Mitsuo Yasushi

Treatment of a depressive disorder patient with EEG-driven photic stimulation

This study examined the effects of electroencephalographic-(EEG-) driven photic stimulation on a case of depressive disorder, as measured by a psychometric test of mood states, EEG parameters, and several autonomic indices. The EEG-driven photic stimulation enhances the alpha rhythm of brain waves using photic signals, the brightness of which is modulated by a subjects own alpha rhythm. The patient was a 37-year-old businessman, who was treated for depression with medication during the 13 months prior to his first visit to our hospital. He underwent two sets of inpatient treatment sessions, comprising first 16 and then 18 treatment sessions. The treatments brought about the following changes: an improvement in general mood state, alpha rhythm increase, cardiac parasympathetic suppression, and increased skin conductance level. In addition, significant correlations between alpha rhythm increase and cardiac parasympathetic suppression or cardiac sympathetic predominance were observed with each inpatient treatment. Significant correlations between alpha rhythm increase, cardiac parasympathetic suppression, or cardiac sympathetic predominance and the improvement of general mood state were also observed. Thus, from these observations, it was concluded that the alpha enhancement induced by EEG-driven photic stimulation produced an improvement in the patients depressive symptomatology connected with cardiac parasympathetic suppression and sympathetic predominance.

EEG-driven photic stimulation effect on plasma cortisol and β-endorphin

The effect of EEG-driven photic stimulation on stress-related endocrine function was studied. Subjects were 16 healthy males divided into a photic stimulation group (n=8) and a control group (n=8). Electrodermal and emotional lability measures were assessed by nonspecific skin conductance response and the Maudsley Personality Inventory, respectively. Plasma cortisol and β-endorphin concentrations were measured both before and after EEG-driven photic stimulation as well as the resting condition. Subjects with electrodermal, emotional, or both lability showed comparable decreases of plasma β-endorphin on photic stimulation as did the stable subjects. Under resting control conditions, however, they showed significant increases of β-endorphin compared to both stable subjects as well as the photic stimulation condition. In addition, labile subjects showed significant alpha enhancement on photic stimulation compared to stable subjects and to the resting control condition. The data suggest that increases of plasma β-endorphin in labile control subjects may denote a stress response to the conditions of these experiments, and that any decrease by EEG-driven photic stimulation may indicate a reduction of responsiveness to an acute stress.

Influences of long- and short-distance driving on alpha waves and natural killer cell activity.

We examined the effective amplitudes of alpha waves (using a mean frequency with a range of ± 0.5 Hz), and activity of natural killer cells in six subjects, before and after a short-distance (43 km, 1 hr.) drive, and after a midnight (am 0:00 am 7:00 to 8:00) long-distance (550 km on average, for 7 to 8 hr.) drive. Following a long-distance drive, the activity of natural killer cells tended to decrease, and the effective amplitudes of alpha waves in the photic feedback period were greater than those observed during the rest period, showing that photic driving had occurred even under physically and mentally stressful conditions. However, after short-distance driving, no photic driving response occurred and activity of natural killer cells tended to increase, possibly related to mental concentration. Avoiding midnight long-distance driving may help prevent excessive stress and preserve high activity in natural killer cells.