This investigation examined the effects of respiratory rate and depth on heart rate level and heart rate variability (HRV). Healthy subjects fit their breathing to sine waves presented on a CRT display. In experiment 1,seven subjects breathed shallowly or deeply at 10,20,and 30 c/m (cycles per minute). In experiment 2,six subjects breathed sinusoidaly at 10,8,6 and 4 c/m, and were asked to breath in or out faster or slower for the 6 and 4 c/m conditions. Finger blood volume and pulse transit time (PTT) were also recorded in experiment 2. In order to ob-serve the real time relationships between the regularly sampled respiration and the other three irregularly sampled measures, a fifth order Lagrange interpolation method was used for the irregularly sampled data, and data for 200 ms were computed. The results are as follows : 1) For 10 c/m to 30 c/m, heart rate levels were affected by respiration amplitude, especially for the 30 c/m, shallow respiration caused lower heart rate levels and deep respiration caused higher heart rate levels. 2) Even for 30 c/m respiratory rates, a clear respiratory influenced HRV was observed. 3) Heart rate levels decreased as r6spiratory rate decreased from 10 c/m to 6 c/m. 4) HRVS increased as the respiration rate slowed and as respiraion amplitude became larger. 5) HRV was mainly caused by inspiration. Cardiac acceleration began after or simultaneously with the onset of inspiration, and its amplitude and duration were defined by the depth and rising speed of inspiration. 6) The baseline of finger blood volume fluctuated with respiration and the fluctuation has a 1 or 2 sec constant phase lag with HRV. 7) PTT also fluctuated with the respiratory cycle, but PTT fluctuation was not as clear as for heart rate and blood volume. The results of PTT suggested that aortic pressure dropped rapidly at the onset of inspiration. Most of the results obtained in this investigation are consistent with the hemodynamic interpretation.
The effects of awareness and the spontaneous strategies on the skin temperature biofeedback training was considered Subjects were 16 female nursing school students, and they participated in pre-test, feedback training, and post-test. They were instructed to raise their finger skin temperature, and the visual feedback was presented only during the feedback training. The performances of the skin temperature control of the subjects were identified as belonging to any of the following three stages of voluntary control. (1) The stage of internal control : the stage where the subjects succeededed the skin temperature control not only on the feedback training sessions but also on the post-test session. (2) The stage dependent on the external feedback : the stage where the subjects succeeded only in the feedback traning seeeions. (3) Unsuccessful stage on any session. Then, the awareness and the spontaneous strategies of the subjects on each of the three stages were analyzed. Results were as follows : (a) The subjects of the stage of internal control were aware of the internal feedback of the skin temperature change, however the subjects of other stages were not. (b) All subjects had some awareness of thier subjective activites that they used as the strategies of the skin temperature control. (c) The differences of the spontaneous strategies among the subjects of the three stages were not found. These results suggest that the subjects are aware of their activities that they use as the strategies in the early stage of the learning, and they examine whether the strategies are adequate by the external feedback. And also the results suggest that the subjects came to have awareness of the internal feebback of the skin temperature change too as they reach the stage of internal control.
The frequency of SCR has been used more often in biofeedback technique than SCL as an indicator of bodily responses. However, it is not easy to take out the frequency of SCR as an instantly understandable information. In the present study the following experiment was conducted for the purpose of clarifying whether the SCL, which can be changed into an instantly understandable signal, can serve as an indicator of bodily responses in biofeedback technique. Fifteen men and five women were used as subjects. The experiment was recorded by the continuous pen recorder of the GSR-Detector manufactured by Nihon Koden (GSR-2100). The throwaway electrodes manufactured by Nihon Koden (NR-200 T) were attached to the subjects' palms and wrists. Measurements were taken for a period of seven minutes after the subjects had been instructed to keep calm ; and the subjects' own reports were made on their emotional stability both at the beginning and at the end of the measurements. The measurement showed a general tendency of declining throughout the experiment, and the value of SCL and the frequency of spontaneous SCR showed high correlations. The change in SCL showed higher correlations with the value of SCL than with the frequency of spontaneous SCR. While the subjects' reports on their emotional stability showed high correlations with the changein SCL, correlations with the change in spontaneous SCR was hardly observed. In fact, spontaneous SCR seldom appeared except in six of the total 20 subjects. It has been made clear by the above experiment that SCL can serve as a more sensitive indicator than SCR as that of bodily responses in biofeedback technique when we consider the tendency of the subjects' emotional stability and its relations with changes in SCL and SCR, and that SCL can be handled more easily than SCR.
In many previous researches of pseudofeedback control, it was showed that self-persuation could promote the effects of biofeedback. In most of these studies, the effects of HR biofeedback or EMG biofeedback were reported. Our experimental study was designed to examine the effect of intentional feedback signal on alpha feedback training. After the base-line period, during which 10 sessions were used to assess the effect of alpha enhancement in relaxation and biofeedback training, 8 subjects were devided into 2 groups, that is, Group A (correct feedback) and Group B (intentional feedback). The threshold of the feedback signal in Group A was the same value as that during the pre-training period (20μV). But the threshold of the feedback signal in Group B was varied according to the experimenter's intention (25μV or 15μV). At first, Group B subjects were not told that fact, so they had believed that the auditory biofeedback signals were the same sorts as before. Then Group A and Group B received 20 sessions of training. The results of this experiments showed as follows : When the threshold was set upward, the quantifications of the feedback signals were decreased and alpha activities of the subjects were suppressed, and when the threshold was set downward-the quantifications of the feedback signals were increased-alpha activities were enhanced. Subsequently, we examined the effect of intentional feedback signal when Group B subjects were told the experimenter's intention. In this case, in spite of the threshold was set upward, alpha activities were enhanced more and more. And when threshold was set downward, alpha activities were not so much enhanced. It is considered that the feedback signals to the nervous control center include not only the signals transmitted from the biofeedback instruments but also the subject's psychologically estimated values. The psychological estimation of the subject depend upon his self-suggestion. Therefore, by the results of our experiments, it was concluded that self-persuation played an important role in alpha activity increasing.
The purpose of this study was to objectively assess the effects of EMG biofeedback training in cerebral palsy. Bipolar silver/silver chloride surface electrodes were placed over the belly of the biceps brachii muscle. The signal was full wave rectified (IEMG), and was put into the microcomputer based biofeedback system. In case of need, co-contraction of the triceps brachii, deltoideus and trapezius were monitored on another channel. The client was 54-year-old man with cerebral palsy and accompanied cerebrovascular accident (CVA). Visual feedback of IEMG signal was indicated on the CRT display. If IEMG level was higher than target level, audio-feedback was also provided. Training conditions were as follows : 1 feedback trial, 2 nonfeedback trial, 3 rest trial. The client was instructed to decrease IEMG activity, and on condition of feedback trial or non-feedback trial, the client was asked to perform uttering task. During each training session, continuous data in acquisition was carried out to objectively assess the effects of therapy. Results indicate that electromyographic activity was reduced rapidly as the feedback trial proceeds. Additionally, the facilitating effect of feedback trial transferred to another trials. After training, the client learned to suppress phasic electromyographic activity evoked by emotional strain. It was shown that computer assisted biofeedback training system can more accurately assess the treatment effects in rehabilitation training.
Tic syndrome usually begins in childhood and the symptoms mostly fluctuating, persisting beyond adolescence or lifelong. The treatment has behaviorally involved providing negative practice, desensitization, aversive techniques and so on. Recently some researchers have tried EMG biofeedback training on tic syndrome patients and the results seemed to be effective. From March, 1980 to May, 1985,the author has tested EMG biofeedback therapy on 37 children who suffered from tic disorders. In order to control their forehead EMG activities, they tried to decrease the biofeedback signals of tone or hold down the swing of the meter needle which shows EMG voltage. At the same time binary signals of red and blue color were also given, as prescribed by criteria which the therapist arranged in advance. So the strategy by the patients to control their involuntary muscle movements is arbitrary to some degree. That is to say, some concentrated on binary signals of colors and the others chose the change of tone, or needle swing. The numder of sessions were from two times to forty, depending on the therapeutic effects. The author also tried EMG biofeedback training on the patients of multiple tics, measuring the change of EMG of muscles sternocleidomastoideus at the same time. This is the bimodal assessment of EMG activities of the tic patient. In this way generalized effects of biofeedback training would be studied. The results of generalization, however not yet to be definitive. Then family therapy was performed in all the cases. The parents or one of them, it was observed, were controlling, crushing or overprotecting as noticed previously. Generally speaking, multiple tic seemed to be intractable. Moreover, we cannot give a decisive conclusion about the result, because tic syndrome follows a process of wax and wane. So the conclusion of this report tentatively is as follows : The patients of tic syndrome have learnt how to control their involuntary muscle movements through biofeedback training. This method was useful with the therapeutic intervention regarding family situations. The bimodal assessment on EMG activities of measuring muscles sternomastoideus show that the generalized effects are somehow equivocal at the present stage.
The present study was performed to examine whether the combined use of the desensitization technique and heart rate biofeedback training might contribute for better control of sinus tachycardia. A research setting of this study is as follows ; one of major issues in clinical practice of heart rate biofeedback training is that the effect of heart rate biofeedback training seems to be interfered by emotional distortion and other factors, and it's effect produces no more than placebo effect in many cases. Previous study revealed that the non-neurotic subjects showed better self-regulation of sinus tachycardia than the neurotic subjects, and the non-depressive subjects did better in heart rate biofeedback control of sinus tachycardia than the depressive ones. So our conclusion lead that emotional state of subjects is extremely important when using biofeedback training of heart rate. 40 subjects were divided into two groups ; 1) The Control Group (Simple Heart Rate Biofeedback Training Group) (N=16) in which subjects performed simple biofeedback training of heart rate, and 2) The Desensitization Heart Rate Biofeedback Training Group (N=24) in which they practiced stress loaded heart rate biofeedback training. The result showed that 1) the both groups performed significant heart rate decrease between the first and the last sessions, 2) although there seemed to be some trends of modification in stress responce before and after the desensitization training, it was not significant evidence. 3) it took less numbers of sessions for tachycardiac subjects to return to normal range of heart rate in The Desensitization Heart Rate Biofeedback Training Group than The Control Group. 4) 6 months follow-up revealed that the former group did better in prognosis. (Acknowledgement : The author would like to express sincere thanks to Professor H. Saito and Associate professor M. Minami, 1st Department of Pharmacology. Hokkaido University School of Medicine, and Dr. S. Okuse, President of Meiwa Hospital, Sappro, for their criticism and advice. I am indebted to Dr. Theodore Weiss, Associate professor of Psychiatry, University of Pennsylvania, for regarding manuscript and suggestion.)