Positive effect of inaudible high-frequency components of sounds on glucose tolerance: a quasi-experimental crossover study.

Although stress significantly impacts on various metabolic syndromes, including diabetes mellitus, most stress management techniques are based on psychological and subjective approaches. This study examined how the presence or absence of the inaudible high-frequency component (HFC) of sounds, which activates deep-brain structures, affects glucose tolerance in healthy participants using the oral glucose tolerance test (OGTT). Sounds containing HFC suppressed the increase in glucose levels measured by incremental area under the curve in the OGTT compared with the otherwise same sounds without HFC. The suppression effect of HFC was more prominent in the older age group and the group with high HbA1c. This suggests that sounds with HFC are more effective in improving glucose tolerance in individuals at a higher risk of glucose intolerance.

Induction of prolonged natural lifespans in mice exposed to acoustic environmental enrichment.

We investigated the effect of acoustic environmental enrichment (EE) on the lifespans and behaviours of mice to the end of their natural lifespan in different acoustic environments. Acoustic EE induced a significantly prolonged natural lifespan (nearly 17% longer) and was associated with increased voluntary movements. However, no correlation between lifespan and voluntary movements was detected, suggesting that increased voluntary movements are not a primary cause of lifespan prolongation. Analyses of individual differences in lifespan demonstrated that lifespan extension induced by acoustic EE could be related to changes in social relationships (e.g., reduction of social conflict) among individuals kept within a cage. Therefore, an acoustic component may be an important factor inducing the positive effects of EE.

Electroencephalogram characteristics during possession trances in healthy individuals.

Despite intensive studies on cerebral activity during trances involving tranquil arousal states, there are little data on physiological basis of naturally induced possession trances involving hyperarousal active states because of the difficulty of gathering data from participants within a natural cultural context in the field. We investigated the characteristics of electroencephalograms (EEGs) that were specific for naturally induced possession trances involving hyperarousal states in actual rituals. We measured the EEG signals of 12 healthy participants, seven with trance and five without trance, before, during, and after a dedicatory ritual drama in Bali, Indonesia, using a custom-modified field telemetry system. During trance, θ (4-7.5 Hz), α-1 (8-9.5 Hz), α-2 (10-12.5 Hz), and ß (13-30 Hz) signals were significantly increased compared with those during the control phases. Such findings were not observed in participants without trance when they performed similar movements in the rituals. The α-1 and α-2 signals tended to remain elevated for several minutes postritual compared with those recorded during the preritual resting state. These results suggest that spontaneous EEG patterns during possession trances may be related, at least in part, to the activation of the reward-generating neuronal system situated in deep-lying brain structures and deactivation of the cerebral cortex.

Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10-13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

Evolutionary acquisition of a mortal genetic program: the origin of an altruistic gene.

As part of our research on programmed self-decomposition, we formed the hypothesis that originally immortal terrestrial organisms evolve into ones that are programmed for autonomous death. We then conducted evolutionary simulation experiments in which we examined this hypothesis using an artificial ecosystem that we designed to resemble a terrestrial ecosystem endowed with artificial chemistry. Notable results corroborating our hypothesis were obtained, which showed that mortal organisms emerged from indigenous immortal organisms through mutation; such mortal organisms survived and left behind offspring, albeit very rarely, and, having survived, surpassed immortal organisms without exception. In this article, we report the details of the above findings and also discuss a background framework we previously constructed for approaching altruism.

An effective hierarchical model for the biomolecular covalent bond: an approach integrating artificial chemistry and an actual terrestrial life system.

Under the AChem paradigm and the programmed self-decomposition (PSD) model, we propose a hierarchical model for the biomolecular covalent bond (HBCB model). This model assumes that terrestrial organisms arrange their biomolecules in a hierarchical structure according to the energy strength of their covalent bonds. It also assumes that they have evolutionarily selected the PSD mechanism of turning biological polymers (BPs) into biological monomers (BMs) as an efficient biomolecular recycling strategy We have examined the validity and effectiveness of the HBCB model by coordinating two complementary approaches: biological experiments using existent terrestrial life, and simulation experiments using an AChem system. Biological experiments have shown that terrestrial life possesses a PSD mechanism as an endergonic, genetically regulated process and that hydrolysis, which decomposes a BP into BMs, is one of the main processes of such a mechanism. In simulation experiments, we compared different virtual self-decomposition processes. The virtual species in which the self-decomposition process mainly involved covalent bond cleavage from a BP to BMs showed evolutionary superiority over other species in which the self-decomposition process involved cleavage from BP to classes lower than BM. These converging findings strongly support the existence of PSD and the validity and effectiveness of the HBCB model.

The role of biological system other than auditory air-conduction in the emergence of the hypersonic effect.

Although human beings cannot perceive elastic vibrations in the frequency range above 20 kHz, nonstationary sounds containing a wealth of inaudible high-frequency components (HFC) above the human audible range activate deep-lying brain structures, including the brainstem and thalamus and evoke various physiological, psychological, and behavioral responses. In the previous reports, we have called these phenomena collectively "the hypersonic effect." It remains unclear, however, if vibratory stimuli above the audible range are transduced and perceived solely via the conventional air-conducting auditory system or if other mechanisms also contribute to mediate transduction and perception. In the present study, we have examined the emergence of the hypersonic effect when inaudible HFC and audible low-frequency components (LFC) were presented selectively to the ears, the entrance of an air-conducting auditory system, or to the body surface including the head which might contain some unknown vibratory sensing mechanisms. We used two independent measurements based on differing principles; one physiological (alpha 2 frequency of spontaneous electroencephalogram [alpha-EEG]) and the other behavioral (the comfortable listening level [CLL]). Only when the listener's entire body surface was exposed to HFC, but not when HFC was presented exclusively to the air-conducting auditory system, did both the alpha-EEG and the CLL significantly increase compared to the presentation of LFC alone, that is to say, there was an evident emergence of the hypersonic effect. The present findings suggest that the conventional air-conducting auditory system alone does not bring about the hypersonic effect. We may need to consider the possible involvement of a biological system distinct from the conventional air-conducting auditory nervous system in sensing and transducing high-frequency elastic vibration above the human audible range.

Electroencephalographic measurement of possession trance in the field.

OBJECTIVES: To verify the utility of a portable electroencephalogram (EEG) measurement system developed for investigating spontaneous EEG from vigorously moving healthy subjects in a possession trance under a natural condition. METHODS: A portable multi-channel EEG telemetry system was developed to record the EEGs of 3 healthy male Balinese while they were performing a ritual dedicatory drama in the field. After reducing extraneous artifacts using a digital filter, the EEGs and their power spectra were analyzed in terms of evolution from one state to another. RESULTS: During the drama, one of the subjects became possessed while the others did not. The EEG of the possessed subject did not show any pathological findings including epileptic discharges, but indicated enhanced power in the theta and alpha frequency bands during the trance. This finding was not observed in the other two subjects, who did not go into trances, with no pathological EEG findings. CONCLUSIONS: The measurement system and data analysis methods we developed have allowed us, for the first time, to obtain an EEG from healthy subjects who are vigorously moving while in a possession trance. The present technique enables us to use a spontaneous EEG as a marker of the underlying physiology of a state of possession trance.