Norihiro Sadato

• MD, PhD
• Professor at Ritsumeikan University

We conducted an fMRI study to investigate the neural basis of bimanual coordination, which is fundamental to upper extremity control. Considering bimanual movement as a combination of bimanual chord formation and sequence control, we hypothesized that the areas with the learning effect of both chord formation and sequence learning are critical in b...

Taste and health are critical factors to be considered when choosing foods. Prioritizing healthiness over tastiness requires self-control. It has also been suggested that self-control is guided by cognitive control. We then hypothesized that neural mechanisms underlying healthy food choice are associated with both self-control and cognitive control...

Hyperscanning functional magnetic resonance imaging (fMRI) was developed to gain deeper insight into the neural basis of social cognition. Simultaneous imaging of brain activity in multiple subjects facilitates analysis of the neural basis of real-time interactions and communication. This method reveals the neural basis of social interactions, incl...

Deciding whether to wait for a future reward is crucial for surviving in an uncertain world. While seeking rewards, agents anticipate a reward in the present environment and constantly face a trade-off between staying in their environment or leaving it. It remains unclear, however, how humans make continuous decisions in such situations. Here, we s...

Effective human communication is a complex process that involves transmitting and sharing information, ideas, and attitudes between two or more individuals. Researchers need to explore both transmission and sharing concepts to understand the neural basis of communication. Face-to-face communication refers to changing someone’s mental state by shari...

Objective. Electroencephalograms (EEGs) are often used to monitor brain activity. Several source localization methods have been proposed to estimate the location of brain activity corresponding to EEG readings. However, only a few studies evaluated source localization accuracy from measured EEG using personalized head models in a millimeter resolut...

Taste and health are critical factors to be considered when choosing foods. Prioritizing healthiness over tastiness requires self-control. It has also been suggested that self-control is guided by cognitive control. We then hypothesized that neural mechanisms underlying healthy food choice are associated with both self-control and cognitive control...

In this study, the roles of shape and color features in metaphor generation for abstract images were investigated through simulations using retrained convolutional neural network (CNN) models based on the pretrained CNN model, AlexNet. A computational experiment was conducted using five types of retrained object recognition models: an object recogn...

Purpose: Hemodynamics is important in the initiation, growth, and rupture of intracranial aneurysms. Since intracranial aneurysms are small, a high-field MR system with high spatial resolution and high SNR is desirable for this hemodynamic analysis. The purpose of this study was to investigate whether the accuracy of MR fluid dynamic (MRFD) results...

Motivation facilitates motor performance; however, the neural substrates of the psychological effects on motor performance remain unclear. We conducted a functional magnetic resonance imaging experiment while human subjects performed a ready-set-go task with monetary incentives. Although subjects were only motivated to respond quickly, increasing t...

Functional MRI (fMRI) has been instrumental to understanding how cognitive processes are spatially mapped in the brain, yielding insights into brain region and function. Here we propose a different approach to fMRI analysis, called Cognitive Dynamics Estimation (CDE), that models how cognitive processes occur over time. Conventional analysis regres...

Functional MRI (fMRI) has been instrumental in understanding how cognitive processes are spatially mapped in the brain, yielding insights about brain regions and functions. However, in case the orthogonality of behavioral or stimulus timing is not guaranteed, the estimated brain maps fail to dissociate each cognitive process, and the resultant maps...

A comparison of neuroanatomical features of the brain between humans and our evolutionary relatives, nonhuman primates, is key to understanding the human brain system and the neural basis of mental and neurological disorders. Although most comparative MRI studies of human and nonhuman primate brains have been based on brains of primates that had be...

Conversation enables the sharing of our subjective experiences through verbalizing introspected thoughts and feelings. The mentalizing network represents introspection, and successful conversation is characterized by alignment through imitation mediated by the mirror neuron system (MNS). Therefore, we hypothesized that the interaction between the m...

Neuroscience research has been expanding, providing new insights into brain and nervous system function and potentially transformative technological applications. In recent years, there has been a flurry of prominent international scientific academies and intergovernmental organizations calling for engagement with different publics on social, ethic...

Grammar acquisition by non-native learners (L2) is typically less successful and may produce fundamentally different grammatical systems than that by native speakers (L1). The neural representation of grammatical processing between L1 and L2 speakers remains controversial. We hypothesized that working memory is the primary source of L1/L2 differenc...

We previously showed that cognitive performance declines when the retrieval process spans an expiratory-to-inspiratory (EI) phase transition (an onset of inspiration). To identify the neural underpinning of this phenomenon, we conducted functional magnetic resonance imaging (fMRI) while participants performed a delayed matching-to-sample (DMTS) rec...

Several neuroimaging studies have analyzed the neural networks involved in thermal sensation. In some of these studies, participants were instructed to evaluate and report the thermal sensation using a point scale, visual analog scale, or other psychophysical rating tool while the imaging data were obtained. Therefore, the imaging data may reflect...

Neuroethics is the study of how neuroscience impacts humans and society. About 15 years have passed since neuroethics was introduced to Japan, yet the field of neuroethics still seeks developed methodologies and an established academic identity. In light of progress in neuroscience and neurotechnology, the challenges for Japanese neuroethics in the...

Functional magnetic resonance imaging (fMRI) is a promising approach for the simultaneous and extensive scanning of whole-brain activities. Optogenetics is free from electrical and magnetic artifacts and is an ideal stimulation method for combined use with fMRI. However, the application of optogenetics in nonhuman primates (NHPs) remains limited. R...

Temporal prediction ability is vital for movement synchronization with external rhythmic stimuli (sensorimotor synchronization); however, little is known regarding individual variations in temporal prediction ability and its neural correlates. We determined the underlying neural correlates of temporal prediction and individual variations during aud...

The dorsal premotor cortex (PMd) plays an essential role in visually guided goal-directed motor behavior. Although there are several planning processes for achieving goal-directed behavior, the separate neural processes are largely unknown. Here, we created a new visuo-goal task to investigate the step-by-step planning processes for visuomotor and...

Our preference for a reward depends on the time of delay for its delivery. Here we show that changes in the external environment can manipulate the perceived duration of time, which alters the formation of the choice preference through value signals in the cortical and subcortical brain regions. Humans anticipated a real liquid reward delayed by te...

During conversation, sarcasm is perceived as an incongruity between the context, content, and prosody of the utterance. We hypothesized that prosody modifies the context‒content incongruity effect. Thus, we conducted a functional magnetic resonance imaging study with an auditory sarcasm detection task in 22 healthy adult participants. The participa...

Despite the multiple regions and neural networks associated with value-based decision-making, the orbitofrontal cortex (OFC) is possible a particularly important one. Although the role of the OFC in reinforcer devaluation tasks, which assess the ability to represent identity, sensory qualities, and subjective values of the expected outcomes, has be...

Time duration, an essential feature of the physical world, is perceived and cognitively interpreted subjectively. While this perception is deeply connected with arousal and interoceptive signals, the underlying neural mechanisms remain elusive. As the insula is critical for integrating information from the external world with the organism's inner s...

Grammar acquisition by non-native learners (L2) is typically less successful and may produce fundamentally different grammatical systems than that by native speakers (L1). The neural representation of grammatical processing between L1 and L2 speakers remains controversial. We hypothesized that working memory is the primary source of L1/L2 differenc...

Grammar acquisition by non-native learners (L2) is typically less successful and may produce fundamentally different grammatical systems than that by native speakers (L1). The neural representation of grammatical processing between L1 and L2 speakers remains controversial. We hypothesized that working memory is the primary source of L1/L2 differenc...

This chapter provides an overview of the role of culture in technological innovation for global mental health. Culture influences basic mechanisms of psychological processes and neurobiological mechanisms of behavior. Technological innovation plays an important role in the discovery and delivery science of global mental health. Technological innova...

Cultural and environmental systems mutually influence the production and regulation of human behavior. Culture maintains and regulates the mental capacities important for the navigation of the social and physical environment. Geographic variation in environmental features are associated with cultural dimensions that serve as a protective factor. Id...

Culture affects the processes of emotion across multilevel mechanisms. Culture influences distinct stages of emotion, from generation and recognition to experience and regulation of emotion. Theoretical approaches posit causal models of how culture influences mental constructs and neurobiological mechanisms of emotion. Methodological approaches in...

Advances in cultural neuroscience demonstrate that culture affects how neural systems maintain and regulate social and emotional information. Understanding how neural representations dynamically interact with environmental and cultural factors provides novel insight into how psychophysiological and neural mechanisms encode culture. Research on psyc...

This handbook is currently in development, with individual articles publishing online in advance of print publication. At this time, we cannot add information about unpublished articles in this handbook, however the table of contents will continue to grow as additional articles pass through the review process and are added to the site. Please note...

Cultural and genomic systems maintain and regulate neural systems and behavior underlying mental health. Cultural and genomic systems affect the functional organization of the nervous system. Cultural processes influence the behavioral and genetic expression of functional neural circuitry. Cultural and genetic systems contribute to the neurodevelop...

Advancements in novel neurotechnologies, such as brain computer interfaces (BCI) and neuromodulatory devices such as deep brain stimulators (DBS), will have profound implications for society and human rights. While these technologies are improving the diagnosis and treatment of mental and neurological diseases, they can also alter individual agency...

Visual self-body recognition is one of the fundamental cognitive functions, and a major contributor to social development. Previous studies have shown that body identity judgement becomes difficult when subjects viewed their hand from a third-person perspective, and that this perspective effect was not observed when viewing the hand of another pers...

The human brain continuously generates predictions of incoming sensory input and calculates corresponding prediction errors from the perceived inputs to update internal predictions. In human primary somatosensory cortex (area 3b), different cortical layers are involved in receiving the sensory input and generation of error signals. It remains unkno...

Multivoxel pattern analysis (MVPA) has become a standard tool for decoding mental states from brain activity patterns. Recent studies have demonstrated that MVPA can be applied to decode activity patterns of a certain region from those of the other regions. By applying a similar region-to-region decoding technique, we examined whether the informati...

Foraging is a fundamental food-seeking behavior in a wide range of species that enables survival in an uncertain world. During foraging, behavioral agents constantly face a trade-off between staying in their current location or exploring another. Despite ethological generality and importance of foraging, it remains unclear how the human brain guide...

Susceptibility to motion sickness varies greatly across individuals. However, the neural mechanisms underlying this susceptibility remain largely unclear. To address this gap, the current study aimed to identify the neural correlates of motion sickness susceptibility using multimodal MRI. First, we compared resting‐state functional connectivity bet...

Many older adults have difficulty seeing brief visual stimuli which younger adults can easily recognize. The primary visual cortex (V1) may induce this difficulty. However, in neuroimaging studies, the V1 response change to the increase of temporal frequency of visual stimulus in older adults was unclear. Here we investigated the association betwee...

Sensory conflicts leading to motion sickness can occur not only between but also within sensory modalities. The vestibular organs are located in both left and right inner ears, and their misalignment can be a source of self-motion related sensory conflicts. In the current study, using inner ear magnetic resonance imaging, we examined whether morpho...

Social interaction is thought to provide a selection pressure for human intelligence, yet little is known about its neurobiological basis and evolution throughout the primate lineage. Recent advances in neuroimaging have enabled whole brain investigation of brain structure, function, and connectivity in humans and non-human primates (NHPs), leading...

The primary motor cortex (M1) is crucial for motor learning; however, its interaction with other brain areas during motor learning remains unclear. We hypothesized that the fronto-parietal execution network (FPN) provides learning-related information critical for the flexible cognitive control that is required for practice. We assessed network-leve...

Sharing experience is a fundamental human social cognition. Since visual experience is a mental state directed toward the world, we hypothesized that sharing visual experience is mediated by joint attention for sharing directedness and mentalizing for mental state inferences. We conducted a hyperscanning fMRI with 44 healthy adult volunteers to tes...

The extrastriate body area (EBA) in the lateral occipito-temporal cortex has an important role in reciprocal interaction, as it detects congruence between self and other’s hand actions. However, it is unclear whether the EBA can detect congruence regardless of the type of action. In the present study, we examined the neural substrate underlying con...

The primary motor cortex (M1) is crucial in motor learning. Whether the M1 encodes the motor engram for sequential finger tapping formed by an emphasis on speed is still inconclusive. The active states of engrams are hard to discriminate from the motor execution per se. As preparatory activity reflects the upcoming movement parameters, we hypothesi...

Professional boxers train to reduce their body mass before a match to refine their body movements. To test the hypothesis that the well-defined movements of boxers are represented within the motor loop (cortico-striatal circuit), we first elucidated the brain structure and functional connectivity specific to boxers and then investigated plasticity...

Japanese English learners have difficulty speaking Double Object (DO; give B A) than Prepositional Object (PO; give A to B) structures which neural underpinning is unknown. In speaking, syntactic and phonological processing follow semantic encoding, conversion of non-verbal mental representation into a structure suitable for expression. To test whe...

Unlike the assumption of modern linguistics, there is non-arbitrary association between sound and meaning in sound symbolic words. Neuroimaging studies have suggested the unique contribution of the superior temporal sulcus to the processing of sound symbolism. However, because these findings are limited to the mapping between sound symbolism and vi...

Humans and now computers can derive subjective valuations from sensory events although such transformation process is largely a black box. In this study, we elucidate unknown neural mechanisms by comparing representations of humans and convolutional neural networks (CNNs). We optimized CNNs to predict aesthetic valuations of paintings and examined...

Psychiatric and neurological disorders are afflictions of the brain that can affect individuals throughout their lifespan. Many brain magnetic resonance imaging (MRI) studies have been conducted; however, imaging-based biomarkers are not yet well established for diagnostic and therapeutic use. This article describes an outline of the planned study,...

Face-to-face imitation is a unique social interaction wherein a shared action is executed based on the feedback of the partner. Imitation by the partner is the feedback to the imitatee's action, resulting in sharing actions. The neural mechanisms of the shared representation of action during face-to-face imitation, the core of inter-subjectivity, a...

The primary motor cortex (M1) is crucial for motor learning. However, the interaction of the M1 with other brain areas during motor learning remains unclear. We hypothesized that the fronto-parietal execution network (FPN) provides the learning-related information that is crucial for flexible cognitive control required for practice. We assessed the...

Background: Although 7T functional MRI (fMRI) provides better signal-to-noise ratio and higher spatial resolution than 3T fMRI, geometric distortions become more challenging because fMRI is more susceptible to distortions than structural MRI. Accurate alignment of 7T fMRI to structural MRI data is critical for precise cortical surface-based analys...

Praise enhances motor performance; however, the underlying feedback pathway is unknown. Here, we hypothesized that the social evaluation feedback to the motor system is modified by the top-down effect of the social contingency valuation system, such as the anterior rostral medial prefrontal cortex (arMPFC). We developed a pseudo-interactive task th...

Emotion perception from facial and vocal expressions is a multisensory process critical for human social interaction. When asked to judge emotions by attending to either face or voice, the accuracy was higher when facial expressions are congruent with vocal expressions than when they are incongruent. This congruency effect was shown to be affected...

How coherent neural oscillations are involved in task execution is a fundamental question in neuroscience. Although several electrophysiological studies have tackled this issue, the brain-wide task modulation of neural coherence remains uncharacterized. Here, with a fast fMRI technique, we studied shifts of brain-wide neural coherence across differ...

Introduction The sleep onset period, involving so-called stage N1 sleep largely, is characterized by a reduction in the amount of alpha activity compared to wakefulness. Various kinds of physiological and psychological changes are also apparent, such as slow eye movements, changes in muscle tonus, and the hypnagogic dream-like mentation. These phen...

Psychiatric and neurological disorders are afflictions of the brain that can affect individuals throughout their lifespan. Many brain magnetic resonance imaging (MRI) studies have been conducted; however, imaging-based diagnostic and therapeutic biomarkers are not yet well established. The Brain/MINDS Beyond human brain MRI project (FY2018 ~ FY2023...

Affective communication, communicating with emotion, during face-to-face communication is critical for social interaction. Advances in artificial intelligence have made it essential to develop affective human–virtual agent communication. A person’s belief during human–virtual agent interaction that the agent is a computer program affects social-cog...

The social motivation hypothesis posits that people with autism spectrum disorder (ASD) find social stimuli less rewarding and are therefore less motivated towards social interaction than people with neuro-typical development (TD). However, the less rewarding social stimuli characteristics during social interaction for people with ASD are largely u...

Understanding others as intentional agents is critical in social interactions. We perceive others' intentions through identification, a categorical judgment that others should work like oneself. The most primitive form of understanding others' intentions is joint attention (JA). During JA, an initiator selects a shared object through gaze (initiati...

To date, a neuroscientific investigation of drivers’ steering behavior has never been performed because the reaction forces generated by the mechanical characteristics of a steering wheel have been difficult to assess in a magnetic resonance imaging (MRI) environment. In this study, using our previously developed MRI-compatible unit for steering re...

Cultural factors, such as cultural group membership, have been shown to affect neural bases of face and emotion perception. However, little is known about how cultural factors influence neural processing of emotional faces expressed by in-group and out-group members. In this study, we examined cultural influences on neural activation during the int...

Humans reliably categorize configurations of facial actions into specific emotion categories, leading some to argue that this process is invariant between individuals and cultures. However, growing behavioral evidence suggests that factors such as emotion-concept knowledge may shape the way emotions are visually perceived, leading to variability—ra...

The posterior insula (pIns) is a major brain region that receives itch-related signals from the periphery and transfers these signals to broad areas in the brain. Previous brain imaging studies have successfully identified brain regions that respond to itch stimuli. However, it is still unknown which brain regions receive and process itch-related s...

Many species use touching for reinforcing social structures, and particularly, non-human primates use social grooming for managing their social networks. However, it is still unclear how social touch contributes to the maintenance and reinforcement of human social networks. Human studies in Western cultures suggest that the body locations where tou...

Humans are adept at perceiving physical properties of an object through touch. Tangible object properties can be categorized into two types: macro-spatial properties, including shape and orientation; and material properties, such as roughness, softness, and temperature. Previous neuroimaging studies have shown that roughness and temperature are ext...

Neural substrates of motor engrams in the human brain are hard to identify because their dormant states are difficult to discriminate. We utilized eigenvector centrality (EC) to measure the network information that accumulates as an engram during learning. To discriminate engrams formed by emphasis on speed or accuracy, we conducted functional MRI...

Automatic mimicry is a critical element of social interaction. A salient type of automatic mimicry is eye contact characterized by sharing of affective and mental states among individuals. We conducted a hyperscanning functional magnetic resonance imaging study involving on-line (LIVE) and delayed off-line (REPLAY) conditions to test our hypothesis...

The Brain/MINDS project aims to further understand the human brain and neuropsychiatric disorders through “translatable” biomarkers. Here, we describe the neuroethical issues of the project that have arisen from clinical data collection and the use of biological models of neuropsychiatric disorders.

During joint action, two or more persons depend on each other to accomplish a goal. This mutual recursion, or circular dependency, is one of the characteristics of cooperation. To evaluate the neural substrates of cooperation, we conducted a hyperscanning functional MRI study in which 19 dyads performed a joint force-production task. The goal of th...

The conscious perception of thermal stimuli is divided into two categories: thermal sensation (i.e., discriminative component) and pleasantness/unpleasantness (i.e., hedonic component). There have been very few studies which clearly dissociated the two components. The aim of the present study was 1) to identify brain regions involved in perception...

Good reputation enhances positive self-image, which motivates prosocial behavior, a phenomenon known as indirect reciprocity. Thus, good reputation should promote prosocial behavior toward estranged people to whom affective responses leading to direct reciprocity are suppressed. We predicted that such behaviors involve an interrelationship between...

Background: Patients with social anxiety disorder (SAD) have heightened self-reflection. In the self-focused cognition, they ruminate negative self-image or evaluation both by themselves and others. It leads to self-conscious emotions, such as embarrassment. Previous functional magnetic resonance imaging (fMRI) studies with healthy subjects reveale...

Humans are adept at perceiving textures through touch. Previous neuroimaging studies have identified a distributed network of brain regions involved in the tactile perception of texture. However, it remains unclear how nodes in this network contribute to the tactile awareness of texture. To examine the hypothesis that such awareness involves the in...

Detecting relationships between our own actions and the subsequent actions of others is critical for our social behavior. Self-actions differ from those of others in terms of action kinematics, body identity, and feedback timing. Thus, the detection of social contingency between self-actions and those of others requires comparison and integration o...

The present study attempted to reconstruct 3D brain shape of Neanderthals and early Homo sapiens based on computational neuroanatomy. We found that early Homo sapiens had relatively larger cerebellar hemispheres but a smaller occipital region in the cerebrum than Neanderthals long before the time that Neanderthals disappeared. Further, using behavi...

Background Individuals with autism spectrum disorder (ASD) appear to have a unique awareness of their own body, which may be associated with difficulties of gestural interaction. In typically developing (TD) individuals, the perception of body parts is processed in various brain regions. For instance, activation of the lateral occipito-temporal cor...

State self-esteem, the momentary feeling of self-worth, functions as a sociometer involved in maintenance of interpersonal relations. How others' appraisal is subjectively interpreted to change state self-esteem is unknown, and the neural underpinnings of this process remain to be elucidated. We hypothesized that changes in state self-esteem are re...

Despite the ubiquity and importance of speeding offenses, there has been little neuroscience research regarding the propensity for speeding among vehicle drivers. In the current study, as a first attempt, we examined the hypothesis that visual inputs during high-speed driving would activate the mesolimbic dopaminergic system that plays an important...