRS, as index of frontal activation, during a VSWM task, namely the Advanced Trail Making Test (ATMT). This task consists of Task R and Task F: the former is believed to measure motor factors only, and the latter is thought to measure motor and cognitive factors, which are involved in speeded and rather unconscious VSWM operations. Results: Changes in [oxy-Hb] during the ATMT were determined in fifty-two measurement points (channels) on the frontal area. Activated channels during Task F performance were distributed bilaterally over the dorsolateral and ventrolateral prefrontal cortices. This cortical activation might reflect central executive function of working memory. On the other hand, the channels activated by Task R were observed only over the left ventrolateral prefrontal cortex which was also activated during Task F performance and presumably represents subvocal articulatory rehearsal or task-related motor factors activation. Conclusions: It was confirmed that application of multichannel NIRS during ATMT performance is feasible to measure VSWM-induced cortical activation in a similar way that VSWM is used in daily activities. P8-7 Effects of aging on activity of the prefrontal cortex during shiritori task A. Yamamoto1 , K. Morita1 , Y. Shoji1,2 , Y. Nakashima1 , Y. Okamoto1 , N. Uchimura2 1 Cognitive and Molecular Research Institute of Brain Diseases, Fukuoka, Japan, 2 Department of Neuropsychiatry Kurume University School of Medicine, Fukuoka, Japan Changes in oxy-Hb during performing a shiritori (Japanese word-chain game) task were compared among generations in healthy subjects using optic topography (NIRS). The subjects were junior high school students (age: 12.9±0.67 years), adults (age: 30.7±11.32 years), and elderly persons (age: 70.7±3.03 years). They alternately performed control (6 times) and shiritori (5 times) tasks every 30 seconds, and the total number of words produced during the shiritori task was regarded as the result. Changes in oxy-Hb during performing the task were measured via a 44 channel set on the bilateral sides using an NIRS system (ETG4000, Hitachi). The task result was not significantly different among the 3 generation groups, but significant differences in oxy-Hb changes were noted in the left measurement region during performing the shiritori task between the junior high school student and adult groups and between the