Self-awakening, sleep inertia, and P3 amplitude in elderly people

It is well known that sleepiness is sometimes experienced in the afternoon. A short afternoon nap is thought to be effective in reducing sleepiness. However, sleep inertia occurs even after a short nap, and this could be a major risk factor for injuries from falling by the elderly. In the present study, the effect of self-awakening on sleep inertia after a 20-min. nap was examined. Nine participants (M=74.1 yr., SD=5.0 yr.) took part in the three experimental conditions: the self-awakened nap, the forced-awakened nap, and the control (no-nap) conditon. Analysis showed sleepiness and performance after the nap significantly improved compared with the control condition. P3 amplitude tended to be larger after self-awakening than after forced-awakening. The present study indicates a 20-min. nap reduces afternoon sleepiness, and the application of self-awakening may contribute to higher arousal after a nap taken by this elderly group.     

Changes in Hedonic and Eudaimonic Well-Being After a Severe Nationwide Disaster: The Case of the Great East Japan Earthquake

This paper presents the results of a longitudinal survey (N = 10,744) that examined how the Great East Japan Earthquake of March 2011 affected the hedonic and eudaimonic well-being of young people in Japan outside of the afflicted area. Our dataset consists of Japanese citizens in their 20 and 30s from all non-afflicted prefectures. We conducted two surveys on well-being, one before the earthquake (December 2010) and one after (March 2011). The results suggested that people who were thinking about the earthquake when they completed the second survey had slightly increased general well-being after the earthquake as compared to before, showing that reflecting on the earthquake had prompted them to reevaluate their lives and increased eudaimonia. However, they experienced temporary negative emotional reactions more frequently, which shows that their sympathy for those in the afflicted area decreased their hedonic well-being. After the earthquake, Japanese youth were likely to value social connectedness and ordinary life. Moreover, this mindset promoted prosocial behaviors such as making donations and volunteering.     

What to copy: the key factor of observational learning in striped jack (Pseudocaranx dentex) juveniles

Animals in social environments can enhance their learning efficiency by observing the behaviour of others. Our previous study showed that learning efficiency of schooling fish increased through the observation of the behaviour of trained demonstrator conspecifics. The present study aimed to verify the key factor of observational learning by investigating what information is important for social transmission of feeding information. A striped jack (Pseudocaranx dentex) observer was provided with one of the five observation treatments: (a) pellets observation, where pellets were dropped near the aeration in an adjacent tank; (b) responding conspecific observation, where a trained conspecific demonstrator responded to the aeration without food in the adjacent tank; (c) foraging conspecific observation, where a conspecific demonstrator foraged near the aeration in the adjacent tank; (d) nearby pellets observation, where pellets were dropped in a transparent column near the aeration in the observer tank; and (e) foraging heterospecific observation, where a filefish (Stephanolepis cirrhifer) demonstrator foraged near the aeration in the adjacent tank. The response to the aeration in these observers was compared with that of controls who did not observe any behaviour. Only individuals who observed foraging conspecifics showed a response to the aeration after observing. These results suggest that observer fish acquire feeding information not through recognition of prey items or through imitation of the demonstrator, but through the vicarious reinforcement of a conspecific for foraging.     

Cross-cultural comparison of ADHD symptoms among Japanese and US university students

Problems related to attention, hyperactivity, and impulsiveness are known to impact social, academic, and vocational success. When the problems begin in childhood and lead to impaired functioning, the syndrome is identified as attention-deficit/hyperactivity disorder (ADHD). Symptoms of the syndrome persist into adolescence and adulthood for many individuals, but less is known about characteristics of adults compared to children, especially adults attending university. Furthermore, there is little cross-national and cross-cultural research. This study compared DSM-IV-TR ADHD symptoms of US university students (N=271) to Japanese peers (N=712). Comparison of group means on a DSM-IV-TR-based checklist indicated that Japanese students reported more problems with inattention (and overall ADHD symptoms) but not hyperactive-impulsive symptoms. Although differences were statistically significant, effect sizes were small, indicating that for practical purposes, the students reported similar levels of symptoms. Japanese students reported higher rates of meeting or exceeding symptom counts that comprise diagnostic criteria for ADHD, but differences were quite small. Using DSM-IV-TR thresholds, 5.70% of US students and 6.27% of Japanese students reported enough symptoms to meet the cut-off for inattentive, hyperactive/impulsive, or combined type during childhood. With regard to recent problems, 2.66% of US students and 4.52% of Japanese students reported enough symptoms to meet the cut-off for one of the three subtypes. Comparisons using other methods of calculating rates are also provided. This research adds to the limited knowledge of ADHD symptoms in university students across countries and it supports the view that ADHD is not merely a cultural construct. This study is among the first to identify potential attention problems in Japanese university students.     

Shuffle-set dislocation nucleation in semiconductor silicon device

We have found that a shuffle-set dislocation is nucleated in a semiconductor silicon device subjected to severe thermal processing. The dislocation transforms into a dissociated glide-set dislocation after annealing at 500°C. A possible mechanism for the nucleation of a perfect shuffle-set dislocation during thermal processing is that the dislocation nucleus was nucleated at a low temperature during prior ion-implantation processing.     

Performance of an Adapted Version of the Timed Up-and-Go Test in People with Cognitive Impairments

In clinical practice, older people with cognitive impairment may have difficulties to understand the instructions of the Timed Up-and-Go (TUGT) test and present a bad performance. The purpose of this study was to identify differences in the TUGT performance, in an adapted version, between older adults with preserved cognition (PC), mild cognitive impairment (MCI) and Alzheimer's disease (AD), and to identify the association between the adapted TUGT performance and cognition among groups. A cross-sectional study was conducted with 118 community-dwelling older adults divided in three groups: PC (n?=?40), MCI (n?=?40) and AD (n?=?38). The evaluation was composed by the adapted TUGT and cognitive assessment (Addenbrooke's Cognitive Examination and Frontal Assessment Battery). Only the cadence of TUGT presented significant difference between groups, specifically between AD versus MCI and PC groups. The main correlations were found between time of TUGT with fluency domain and global cognitive function, especially in the AD Group. The findings contribute to the understanding of how cognition interferes on functional mobility in older people with MCI and AD. The adapted TUGT is easy to perform in clinical practice and can be useful when assessing mobility in people with cognitive impairment.     

Dual frames for causal induction: the normative and the heuristic

Causal induction in the real world often has to be quick and efficient as well as accurate. We propose that people use two different frames to achieve these goals. The A-frame consists of heuristic processes that presuppose rarity and can detect causally relevant factors quickly. The B-frame consists of analytic processes that can be highly accurate in detecting actual causes. Our dual frame theory implies that several factors affect whether people use the A-frame or the B-frame in causal induction: among these are symmetrical negation, intervention and commitment. This theory is tested and sustained in two experiments. The results also provide broad support for dual process accounts of human thinking in general.     

Mind perception of God in Japanese children

There is a theoretical debate regarding whether children represent God with reference to a human. Most previous studies have assessed this issue focusing on knowledge/omniscience in western children. This study used a theoretical framework characterising mental capacities in terms of motivational/emotional (experience) and cognitive (agency) mental capacities and tested whether Japanese children discriminated between God, a human, a baby and an invisible agent according to these capacities. Three‐ to 6‐year‐old children were asked about the experience and agency of the agents. The results revealed that children discriminated God from a human in terms of mental capacities including experience and agency in 3‐year‐old children. On the other hand, 4‐ to 6‐year‐old children, but not 3‐year‐old children, discriminated a human from a baby and an invisible person. The results suggest that the Japanese children's representations of God differed from their representation of a human during preschool years.     

Temporal modulations of agonist and antagonist muscle activities accompanying improved performance of ballistic movements

Although many studies have examined performance improvements of ballistic movement through practice, it is still unclear how performance advances while maintaining maximum velocity, and how the accompanying triphasic electromyographic (EMG) activity is modified. The present study focused on the changes in triphasic EMG activity, i.e., the first agonist burst (AG1), the second agonist burst (AG2), and the antagonist burst (ANT), that accompanied decreases in movement time and error. Twelve healthy volunteers performed 100 ballistic wrist flexion movements in ten 10-trial sessions under the instruction to "maintain maximum velocity throughout the experiment and to stop the limb at the target as fast and accurately as possible". Kinematic parameters (position and velocity) and triphasic EMG activities from the agonist (flexor carpi radialis) and antagonist (extensor carpi radialis) muscles were recorded. Comparison of the results obtained from the first and the last 10 trials, revealed that movement time, movement error, and variability of amplitudes reduced with practice, and that maximum velocity and time to maximum velocity remained constant. EMG activities showed that AG1 and AG2 durations were reduced, whereas ANT duration did not change. Additionally, ANT and AG2 latencies were reduced. Integrated EMG of AG1 was significantly reduced as well. Analysis of the alpha angle (an index of the rate of recruitment of the motoneurons) showed that there was no change in either AG1 or AG2. Correlation analysis of alpha angles between these two bursts further revealed that the close relationship of AG1 and AG2 was kept constant through practice. These findings led to the conclusion that performance improvement in ballistic movement is mainly due to the temporal modulations of agonist and antagonist muscle activities when maximum velocity is kept constant. Presumably, a specific strategy is consistently applied during practice.