The arousal level of consciousness required for working memory performance: An anaesthesia study.

Regarding the stage of arousal level required for working memory to function properly, limited studies have been conducted on changes in working memory performance when the arousal level of consciousness decreases. This study aimed to experimentally clarify the stages of consciousness necessary for optimal working memory function. In this experiment, the sedation levels were changed step-by-step using anaesthesia, and the performance accuracy during the execution of working memory was assessed using a dual-task paradigm. Participants were required to categorize and remember words in a specific target category. Categorization performance was measured across four different sedative phases: before anaesthesia (baseline), and deep, moderate and light stages of sedation. Short-delay recognition tasks were performed under these four sedative stages, followed by long-delay recognition tasks after participants recovered from sedation. The results of the short-delay recognition task showed that the performance was lowest at the deep stage. The performance of the moderate stage was lower than the baseline. In the long-delay recognition task, the performance under moderate sedation was lower than that under baseline and light sedation. In addition, the performance under light sedation was lower than that under baseline. These results suggest that task performance becomes difficult under half sedation and that transferring information to long-term memory is difficult even under one-quarter sedation.

Dose-Response Effects of Acute Aerobic Exercise Intensity on Inhibitory Control in Children With Attention Deficit/Hyperactivity Disorder.

The present study aimed to examine whether the effect of acute aerobic exercise on inhibitory control of children with attention-deficit/hyperactivity disorder (ADHD) is moderated by exercise intensity. Using a within-subjects design, 25 children with ADHD completed a flanker task with concurrent collection of electroencephalography (EEG) data after three different intensities of treadmill running. The results showed that low- and moderate-intensity exercises resulted in shorter reaction times (RTs) relative to vigorous-intensity exercise during the incompatible condition of the flanker task regardless of task congruency. A P3 congruency effect was observed following low- and vigorous-intensity exercises but not after moderate-intensity exercise. The mean alpha power, a measure of cortical arousal, increased following low- and moderate-intensity exercises but decreased following vigorous-intensity exercise. In addition, the change in arousal level after moderate-intensity exercise was negatively correlated with RT during incompatible flanker tasks. The current findings suggest that children with ADHD have better inhibitory control following both low- and moderate-intensity exercises relative to vigorous aerobic exercise, which could be characterized by an optimal state of cortical arousal.

Effects of social information on duration perception by different mechanisms in sub- and supra-second range: Evidence from face features.

Human faces convey abundant social information. The influence of social information on duration estimation was examined by comparing a cartoon face (CF; social) condition with geometric plane figures, or CFs with internal elements disturbed from their normal position (non-social) condition, and also by comparing a human portrait facing the front (more social interaction) condition with the portrait facing the back (less social interaction) condition. Results showed that in the supra-second range, both CFs and human portraits facing the front led to an underestimation compared with non-social or less social information conditions. In the sub-second range, only portraits facing the front were overestimated compared with those facing the back and with the CFs. These results suggest that in the millisecond range, the biological information conveyed by faces may lead to higher arousal, which may result in accelerated clock speed and overestimation. In the supra-second range, it is possible that attention was diverted by social information, resulting in duration underestimation. Taken together, our results suggest that the different mechanisms were involved in duration perception of social information conveyed by face feature in the sub- and supra-second range.

To Be Expressive or Not: The Role of Teachers' Emotions in Students' Learning.

Understanding the role of teachers' facial expressions in students' learning is helpful to improve online teaching. Therefore, this study explored the effects of teacher's facial expressions on students' learning through analyzing three groups of video lectures. Participants were 78 students enrolled in three groups: one with an enhanced-expression teacher, one with a conventional-expression teacher, and one with the teacher's audio only. ANOVA was used to explore whether video lectures instructed by the enhanced-expression teacher were better than those instructed by the conventional-expression teacher and the audio-only teacher for facilitating students' learning, and what is the role of the teacher's emotions in students' perceived social presence, arousal level, cognitive load, and learning. The results showed that the video lecture by the enhanced-expression teacher was better than those with the conventional-expression teacher and with the audio-only for facilitating students' social presence, arousal level, and long-term learning. Interestingly, it was found that the teacher's emotions could relieve students' cognitive load. These results explained the inconsistency of existing studies by exploring the mechanism of teachers' emotions in students' learning. It also provides teachers with practical guidance for video lecture design.

Evaluation of the Severity of Major Depression Using a Voice Index for Emotional Arousal.

Recently, the relationship between emotional arousal and depression has been studied. Focusing on this relationship, we first developed an arousal level voice index (ALVI) to measure arousal levels using the Interactive Emotional Dyadic Motion Capture database. Then, we calculated ALVI from the voices of depressed patients from two hospitals (Ginza Taimei Clinic (H1) and National Defense Medical College hospital (H2)) and compared them with the severity of depression as measured by the Hamilton Rating Scale for Depression (HAM-D). Depending on the HAM-D score, the datasets were classified into a no depression (HAM-D < 8) and a depression group (HAM-D ≥ 8) for each hospital. A comparison of the mean ALVI between the groups was performed using the Wilcoxon rank-sum test and a significant difference at the level of 10% (p = 0.094) at H1 and 1% (p = 0.0038) at H2 was determined. The area under the curve (AUC) of the receiver operating characteristic was 0.66 when categorizing between the two groups for H1, and the AUC for H2 was 0.70. The relationship between arousal level and depression severity was indirectly suggested via the ALVI.

Non-visual effects of diurnal exposure to an artificial skylight, including nocturnal melatonin suppression.

BACKGROUND: Recently, more consideration is being given to the beneficial effects of lighting on the maintenance and promotion of the health and well-being of office occupants in built environments. A new lighting technology using Rayleigh scattering has made it possible to simulate a blue sky. However, to date, no studies have examined the possible beneficial effects of such artificial skylights. The aims of this study were to examine the non-visual effects of artificial skylights and conventional fluorescent lights in a simulated office environment and to clarify the feature effects of the artificial skylights. METHODS: Participants were 10 healthy male adults. Non-visual effects were evaluated based on brain arousal levels (α-wave ratio and contingent negative variation [CNV]), autonomic nervous activity (heart rate variability [HRV]), work performance, and subjective responses during daytime exposure to either an artificial skylight or fluorescent lights, as well as nocturnal melatonin secretion. RESULTS: Subjective evaluations of both room lighting-related "natural" and "attractive" items and the "connected to nature" item were significantly higher with the skylight than with the fluorescent lights. Cortical arousal levels obtained from the early component of the CNV amplitude were significantly lower with the skylight than with the fluorescent lights, whereas α-wave ratio and work performance were similar between the two light sources. The HRV evaluation showed that sympathetic nerve tone was lower and parasympathetic nerve tone was higher, both significantly, for the skylight than for the fluorescent lights during daytime. Nocturnal melatonin secretion was significantly greater before and during light exposure at night under the daytime skylight than under the fluorescent lights. CONCLUSIONS: Our results suggest that artificial skylights have some advantages over conventional fluorescent lights in maintaining ordinary work performance during daytime with less psychological and physiological stress. The findings also suggest that the artificial skylights would enable built environments to maintain long-term comfort and productivity.

The integrated ultradian organization of behavior and physiology in mice and the contribution of orexin to the ultradian patterning.

Our series of rat experiments have shown that locomotor activity, arousal level, body and brown adipose tissue temperatures, heart rate and arterial pressure increase episodically in an integrated manner approximately every 100min (ultradian manner). Although it has been proposed that the integrated ultradian pattern is a fundamental biological rhythm across species, there are no reports of the integrated ultradian pattern in species other than rats. The aim of the present study was to establish a mouse model using simultaneous recording of locomotor activity, eating behavior, body temperature, heart rate and arousal in order to determine whether their behavior and physiology are organized in an ultradian manner in normal (wild-type) mice. We also incorporated the same recording in prepro-orexin knockout (ORX-KO) mice to reveal the role of orexin in the brain mechanisms underlying ultradian patterning. The orexin system is one of the key conductors required for coordinating autonomic functions and behaviors, and thus may contribute to ultradian patterning. In wild-type mice, locomotor activity, arousal level, body temperature and heart rate increased episodically every 93±18min (n=8) during 24h. Eating was integrated into the ultradian pattern, commencing 23±4min (n=8) after the onset of an electroencephalogram (EEG) ultradian episode. The integrated ultradian pattern in wild-type mice is very similar to that observed in rats. In ORX-KO mice, the ultradian episodic changes in locomotor activity, EEG arousal indices and body temperature were significantly attenuated, but the ultradian patterning was preserved. Our findings support the view that the ultradian pattern is common across species. The present results also suggest that orexin contributes to driving ultradian episodic changes, however, this neuropeptide is not essential for the generation of the ultradian pattern.

Modulation of Recognition Memory for Emotional Images by Vertical Vection.

Our previous research showed that vertical vection could modulate human mood. We further examined this possibility by using memory recognition task of positive, negative and neutral emotional images with high and low arousal levels. Those images were remembered accidentally while the participants did visual dummy task, and later presented together with novel images during vertical vection-inducing or neutral visual stimuli. The results showed that downward vection facilitated the recognition of negative images and inhibited the recognition of positive ones. These modulations of incidental memory task provide an additional evidence for vection influence on cognitive and emotional processing, and also provide a new paradigm that can be used in future vection and embodied cognition research.

Cultural differences in emotion: differences in emotional arousal level between the East and the West.

Whether emotion is universal or social is a recurrent issue in the history of emotion study among psychologists. Some researchers view emotion as a universal construct, and that a large part of emotional experience is biologically based. However, emotion is not only biologically determined, but is also influenced by the environment. Therefore, cultural differences exist in some aspects of emotions, one such important aspect of emotion being emotional arousal level. All affective states are systematically represented as two bipolar dimensions, valence and arousal. Arousal level of actual and ideal emotions has consistently been found to have cross-cultural differences. In Western or individualist culture, high arousal emotions are valued and promoted more than low arousal emotions. Moreover, Westerners experience high arousal emotions more than low arousal emotions. By contrast, in Eastern or collectivist culture, low arousal emotions are valued more than high arousal emotions. Moreover, people in the East actually experience and prefer to experience low arousal emotions more than high arousal emotions. Mechanism of these cross-cultural differences and implications are also discussed.

Attenuated sensitivity to the emotions of others by insular lesion.

The insular cortex has been considered to be the neural base of visceral sensation for many years. Previous studies in psychology and cognitive neuroscience have accumulated evidence indicating that interoception is an essential factor in the subjective feeling of emotion. Recent neuroimaging studies have demonstrated that anterior insular cortex activation is associated with accessing interoceptive information and underpinning the subjective experience of emotional state. Only a small number of studies have focused on the influence of insular damage on emotion processing and interoceptive awareness. Moreover, disparate hypotheses have been proposed for the alteration of emotion processing by insular lesions. Some studies show that insular lesions yield an inability for understanding and representing disgust exclusively, but other studies suggest that such lesions modulate arousal and valence judgments for both positive and negative emotions. In this study, we examined the alteration in emotion recognition in three right insular and adjacent area damaged cases with well-preserved higher cognitive function. Participants performed an experimental task using morphed photos that ranged between neutral and emotional facial expressions (i.e., anger, sadness, disgust, and happiness). Recognition rates of particular emotions were calculated to measure emotional sensitivity. In addition, they performed heartbeat perception task for measuring interoceptive accuracy. The cases identified emotions that have high arousal level (e.g., anger) as less aroused emotions (e.g., sadness) and a case showed remarkably low interoceptive accuracy. The current results show that insular lesions lead to attenuated emotional sensitivity across emotions, rather than category-specific impairments such as to disgust. Despite the small number of cases, our findings suggest that the insular cortex modulates recognition of emotional saliency and mediates interoceptive and emotional awareness.