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Biomedical subjects

N Sumitsuji

Publications and source records attributed to N Sumitsuji.

12 recordsLinked to original sources
PubMed1980

EEG changes induced by light stimuli modulated with the subjects alpha rhythm.

A new method, named the 'alpha wave modulated light' (AML) stimulation, has been used for controlling the frequency of sine wave modulated light by the subject's on-going alpha rhythm. The EEG was recorded from O1 and O2. With the AML stimulation using either the left occipital alpha rhythm or the right, two phase differences of O degrees and 180 degrees were created between AML and the alpha rhythmn. The peak frequency and power of occipital alpha in both hemispheres and the coherence and phase between the left and right occipital EEG were obtaned for 7 subjects. The alpha power was larger at a 180 degrees phase shift than at a 0 degrees phase shift with ipsilateral AML stimulation. The ipsilateral increase in the alpha power was greater than the contralateral at a 180 degrees phase shift. Larger coherence value and right phase lead were observed at 180 degrees phase shift by use of the right alpha rhythm. The possible mechanisms of influences of AML stimulation on the alpha activity were discussed.

Adolescent↗
PubMed1977

Memory retention of stimulations during REM and NREM stages of sleep.

In 51 normal young female subjects, stimulation by name calling or by intermittent photic stimulation was given during sleep. At different intervals after the stimulation, the subject was awakened and asked if she could recall it. If alpha activity had not been elicited by the stimulus, there was no recall. If the time occupied by alpha activity evoked by the stimulation was more than 30 sec, the stimulus could be recalled after a long period of sleep. When the evoked alpha activity lasted for less than 30 sec and the subject slept again, the longer the evoked alpha activity, the longer the sleeping time span with the memory retention of the preceding stimulation. With equal durations of evoked alpha activity, retention of the stimulus was better when the sleep following was REM stage than when it was NREM stage (stage 2). The results might be explained by the assumption that process of consolidation takes place most rapidly during wakefulness and is inhibited during sleep but to a lesser degree during REM stage than during NREM stage (stage 2).

Adult↗
PubMedDate not supplied

Electromyographic study of facial expressions during pathological laughing and crying.

We studied facial expressions during pathological laughing and crying in 6 patients using EMG investigation. Increased EMG discharges of M. frontalis and M. corrugator supercilii are characteristic of pathological laughing and crying in addition to an increase of EMG discharges of M. orbicularis oculi, M. levator labii superiors, M. zygomaticus major, M. risorius and M. mentalis which we observed during natural laughing. Its patterns of facial expressions are similar to that of crying in normals. From the fact that normals show the same expression of laughing and crying in an extreme emotional outburst, we speculate that pathological laughing and crying is maximal manifestations of facial expressions caused by a release phenomenon of the upper center.

Adult↗