Biology subjects

Yamawaki, S.

Publications and source records attributed to Yamawaki, S..

9 recordsLinked to original sources

bioRxiv2023

Body Maps of Uncertainty and Surprise in Musical Chord Progression and its individual differences in Depression and Body Perception Sensitivity

Music has profoundly shaped the human experience across diverse cultures and generations, yet the mechanisms that it influences our minds and bodies remain elusive. This study examined how the perception of music chords elicits bodily sensations and emotions through predictive processing of the brain. By deploying body-mapping tests and emotional evaluations on 527 participants exposed to chord progressions, we unveil the intricate interplay between musical uncertainty, prediction error, and temporal dynamics in eliciting specific bodily sensations and emotions. Our results demonstrated that the chord progressions characterized by low uncertainty coupled with high surprise or predictability evoke bodily sensations closely associated with interoception including the cardiac and abdominal regions. Notably, these sensations are associated with aesthetic appreciation, with the intensity of cardiac sensations being positively correlated with valence in chord progressions with low uncertainty and high surprise. These results highlight the pivotal role of uncertainty and prediction error in shaping emotional responses and also suggest a hypothesis for emotion generation through predictive processing and sound embodiment. This study offers a tantalizing glimpse into the potential nexus between interoception by music and mental well-being, underscoring the importance of recognizing diverse forms of musical pleasure and their unique effects on our minds and bodies.

neuroscience↗

bioRxiv2023

The anterior cingulate cortex is involved in intero-exteroceptive integration for spatial image transformation of the self-body.

Spatial image transformation of the self-body is a fundamental function of visual perspective-taking. Recent research underscores the significance of integration of intero-exteroceptive information to construct representations of our embodied self. This raises the intriguing hypothesis that interoceptive processing might be involved in the spatial image transformation of our self-body. To test this hypothesis, the present study used functional magnetic resonance imaging to measure brain activity during an arm laterality judgment (ALJ) task. In this task, participants were tasked with discerning whether the outstretched arm of a human figure, viewed from the front or back, was the right or left hand. The reaction times for the ALJ task proved longer when the stimulus presented orientations of 0{degrees}, 90{degrees}, and 270{degrees} relative to the upright orientation, and when the front view presented as compared to the back view. Corresponding to the increased reaction time, increased brain activity was manifested in a cluster centered on the dorsal anterior cingulate cortex (ACC). Furthermore, this cluster of brain activity exhibited overlap with regions where the difference in activation between the front and back views positively correlated with the participants interoceptive sensitivity, as assessed through the heartbeat detection task, within the pregenual ACC. These results suggest that the ACC plays an important role in integrating intero-exteroceptive cues for the purpose of spatially transforming the image of our self-body.

neuroscience↗

bioRxiv2023

Body Maps of Sound Pitch and its individual differences in Alexithymia and Depression

Sound perception extends beyond the boundaries of auditory sensation, encompassing a profound engagement with the entire human body. This intricate interplay between sound and body sensation has long captivated the interest of researchers. In this study, we examined the relationship between our perception of sound pitch and our bodily position senses, while also exploring the role of emotions in shaping this intriguing cross-modal correspondence. We also compare the topography of pitch-triggered body sensations between depressive, alexithymia, and the control groups, and examine their associations with anxiety. Our findings reveal that individuals with depression and alexithymia experience diffuse and less localized body sensations in response to sound pitch, accompanied by heightened feelings of anxiety and negative emotions. These findings imply that diffuse bodily sensations in response to sound may trigger negative emotions such as anxiety and indicate that monitoring pitch-triggered body sensations could serve as a valuable biomarker for emotional disorders. Our study sheds light on the profound importance of body sense awareness in response to sounds, a phenomenon that may be mediated by interoception. This research enhances our understanding of the intricate relationship between sound, emotions, and the human body, offering insights for potential interventions in emotional disorders.

physiology↗

bioRxiv2023

Rapamycin-sensitive mechanisms confine the growth of fission yeast below the temperatures detrimental to cell physiology

Cells cease to proliferate above their growth-permissible temperatures, a ubiquitous phenomenon generally attributed to protein denaturing and heat damage to other cellular macromolecules. We here report that, in the presence of the macrolide compound rapamycin, the fission yeast Schizosaccharomyces pombe can proliferate at high temperatures that normally arrest its growth. Rapamycin is a potent inhibitor of the protein kinase complex TOR Complex 1 (TORC1), and consistently, mutations to the TORC1 subunit RAPTOR/Mip1 and the TORC1 substrate Sck1 significantly improve cellular heat resistance. These results suggest that TORC1, a well-established growth promoter, restricts the high-temperature growth of fission yeast and that compromised TORC1 signaling allows cell proliferation at higher temperatures. Aiming for a more comprehensive understanding of the negative regulation of high-temperature growth, we conducted genome-wide screens in S. pombe, which identified Sck1 and additional factors that appear to suppress cell proliferation at high temperatures. Our study has uncovered unexpected mechanisms of growth restraint even below the temperatures deleterious to cell physiology. Thus, growth arrest at high temperatures may not directly result from heat damage to cellular components essential for proliferation and viability. Significance StatementThe immunosuppressant rapamycin is a specific inhibitor of the protein kinase Target Of Rapamycin (TOR), and the drug is known to extend the lifespan of diverse eukaryotic organisms. In this study, we have found that rapamycin confers heat resistance on fission yeast, allowing its proliferation above the normal permissive temperatures. This unexpected observation suggests that TOR, which is known as a growth-promoting kinase, is inhibitory to cell proliferation at high temperatures. Our genome-wide screens have identified additional genes whose deletion leads to improved growth under heat stress. Thus, cells may have mechanisms that restrict proliferation even below the temperatures deleterious to their physiology.

cell biology↗

bioRxiv2021

Interoceptive sensitivity modulates heart rate and insula activity when listening to music

Interoception plays an important role in emotion processing, but the relationship between the physiological responses associated with emotional experience and interoception is unclear. In this study, we measured interoceptive sensitivity using the heartbeat discrimination task and investigated the effects of individual differences in interoceptive sensitivity on changes in heart rate and insula activity in response to music-induced emotions. We found that the heart rate increased when listening to the music pieces rated as emotionally high-touching in the high interoceptive sensitivity group only. Compared to the emotionally low-touching music, listening to the emotionally high-touching music was associated with higher insula activity. Furthermore, relative to individuals with low interoceptive sensitivity, the region of interest analysis of the insula subregions for individuals with high interoceptive sensitivity revealed significant activity in the bilateral dorsal granular insula, the right ventral dysgranular insula, and the right granular and dorsal dysgranular insula while listening to the high-touching music pieces. Our results suggest that individuals with high interoceptive sensitivity use their physical condition to assess their emotional level when listening to music. Furthermore, the insula activity may reflect the use of interoception to estimate emotions.

neuroscience↗

bioRxiv2021

Modulation of certainty and valence in cardiac autonomic regulation mediated by high depressive risk

Recent studies have highlighted the essential role of interoception in healthy emotional processing and the pathology of major depressive disorder. However, it is unclear how individual differences in healthy people with high depression risk (HDR; i.e., individual differences in depression risk) are related to the neurophysiological underpinnings of interoception and emotional reactions under different degrees of certainty. We examined whether an individuals depression risk mediates the relationships of heartbeat-evoked potentials (HEPs), a neurophysiological marker of cardiac interoception, with heart rate (HR) and heart rate variability (HRV), indices for cardiac reactivity. In a concurrent electroencephalogram-electrocardiogram (EEG-ECG) experiment, 26 healthy participants completed an emotion-evoking picture-evaluation task. Each trial began with a differential auditory cue that was associated with the certainty of subsequently seeing a pleasant or unpleasant picture. The results showed the following: after participants saw a cue of uncertainty, HDR was associated with 1) reduced neural activity when anticipating upcoming pictures and 2) enhanced physiological reactions to unexpected, unpleasant pictures. These results suggest that weaker predictions and augmented prediction errors for negative emotional stimuli reflect depression risk. Moreover, depression risk significantly mediated the relationships between HEPs and HR and between HEPs and HRV for unexpected, unpleasant stimuli. This study provides evidence that interoception and autonomic cardiac regulation may be altered by depression risk. This highlights the insights provided by specific indices of brain-heart interactions, such as HEPs, into the underlying activity of the autonomic nervous system and unique interoceptive disturbances associated with depression risk.

neuroscience↗

bioRxiv2021

Neural basis for anxiety and anxiety-related physiological responses during simulated driving: An fMRI study

While the exteroceptive and interoceptive prediction of a negative event increases a persons anxiety in daily life situations, the relationship between the brain mechanism of anxiety and the anxiety-related autonomic response has not been fully understood. In this fMRI study, we examined the neural basis of anxiety and anxiety-related autonomic responses in a daily driving situation. Participants viewed a driving video clip in the first-person perspective. During the video clip, participants were presented with a cue to indicate whether a subsequent crash could occur (attention condition) or not (safe condition). Enhanced activities in the anterior insula, bed nucleus of the stria terminalis, thalamus, and periaqueductal gray, and higher sympathetic nerve responses (pupil dilation and peripheral arterial stiffness) were triggered by the attention condition but not with the safe condition. Autonomic response-related functional connectivity was detected in the visual cortex, cerebellum, brainstem, and MCC/PCC with the right anterior insula and its adjacent regions as seed regions. Thus, the right anterior insula and adjacent regions, in collaboration with other regions play a role in eliciting anxiety based on the prediction of negative events, by mediating anxiety-related autonomic responses according to interoceptive information.

neuroscience↗

bioRxiv2021

Resting-state brain activity can predict target-independent aptitude in fMRI-neurofeedback training

Neurofeedback (NF) aptitude, which refers to an individuals ability to change its brain activity through NF training, has been reported to vary significantly from person to person. The prediction of individual NF aptitudes is critical in clinical NF applications. In the present study, we extracted the resting-state functional brain connectivity (FC) markers of NF aptitude independent of NF-targeting brain regions. We combined the data in fMRI-NF studies targeting four different brain regions at two independent sites (obtained from 59 healthy adults and six patients with major depressive disorder) to collect the resting-state fMRI data associated with aptitude scores in subsequent fMRI-NF training. We then trained the regression models to predict the individual NF aptitude scores from the resting-state fMRI data using a discovery dataset from one site and identified six resting-state FCs that predicted NF aptitude. Next we validated the prediction model using independent test data from another site. The result showed that the posterior cingulate cortex was the functional hub among the brain regions and formed predictive resting-state FCs, suggesting NF aptitude may be involved in the attentional mode-orientation modulation systems characteristics in task-free resting-state brain activity.

neuroscience↗

bioRxiv2019

Quantification of anticipation of excitement with three-axial model of emotion with EEG

ObjectivesMultiple facets of human emotions underlie diverse and sparse neural mechanisms. Amongst many models of emotions, the circumplex model of emotion is one of a significant theory. The use of the circumplex model allows us to model variable aspects of emotion; however, such momentary expression of ones internal mental state still lacks to consider another, the third dimension of time. Here, we report an exploratory attempt to build a three-axial model of human emotion to model our sense of anticipatory excitement, "Waku-Waku (in Japanese)," when people are predictively coding upcoming emotional events. ApproachElectroencephalography (EEG) was recorded from 28 young adult participants while they mentalized upcoming emotional pictures. Three auditory tones were used as indicative cues, predicting the likelihood of valence of an upcoming picture, either positive, negative, or unknown. While seeing an image, participants judged its emotional valence during the task, and subsequently rated their subjective experiences on valence, arousal, expectation, and Waku-Waku immediately after the experiment. The collected EEG data were then analyzed to identify contributory neural signatures for each of the three axes. Main ResultsA three axial model was built to quantify Waku-Waku. As was expected, this model revealed considerable contribution of the third dimension over the classical two-dimension model. Distinctive EEG components were identified. Furthermore, a novel brain-emotion interface is proposed and validated within the scope of limitations. SignificanceThe proposed notion may shed new light on the theories of emotion and supports multiplex dimensions of emotion. With an introduction of the cognitive domain for a brain-computer-interface, we propose a novel brain-emotion-interface. Limitations and potential applications are discussed.

neuroscience↗