The developmental changes of occipital EEGs were investigated through follow-up recordings of 13 normal children. Their ages were from 6 to 10 years when the first EEG recording was made. Each follow-up recording lasted about 5 years. On these occipital EEGs an auto-power spectrum analysis was made. Of the 13 subjects there were 7 subjects who showed a single alpha component and 6 subjects who showed multiple peaks in θ and α bands. It was found that with the advancement of age the components which appeared at low frequencies among the multiple peaks diminished in power and disappeared, whereas the component of the highest frequency showed a gradual increase in peak frequency. The single α component also increased in its peak frequency with age. Thus, many components which exhibited distinct chronological changes were found in children's occipital EEGs. It was postulated that different maturational processes of the brain may be responsible for these changes.
Effects of instructed imagery and/or feedback on the deceleration of heart rate (HR) were investigated using 28 male and female undergraduate students. The experiment consisted of one pretest, three training and one posttest sessions. In the pre and posttest sessions all subjects were instructed to decrease HR without imagery, and in the three training sessions they were asked to do so under one of the four conditions, (a) no feedback-no imagery (control), (b) no feedback-imagery, (c) feedback-no imagery, and (d) feedback-imagery. It was found that (1) only the feedback-imagery condition tended to have an effect on decelerating HR, (2) subjects who had the no feedback-no imagery condition showed a decrease in HR in the posttest session but not in the training sessions, and (3) a continuous use of appropriate cognitive strategies was required to decrease HR. These results were discussed in relation to the intrinsic nature of feedback stimulus such as to increase a level of arousal, and also to the possibility that subjects may have been aquainted with various strategies relevant to lower HR before the experiment.
The purpose of the experiment was to examine the effect of the background letters of the Japanese Kana-list which 10 students searched under three conditions on visual processing. One kind of background letters was physically similar to the target (PS condition), or was the nominally identical with the target (NI condition). In the control (C) conditon, neither of these letters was involved. The searching time through a list was longer in NI than in C and was longer in PS than in NI condition. The results suggested that the stimulus was coded not only at the physical level but at the nominal level. The fixation time was prolonged in PS and NI than in C. The number of saccades increased in PS and NI than in C, and it showed the tendency to increase in PS than in NI. It was suggested that the two factors affected the processing of background : One was the ability of capturing a letter by peripheral vision. The other was the degree of difficulty to decide whether the letter was the target or not.
This study was designed to examine relationships between the amplitudes of skin conductance response (SCR) and the delays of subject's verbal answer on Guilty Knowledge Technique (GKT). Thirty-six adults males were requested to select an item on the criminal situation and to deny 5 questions which including the selected (critical) item during examination. The first group was instructed to answer immediately after onset of items lasting for 8 s. The second was to delay their answers, until the offset of items given for 8 s. The third was to delay their answers for 6 s after offset of items lasted for 2 s. Results yielded that SCR amplitudes were more distinctive to the onset of critical items under delayed answer procedures. There were, however, no significant differences between amplitudes obtained under two delayed procedures. It was concluded that delayed answer procedure was effective to identify the critical item on GKT.
Firstly the effects of electrode arrangements on the REG amplitude changes were examined by the computer model in which a cerebral hemisphere was simulated as a semicircle composed of three layers. The sensitivity maps, which were calculated for six kinds of electrode arrangements, demonstrated that the more closely spaced the measuring electrodes (E-E) or the more widely spaced the current and its paired measuring electrodes (I-E), the greater the sensitivity in the superficial brain areas between those measuring electrodes. Secondly the REGs around Oz and Fpz were measured on ten human subjects in two conditions ; eye closing and TV watching. The increasing rate of REG amplitudes by visual activation became significantly greater around Oz as the E-E separation became shorter, and the same tendency occurred when the I-E separation became longer. Such E-E separation effects, however, were not obtained around Fpz. These results on human corresponded well with the sensitivity maps constructed by the computer model, and they would suggest the possibility of finding effective electrode arrangemens to get greater REG changes.