Yasuyo Minagawa

• Doctor of Philosophy
• Professor (Full) at Keio University

Pre-babbling infants can track nonadjacent dependencies (NADs) in the auditory domain. While this forms a crucial prerequisite for language acquisition, the neurodevelopmental origins of this ability remain unknown. We applied functional near-infrared spectroscopy in neonates and 6- to 7-month-old infants to investigate the neural substrate support...

Although the development of prosocial behavior has been widely studied from the behavioral aspect, the neural mechanisms underlying prosocial behavior in the early stages of development remain unclear. Therefore, this study investigated the neural mechanisms underlying the emergence of prosocial behavior in 3-year-old children. Brain activity in th...

Pre-babbling infants can track nonadjacent dependencies (NADs) in the auditory domain. While this forms a crucial prerequisite for language acquisition, the neurodevelopmental origins of this ability remain unknown. We applied functional nearinfrared spectroscopy in neonates and 6-7-month-old infants to investigate the neural substrate supporting N...

Maternal bonding for mammalian infants is critical for their survival. Additionally, it is important for human infants’ development into social creatures. However, despite the ample neurobiological evidence of attachment for the mother’s brain, the interplay of this system in infants is poorly understood. We aimed to identify the neural substrates...

Functional Near-Infrared Spectroscopy (fNIRS) is a non-invasive optical technique that measures cerebral hemodynamics across multiple regions of interest, and thereby characterises brain functional activation. Since its first description in 1993, fNIRS has undergone substantial developments in hardware, analysis techniques, and applications. Thirty...

Significance: Functional near-infrared spectroscopy (fNIRS) is a frequently used neuroimaging tool to explore the developing brain, particularly in infancy, with studies spanning from birth to toddlerhood (0 to 2 years). We provide an overview of the challenges and opportunities that the developmental fNIRS field faces, after almost 25 years of re...

Significance: In hyperscanning studies of natural social interactions, behavioral coding is usually necessary to extract brain synchronizations specific to a particular behavior. The more natural the task is, the heavier the coding effort is. We propose an analytical approach to resolve this dilemma, providing insights and avenues for future work...

This study developed a telehealth parent-training program to teach parents of children with autism spectrum disorder the process of mand-training implementation in Japan, and to further the international dissemination of evidence-based training strategies. Parent-training sessions were based on a behavioral skills training (BST) model, combined wit...

The simultaneous recording of brain activity in two or more people, termed hyperscanning, is an emerging field of research investigating the neural basis of social interaction. Hyperscanning studies of adult–infant dyads (e.g., parent and infant) have great potential to provide insights into how social functions develop. In particular, taking advan...

The present study examined cerebral hemodynamic responses and functional connectivity during joint attention either initiated by infants (Initiating Joint Attention, IJA condition) or by their partner (Responding to Joint Attention, RJA condition). To capture responses to natural social cues in infants aged 7–12 months using functional near-infrare...

Brain complexity analysis using functional near-infrared spectroscopy (fNIRS) has attracted attention as a biomarker for evaluating brain development and degeneration processes. However, most methods have focused on the temporal scale without capturing the spatial complexity. In this study, we propose a spatial time-delay entropy (STDE) method as t...

Background Among preterm infants, higher morbidities of neurological disturbances and developmental delays are critical issues. Resting-state networks (RSNs) in the brain are suitable measures for assessing higher-level neurocognition. Since investigating task-related brain activity is difficult in neonates, assessment of RSNs provides invaluable i...

This study aims to quantify the effect of several information sources: acoustic, higher-level linguistic, and knowledge of the prosodic system of the language, on the perception of prosodic boundaries. An experiment with native and non-native participants investigating the identification of prosodic boundaries in Japanese was conducted. It revealed...

Research has discovered the modulatory effect of peripheral stimulation simulating altered bodily signals on emotion. Whether such an effect varies depending on one’s interoceptive accuracy (IAc) remains unclear. Therefore, we provided haptic stimulation simulating participants’ slowed-down heartbeats or no stimulation while they engaged in sociall...

Significance: The establishment of a light propagation analysis-based scalp-cortex correlation (SCC) between the scalp location of the source-detector (SD) pair and brain regions is essential for measuring functional brain development in the first 2 years of life using functional near-infrared spectroscopy (fNIRS). Aim: We aimed to reveal the optic...

The biological and neurological processes during the lifespan are dynamic with significant alterations associated with different stages of life. The phase and coupling of oxy-hemoglobin (Δ[HbO]) and deoxy-hemoglobin concentration changes (Δ[Hb]) measured by functional near-infrared spectroscopy (fNIRS) are shown to characterize the neurovascular an...

Individuals with autism spectrum disorders (ASD) are impaired not only in social competencies but also in sensory perception, particularly olfaction. The olfactory ability of individuals with ASD has been examined in several psychophysical studies, but the results have been highly variable, which might be primarily due to methodological difficultie...

We demonstrate capture of event-related potentials (ERPs) using candle-like dry microneedle electrodes (CMEs). CMEs can record an electroencephalogram (EEG) even from hairy areas without any skin preparation, unlike conventional wet electrodes. In our previous research, we experimentally verified that CMEs can measure the spontaneous potential of E...

(200 words) Live social interaction is the dominant form of human social activity, but it remains unclear if brain processing of live interactive social stimuli differs substantially from processing of non-interactive social stimuli, mainly because of technical difficulties measuring brain activity during natural social interactions. This distincti...

Language development and the capacity for communication in infants are predominantly supported by their mothers, beginning when infants are still in utero. Although a mother's speech should thus have a significant impact on her neonate's brain, neurocognitive evidence for this hypothesis remains elusive. The present study examined 37 neonates using...

Despite motion artifacts are a major source of noise in fNIRS infant data, how to approach motion correction in this population has only recently started to be investigated. Homer2 offers a wide range of motion correction methods and previous work on simulated and adult data suggested the use of Spline interpolation and Wavelet filtering as optimal...

Despite motion artifacts are a major source of noise in fNIRS infant data, how to approach motion correction in this population has only recently started to be investigated. Homer2 offers a wide range of motion correction methods and previous work on simulated and adult data suggested the use of Spline interpolation and Wavelet filtering as optimal...

Biofeedback, which is a technique for controlling human physiological indices by detecting outputs such as heartbeats and brain waves and re-outputting them through a feedback device, has attracted attention. This technique has been applied to the treatment of diseases and maintenance of health. We developed an application that transfers heartbeats...

This paper describes evaluation of we-mode by simultaneous electroencephalography (EEG) measurement between two subjects using candle-like dry microneedle electrodes. In this work, using the interior designing game, we investigated the temporal changes of power spectral density (PSD) of theta wave (4-8 Hz) and that of alpha wave. As a result, we di...

Objective. Assessing an infant’s brain development remains a challenge for neuroscientists and pediatricians despite great technological advances. As a non-invasive neuroimaging tool, functional near-infrared spectroscopy (fNIRS) has great advantages in monitoring an infant’s brain activity. To explore the dynamic features of hemodynamic changes in...

Human social activity is a continuous dynamic behavior consisting of live social signal exchanges; thus, studying interactions among multiple humans is critical to understanding social cognition. Indeed, social neuroscience focusing on such aspects—interactive social neuroscience—is an emerging field of interest. Functional near‐infrared spectrosco...

This paper reports successful measurement of even-related potential (ERP) using candle-like dry microneedle electrodes, which can acquire high-quality electroencephalogram (EEG) from hairy parts without any pretreatment. In our previous work, we successfully measured spontaneous EEG activity and its application to assess the stress state of the sub...

Higher brain dysfunction, such as language delay, is a major concern among preterm infants. Cerebral substrates of cognitive development in preterm infants remain elusive, partly because of limited methods. The present study focuses on hemodynamic response patterns for brain function by using near-infrared spectroscopy. Specifically, the study inve...

This paper reports evaluation of lateralization of vowel and prosody processing in the auditory areas using candle-like dry microneedle electrodes, which can acquire high-quality electroencephalogram (EEG) from hairy parts without any pretreatment. In our previous work, we successfully measured spontaneous potential and even-related potential (ERP)...

This paper reports successful measurement of event-related potential (ERP) using candle-like dry microneedle electrodes, which can measure high-quality electroencephalogram (EEG) from hairy parts without the conventional skin preparation. In our previous work, we proved that the electrode could measure EEG from hairy part as the conventional wet el...

While the influence of the mother's voice on neonatal heart-rate response and its relevant activity on cerebral cortex and the autonomic nervous system (ANS) are well known, few studies have assessed its influence on respiratory activity. We investigated the relationship among the respiration rate, the delta wave amplitudes through electroencephalo...

This study aims to quantify the relative contributions of phonetic categories and acoustic detail on phonotactically induced perceptual vowel epenthesis in Japanese listeners. A vowel identification task tested whether a vowel was perceived within illegal consonant clusters and, if so, which vowel was heard. Cross-spliced stimuli were used in which...

Segmenting word units from running speech is a fundamental skill infants must develop in order to acquire language. Despite ample behavioral evidence of this skill, its neurocognitive basis remains unclear. Using behavioral testing and functional near-infrared spectroscopy, we aimed to uncover the neurocognitive substrates of word segmentation and...

Numerous neurocognitive studies have used functional near-infrared spectroscopy (fNIRS) due to its advantages, such as portability and tolerance to participantsʼ motion-related artifacts. The present paper focuses on developmental cognitive neuroscience addressing typical and atypical brain development involving Autism spectrum disorders (ASD) base...

In natural settings, infants learn spoken language with the aid of a caregiver who explicitly provides social signals. Although previous studies have demonstrated that young infants are sensitive to these signals that facilitate language development, the impact of real-life interactions on early word segmentation and word–object mapping remains elu...

A central assumption in the perceptual attunement literature holds that exposure to a speech sound contrast leads to improvement in native speech sound processing. However, whether the amount of exposure matters for this process has not been put to a direct test. We elucidated indicators of frequency-dependent perceptual attunement by comparing 5-8...

The present study used functional near-infrared spectroscopy (fNIRS) to measure 5- to 6-month-old infants’ hemodynamic response in the prefrontal cortex (PFC) to visual stimuli differing in saliency and social value. Nineteen Japanese 5- to 6-month-old infants watched video clips of Peek-a-Boo (social signal) performed by an anime character (AC) or...

This paper describes a utility of dry micro-needle electrodes in measurement of electroencephalogram (EEG). Usual wet electrodes need abrasion of stratum corneum and pasting of electrolyte paste as preparation of measurement. Therefore, it would be unpleasant for subjects and time-consuming for experimenters. Thereupon, we developed dry micro-needl...

Despite improved survival rates of infants, higher brain dysfunction in surviving infants remains a considerable problem. Most infants with higher brain dysfunctions are born preterm. Magnetic resonance imaging (MRI) is a useful tool to detect structural brain damage and provides important information to evaluate the neurologic sequelae of such pre...

Atypical gaze behavior in response to a face has been well documented in individuals with autism spectrum disorders (ASDs). Children with ASD appear to differ from typically developing (TD) children in gaze behavior for spoken and dynamic face stimuli but not for nonspeaking, static face stimuli. Furthermore, children with ASD and TD children show...

The traveling salesperson problem (TSP) refers to a task in which one finds the shortest path when traveling through multiple spatially distributed points. Little is known about the developmental course of the strategies used to solve TSPs. The present study examined young children's performance and route selection strategies in one-way TSPs using...

In the adult brain, speech can recruit a brain network that is overlapping with, but not identical to, that involved in perceiving non-linguistic vocalizations. Using the same stimuli that had been presented to human 4-month-olds and adults, as well as adult macaques, we sought to shed light on the cortical networks engaged when human newborns proc...

To reveal the relation between intellectual disability and the deleted intervals in Williams syndrome, we performed an array comparative genomic hybridization analysis and standardized developmental testing for 11 patients diagnosed as having Williams syndrome based on fluorescent in situ hybridization testing. One patient had a large 4.2-Mb deleti...

The present study investigated the neural correlates of infant discrimination of very similar linguistic varieties (Quebecois and Parisian French) using functional Near InfraRed Spectroscopy. In line with previous behavioral and electrophysiological data, there was no evidence that 3-month-olds discriminated the two regional accents, whereas 5-mont...

Each language has a unique set of phonemic categories and phonotactic rules which determine permissible sound sequences in that language. Behavioral research demonstrates that one's native language shapes the perception of both sound categories and sound sequences in adults, and neuroimaging results further indicate that the processing of native ph...

Until recently, imaging the infant brain was very challenging. Functional Near InfraRed Spectroscopy (fNIRS) is a promising, relatively novel technique, whose use is rapidly expanding. As an emergent field, it is particularly important to share methodological knowledge to ensure replicable and robust results. In this paper, we present a community-a...

Near-infrared spectroscopy (NIRS) is a noninvasive neuroimaging tool that can measure local hemodynamic changes in the brain. Over the past decade, the technical advantage offered by multichannel NIRS has provided various new findings on higher cerebral function of the human brain. These findings have improved our knowledge of cognitive neuroscienc...

Background: A growing body of evidence suggests that meditative training enhances perception and cognition. In Japan, the Park-Sasaki method of speed-reading involves organized visual training while forming both a relaxed and concentrated state of mind, as in meditation. The present study examined relationships between reading speed, sentence comp...

This study focuses on the early cerebral base of speech perception by examining functional lateralization in neonates for processing segmental and suprasegmental features of speech. For this purpose, auditory evoked responses of full-term neonates to phonemic and prosodic contrasts were measured in their temporal area and part of the frontal and pa...

Background: A growing body of evidence suggests that meditative training enhances perception and cognition. In Japan, the Park-Sasaki method of speed-reading involves organized visual training while forming both a relaxed and concentrated state of mind, as in meditation. The present study examined relationships between reading speed, sentence compr...

A number of behavioral studies suggest that infant-directed speech (IDS) plays a more important role in facilitating both: a) speech perception, and b) adult-infant social interactions than does adult-directed speech (ADS), and hence that IDS contributes to subsequent social and language development. However neural substrates that may underlie thes...

During the past ten years, research using Near-infrared Spectroscopy (NIRS) to study the developing brain has provided groundbreaking evidence of brain functions in infants. This paper presents a theoretically oriented review of this wealth of evidence, summarizing recent NIRS data on language processing, without neglecting other neuroimaging or be...

Past studies have found that, in adults, the acoustic properties of sound signals (such as fast versus slow temporal features) differentially activate the left and right hemispheres, and some have hypothesized that left-lateralization for speech processing may follow from left-lateralization to rapidly changing signals. Here, we tested whether newb...

Developmental stuttering is a speech disorder in fluency characterized by repetitions, prolongations, and silent blocks, especially in the initial parts of utterances. Although their symptoms are motor related, people who stutter show abnormal patterns of cerebral hemispheric dominance in both anterior and posterior language areas. It is unknown wh...

The present study using near-infrared spectroscopy (NIRS) examined prefrontal activation associated with maze-solving performance in adult humans. The participants were required to solve a plus-shaped maze, comparable to the one used for pigeons and human children to behaviorally assess planning processes, by moving a target square to a goal square...

A wealth of behavioral research suggests that infants become increasingly specialized in their native dialect∕language in infancy. In contrast, few studies document how this early specialization is reflected in neural activation, most of which have compared familiar and unfamiliar languages, and none focused on different dialects. This study aimed...

This study uses near-infrared spectroscopy in young infants in order to elucidate the nature of functional cerebral processing for speech. Previous imaging studies of infants' speech perception revealed left-lateralized responses to native language. However, it is unclear if these activations were due to language per se rather than to some low-leve...

This study examined the cerebral functional lateralization, from a phonological perspective, in children with autism spectrum disorder (ASD) and typically developing children (TDC). With near infrared spectroscopy, we measured auditory evoked-responses in the temporal areas to phonemic and prosodic contrasts in word contexts. The results of TDC sho...

Attachment between mothers and infants is the most primitive and primary form of human social relationship. Many reports have suggested that the orbitofrontal cortex (OFC) plays a significant role in this attachment; however, only a select few provide experimental neurophysiological evidence. In the present study, to determine the neural substrates...

Near-infrared spectroscopy (NIRS) provides a unique method of monitoring infant brain function by measuring the changes in the concentrations of oxygenated and deoxygenated hemoglobin. During the past 10 years, NIRS measurement of the developing brain has rapidly expanded. In this article, a brief discussion of the general principles of NIRS, inclu...

To elucidate the developmental neural attunement process in the language-specific phonemic repertoire, cerebral hemodynamic responses to a Japanese durational vowel contrast were measured in Japanese infants using near-infrared spectroscopy. Because only relative durational information distinguishes this particular vowel contrast, both first and se...

While newborn infants discriminate speech sounds from languages that they have never heard, 6- month-olds demonstrate the beginnings of vowel classification specific to their native-language. The neuronal correlates involved in such a dramatic perceptual reorganization process, however, are not well understood. Using near-infrared spectroscopy (NIR...

Near-infrared spectroscopic measurement of cerebral hemodynamics was used to investigate cerebral dominance during auditory language processing in preschool and school-age children who stutter. Analysis-synthesized Japanese words (/itta/ and /itte/) and intonation contrasts (/itta/ and /itta?/) were used for stimuli. The baseline block contained on...

Near-infrared spectroscopy (NIRS) enables noninvasive measurement of concentration changes of oxy- and deoxy-hemoglobin. The present study investigated cerebral representations of motion illusion by NIRS and examined several experimental procedures to determine an efficient procedure that can shorten the experimental time. We compared hemodynamic r...

The present study using near-infrared spectroscopy examined the neuronal correlates of Japanese long/short vowel contrast discrimination and its relationship with behavioral performance by comparing native Japanese (L1) subjects and Korean subjects learning Japanese as a second language (L2). Phoneme-specific responses were predominantly observed i...

Near-infrared spectroscopic measurement of cerebral hemodynamics was performed to investigate cerebral dominance during auditory language processing in adults who stutter. Analysis-synthesized Japanese words including phoneme (/itta/ and /itte/) and intonation (/itta/ and /itta?/) contrasts were used for stimuli. The baseline block contained only /...

Near-infrared spectroscopy was used to measure hemodynamic responses in Korean subjects learning Japanese as a second-language to Japanese phonemic contrasts that are either phonologically distinctive or non-distinctive in their first-language. These results were compared with those of Japanese native listeners reported previously. Unlike the resul...

Infant's developmental changes in cerebral lateralization in response to speech stimuli were assessed using a multi-channel near infrared spectroscopic measurement system. Analysis-synthesized Japanese word stimuli were used as phoneme (/itta/ and /itte/) and pitch (/itta/ and /itta?/) contrasts. The baseline blocks contained only/itta/, whereas /i...

The present study examined cerebral representations of Japanese long and short vowel categories with near-infrared spectroscopy (NIRS) by measuring the hemodynamic changes. Results showed that NIRS could capture phoneme-specific information. The left side of the auditory area showed large hemodynamic changes only for contrasting stimuli between whi...

The present study examined cerebral responses to phoneme categories, using near-infrared spectroscopy (NIRS) by measuring the concentration and oxygenation of hemoglobin accompanying local brain activities. Targeted phonemes used here are Japanese long and short vowel categories realized only by durational differences. Results of NIRS and behaviora...

The difficulty for non-native speakers in producing Japanese geminate stops with a long enough closure has been pointed out and extensively studied. However, the reverse problem exists for particular language speakers such as Chinese. For these speakers, production of Japanese intervocalic single stops sound like geminate stops. This study aimed to...

Thirty Korean, Chinese, Thai, American, and Spanish, subjects heard two?syllable Japanese words including geminate or single stops in two pitch accent contexts. The subjects discriminated between geminate and single stops. Their discrimination ability was examined and compared among these different speakers. Five language groups were clearly separa...