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Information volume, evoked potentials and reaction time with voice were studied for reading Japanese cursive syllabary “HIRAGANAs”. Thirty-two EEGs with a filter from DC to 100 Hz were sampled at 2 kHz into 24 bits during 1000 ms after displaying HIRAGANAs. Evoked potentials were marked over the frontal and occipital areas, because of referring to scalp central areas, then the potentials were converted with the current source derivation. Reaction times for voice were 623±137 for one HIRAGANA, 819±136 for two HIRAGANAs, 993±169 ms for four HIRAGANAs. Broad central areas showed graded different potentials between reading silently and aloud, corresponding to the volume of the information, after 100 ms before 500 ms displaying HIRAGANAs.

To study cerebral cortical function in equilibrium, cortical oxyhemoglobin saturation rate was measured during Caloric test for five volunteers. Near-infrared spectroscopy (NIRS) measuring backscattered reflection is a non-invasive, good method to study human cortical activation. Over both temporal areas, the oxyhemoglobin saturation rate changed during the irrigation to the auricle, the irrigation to the ear meatus, and during nystagmus. Caloric test induced various cortical activation; e.g., the sensation in irrigating iced water, vestibulo-autonomic response, vestibulo-ocular response, anticipation to the stimuli and so on.

Dipole source localization corresponding to interictal spikes were estimated using EEG dipole tracing with a realistic three-shell head model in three patients with cryptogenic gelastic epilepsy. The dipole sources in two patients, whose gelastic seizures were accompanied by a subjective feeling of mirth, were estimated in the right or left medio-basal temporal regions. In the other patient, with gelastic seizures without a sense of mirth, the dipole sources were localized in the right frontal region corresponding to the anterior cingulate. The results suggest that the neural activities in hippocampal regions are involved with the generation of gelastic seizures with a sense of mirth and those in the cingulate might be associated with the motor act of laughter.

We studied precise spectra of evoked EEGs in the word recognition analyzed with multiple band-pass filters (MBFA). The filter was infinite impulse response in 2nd order. Firstly, a signal swept from 5 to 100 Hz sine wave was tested with MBFA, fast Fourier transform and Wavelet transform. Ten evoked EEGs with word visual stimuli were recorded from three volunteers. The EEGs were sampled at 1 kHz in 14 bits for 1 s, and were analyzed with MBFA to make spectra from 5 to 100 Hz, and the spectra were averaged 10 times for observation. Evoked powers were noted at alpha band over the occipital area and suppressed powers were noted at beta and alpha bands afterward. Gamma bands were noted to be evoked over the posterior central area in the normalized Event-related spectra.