The aim of this study is to examine the effects of unilateral cerebral lesions on MLRs.
Five patients had either temporal lobe or/and subcortical lesions resulting from cerebrovascular accidents. All patients were normal in pure tone audiometry and in ABR. All patients had ear extinctions which were ascertained by dichotic listening test.
Neuro-electrical activity was recorded at 3 scalp locations in the coronal plane. Electrodes were sited Cz, C6 (halfway between T4 and C4), C5 (halfway between T3 and C3). MLRs were elicited by 90 dBpeSPL clicks at a rate of 2/sec with earphones. During testing, the patients were awake and resting comfortably on the bed. Evoked responses were measured from average of 700 responses with a duration of 200 ms.
According to the MLR records, Pa was largest on the intact hemisphere and was absent on the lesioned side.
These results support the hypothesis that Pa is bilaterally generated by two vertically oriented dipole sources located about the temporal lobes.

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In order to confirm the relationships between the physiological and psychological responses under background music, the focus of the present study is on the correlation analysis between autonomous responses of the sympathetic nervous system to music and the psychological indicators before and after music presentation. For that were measured POMS (Profile of Mood State), _??_DPG (Differential Digital Photoplethysmogram) -P amplitudes, EEG, and HR. There were certain linear relationships between the change of _??_DPG-P amplitudes and EEG frequency with background music and the change of POMS score at the pre-and post-music session. It was found that the subjects whose _??_DPG-P amplitudes decreased more, showed increment in EEG frequency, and decrement in mood factor : Tension, Depression, Anger, Fatigue. The result showed that the increase of the sympathetic nervous activity correlates with the decrease in mental tension. Therefore, it was suggested that the sympathetic nervous activity during music presentation differs in profile from the tension in mental task stimulation.

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Event-related brain potentials in a passive two-or three-stimulus auditory oddball were recorded from seven adults with moderate or severe mental retardation, and were compared with data from normal subjects. In Experiment 1, subjects were presented with a random sequence of 1000Hz (p=.8) and 2000Hz (p=.2) tones. Two of the seven retarded subjects and all of the four normal subjects showed N2-P3 to the rare tone. Five retarded subjects showed only negative waves. In Experiment 2, the stimulus sequence comprised a frequent tones (1000Hz : p=.7), rare tones (2000Hz : p=.15) and novel sounds (noise : p=.15). Five of the seven retarded and all of the six normal subjects showed positive waves to novel stimuli. It is suggested that novel stimuli may elicit P3 (P3a) even in severely retarded people.

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Following the studies of Ito et al. (1993, 1995), in which equilateral triangle elicited larger N1 responses compared to square and circle, we compared the effects of partial forms of triangle and circle, in order to understand the roles of three angular parts of triangle. Two groups of sharp or round figures were tachistoscopically presented to the lower visual field for eight subjects. One consisted of an equilateral triangle and its three sharp parts, the other of a circle and its three round parts. Transient VEPs were obtained monopolarly at five locations around occipital area. Subtracted waves between figure and control (blank) conditions were computed and analyzed. As a main result, any three sharp parts of triangle elicited significantly larger N1 amplitudes than did the corresponding round parts of circle, while the triangle was of a significantly larger N1 amplitude than the circle. Thus, the increase of the N1 response for equilateral triangle as compared to circle could be attributable to the N1 increases for all the three acute-angled parts of triangle.

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The Mongolian gerbil (Meriones unguiculatus) is a genetic animal model of epilepsy which shows epileptic seizures elicited by several kinds of weak stimulus. In the adult animals, so-called psychological stress is also known to induce seizures. In such animals, recording of brain wave with wires has disadvantage since the animals may receive some stress while they are restricted with wires. The use of wireless recording system is favorable for such animals but the machines available were mostly so bulky. In this study, a telemeter machine for rat (Unimec Co. Ltd., Tokyo) was applied successfully to record the interictal electrocorticogram of the gerbil (body weight, 70 g) without restriction of the daily activity. With this method, characteristic electrical activity was observed in an area of the cerebral cortex which seemed to respond to some stimuli.

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Reactivity hypothesis states that subjects showing an augmented blood pressure reactivity to standardized mental stressor (pressor test) may be at risk of developing hypertension, and in its stronger form, that such hyperreactivity plays a causal role. In the present review, the hypothesis was revaluated, applying the concepts of reliability and validity of psychological tests to the pressor test. Assessment was done on intra-test, inter-test, and test-episode (lab-life) reliabilities, and on predictive validities in a broad (as a predictor) and a narrow (as a contributor) sense, as well as on concurrent validity in a broad sense (the test vs. family history of hypertension). Collectively, the pressor tests seemed to be, at most, moderately reliable and valid and consequently the content of reactivity hypothesis could not be fully affirmed.

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