Single unit activity was recorded from the hippocampi (Ammon's horn and fascia dentata) of rats placed in the open-field with a start-box. The units recorded were classified into theta cells (N=6) and complex spike cells (N=9) according to their firing patterns. To detect possible behavioral correlates of activity of these units, the relationships between firing rates (or ratio) and behavioral categories were examined in every I s period. Most of the theta cells (5 out of 6) increased their firing rates during locomotion and sniffing, this activity also being accompanied by theta rhythms in the hippocampal EEG. The remaining theta cell showed a high firing rate also during slow-wave sleep unaccompanied by theta rhythms. Statistically significant differences in firing ratio across behavioral categories were found in 6 out of 9 complex spike cells. In contrast to the theta cells, they exhibited individual patterns which varied from one to another. In addition to these behavioral correlates, place correlates of firing ratios were found in some complex spike cells.
This study was designed to examine the synchronous changes of HR and subjective feeling in aversive situation. Seven subjects were employed on two types of experimental sessions differed in degree of temporal predictability, in which they recieved a 7-10mA electric shock after every 4-minutes anticipatory period. Both HR measures led by a standard type II wiring and subjective ratings of anxious feeling changed in time sequence were used as indices of anxiety reaction. The range of HR variability from 0.004 to 0.1Hz was devided into six regions, and in each region HR measures were integrated per 20 seconds for multiple regression analysis. Spectral analysis disclosed a marked difference of temporal predictability in the 0.004-0.017Hz region of HR changes. Multiple regression analysis, using subjective rating of anxiety as the dependent variable, indicated that the 0.038-0.1Hz region of HR changes highly correlated with the changes of anxious feeling.
The main purpose of this study was to examine the effect of heartbeats (HB) discrimination training as well as the knowledge of results (KR) on the accuracy of HB detection. The accuracy of HB detection was assessed by pre-test, four training blocks, and post-test, using Katkin's HB detection technique, which is based on the theory of signal detection. Twenty subjects were assigned to either KR or non-KR groups. The KR group was given the knowledge of results during the four training blocks. The results showed that the KR group tended to show greater accuracy of HB detection than the non-KR group. The following two points were also analyzed and discussed in this paper : (1) Whether or not the level of HB detection on the pre-test influenced the four training blocks and the post-test. (2) What was the relationship between the subject's own understanding of his or her method of HB detection and the level of HB detection.
Developmental changes in ABR (recorded from a surface electrode as short latency evoked potentials) were studied in healthy human subjects ranging in age from newborn to six years. Data were collected on 278 occasions and the appearance of wave, latency, interpeak latency (IPL) and amplitude characteristics from wave I to V were analyzed. On the day of birth very few subjects showed any type of wave, but this situation changed rapidly with the passage of time, and became stable by the 4th day. For neonates, no significant changes were seen in the above measures except for changes in latency in III and IV after the 8th or 9th day. For neonates and infants, significant age effects were observed for all measures with the exception of wave appearance. Infants' II -V latencies and IPLs decreased as a function of age until the ages of 3-4 years. Amplitudes then increased until the ages of 5-6 years. These data were discussed mainly in terms of effects from spontaneous labor and the development of auditory brainstem pathways.
ERPs to auditory stimuli during an oddball task were recorded from 47 adolescents ranging in age from 14 to 19 years. Relationships between each of the ERP components (N100, P200 and N200 and P300) and age or IQ were examined. No correlationship between the peak-latencies of the components and age could be detected, but the peak-amplitudes of N200 recorded on the Fz showed an age-related change (r=.396). As age increased, N200 amplitude decreased. It was suggested that young adolescents were differed from adults in the detection process of a task-relevant rare stimulus. In regard to IQ, the peak-latency of P300 was longer for the lower IQs than the higher IQs (r=-319 at Cz and r=-465 at Pz) and the peak-amplitude was also smaller (r=.298 at Pz). These correlations suggest that the endogenous brain potential is related to intellectual capacity.
Waveforms of the orienting skin conductance response to a tone were analysed using skin conductance measures obtained from a digital meter with a constant voltage of 0.5V. The response was recorded in 28 female college students who heard a single presentation of a 1000Hz, 70dB, pure tone of 2 s duration through headphones. Large individual differences were observed in the waveform after the peak of the response. It was suggested that investigating possible psychological processes involved which account for the differences might be of great interest in psychophysiological study.