Chronic neonatal blockade of N-methyl-D-aspartate (NMDA) receptors produces behavioral and physiological changes in adult animals. Temporal information processing was investigated by testing the effects of chronic neonatal NMDA-R blockade with MK-801 (0.4 mg/kg twice per day) on temporal cognition in adult rats. Rats were trained to discriminate between 2-s and 8-s anchor durations, and they were then required to classify probe duration in the bisection task. Neonatal chronic MK-801 treatment did not disrupt duration discrimination. Conversely, MK-801-treated rats showed a leftward shift of their timing function. The results of the present study suggest that chronic blockade of NMDA receptors in the critical period of neurodevelopment induces long-lasting changes in temporal cognition processing. Therefore, MK-801-treated rats present a potential animal model of disorders that involve abnormal temporal cognition.

This study examined physiological changes in response to the feelings of sadness induced by two different situations. A previous study (Shirai & Suzuki, 2016) indicated that sadness induced by the “loss of someone” is different from sadness induced by the “failure to achieve a goal.” In the present study, each participant was asked to imagine one of three situations: “loss,” “failure to achieve a goal,” or “daily.” Heart rate, systolic and diastolic blood pressure, skin conductance level, and high frequency component of heart rate variability were assessed during this imagery task. Concerning the physiological measures, DBP increased only in the “loss” situation during the task. These findings suggest that the sadness elicited by two different situations is the slight different in terms of physiological measures. However, a clear difference was not found in the physiological measures elicited in these sadness situations. Further explorations are needed to clarify sadness differences within these same emotional categories.

This study aimed to use physiological/psychological indicators to investigate the effects of tactile massage on mothers of children with autism spectrum disorder. Under fixed room conditions, some of the 17 participants were treated with the tactile procedure (tactile massage) for 20 minutes on the first day and with the resting procedure (resting in a seated position) for 20 minutes on the next day, while the others were treated with the resting procedure on the first day and the tactile procedure on the next day. Salivary cortisol concentration, salivary secretory immunoglobulin A concentration, and heart rate variability were used as physiological indicators, while the State-Trait Anxiety Inventory Form JYZ and the Profile of Mood States-Brief Form were used as psychological indicators. Our results revealed no marked differences in physiological indicators between participants treated with the tactile procedure and those treated with the resting procedure. However, tactile massage treatment led to significant improvements in the anxiety and mood psychological indicators.

Russell & Bullock (1985) proposed that facial expressions are emotionally categorized through psychological evaluation consisting of two dimensions, i.e., “pleasure (pleasant feeling–unpleasant feeling)” and “arousal (high arousal–sleepiness)”. On the other hand, previous ERP (event-related potential) studies for facial expression recognition suggest that ERP amplitude and latency vary depending on facial emotion categories. In the present study, participants received the neutral face as the first stimulus, which was immediately followed by the facial expression (happy, angry, and surprise) or random dots as the second stimulus. In addition, each facial expression was evaluated by the Affect Grid. Both the arousal score and the P130 amplitude for surprise facial expression were greater than those for happy and angry facial expressions. The amplitude and latency of N170 and P300 were not different among the facial expressions. These results suggest that changes in the arousal dimension elicited by emotional faces may be linked to early visual processing shown in P130.

The scientific report by Wolfson and Carskadon (1998) emphasized the key factors such as puberty, school schedule (start time) and academic performance that affected adolescents’ later bed times and later rise times, which in turn were likely to lead to the decreased daytime function. The present paper reviewed the significance of their work in relation to sleep education of Japan. First, their work highlighted the educational significance of epidemical and developmental approach to children’s sleep habit. Secondly, their work contributed to establishment somnology in Japan which was authorized by the Science Council of Japan in 2002 as a new interdisciplinary scientific study of sleep. Third, they addressed the influence of the environmental constraints (school schedule) on adolescents’ sleep, stimulating recent researches designed to experimentally examine the effects of delaying school start times or taking naps during lunchtime at school on daytime function.

It is important to note that Wolfson and Carskadon carefully discussed their own outcomes, stating that the results did not show a one-to-one relation between sleep patterns and academic performance, and their discussion seems to be insufficiently introduced to somnology in Japan in terms of understanding of sleep patterns as dependent and independent variables. One of their most notable findings may be the fact that adolescents require at least 7 hours and 20 min of sleep time to optimally cope with academic demands and otherwise their poor sleep habits are most likely to negatively influence their daytime mood and behavior. This may mean the importance of environmental adjustments for prioritizing adolescents’ sleep as best we can, which will be true with in Japan.

Although cortisol levels in fingernails may reflect the hormone’s long-term cumulative production, a standard measuring procedure has not yet been established. In this study, we investigated the effects of ground-fingernail grain size and cortisol extraction time on the measurement of fingernail cortisol. Fourteen healthy males provided fingernail samples, which were ground for 1, 4, or 16 minutes (coarse-, medium-, or fine-grading conditions, respectively). Subsequently, cortisol was extracted in pure methanol for 1, 6, 24, or 48 hours (four extraction time conditions). The clear supernatant was filtered and dried, and extracted cortisol was measured using an enzyme-linked immunosorbent assay. ANOVA results indicated that finer grading and longer extraction time was associated with higher cortisol levels. Furthermore, an interaction between grading and extraction-time conditions was observed: cortisol levels between medium- and fine-grading conditions were comparable in 48-hour extraction. This study clearly demonstrated that the grain-size of ground fingernails and extraction time could affect the amount of extracted cortisol obtained from fingernails and should therefore be considered during fingernail cortisol assay.