In this article, clinical researches on heart rate variability (HRV) were reviewed, and some problems to solve were arranged. First of all, depression of HRV in acute myocardiac infarction is paid attention as not only prognostic index but also a comprehensive predictor of risk in this disease prevention. Additionally, clinical researches on HRV including circulatory system such as cardiac failure, and psychosomatic medicine were introduced. Next, we mentioned about the limitation of clinical application of HRV. The methodology of frequency analysis is a problem because it has not been standardized. Moreover, it is inadequate to evaluate function of autonomic nervous system only from HRV. Clinical application of HRV is clearly recognized as a predictor of risk of arrhythmic events or sudden cardiac death after acute myocardiac infarction and as a clinical marker of evolving diabetic neuropathy. Finally, the view of a clinical application of HRV in the future was described.
In this brief review, the availability of heart rate variability (HRV) in psychophysiological research was discussed. First, HRV-related measures were classified into two large groups : time- vs. frequency-domain ones, and the latter (i.e., spectral powers) were described in some detail. Second, possible interpretations of the spectral powers with high and low frequency bands were summarized, in association with autonomic activities. While the former reflects mostly cardiac vagal activity, the latter, whether it is normalized or not, seems only partly associated with cardiac sympathetic activity. Third, it was shown that qualitative features of the stressful task (i.e., active vs. passive coping) are contributable to the hemodynamic mechanisms or blood pressure elevation and thus to underlying autonomic activities. Therefore the spectral powers during stressful tasks could be altered in accordance with the qualitative features of the task. Finally, it was suggested that the psychophysiological availability of the spectral powers (especially that with low frequency band) is questionable and that other noninvasive parameters such as baroreflex sensitivity, pre-ejection period, and normalized pulse volume are superior to the spectral powers.
The present study was undertaken to clarify the relationship between cardiovascular reactivity to laboratory stressors and individual characteristic of alexithymia. Twenty-five healthy male and female undergraduates participated in the following four sessions : a 20-min baseline rest, mental arithmetic (MA), cold pressor (CP), and a 5-min post-rest. All subjects completed the 20-item Toronto Alexithymia Scale (TAS-20) and the Minnesota Multiphasic Personality Inventory (MMPI). Subjects were then divided into high- and low-alexithymic groups based on the median value of the TAS-20. The following results were obtained : (1) heart rate and mean blood pressure increased significantly from baseline to MA and CP conditions, (2) changes in heart rate for high alexithymic group were significantly less than those for low alexithymic group, (3) there was no difference in mean blood pressure between high- and low- alexithymic groups, and (4) high alexithymic subjects scored significantly lower on the MMPI validity scale (K) and higher on depression (D), psychasthenia (Pt), and social introversion (Si) scales. These results showed that high alexithymic subjects are characterized with high subjective arousal and low cardiac reactivity.
We have been developing a new objective method to diagnose senile dementia. A pocket-light is used as a light-stimulus, a CCD camera is used to observe the miotic-reflex and then the pictures are taken into a personal computer to measure the size of the pupil. The senile dementia patients showed significant smaller miotic rate and significant longer miotic time than the normal elders when their pupils were lightened by the visible light. There was positive correlation between the miotic reaction and the HDS-R (the Revised version of Hasegawa's Dementia Scale) scores of the patients with senile dementia. As ACh is decreased in the brain of the dementia than the normals, it is considered that the miotic-reflex of the dementia is weaker than the normals These results lead to the assumption that patients with dementia can be rehabilitated by BF training with the miotic-reflex. The light-stimuli were given to five patients 3 times in I min (5- sec stimulus at intervals of 15 sec) as one set of training. They were given 3 sets of training a day (1 set of training at intervals of 29 min), and continued for 3 days. The HDS-R scores were recorded before the training and the fourth day of the training to estimate the effects of the training. From the fact that not only the miotic-reflex but also the HDS-R scores of some patients were improved than before training, we could conclude that the miotic-reflex training as a BF method is beneficial to rehabilitation of patients with dementia.
Factors influencing the human biochemical responses to mental stresses were studied by examining urine samples from male and female subjects before and after receiving two different kinds of mental stresses : per-forming mathematical calculation and riding roller coasters. Psychological tests (MPI and TGE) were also given to all the subjects in order to elucidate the relationship between the psychological characteristics and the biochemical data. The results suggest that the human biochemical responses to mental stresses, which are reflected by changes in the urinary excretion levels of catecholamines and some major minerals, vary according to various factors such as gender, psychological characteristics and differences in properties of the stresses. The results of these experiments indicate that Kai-Gou, a relaxation strategy of qi-gong, is effective in alleviating the calculation stress-induced biochemical changes at least among some of the female subjects with particular psychological characteristics.
In this study, the multifeedback therapy was given to a patient suffering from panic attacks with agora-phobia. The patient was gradually exposed to feared scenes (in vivo desensitization) in steps according to her daily anxiety hierarchy table. At the same time, the patient was trained in self-control of several psychophysiological responses through multifeedback training. With the training, the patient became increasingly successful in controlling her psychophysiological responses. Moreover having confirmed, such progress herself, the patient was ready to be introduced to higher anxiety levels in the desensitization process with less psychological resistance. After several sessions of the combined therapy for 3 months, agoraphobia was eliminated from her symptoms and the patient was able to return to work. The results warrant further research on the combination of in vivo desensitization and multifeedback therapy in the treatment of agoraphobia, which is often considered difficult to cure with conventional methods.
Recently it has become popular to measure bio-information by using computer. Along with acceleration of CPU, many jobs, which used to be processed by hardware, now can be processed by software. The development of biofeedback system used to be relatively difficult and tended to lack generality. But recently, many less ex-pensive and powerful tools have become available, and by making use of them we can make highly sophisticated and stable biofeedback system in short term. And the rapid development of multimedia technology enables us to process feedback information into various forms. This brings us benefits in the following two respects : First, by utilizing software, we can transform the information into more comprehensible style for subjects. Secondly, by doing that, we can keep subjects' motivation high and can improve the efficiency of training. In this study, we tried to make prototype of biofeedback system, which has the following three characteristics, 1) apply the latest multimedia technologies in feedback method, 2)build client/server style network (measuring bio-information in server side and sending them to client side for feedback), 3) simple system which anybody can build easily. The performance and potential of the system, and some consideration is included.