Using the cross correlation technique, the relation among finger skin temperatures during voluntary control training was examined. Ten female undergraduates were asked to decrease the skin temperature of their index finger on the dominant hand. The skin temperature of both hands was remotely measured by infrared telethermography. The subjects received five training sessions. Each session consisted of 3 periods. The pretraining period (about 10 minutes) was given for the purpose of stabilizing their finger temperature. In the training period, the thermographic display was presented for 15 minutes as the feedback stimulus and each subject was instructed that rewards (\100) were given when they lowered the finger temperature with every 1℃. Then the post training period was given for five minutes. The results showed training effects in eight out of ten subjects. The cross correlation technique, however, revealed that the only two examples showed gradual temperature changes session by sesion. In the case of the subject(MM), who showed gradual decrease in skin temperature of index finger through the sessions, the skin temperature of all the fingers changed simultaneously and the cross correlation coeffecients among fingers were significantly high in the earlier sessions. But in the 3rd session, the coeffecients among fingers that innervate the same motor nerve became higher than those that innervate different motor nerves. These results indicate the possibility of the mediation by skeletal muscles in the biofeedback training of skin temperature. In the 4th session, however, the coefficients among fingers that innervate the same motor nerve also became lower. This suggests the skin temperature of the index finger decreased independently of other fingers during this session. The subject(KK)also showed gradual decrease in skin temperature, but the temperature of all his fingers decreased simultaneously and his index finger temperature decreased dependently on other fingers in the later sessions. These findings suggest that the changes of autonomic response are established by the mediation of skeletal muscles first, then the autonomic response alone changes.
Isometric exercise is one of the commonly used physiotherapeutic modalities for muscle strengthening. Under verbal command from a physiotherapist the patient is asked to make the maximum voluntary effort to contract a muscle or a muscle group. One cannot, however, exactly know whether the muscle or the muscle group is contracting maximally. The purpose of this investigation was to determine whether one would exert maximum contraction of the hip abductors (HA) using visual digital dynamometric feedback (VDDF) and if each contraction would be consistent over a series of trials in comparison to the traditional method of isometric contraction only. The subjects consisted of 20 healthy female college students with their age ranging from 18 to 22 (mean 20.1±2.4) years old, height from 151 to 170 (mean 158.7±4.9) cm, and weight from 43 to 67 (mean 51.9±6.5) kg. A cuff was fitted around each ankle joint of the subjects lying supine. The sensor of a digital dynamometer was attached between the cuffs to measure in kg the maximum isometric tension bilaterally of HA. Each hip was in approximately 10 degrees of abduction. Using each subject as her own control, we measured the subjects' HA tension under two experimetal conditions. Each subject in the isometric alone (1) group contracted HA maximally for 3 seconds, followed by a 30-second rest, and repeated it 5 times. Each subject in the isometric contraction (F) group with VDDF performed the exercise in the same way, but was allowed to watch the dynamometer reading. The result showed that the average maximum tension of HA for Group I was 9.79±0.49kg as opposed to 10.57±0.49kg for Group F. The difference between these groups was approximately 0.8kg which was statistically significant. Furthermore, regarding the average maximum tension for each trial. Group F consistently achieved a stronger contraction. The maximum HA tention at each trial fluctuated widely in Group I compared to Group F. However, a one-way analysis of variance revealed no significant differences in the fluctuations amongst the trials. The visual cues from the digital dynamometer encouraged the subjects in Group F to achieve greater tension. We can therefore hypothesize that isometric contraction with VDDF consistently sustains maximum contraction. In other words, VDDF appears to have enabled the subjects to produce overflow at synapses of the motor end-plates by a possible increase in the number of motor units recruited. Usually, both auditory and visual biofeedback are employed to commence training. One may eventually discard either one of them depending on one's purpose and the patient's condition. Possible advantages of VDDF are : 1) signal presentation in the form of numbers; 2) easy and simple fitting of cuffs; and 3) no need for electrodes/leads and exposure of the skin over the target muscle or muscle group. At present, biofeedback instrumentation for exercise therapy includes EMG, electrogoniometry, and pressure transducers. The result of this investigation may provide a rationale for the addition of VDDF to the repertoire of biofeedback therapy.
The human nervous system is one of the model-reference learning control systems. Every individual forms a neuronal record of his own screen of consciousness. And successive recoding is compared with previous recording, so that every psychological response to stimulation is learned and preserved. It is supposed that this neuronal record is inserted into the command feedforward circuit in the nervous association system. It is already known that repetitive stimuli under a set condition provide the behavior program in the association cortex, and the program is corrected when the input condition is varied. If, suddenly, a given stimulus is removed in process of repetitive set stimuli, the subject will indicate the same or approximate response as the previous responses at the expected time. It is supposed that this response is produced by the error output of the command feedforward system. We should not lose our mental stability by unimportant prognosis. In this study, we tried to examine the appearance of probablistic prognosis response and to access the effectiveness of alpha feedback on prognosis response decreasing. Subjects were eight healthy male volunteers (20 〜22yrs.). Each subject was given the auditory discrete impulse stimuli (95dB, white noize) 30sec. after the warning signal. But, in the first experiment, we kept the number of impulse stimuli secret from the subjects, and next, we notified them of the number. We set the number of impulse, O, l, 2,- - - 6 irregularly. To access the effectiveness of feedback training, the subjects were instructed to be stimulated first at rest, and consecutively during feedback training. The results of these experiments suggested that to experience feedback training and to be well aware of the stimulating schedule are both effective on unimportant pregnosis response decreasing. In the case of feedback training, feedback signals modify the feedforward function, and so a feedback compensated feedforward control system is constructed. The stimulating schedule plays a role in establishing the parameters of the feedforward circuit correctly.
The author reports on the new types of programming languages that can be used by biofeedback systems. The new languages --Turbo pascal, Quick BASIC, and Quick c --are characterized by their high quality performance and notably inexpensive prices. The merits of these languages for researchers who develop biofeedback systems are several. First, that they can easily use external routines (for example, those written in Machine language and those written by other programmers) together with reserved words. Secondly, the languages provide a good programming environment which that faciliates the speed of programming. It has also been found that the similarity in grammar may be beneficial to BASIC programmers in using Quick BASIC.