Contingent negative variations were recorded while 8 adult subjects performed either letter or drawing task. The letter task required subjects to pay attention to a letter in a letter-drawing embedded figure and classify it into Hiragana and digit ; the drawing task was to classify a drawing in an embedded figure into animal and plant. In a blocked condition, subjects performed one of the two tasks over all 32 trials within a block, whereas in a mixed condition the task to be required was informed by different pitches of a warning tone and hence varied across trials. The subjects received 4 blocks per condition. Irrespective of these conditions, the CNV during the foreperiod for the drawing task was larger at the right temporo-parietal site than its left hemisphere homologue, while no such difference was found in the letter task. The CNV asymmetry, therefore, is interpreted as to reflect the cognitive set that determines which hemisphere engages in the task more predominantly. The lack of blocked/ mixed effect indicates that the cognitive set can be switched from trial to trial during such a short foreperiod of 2.45s. The correct classification score, however, was lower for the mixed than the blocked condition, suggesting that a longer period would be necessary to make up the cognitive set for the higher level of task-performance.
Intracranial and epicranium recordings of the average evoked potentials in response to acoustic clicks were conducted using the hill mynah. Records under some experimental conditions and tests after monaural lesion show that these potentials are in fact brain stem auditory evoked potentials (BAEPs). A typical waveform of the mynahs'BAEPs is composed of a series of brief spike-like potentials with latencies of one to 4ms after stimulation. This BAEP pattern is similar to that extensively studied in mammals. In an immobilized bird the BAEP can be recorded by a small number of stimulus presentations because of the high S/N ratio. BAEP research promises significant contributions in the field of neuroethology and behavioral neurobiology since it can be carried out without injuring the brain. We believe that the BAEP may yield valuable data regarding the degree and recovery process of temporary hearing deficiencies resulting from an experimentally produced acoustic trauma in birds.
Three adult tetraplegic cerebral-palsied clients were given EMG biofeedback training for reduction of muscle activity. The program involved one and sometimes two 1 hour sessions per week. Integrated myoelectric activity was used as a feedback signal. Audio-visual feedback signal presentation and data acquisition were controlled by a microcomputer-assisted training system. During feedback/nonfeedback trials, clients were asked to relax target muscle as much as possible. Early in the course of the sessions, the muscle activity increased transitorily, but by the latter half of the sessions each client was able to suppress undesired muscle activities. One client was successful in suppressing ATNR (asymmetrical tonic neck reflex) responses. An analysis of the results suggests that the voluntary control of muscle had been acquired through the training. The results indicate that EMG biofeedback training promises to be an effective technique in improving motor functions among severely handicapped cerebral-palsied clients.
Amplitude characteristics of visual evoked potentials to number (sharp contour) and blurred spot (diffuse contour) stimuli were examined in this experiment. Five male and two female college students were exposed to a series of trials. Each trial consisted of the presentation of seven successive stimuli-a warning stimulus followed by a first triplet of three identical stimuli (stimulus positions 1-3) and a second triplet of another three identical stimuli (positions 4-6). For the numerical stimuli which possessed sharp contours, subjects were required to identify the stimulus pattern by name. For the blurred spot stimuli with diffuse contours, only eye fixation was required of the subjects. Analysis of occipital P260 amplitude revealed significant enhancement at stimulus positions 2 and 3 for the numerical stimuli but not for the blurred spot stimuli. These findings were discussed in terms of the representation process during visual perception.
The present study examined the effects of stimulus coding upon the orienting skin conductance response (SCR). Two kinds of tones, a 525Hz tone (“C” on the musical scale.) and a 658Hz tone (“E”) with the intensity of 70dB (c) were selected. A pair of the same tones (525Hz) was presented (S-Condition) in the first habituation session, whereas in the following session the pair of tones was changed to a 525Hz tone and a 658Hz tone (D-Condition). The duration of each tone was 1 s with an interval of 100 ms between the two tones. Each session was run with ITIs of 30 s in average until habituation was attained. Thirty-two female college volunteers were assigned to two groups, the Tone Group (N=14) and the Musical Scale Group (N=18) according to whether they perceived the tones as simple physical tones or tones on the musical scale. The data indicated that in the first session with S-Condition there were no differences in any measures of response between the two groups, but in the second session with D-Condition the Musical Scale Group showed a significantly slower rate of habituation and a higher degree of responsivity than the Tone Group. The results were discussed in terms of cognitive set.
In order to facilitate the documentation of EEG recording during long periods of measurement such as sleep, a system for experimental control and analysis of data is developed. It consists of a personal computer system, which operates under the multi-task and realtime operating system, an EEG machine, an FM tape recorder and other instruments. (Fig.1) The EEG machine and the tape recorder are connected to the computer with General Purpose Interface Bus (GPIB), which allows easy and automated operation of them with simple programs. Main features of this system are as follows: 1) Before experiment, it can automatically set up the characteristics of the EEG amplifiers, a montage and a tape speed of the tape recorder. 2) During experiment, it picks up ID-codes of the tape recorder in a serial number at every 30 second, and marks them on the recording paper to let tape recordings match with paper recordings. If any modifications of the montage and the chracteristics of the EEG amplifiers were made, the history of those is stored on the floppy disk with the ID-code and the time. 3) After experiment, this system can also control the tape recorder from the computer and makes it possible to locate any desired point in the magnetic recording by means of the ID-code marked on the paper recording. This system helps to save experimener's labor, especially when only a small number of staff is available, and to increase the reliability of measurement as well.