TY - JOUR
T1 - Objective examination for two-point stimulation using a somatosensory oddball paradigm
T2 - An MEG study
AU - Akatsuka, Kosuke
AU - Wasaka, Toshiaki
AU - Nakata, Hiroki
AU - Kida, Tetsuo
AU - Hoshiyama, Minoru
AU - Tamura, Yohei
AU - Kakigi, Ryusuke
PY - 2007/2
Y1 - 2007/2
N2 - Objective: To establish an objective two-point discrimination test using magnetoencephalography (MEG). Methods: First, we determined the discrimination threshold (DT) of the two-points. In the first experiment, we applied 0.9DT as standard stimuli, and 0.8DT, 1.1DT and 2DT as deviant stimuli in Conditions 1, 2 and 3, respectively. In the second experiment, we used 2DT and 0.9DT as the standard and deviant stimuli, respectively, in Condition 1. We applied two-stimuli that subjects felt as definitely one point or two-points in Condition 2 and 3, respectively. Results: In the first experiment, the components peaking around 30-70 and 150-250 ms following deviant stimuli were significantly larger than those following standard stimuli. Considering the peak latency, these components seem consistent with the magnetic mismatch field (MMF). In the second experiment, the MMF was recorded only in Condition 1. Therefore, it is considered that the MMF was recorded only when subjects automatically discriminate one point from two-points stimuli. Conclusions: This novel method can be used in neurophysiological two-point discrimination tests without the need to rely on the examiners' skills and subjects' reactions. Significance: We confirmed that our new method could be used for the objective examination of two-point spatial discrimination.
AB - Objective: To establish an objective two-point discrimination test using magnetoencephalography (MEG). Methods: First, we determined the discrimination threshold (DT) of the two-points. In the first experiment, we applied 0.9DT as standard stimuli, and 0.8DT, 1.1DT and 2DT as deviant stimuli in Conditions 1, 2 and 3, respectively. In the second experiment, we used 2DT and 0.9DT as the standard and deviant stimuli, respectively, in Condition 1. We applied two-stimuli that subjects felt as definitely one point or two-points in Condition 2 and 3, respectively. Results: In the first experiment, the components peaking around 30-70 and 150-250 ms following deviant stimuli were significantly larger than those following standard stimuli. Considering the peak latency, these components seem consistent with the magnetic mismatch field (MMF). In the second experiment, the MMF was recorded only in Condition 1. Therefore, it is considered that the MMF was recorded only when subjects automatically discriminate one point from two-points stimuli. Conclusions: This novel method can be used in neurophysiological two-point discrimination tests without the need to rely on the examiners' skills and subjects' reactions. Significance: We confirmed that our new method could be used for the objective examination of two-point spatial discrimination.
KW - Magnetoencephalography
KW - Mismatch field
KW - Somatosensory
KW - Spatial discrimination
KW - Two-point discrimination
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U2 - 10.1016/j.clinph.2006.09.030
DO - 10.1016/j.clinph.2006.09.030
M3 - Article
C2 - 17095288
AN - SCOPUS:33845959148
VL - 118
SP - 403
EP - 411
JO - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
JF - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
SN - 1388-2457
IS - 2
ER -