Serotonergic innervation in the lateral hypothalamic area (LHA) has been implicated in mouse-killing behavior, muricide, of rats. In the present study, functional activation of neurons in the LHA was demonstrated by immunohistochemistry of Fos-protein, a marker of activated neurons, following raphe lesion-induced muricide. Fos-protein induction was seen in the ventral part of the intermediate hypothalamic area (IHA) of the LHA in the muricide rat. Following raphe transplantation into the brain near the bilateral IHA, a significant decrease in the number of Fos-immunoreactive cells was observed in this area, coinciding with decreased muricide behavior. The present results suggest that the decline in Fos-protein expression in this area may be associated with the inhibition of this behavior.

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In order for humans to communicate, it is important to predict the feelings, thoughts, and intentions of other people not just through verbal information but also through movement information. Therefore we must identify what an action of a person is in. Although it appears to be a highly complicated and difficult task, humans can recognize complex movements of an individual even with impoverished motion information. We examined how presentation rates (speeds) affect the detection of biological motion. In a two-alternative forced-choice task, subjects discriminated normal biological motion sequences from scrambled versions. Upright and inverted stimuli were presented in a forward or backward order at various presentation rates. Performance was generally higher in the condition where the stimuli were presented upright in a forward manner than the other conditions. A clear tuning curve for presentation rate was observed only in the upright-forward condition. These results suggest that the perception of natural biological motion takes into account previous experience in observing human actions.

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In this study, we applied a gaze-contingent window method to measure the spatial distribution of visual attention while playing an action video game. The peripheral visual field of a player was restricted to an area around the gaze by masks with various spatial extents. The quantitative relationship between window size and game performance confirmed that superior players had a wider distribution of visual attention than inferior players. An additional analysis of eye movements showed that the mean length of saccadic eye movements (indicating an overt allocation of attention) of inferior players was comparable to that of superior players. These results suggest that the difference in game performance between inferior and superior players may be due to the qualitative difference in the efficiency of covert allocation of visual attention. The present study also indicates the applicability of the gazecontingent window method for the online evaluations of performance and learning during dynamic visual-motor tasks.

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Serotonin is a neurotransmitter of a monoamine group together with dopamine and noradrenalin. In the adult brain, serotonin neurons are located in restricted regions in the brainstem and send axons to widespread brain regions, modulating overall neuronal activities throughout the brain. During the ontogeny, serotonin acts as a developmental regulator. Serotonin neurons are generated early in the fetal brain and animal experiments have revealed that serotonin regulates various aspects of developmental events including neurogenesis (differentiation of neurons), dendritogenesis (elongation and branching of dendrites) and synapse formation. The spatio-temporal regulation of the expression of 14 serotonin receptors underlies the effects of serotonin on different neurons at specific developmental stages. Serotonin system is easily affected by environmental factors such as stress, and alterations in this system in fetal and neonatal brain induce permanent changes in the structure and function of brain. In human, dysregulations of the serotonin functions are closely related to the psychological and mental disorders including depression and anxiety disorder, and alterations in the fetal brain may be the cause of developmental disorder such as autism.

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Kansei, a kind of sensitivity and mental reaction specific to humans, is thought to be generated by a highly advanced function of the human brain, although natural science has hardly explained it yet. In this review, we propose a model of neural mechanisms for kansei from a physiological viewpoint and discuss its applicability to feelings of a car driver. After introducing our model, based on the principles of motor control by the central nervous system (CNS), we point out that it is similar to a driver model that describes interactions of a driver's behavior and vehicle dynamics. We examine physiological responses of a driver in a moving vehicle and correlate these responses with vehicle dynamics. Attention is directed to muscle activity, the final motor output of the CNS that reflects a command signal originating from the higher motor center. Our study shows that the sternocleidomastoid muscle in the neck contributes to maintaining the head position in the pitch and roll planes against backward and lateral inertial forces during driving. The research may potentially pave the way for a challenging approach to objective evaluation of a driver's feelings. Finally, we discuss possible future directions of this approach. Objective analysis of physiological data, combined with appropriate subjective evaluation of a driver's feelings, may provide an insight into the neural mechanisms of kansei. Such a cross-disciplinary research that covers neuroscience, information science and kansei engineering is expected to clarify this advanced function of the brain and to create a new research field of ‘kansei science’.

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We are developing a control system for a mechanical pet, in which the mechanical pet, judging the user's alpha waves, moves in a way that makes the user feel most comfortable. We constructed a real-time control system for customizing the mechanical pet motions according to the user's measured alpha waves. Compared with the ordinary biofeedback system, in which the user makes an effort to intentionally relax by being informed of the state of his/her alpha waves, our system makes it possible for the user to unintentionally and comfortably relax by watching his/her own particular favorite mechanical pet motions, which are controlled by his/her own alpha waves. The results of experiments valuating the constructed system show the system's effectiveness and necessity.

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We studied the effects of prenatal stress on early postnatal development of the brain in mouse pups (PS) whose dams had been exposed daily to restraint stress during pregnancy (gestational days 14-18), with special reference to the expression of corticotropin-releasing factor (CRH), vesicular glutamate transporters (VGLUT1 and VGLUT2), and a synaptic vesicle marker protein (SV2). In a comparison with age-matched control pups born of unstressed dams, in situ hybridization analysis revealed a statistically significant reduction of CRH gene expression in the hypothalamic paraventricular nucleus of the PS pups at postnatal days 10 (P10), suggesting a functional alteration in the core neuroendocrine circuit of the stress response mechanism. Immunohistochemical analysis of the medial habenular nucleus followed by semi-quantitative evaluation revealed that VGLUT1 staining, but not VGLUT2 staining, is markedly reduced in the P10 PS pups compared to controls of the same age, and that such a difference between PS and control pups becomes undetectable at P21. These findings suggest that the embryonic environment, at least during late pregnancy, alters the activity of the neuroendocrine system involved in the stress response and influences the early postnatal development of glutamatergic neurons in a particular brain region.

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The dopaminergic system plays an important role in emotional and rewarding properties, which may be a fundamental brain mechanism of mental functions such as emotion motivation and kansei. Cannabinoid compounds such as Δ⁹-tetrahydrocannabinol (Δ⁹-THC), a major active constituent of marijuana (Cannabis sativa), are responsible for central nervous system (CNS) effects. The CNS responses to cannabinoid compounds are mediated exclusively by CB1 cannabinoid receptors. To reveal the function of those receptors in dopamine release in projection areas of the mesolimbic and mesocortical dopaminergic fibers, we performed an in vitro superfusion experiment using synaptosomes from the nucleus accumbens, striatum or frontal cortex in rats. A high [K+] -induced release of dopamine was increased by CB 1 agonists, an effect that was blocked by pretreatment with a CB1 receptor antagonist SR141716A. This antagonist pretreatment also suppressed the high [K+] -induced release of dopamine. These results indicate that the CB1 receptor agonist increases the dopamine release from the depolarized synaptosomes through interaction with CB1 receptors. Furthermore, the results suggest the involvement of an endogenous cannabinoid system in the regulation of dopamine release from synaptic terminals. A neuronal modulation such as the depolarization-induced suppression of inhibition may act as one of the mechanisms underlying the cannabinoid effects on dopamine release.

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This research poses the hypothesis that it is possible to associate human emotions during driving to potential parameters of physical and controlling of automobile movement. Thus, its purpose is t determine the relationship between emotional expressions as demonstrated by electroencephalograph (EEG) that indicate valence as well as arousal and vehicle's characteristics in movement.
As an experimental methodology, we performed repeated tests of acceleration and braking under certain conditions during vehicular linear movement, during which changes in vehicular movement characteristics were noted as well as measurements taken of each driver's EEG patterns. From this data, we extracted significant levels of left-right brain frequency fluctuations showing driver comfortableness at certain intervals. Through regression analysis of time series data, we were able to obtain measurements of the contribution of each vehicle's characteristics movement to driver comfortableness.
This research extracted driver's real-time physiology reaction accompanied the feeling of driving by measured the EEG, and it is an attempt to make objectively evaluation for the driver's subjective experience. It was verified vehicle's characteristics in movement could be reflected objectively from the driver's physiology reaction.

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This research aimed to investigate individual differences in human cognitive style using working memory span task and dual-task paradigm. It would be important to know individual differences in performance on dual-task situations, because almost our everyday life is under dual or multi task situations: driving while talking with passenger, emailing while listening to music, or cooking while talking on the phone. We examined the character of “low”working memory span score subjects in detail, because they are more likely to have troubles than high working memory span score subjects when using some tool, devise, and interface in daily dual-task situations. The understanding their performances under dual-task situations can lead to better universal design. First, we divided low working memory span subjects into two groups based on their primary task (listening comprehension task) performances: good-low-span group (G-group) and poor-low-span group (P-group). Then, we compared performances under dual-task conditions between two groups. Secondary tasks were writing task and memory task. The results showed that primary task performances of G-group were decreased under either the writing task or the memory task, on the contrary that of P-group increased under both of dual-tasks. It is interesting to note that their performances were different under dual-task conditions even though their working memory span scores were not different. These results suggested that human cognitive style is highly diversified like G-group and P-group. Thus, they differently interact with tool, machine, or environment, etc. These findings can apply for engineering or designing of man-machine interface and for evaluating the concept of safety or usability.

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