Frontiers in Human Neuroscience

Creativity is one of the unique cognitive constructs in human beings and its neurobiological correlates are one of the current hot topics in neuroscience. The "Different Hearing" program (DHP) is an educational activity aimed at stimulating musical creativity by means of group composing in the classroom, alternative to the mainstream model of music education in Czechia. In our previous study, the data from task-related functional MRI with passive listening was analyzed. The results suggested that DHP training modified the response to diverse sound samples, differentially changing the engagement of functional networks known to be related to creative thinking, namely, increasing default mode network activation and decreasing activation of executive and salience networks. In the present study, we hypothesized that the DHP short-term (2 days) intense workshop would also induce changes in the resting-state networks that were significantly modified during task. To investigate it, seed-based, ROI-to-ROI resting-state functional connectivity and degree centrality analysis were performed on the acquired resting-state fMRI data. The results showed no significant group-by-time interaction.

Virtual reality (VR) has become a prominent medium for computer-mediated social interaction, yet the psychological and neural mechanisms underpinning avatar-mediated communication remain insufficiently understood. This study investigated how dynamically modulated avatar facial expressions shape interpersonal interaction in VR. Pairs of participants engaged in a collaborative creativity task while interacting via avatars whose facial expressions were either amplified, natural, or expressionless. We collected subjective measures of body ownership, social presence, and interpersonal attraction, while simultaneously recording neural activity using functional near-infrared-spectroscopy-based hyperscanning to assess inter-brain synchrony (IBS). Avatars displaying facial expressions, particularly amplified ones, significantly enhanced body ownership, social presence, and interpersonal attraction compared to expressionless avatars. At the neural level, visible avatar facial expressions were associated with IBS in the right temporo-parietal junction (TPJ) and the dorsolateral prefrontal cortex (dlPFC), regions that are commonly implicated in social-cognitive processes such as mentalizing and executive control. Although task performance did not differ across conditions, social presence was positively correlated with creative performance, suggesting that psychological connectedness supports collaborative creativity. Together, these findings indicate that avatar facial expressivity functions as a critical nonverbal social cue that facilitates affective and cognitive alignment between interaction partners. By linking subjective experience with inter-brain neural dynamics, this study provides empirical guidance for the design of virtual environments that promote social engagement and effective collaboration.

Humanity has always admired and created artwork, but the neurocognitive mechanisms behind artistic experience are still elusive. Professional artists and their intimate relationship with their artworks provide a unique opportunity to study the nature of art experience due to their expertise in both art making and art appreciation. During two fMRI tasks, professional artists (N=20) made aesthetic judgments on their own and other artists paintings (aesthetic appreciation task); they also mentally reconstructed the moments when they conceived their artworks or, as a control condition, when they visited now-familiar places for the first time (reconstruction by imagery task). During art appreciation of their own (as compared to other artists) paintings, participants showed stronger recruitment of bilateral posterior parietal cortices, the left lateral occipitotemporal cortex, and the dorso-central sector of the right insula, that is, action-related brain regions also involved in encoding the emotional components of movements. The reconstruction of their own artistic creation (as compared to episodic memory retrieval) involved the left fronto-parietal network associated with motor cognition. Altogether, these results suggest that the mental representations of the actions involved in creating art are integral to the overall artistic experience of painters, supporting an embodied view of the artists experience of art.

Observing touch activates brain regions similar to those activated by experiencing actual touch, suggesting that visual information can cross-modally influence tactile perception. In this electroencephalography (EEG) study, we investigated how viewing visual displays of an arm being touched may affect the perception and processing of digitally rendered touch patterns designed to resemble either stroking or tapping. Thirty-one participants experienced touch patterns delivered to their left forearm via a wearable sleeve while viewing either a photo of an arm or spatiotemporally aligned videos of an arm being touched in synchrony with either of the two touch patterns. Continuity and pleasantness ratings of touch stimuli were higher for stroking than for tapping. Correlations between continuity and pleasantness ratings were stronger when touch was accompanied by videos of touch than by the photo of an arm. Analysis of evoked brain responses revealed visual modulation of touch processing at centroparietal electrodes beginning at around 0.9 s, with the cross-modal effects diverging between stroking and tapping at about 1.6 s. Furthermore, the interaction effects of cross-modal influences between stroking and tapping at the neural level positively correlated with the visual modulation of pleasantness ratings in two right frontal clusters at around 1.4 s and 1.8 s. These results suggest that observing touch influences the perception and processing of touch through initial sensory integration at centroparietal sites, followed by later frontal valuation processes. This extends previous findings on affective touch by demonstrating that visual inputs can cross-modally shape the hedonic evaluation of digitally actuated touch.

Prolonged esports play induces cognitive fatigue that is not fully captured by subjective awareness, motivating practical, non-stimulant nutritional strategies supported by objective physiological markers. We here tested whether acute milk protein intake attenuates fatigue-related physiological responses during prolonged esports play and supports subjective state, executive control, and in-game performance. In a randomized, single-blind (assessor-blind), energy-matched controlled crossover study, 15 healthy young adults with esports experience completed two sessions in which they consumed either a milk protein drink or an energy-matched apple juice control before a 3-h virtual soccer task. Physiological measures included pupillometry during gameplay, salivary cortisol, continuous interstitial glucose monitoring, and heart rate. Subjective ratings (VAS) and executive function (flanker task) were assessed across post-ingestion time points, and in-game performance metrics were aggregated within hourly gameplay blocks. Milk protein intake was associated with a coherent pattern of physiological advantages, including larger pupil diameter during gameplay, smoother interstitial glucose dynamics, and lower salivary cortisol, while heart rate showed time-dependent changes without a clear condition effect. These physiological changes co-occurred with higher enjoyment and lower hunger, improved flanker performance, and condition-dependent improvements in in-game performance, most notably higher shot success rate. Additionally, pupil diameter during gameplay was associated with inhibitory-control efficiency on the flanker task. These findings suggest that acute milk protein intake may serve as a practical, non-stimulant nutritional strategy to sustain physiological state and cognitive-behavioral performance during prolonged esports (virtual soccer) play. Highlights- Prolonged esports play models modern digital cognitive activity and cognitive fatigue. - Acute milk protein intake increases pupil diameter during prolonged esports play. - Interstitial glucose dynamics are smoother and salivary cortisol is lower with milk protein. - Enjoyment increases and hunger decreases during 3 h of virtual soccer play. - Executive function and in-game performance improve, most notably shot success rate.

Chronic low back pain (CLBP) is persistent and refractory, affecting 20-30% of population worldwide. Neurofeedback has been explored as a potential non-pharmacological intervention for chronic pain, although evidence in CLBP remains limited. This study evaluated PainWaive, a consumer-grade digitally-delivered neurofeedback intervention targeting multiple pain-related frequency bands recorded over the sensorimotor cortex in individuals with CLBP. In a multiple-baseline experimental design, four participants completed daily assessments of pain severity and pain interference during randomly-assigned baseline phases of 7, 10, 14, and 20 days, followed by 20 sessions of the PainWaive intervention over four weeks. Daily pain assessments continued during the post-intervention and follow-up phases. Participants rated PainWaive's usability and acceptability at post-intervention. Anxiety, depression, wellbeing, and sleep disturbance were assessed at three timepoints. Aggregated Tau-U analyses indicated a large effect (-0.67) on pain severity from baseline to intervention and very large from baseline to post-intervention (-0.92) and follow-up (-0.92) phases. Large effects (-0.63, -0.62, and -0.70) were also observed for pain interference. Individual-level analyses showed significant reductions across all participants, with visual inspection confirming progressive decreases over time. The intervention was rated usable and acceptable by all participants, while psychological outcomes were mixed and varied across participants. The findings provide promising evidence that the PainWaive neurofeedback intervention may reduce pain severity and pain interference in some individuals with CLBP. By prioritising accessibility, usability, and self-administration, PainWaive supports a foundation for more patient-centred, technology-enabled approaches to chronic pain management. Further evaluation of this approach in randomised trials is required to establish efficacy.

Neural mechanisms underlying handedness remain poorly understood. We used functional magnetic resonance imaging (fMRI) to study performance of a visually guided drawing task with each hand. We hypothesized that the left superior parietal lobule supports drawing with either hand, and individuals with chroninc peripheral nerve injury (PNI) to the dominant hand use the same mechanism as healthy adults. Methods33 right-handed adults (23 healthy, 10 patients) underwent fMRI while performing a precision drawing task, alternating between the right hand (RH) and left hand (LH). 20 regions of interest (12 a priori and 8 post-hoc) were examined for LH>RH effects on BOLD magnitude and on functional connectivity (FC) modulation via generalized psychophysiological interaction. ResultsDuring LH drawing, contralateral primary motor cortex (M1) had lower magnitude, and greater FC with two networks of equal-or-greater magnitude: left M1-dorsal premotor, and intrahemispheric parieto-temporal network. Contralateral M1 also had reduced interhemispheric FC with inferior parietal lobule, which exhibited lower magnitude. Patient group did not interact with these effects. ConclusionsThree neural mechanisms differentiate LH from RH drawing. First, a left hemisphere bimanual control network engages intrahemispherically (directly) during RH drawing and interhemispherically (indirectly) during LH drawing. Second, LH drawing increases engagement of a contralateral network that may reflect increased task demands. Third, RH drawing increases engagement of an interhemispheric tool use network. The first and third networks may explain the dominant hands performance advantages. PNI patients use the same mechanisms, highlighting their potential as a neuromodulatory target to enhance LH performance after RH impairment.

Cognitive dysfunction is increasingly recognized as an important feature of chronic pain (CP). However, subjective cognitive complaints and objectively measured cognitive performance frequently diverge. Whether and how these two aspects of cognitive functioning differentially relate to the broad symptomatology and brain function in CP remains unclear. Here, 114 individuals with CP completed patient-reported outcome measures on cognitive functioning and multidimensional CP symptoms, as well as a visuospatial working memory task, and resting-state EEG. Bayesian correlations, network analyses, and Bayesian regression models examined how subjective and objective cognitive functioning relate to multidimensional CP symptoms and EEG activity/connectivity, while controlling for age and sex. Additional models tested whether EEG associations were independent of broader symptom burden. Results indicated that subjective and objective cognitive functioning were uncorrelated. Subjective cognitive functioning was strongly associated with psychosocial symptoms, whereas objective cognitive functioning was largely independent of broader symptom burden. EEG revealed associations between subjective cognitive functioning and bilateral frontotemporal beta connectivity; however, these relationships were substantially attenuated after accounting for broader CP symptom burden. Objective cognitive functioning showed no robust associations with EEG. These findings indicate a dissociation between subjective cognitive complaints and objective cognitive performance in CP. Subjective cognitive complaints were primarily associated with psychosocial symptom burden and beta-band hypoconnectivity. In contrast, objective cognitive performance was unrelated to the broader symptomatology of CP and EEG measures. This dissociation may inform more targeted interventions, optimize the allocation of cognitive assessment resources, and ultimately improve long-term functional outcomes in CP.

High-impact chronic pain (HICP), defined as persistent pain that substantially limits daily activities, affects millions of adults and poses a public health challenge. Yet relatively little is known about how HICP manifests in people's daily lives. To address this gap, this study used the comprehensive Ecological Momentary Assessment of pain (cEMAp) to assess pain-related experiences four times per day over 7 days in individuals with chronic low back pain. Based on the classification using the Graded Chronic Pain Scale-Revised, we compared individuals with HICP (n = 66) with those in the next most severe pain category, bothersome chronic pain (n = 41), defined as having similar pain frequency but less frequent interference with daily activities. On each prompt, participants completed 2-hour assessments of pain intensity, interference, catastrophizing, behaviors, coping strategies, and pain characteristics. In line with prior research, both groups reported similar pain intensity levels, but the HICP group reported more frequent interference with physical, mental, and social activities. There were no group differences in daily mood or catastrophizing. Exploratory analyses suggested that many daily experiences were similar across groups, with differences observed in selected pain qualities, coping strategies, and pain behaviors. Additional analyses of response distributions showed some similarity across groups in many experiences. Overall, although individuals with HICP on average experience higher pain interference in daily life, levels of many day-to-day experiences are similar between the two groups. Data obtained with cEMAp complement traditional retrospective assessment by providing a detailed view of chronic pain in everyday life.

BackgroundUnderstanding the associations among biopsychosocial factors is essential for improving research and treatment of chronic low back pain (CLBP). Here we characterized interrelations among biopsychosocial domains using network analysis and identified the most influential features in CLBP. MethodsData came from Quebec Low Back Pain Study, comprising 4,489 CLBP participants. We modeled relationships among baseline biopsychosocial features as networks, where nodes represent features and edges encode statistical or causal dependencies among them. Undirected network was inferred using distance correlation. Directed network was constructed using the Linear Non-Gaussian Acyclic Model, which estimates plausible causal directions. Influence maximization was performed using the Independent Cascade (IC) model to identify the most influential features in each network. ResultsIn the undirected network, physical function and pain interference were the most central nodes, followed by depression. In the directed network, fear of movement, catastrophizing, and widespread pain emerged as key downstream hubs receiving multiple causal inputs, whereas pain interference, physical function, and depression acted as major upstream drivers exerting broad causal influence. IC diffusion simulations further identified pain interference and physical function as the most influential features in the undirected and directed networks, respectively. ConclusionsPain interference, physical function, and depression consistently emerged as key components of the CLBP biopsychosocial network. These features exert causal effects on fear of movement, catastrophizing, and widespread pain, with diffusion analyses confirming their roles as system-wide drivers. Interventions targeting functionality and pain interference, rather than pain intensity alone, may yield broader benefits across psychological and functional domains.

Dance is a core form of human-environment interaction and a powerful medium for emotional expression, yet dancers are routinely exposed to environmental affective cues that may shape their movement. We tested whether a negative emotional context induced immediately before improvisation alters dance biomechanics. Twenty professional dancers performed two 3-min improvised dances. Between dances, they viewed either Neutral or Negatively valenced pictures from the International Affective Picture System (IAPS; 2 min 40 s, 5 s per image). Eye tracking verified attention to the visual stream. Mood was assessed at four time points (PT1-PT4) using the Brazilian Mood Scale (BRAMS), and full-body, three-dimensional kinematics were captured at 300 Hz using a 9-camera optoelectronic system (Qualisys) and processed to measure global movement amplitude and expansion. Negative IAPS exposure increased tension, depression, fatigue, and decreased vigor from PT2 to PT3. Biomechanically, the Negative Stimulus dancers showed a significant reduction in global movement amplitude after negative IAPS exposure, with reduced movement amplitude of the body extremities. In contrast, global movement expansion remained unchanged; that is, the extremities were not positioned closer or farther from the pelvis. Neutral images produced no mood change and no measurable modulation of movement amplitude or expansion. Together, these results support the hypothesis that improvised dance carries biomechanical signatures of the dancers current affective state, beyond the intended expressive content, and provide an automated motion-capture workflow for studying emotion-movement coupling in spontaneous dance. HighlightsNegative visual context shifted dancers mood toward negative affect Negative images reduced movement amplitude in improvised dance Movement expansion remained stable despite mood induction Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/711707v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@aeaacdorg.highwire.dtl.DTLVardef@14f9bf5org.highwire.dtl.DTLVardef@18805fcorg.highwire.dtl.DTLVardef@1411256_HPS_FORMAT_FIGEXP M_FIG C_FIG

Mental fatigue (MF) arises from sustained cognitive load and produces a multisystem signature spanning subjective experience, task performance, cortical oscillations, and oculomotor dynamics. It may alter higher-order cognitive functions essential to everyday life, underscoring the need for preventive strategies. Although moderate aerobic exercise (EXO) facilitates recovery from MF, its influence on the onset and expression of MF when performed beforehand remains unexplored. This study provided a multimodal characterization of MF, assessed its impact on associative memory and divergent creativity, and examined whether prior EXO modulated these outcomes. Twenty-nine participants completed either 15 min of EXO or rest before a 35-min MF-inducing Time Load Dual Back task. Subjective fatigue and effort, performance, EEG activity, and eye-blink rate were continuously recorded; associative memory and divergent creativity were assessed pre-intervention and post-MF. Both groups showed progressive increases in MF and effort from 7 min onward, stable performance, and a rise in parieto-central alpha power at 18 min. The EXO group exhibited higher frontal-medial theta power and stable blink rates, whereas blink rate in REST increased at 21 min. EXO did not prevent subjective MF nor influence behavioral stability but modulated neurophysiological markers potentially related to compensatory control and dopaminergic regulation. Associative memory remained preserved in both groups, whereas creative flexibility increased in REST but not EXO, suggesting MF-related disinhibition in the former and preserved inhibitory control in the latter. These findings refine temporal and multimodal profile of MF and highlight the need to optimize exercise parameters and task demands to enhance preventive efficacy and guide interventions.

This pre-post-test study investigated 1) pre-post changes in psychosocial domains with a single virtual salsa class; 2) effect sizes relative to an in-person class, and 3) individual factors, including personality, perceived performance, and enjoyment. An experimental group (n=33) of novice dancers 18-30 years old, participated in a single virtual salsa class. Positive and Negative Affect Scale (PAS, NAS), Perceived Stress Scale (PSS), and the Inclusion in Community and Self-Scale (ICS) were administered before and after class. Participants completed the Big Five Inventory-10 (BFI-10) before, and rated their performance and enjoyment (ordinal scale 1-5) after class. Effect sizes were calculated, and pre-post changes were analyzed with Wilcoxon signed-rank tests. Relationships between pre-post changes and individual factors were analyzed with Spearmans rank correlations. PAS, NAS, PSS, and ICS significantly improved and effect sizes were larger than those for an in-person salsa class except for ICS. Change in NAS was negatively correlated with neuroticism. These results suggest that a virtual salsa class may improve mood, stress, and social connection similar to in-person classes and change in mood may be influenced by personality traits such as neuroticism. Understanding the psychosocial effects of virtual dance and the influence of individual factors will facilitate implementation of dance as an accessible rehabilitation intervention to improve psychosocial well-being.

Developmental Language Disorder (DLD) is a neurodevelopmental condition that causes significant difficulties in understanding and using spoken language. Here we use electroencephalography (EEG) recorded during natural speech listening with 9-year-old children to identify dynamic neural processing patterns that characterize children with DLD compared to typically-developing age-matched controls. We applied Principal Components Analysis (PCA) to identify spatial ensembles of channels that represented distinct (uncorrelated) sources of cortical activity, and explored phase-amplitude coupling (PAC) between delta (0.5-4 Hz), theta (4-8 Hz) and low-gamma (25-40 Hz) oscillations. We then isolated EEG common spatial patterns (CSP) that identified children with DLD. The PAC analyses identified the delta band as a key source of group differences, and only delta-low gamma PAC differed significantly between participant groups. The CSP analyses also identified the delta band as a key mechanistic source of group differences. The findings are suggestive of distinct atypical low-frequency neural dynamics during speech encoding for children with DLD, which could be targeted by novel interventions.

Two theoretical models are proposed on the signal processed by the brain to generate the perception of effort (PE): the corollary discharge model and the afferent feedback model. To test the validity of these models, we used electromyostimulation to manipulate the magnitude of the central motor command during voluntary (high motor command), evoked (no motor command) and combined (low motor command) contractions at similar torque outputs. As electromyostimulation evokes sensory volleys to the central nervous system, it was used to evoke muscle contractions and to stimulate afferent feedback. We hypothesized that PE would reflect the magnitude of the central motor command and that evoked muscle contractions in the absence of central motor command would not elicit any PE. Twenty participants (n=10 experienced and n=10 novice with electromyostimulation) volunteered in this study. Participants reported their PE after isometric (10% and 20% MVC) and dynamic (5% and 20% MVC) voluntary, evoked, and combined contractions. For the same torque, participants reported no PE during evoked contractions, but all reported PE during voluntary contractions. Experienced but not novice participants reported lower PE during the combined than during voluntary contractions. This study questions the validity of the afferent feedback model and highlights the key role of motor command-related signals in PE generation. However, results from the novice participants during the combined contractions suggest that other factors such as inhibitory control may affect PE. Future studies should investigate the relationship between the central motor command and PE during physical tasks at various levels of complexity.

The study of contemplative practices has evolved into a mature field, yet current taxonomies tend to classify all mantra-based meditation approaches as a single category, overlooking potentially different neural states induced by different mantras or different instructions. To address this gap, we conducted a study of 50 novice subjects practicing two types of mantra-based meditation over a six week period to evaluate changes in Electroencephalography (EEG) during and after meditation. Participants were randomly assigned to meditating with the Hare Krishna (HK) and Sa-Ta-Na-Ma (SA) mantras. Using spectral parameterization, we assessed the effects of each type of meditation on individual alpha power (IAP), individual alpha frequency (IAF) and center of gravity (CoG). The results revealed marked differences in alpha dynamics between the two practices. On the one hand, the HK group exhibited widespread IAP decrease and an IAF/CoG increase during mantra meditation that was maintained during rest after the meditation, which became more pronounced after training in the HK meditation. On the other hand, the SA group showed a localized IAP reduction during meditation and significant reduction of IAF during meditation after training. We suggest that the higher cognitive demands of HK induce a more activating, attentionally focused state, whereas SA promotes a more relaxed state. Additional psychological data show that both meditation groups had reduction in stress. Thus, these findings challenge the monolithic classification of mantra meditation and highlight the importance of differentiating practices according to their mechanisms, particularly for their targeted application in mental health contexts.

In our study, we used virtual reality to investigate how the colour of an objects surroundings influences colour constancy. Using Unreal Engine, we manipulated lighting and object properties in computer-generated scenes illuminated by five different light sources and presented them through an HTC Vive Pro Eye virtual reality headset. Participants assessed colour constancy by selecting the object that best matched a neutral reference from among five differently coloured options within the scene. Our results demonstrated a significant decline in colour constancy performance when the illuminant colour was in the opposite direction to that of the local surround, highlighting the interactive effects of surround colour and illumination.

Even if they have no dementia, some elderly people find it difficult to imagine the food they may want to eat. However, research into treatments for anorexia in elderly people has not progressed sufficiently due to the lack of a method that can easily measure brain function in clinical settings. In this study, we aim to clarify the relationship of food-dependent medial prefrontal cortex (MPFC) activity with food preference and intake frequency by functional near-infrared spectroscopy (fNIRS) to determine ways to treat the appetite loss and have difficulty in explain what they want to eat. For this purpose, we firstly establish the methodology using young participants experiment. All young participants were asked about their food preferences and intake frequency using a questionnaire, and they were instructed to look and then eat the control dish (CD: typical Japanese home-cooked meal) and their preferred dish (PD: each participant purchased the dish themselves on the day of the experiments) on separate days, and activity of MPFC in each participant was recorded by fNIRS. We found that activity of MPFC during "just-looking" and "eating" were affected by food intake habits and preference. Especially, activity of MPFC during CD eating was affected by food preference (has dislike food or not). We concluded that the activity of MPFC during eating of dishes varies depending on the food intake habits and fNIRS could be a potential technique for estimating such activity.

We investigated whether multimodal sensing that combines functional near-infrared spectroscopy (fNIRS) with peripheral physiological signals can improve subject-independent classification of arousal and valence, the fundamental affective dimensions in Russells circumplex model. We developed Japanese emotion-inducing music-video stimuli (60 seconds each) and recorded subjects central nervous system activity using fNIRS, alongside peripheral physiological measures, specifically electrodermal activity (EDA) and photoplethysmography (PPG), during video viewing. To prioritize reproducibility and methodological transparency, we extracted simple, easily computed features from each modality and performed binary (high vs. low) classification separately for arousal and valence using a support vector machine. The combination of fNIRS and EDA yielded the highest performance, with a macro-averaged F1 score of 0.73 for arousal and 0.64 for valence. These findings underscore the utility of integrating fNIRS with peripheral physiological signals for subject-independent emotion classification.

Sustained attention is an important requirement for high performance in all cognitive processes. Quantifying the level of sustained attention to prevent attention lapses is therefore necessary for effective human-machine interfacing. Furthermore, sustained attention evaluation can help diagnose and treat attention deficit hyperactivity disorders. Attention level can be assessed by brain and heart signals. This study employed functional near infrared spectroscopy (fNIRS) and the heart rate variability (HRV) information extracted from the fNIRS signals to differentiate the rest and three levels of sustained attention states. Sustained attention states are induced by three modified versions of continuous performance tests (CPT). Eight subjects engaged in three sessions of attention tests. fNIRS brain signals were recorded from the right prefrontal and dorsolateral prefrontal cortex. HRV information was then extracted by processing the fNIRS signals. For attention classification, support vector machine (SVM), linear discriminant analysis (LDA), and random forest (RF) algorithms with mutual information based feature selection were applied on the fNIRS and HRV data both separately and together. In the classification of the three levels of attention using fNIRS and HRV data, the LDA classifier showed the best performance accuracy of (80.9 {+/-} 1.5%) and (56.2 {+/-} 1.0%), respectively. For two-class classification between the rest and the attention states (all together), the accuracies of (98.9 {+/-} 0.3%), (95.6 {+/-} 1.2%), and (99.5 {+/-} 0.2%) were obtained using the RF classifier on the fNIRS, HRV, and combined data, respectively. These results demonstrate the effectiveness of the HRV data for classifying sustained attention states. Moreover, using the combined fNIRS and HRV data provides better classification accuracy.