The effect of psychological factors on readiness potential (RP) was examined in 12 healthy, right-handed subjects. RP was recorded from Cz, C3' and C4' areas under the design of manipulating the task difficulty and motivational state. Each subject was asked to pull a lever with the right index finger at his own pace and at a required force level. Subjects heard one of three different pip-tones immediately after each motor performance depending on whether their force-level was adequate to, below or above the required level. Preceeding the motor performance, RP in a difficult task under no reward condition (DT) started to appear earlier than that in an easy task under the same no reward condition (ET). Moreover, RP in the easy task under a reward condition (ER) started to appear much earlier than that in ET, and so did RP in the difficult task under the reward condition (DR). And, irrespective of whether the task was performed under the reward condition or not, RP obtained immediately after the bad (incorrect) motor performance started to appear earlier than that obtained after the good (correct) one. Based on these results, discussion was made on the effects of the psychological process such as mental set or mental effort on RP.
This experiment was designed to examine the possibility for the detection of deception by ERP. A total of 19 subjects received random sequences of the subject's own last name and four other names on a CRT. The subject's task was to orally reply either “true” or “false” to the presented names. In this research, estimated components were calculated by a combination of principal component analysis and multiple regression analysis. The mean wave for P3 was larger for the subject's own name than for the other names regardless of subject's verbal response. In addition, the estimated wave indicated that the difference in P3 depends on P3a component. Furthermore, during Si and S2 the negative component increased and delayed in only false verbal response to the subject's own name. These results suggest that the P3 and the negative component can be used as an index of the detection of deception.
The relationship between thermal imagery and thresholds of a pain response was explored by recording reaction time as a measure of the pain threshold, as well as digital pulse volume and heartbeats, on twenty female undergraduates. While a pain stimulus was being presented, subjects in the experimental group were asked to form the same image in their mind as the sensation produced by one of four image cues given beforehand. Two of the image cues were compatible with the stimulus, i. e., radiant heat, and the others incompatible. The present study showed that, as the cues were changed from “hot” to“ice-cold”, the thresholds were gradually elevated. Besides, the enhancement of the threshold was found even in the post-test block. The data obtained on finger pulse volume, however, differed from those on the thresholds, that the imagination in the test block had no effect on the pulse volume in the post-test period. It is suggested that the incompatible images play a part to decrease pain sensitivity, and that the enhanced threshold is probably related to the thermal imagery per se rather than to the peripheral skin temperature inferred from the vasomotor measure.
The class of faster firing neurons in the superior central raphe (CES) was examined in freely behaving rats, during various motor movements as well as SWS and PS. These non- serotonergic raphe neurons fired slowly during SWS (5.9/s ; mean) and immobility or quiet waking (7.5/s), more frequently during PS (12.8/s), and the most frequently during other various motor behaviors (16.6/s). The CES units tended to fire in bursts during the “twitch periods” of PS, i. e., a kind of movement phase of PS. During various movements, two major types of firing were observed. Type A units had a significantly higher firing rate during Type I behaviors than Type II behaviors according to Vanderwolf's classification. Type B units showed no difference in the firing rate between the two types of behaviors, but, for both types of behaviors, Type B units had a higher firing rate during vigorous movements. These two types of CES neurons equally had a few to several neural discharges in burst firing at the onset of behaviors. The present results suggest a possibility that the faster firing CES neurons may play a role in initiation of behaviors.
The present study investigated the effects of biofeedback training to decrease heart rate on psychophysiological responses and the propositional structure of fear imagery. A female student who showed the most physiological responses during fear imageries was selected as the present case-study subject. She was trained to decrease her heart rate according to biofeedback signals during fear imagery for 8 months. After the training, her physiological responses were measured again during fear imageries, where she was asked to control her heart rate without any feedback signals. Finally, questionnaires were administered to examine possible modification in the propositional structure of fear imagery. Results showed that after the training she achieved heart rate control without any feedback signals during fear imageries. Frontal EMG and respiration also showed decrement in post-training. Peripheral skin temperature in post-training, however, decreased more than in pre-training. It is suggested that the response propositions of fear imagery are modified in the direction of relaxation through the training to decrease heart rate during fear imagery.
This study was conducted as the first step toward the understanding of the functional meaning of self-stimulated behaviors among severely and multiplily handicapped. The change of heart-rate before and after the self-stimulated behavior in two cases with beating of the throat and air-wallowing were examined. Their heart-rate increased gradually before the onset of self-stimulated behavior, but a little change was observed during the behavior. The heart-rate, then, decreased after the end of the behavior. The pattern of changes was the same for both cases. These results were discussed in terms of 1) the average duration needed for the shift from the lowest to the highest heart-rates and their reverse, which was shorter after the self-stimulated behavior, 2) the rate of changes in the heart-rate, which was lower after than before, the self-stimulated behavior, and 3) the statistically significant change of heart-rates at each interval before and after the self-stimulated behavior.
The purpose of this study is to examine the effects of saccade direction upon saccade-related brain potentials (SRPs). Eight college students performed visual tracking tasks, in which an Arabic figure was presented at every 740ms on either one of three positions (center, 8 deg. to right in visual angle, and 8 deg. to left) in random order. While right directed saccades elicited more negative potentials than did left directed ones in both small and large saccades in 5 out of 8 subjects, other 3 subjects showed the opposit effects. In all subjects, however, the right directed saccades elicited more negative SRPs at O1 than at O2. And SRPs elicited by the left saccades were more negative at O2 than at O1. Since the negative shifts started at the onset of saccade and sustained afterwards, they were assumed to be caused by an eye ball potential.