Chronic insomnia (CI) is a prevalent disorder associated with prefrontal cortex (PFC) dysfunction, and it can significantly impair quality of life and psychological well-being. This study explores the use of functional near-infrared spectroscopy (fNIRS) as a tool for rapid screening of CI and for evaluating the efficacy of repetitive transcranial magnetic stimulation (rTMS) in improving brain function and clinical symptoms in CI patients.

A total of 60 participants were enrolled, including 30 healthy controls (HCs) and 30 CI patients. CI patients received a two-week intervention of 1 Hz rTMS targeting the right dorsolateral prefrontal cortex (DLPFC). Symptom severity was assessed using the Pittsburgh Sleep Quality Index (PSQI), Self-Rating Anxiety Scale (SAS), and Self-Rating Depression Scale (SDS). Hemodynamic differences between CI patients and HCs during a verbal fluency task (VFT) were analyzed using fNIRS.

HCs exhibited significantly lower PSQI, SAS, and SDS scores compared to CI patients (p < 0.05). During the VFT, oxygenated hemoglobin (oxy-Hb) levels in the DLPFC and medial prefrontal cortex (mPFC) were significantly higher in HCs than in CI patients (p < 0.05). Following rTMS treatment, CI patients demonstrated significantly increased activation in relevant brain regions compared to pre-treatment levels.

fNIRS has shown considerable potential as a valuable tool for the screening and diagnosis of CI. Compared to HCs, CI patients exhibited significantly weaker PFC responses during the VFT. rTMS treatment was found to alleviate symptoms in CI patients, likely due to its ability to enhance PFC activation.

To map and critically appraise the literature on the feasibility and current use of functional near-infrared spectroscopy (fNIRS) to assess cortical activity, functional connectivity, and neuroplasticity in individuals with cerebral palsy (CP).

A scoping review methodology was prospectively registered and reported following Preferred Reporting Items for Systematic review and Meta-Analysis Extension for Scoping Reviews (PRISMA-ScR) guidelines. A systematic search was conducted in four databases. Empirical studies using fNIRS to assess neural activity, functional connectivity, or neuroplasticity in individuals with CP aged 3 years or older were included.

Sixteen studies met the inclusion criteria. Individuals with CP (age range = 3-43 years; 70% unilateral CP) underwent fNIRS-based assessment for task-evoked activity (studies [n] = 15) and/or resting-state functional connectivity (n = 3). Preliminary observations suggest greater magnitude, extent, and ipsilateral hemispheric lateralization of sensorimotor cortex activity in CP, while magnitude and patterns of prefrontal cortex activity in CP appear dependent on task demands. Normalization of fNIRS-based activity metrics observed postintervention (n = 3) paralleled improvements in functional outcomes, highlighting their potential as promising biomarkers for functional gains in CP.

This review details the use of fNIRS in CP, highlights research gaps and technical limitations, and offers recommendations to support fNIRS implementation for ecologically valid functional neuroimaging in individuals with CP.

Major depressive disorder (MDD) and generalized anxiety disorder (GAD) are highly prevalent mental disorders in psychiatry, but their overlapping symptoms often complicate precise diagnoses. This study aims to explore differential brain activation patterns in healthy controls (HC), MDD, and GAD groups through functional near-infrared spectroscopy (fNIRS) during the verbal fluency task (VFT) to enhance the accuracy of clinical diagnoses.

This study recruited 30 patients with MDD, 45 patients with GAD, and 34 demographically matched HCs. Hemodynamic changes in the prefrontal cortex (PFC) and temporal lobes were measured using a 48-channel fNIRS during the VFT task. Demographics information, clinical characteristics and VFT performance were also recorded.

Compared to HCs, both MDD and GAD share a neurobiological phenotype of hypoactivation in the dorsolateral prefrontal cortex (DLPFC) and medial prefrontal cortex (mPFC) during VFT. Moreover, MDD patients exhibited significantly greater hypoactivation in the left DLPFC and mPFC than GAD patients.

Although both GAD and MDD patients exhibit disrupted cortical function, the impairment is less severe in GAD. These findings provide preliminary neurophysiological evidence supporting the utility of the fNIRS-VFT paradigm in differentiating GAD from MDD. This approach may complement traditional diagnostic methods, inform targeted interventions, and ultimately enhance patient outcomes.

Early infant phonological and non-phonological perceptual abilities are crucial for future language learning. Previous studies have focused on the changes in the cerebral cortex of infants and toddlers during speech perception, while the changes in the cerebral cortex during non-speech perception remain poorly understood.

This study aimed to investigate cortical activation patterns and differences in full-term healthy newborns under different speech and non-speech stimuli by functional near-infrared spectroscopy (fNIRS).

The cohort included 36 full-term healthy neonates (7.4 ± 6.0 days) exposed to two types of speech stimuli (native Mandarin and non-native Spanish) and three non-speech stimuli (music, cat calls, and noise) in a block design. Brain activity was monitored across eight brain regions of interest (ROIs) were monitored using fNIRS (54 channels): frontal pole area (FPA), middle frontal gyrus (MFG), primary sensorimotor cortex, middle temporal gyrus (MTG), superior temporal gyrus (STG), fusiform gyrus (FFG), Wernicke's area, and Broca's area.

Mandarin stimulation activated all ROIs in newborns. Changes in oxygenated hemoglobin concentrations in FPA, MFG, STG, MTG, FFG, Wernicke's area, and Broca's area were significantly higher during Mandarin exposure compared to Spanish (p < 0.05). MTG activation was significantly greater during Mandarin exposure compared to cat calls (p = 0.005), music (p = 0.040), and noise (p < 0.001). Similarly, MFG and Broca's area showed significantly greater activation during music exposure compared to Spanish and noise stimuli (p < 0.05).

The newborn brain can perceive various speech and non-speech stimuli, demonstrating a preference for native language stimuli, followed by music. The ability to perceive non-native languages, animal calls, and noise appears more limited. These findings could provide some references for future research on infant and toddler language development.

Depression is a common mental disorder that significantly impacts global well-being. Although stress is a major contributor to depression, not all stress leads to depressive outcomes due to differences in stress perception. Understanding the neural mechanisms of stress perception may help identify biomarkers for targeted interventions to alleviate stress-related depression.

This study included 113 participants. Each participant completed a Verbal Fluency Task (VFT) while undergoing functional near-infrared spectroscopy (fNIRS) to monitor brain activity. Oxyhemoglobin (Oxy-Hb) concentration data were analyzed using Matlab, and PROCESS v4.1 to examine neural mechanisms connecting stress perception and depression.

Correlation analysis showed a significant negative association between depression severity and Oxy-Hb concentration in several brain regions, including the bilateral dorsolateral prefrontal cortex (DLPFC), bilateral Broca's area (BA), right frontal pole (FP), and right orbitofrontal cortex (OFC). Mediation and moderation analyses revealed that the bilateral DLPFC serves as a key mediator in the relationship between stress perception and depression, with the supplementary motor area (SMA) acts as a moderator. Functional differentiation was observed, with the left DLPFC and left SMA influencing the effect of nervous on depression, and the right DLPFC and right SMA influencing the effect of uncontrolled on depression.

The bilateral DLPFC and SMA play critical roles in mediating and moderating stress perception's impact on depression, suggesting these regions as potential targets for interventions in stress-related depressive disorders.

Functional magnetic resonance imaging provides high spatial resolution but is limited by cost, infrastructure, and the constraints of an enclosed scanner. Portable methods such as functional near-infrared spectroscopy and electroencephalography improve accessibility but require physical contact with the scalp. Our speckle pattern imaging technique offers a remote, contactless, and low-cost alternative for monitoring cortical activity, enabling neuroimaging in environments where contact-based methods are impractical or MRI access is unfeasible.

We aim to develop a remote photonic technique for detecting human brain cortex activity by applying deep learning to the speckle pattern videos captured from specific brain cortex areas illuminated by a laser beam.

We enhance laser speckle pattern tracking with artificial intelligence (AI) to enable remote brain monitoring. In this study, a laser beam was projected onto Wernicke's area to detect brain responses to a clear and incomprehensible speech. The speckle pattern videos were analyzed using a convolutional long short-term memory-based deep neural network classifier.

The classifier distinguished brain responses to a clear and incomprehensible speech in unseen subjects, achieving a mean area under the receiver operating characteristic curve (area under the curve) of 0.94 for classifications based on at least 1 s of input.

This remote method for distinguishing brain responses has practical applications in brain function research, medical monitoring, sports, and real-life scenarios, particularly for individuals sensitive to scalp contact or headgear.

To systematically review technologies that objectively measure cognitive workload (CWL) in surgery, assessing their psychometric and methodological characteristics.

Surgical tasks involving concurrent clinical decision-making and the safe application of technical and non-technical skills require a substantial cognitive demand and resource utilization. Cognitive overload leads to impaired clinical decision-making and performance decline. Assessing CWL could enable interventions to alleviate burden and improve patient safety.

Ovid MEDLINE, OVID Embase, the Cochrane Library, and IEEE Xplore databases were searched from inception to August 2023. Full-text, peer-reviewed original studies in a population of surgeons, anesthesiologists or interventional radiologists were considered, with no publication date constraints. Study population, task paradigm, stressor, cognitive load theory (CLT) domain, objective and subjective parameters, statistical analysis, and results were extracted. Studies were assessed for (1) definition of CWL; (2) details of the clinical task paradigm; and (3) objective CWL assessment tool. Assessment tools were evaluated using psychometric and methodological characteristics.

A total of 10,790 studies were identified; 9004 were screened; 269 full studies were assessed for eligibility, of which 67 met inclusion criteria. The most widely used assessment modalities were autonomic (32 eye studies and 24 cardiac). Intrinsic workload (eg, task complexity) and germane workload (effect of training or expertize) were the most prevalent designs investigated. CWL was not defined in 30 of 67 studies (44.8%). Sensitivity was greatest for neurophysiological instruments (100% EEG, 80% fNIRS); and across modalities accuracy increased with multisensor recordings. Specificity was limited to cardiac and ocular metrics, and was found to be suboptimal (50% and 66.67%). Cardiac sensors were the least intrusive, with 54.2% of studies conducted in naturalistic clinical environments (higher ecological validity).

Physiological metrics provide an accessible, objective assessment of CWL, but dependence on autonomic function negates selectivity and diagnosticity. Neurophysiological measures demonstrate favorable sensitivity, directly measuring brain activation as a correlate of cognitive state. Lacking an objective gold standard at present, we recommend the concurrent use of multimodal objective sensors and subjective tools for cross-validation. A theoretical and technical framework for objective assessment of CWL is required to overcome the heterogeneity of methodological reporting, data processing, and analysis.

Stress is both a driver of objective performance impairments and a source of negative user experience of technology. This review addresses future directions for research on stress and ergonomics in the digital age. The review is structured around three levels of analysis. At the individual user level, stress is elicited by novel technologies and tasks including interaction with AI and robots, working in Virtual Reality, and operating autonomous vehicles. At the organisational level, novel, potentially stressful challenges include maintaining cybersecurity, surveillance and monitoring of employees supported by technology, and addressing bias and discrimination in the workplace. At the sociocultural level, technology, values and norms are evolving symbiotically, raising novel demands illustrated with respect to interactions with social media and new ethical challenges. We also briefly review the promise of neuroergonomics and emotional design to support stress mitigation. We conclude with seven high-level principles that may guide future work.

A growing body of research suggests that the brain is implicated in cognitive impairment, fatigue, neuropathy, pain, nausea, sleep disturbances, distress, and other prevalent and burdensome symptoms of cancer and its treatments. Despite anecdotal evidence of difficulties using gold-standard magnetic resonance imaging (MRI) to study the brain, no studies have systematically reported reasons that patients with cancer do or do not complete research MRI scans, making it difficult to understand the role of the brain related to these symptoms. The goal of this study was to investigate these reasons and to suggest possible solutions.

We analyzed data from 120 patients with cancer (mostly breast and gastrointestinal) from three studies: MRI was mandatory in Study 1; MRI was optional in Studies 2-3. Patients provided reasons for completing or not completing optional research MRI scans.

The percentage of scans completed when MRI was mandatory was 76%, and when optional, it was 35%. The most common reasons for not completing optional scans were claustrophobia (28%), scheduling conflicts (22%), safety contraindications (15%), the scanner being too far away (9%), and discomfort (8%). Older participants were slightly more likely to decline at least one optional scan (log(odds) = 0.06/year, p = 0.02).

Although brain MRI is feasible for many patients with cancer, it can be difficult or not feasible for patients with claustrophobia, safety issues, busy schedules, or transportation issues. Improving communication, comfort, and access to a scanner may help. Reducing inequities related to study participation can improve research supportive care research.

The aim of this study is to explore the differences in cortical activation and gait performance during turning walking under cognitive dual-task conditions between young and older adults during cognitive-turning dual task walking, as well as variations in brain functional connectivity in this context. Seventeen young adults and seventeen older adults were included in the study. All participants completed two tasks: a figure-eight turning walk (single-task, ST) and a figure-eight turning walking while performing a digital alert cognitive task (dual-task, DT). Data collection was conducted using functional near-infrared spectroscopy and a three-dimensional motion capture system to extract and calculate the activation of motor and sensory cortices, functional connectivity, and gait parameters. Compared to ST, the cortical activation in the young adults was significantly increased during DT (p ≤ 0.041) and was higher than that of the older adults (p ≤ 0.003); the older adults showed no significant change in cortical activation, and the stride length decreased (p = 0.013) and was lower than that of the young adults (p = 0.023). Additionally, compared to ST, the functional connectivity between primary somatosensory cortex and other brain regions increased in the older adults during DT (p ≤ 0.035). The older adults are more likely to fall when performing cognitive-turning DT. One of the important reasons for the difference between them and young adults is the distinct brain modulation mechanisms employed by the two groups when facing challenging dual tasks. Enhancing brain functional connectivity may be a more effective strategy for the older adults to promoting dual-task performance. This study provides insights for aging-related steering disorders and more evidence for the influence of aging on neuro-motor control mechanism.

Neurological complications are common in patients with end-stage kidney disease (ESKD). However, the mechanisms underlying neurological complications of ESKD are poorly understood. Research on brain connectivity in patients undergoing peritoneal dialysis (PD) is limited. In this study, we aimed to examine alterations in functional brain connectivity in patients with ESKD undergoing PD compared to the control group using functional near infrared spectroscopy (fNIRS).

We prospectively enrolled 20 patients with ESKD who had been receiving PD for more than 6 months and had no prior history of psychiatric or neurological diseases, along with 20 healthy controls. The fNIRS data were obtained using an NIRSIT Lite instrument. After processing all the data, we used Pearson correlation analysis to create a weighted connectivity matrix. Functional connectivity measures were derived from the connectivity matrix using graph theory. Functional connectivity measures were compared between the controls and patients with ESKD undergoing PD.

The average degree, average strength, and small-worldness were significantly lower in patients with ESKD undergoing PD than in the controls (9.333 [8.000 ~ 11.433] vs. 12.733 [9.600 ~ 13.400], p = 0.030; 6.865 [4.768 ~ 7.560] vs. 8.432 [6.593 ~ 9.432], p = 0.036; 0.836 [0.724 ~ 0.900] vs. 0.949 [0.882 ~ 0.972], p = 0.025, respectively).

This study demonstrated significant alterations in functional brain connectivity in patients with ESKD undergoing PD, suggesting that functional brain connectivity is significantly reduced in patients with ESKD undergoing PD when compared with that in healthy controls.

This meta-analysis examines the challenge of capturing brain activity in real-world and laboratory settings by integrating naturalistic neuroimaging and experimental data with behavioral measures to explore the predictive role of intersubject correlation (ISC) in attention. Using databases such as Web of Science and PubMed, we conducted a comprehensive search from January 2000 to July 2024. Our meta-analysis of 14 studies and 27 effect sizes reveals a significant positive correlation between ISC and attention (r = 0.65, p < 0.001), demonstrating that ISC serves as a reliable neural marker for attentional engagement under various experimental conditions. By incorporating naturalistic stimuli such as video clips and controlled laboratory tasks, we provide insights into the application of ISC to predict attention in ecologically-valid contexts. Moreover, our addition of behavioral data further enhances the understanding of how neural synchronization reflects attentional states. Our results underscore the potential of utilizing ISC to develop personalized assessments and interventions in educational and cognitive settings.

Functional near-infrared spectroscopy (fNIRS) offers a portable, cost-effective alternative to functional magnetic resonance imaging (fMRI) for noninvasively measuring neural activity. However, fNIRS measurements are limited to cortical regions near the scalp, missing important medial and deeper brain areas. We introduce a predictive model that maps prefrontal fNIRS signals to whole-brain fMRI activity during movie-watching. By aligning neural responses to a common audiovisual stimulus, our approach leverages shared dynamics across imaging modalities to map fNIRS signals to broader neural activity patterns. We scanned participants with fNIRS and utilized a publicly available fMRI dataset of participants watching the same TV episode. The model was trained on the first half of the episode and tested on a held-out participant watching the second half to assess cross-individual and cross-stimulus generalizability. The model significantly predicted fMRI time courses in 66 out of 122 brain regions, including areas otherwise inaccessible to fNIRS. It also replicated intersubject functional connectivity patterns and retained semantic information about the movie content. The model generalized to an independent dataset from a different TV series, suggesting it captures robust cross-modal mappings across stimuli. Our publicly available models enable researchers to infer broader neural dynamics from localized fNIRS data during naturalistic tasks.

To evaluate the efficacy of transcranial direct current stimulation (tDCS) in reducing the incidence of postoperative delirium (POD) in elderly patients undergoing hip fracture surgery.

This single-center, double-blind, randomized controlled trial will enroll 160 participants aged 65 years and older, scheduled for elective hip surgery under spinal anesthesia. Participants will be randomly assigned to either the active-tDCS group or the sham-tDCS group. The active-tDCS group will receive two sessions: one pre-surgery and one post-surgery, with electrodes positioned over the left dorsolateral prefrontal cortex and the right supraorbital area. Each session includes 15-second ramp-up phase at the start, 20 min simulation with 2 mA current and 15-second ramp-down phase at the end. The sham-tDCS group will receive two sham procedures with no actual current delivered. Functional brain activity will be monitored before and after each session or sham procedure to assess changes in cortical activation and connectivity using functional near-infrared spectroscopy (fNIRS). The primary outcome measure will be the incidence of POD, assessed using the 3-Min Diagnostic Interview for Confusion Assessment Method (3D-CAM). Secondary outcomes include the severity of delirium, postoperative pain, anxiety, depression, cognitive function, and sleep quality.

The trial was registered at ClinicalTrials.gov (NCT06678529) on Oct 22, 2024.

BackgroundBalance impairments and fatigue are common after stroke and impact physical therapy assessments and treatments. Reasons are multifactorial and include motor dysfunction and changes to cortical activation poststroke. The prefrontal cortex (PFC) is involved in motor control; yet, limited research has explored cortical activation during common physical therapy balance tasks or the link with fatigue.ObjectivesDuring standing balance tasks, the objective was to determine whether PFC activation levels: (1) change between tasks, (2) are asymmetric, and (3) are associated with fatigue.MethodsPatients with hemiparesis were recruited from an inpatient stroke unit and functional near-infrared spectroscopy was applied bilaterally over the PFC to measure cortical activation during balance tasks. Fatigue was assessed using the Fatigue Severity Scale (FSS).ResultsNine participants were included. PFC activation during semi-tandem stance showed greater amplitude than during double-leg stance, indicating more cortical activation. Bilateral PFC activation was observed during both tasks. Participants with greater fatigue (higher FSS score) showed more activation in the ipsilesional PFC than the contralesional PFC.ConclusionPFC activation may occur when performing more challenging balance postures, potentially indicating compensatory activation, and may be linked with greater fatigue.

This study aimed to investigate cortical activation and functional connectivity during Stroop task performance in Parkinson's disease (PD) using functional near-infrared spectroscopy (fNIRS).

Forty-five individuals with PD and fourteen healthy controls completed neuropsychological assessments and underwent fNIRS scanning while performing the Stroop task. PD participants were categorized into normal cognition (PD-NC, n = 6), mild cognitive impairment (PD-MCI, n = 22), and dementia (PDD, n = 17) groups. Z scores were calculated across cognitive domains, including attention, working memory, executive function, language, memory, and visuospatial function.

During the Stroop task, significant hypoactivation in the dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1), and premotor cortex (PMC) were observed in the PD-MCI group, while PDD patients showed increased activation in the medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), and dorsolateral prefrontal cortex (DLPFC). Increased activation in DLPFC was significantly correlated with poorer executive function outcomes. Functional connectivity analysis revealed that both PD-NC and PD-MCI groups had significantly enhanced interhemispheric connectivity compared to healthy controls, with pronounced interhemispheric connectivity in PD-MCI. In contrast, the PDD group exhibited reduced connectivity among the premotor cortex (PMC), ventrolateral prefrontal cortex (VLPFC), and orbitofrontal cortex (OFC), compared to the PD-MCI group.

While PD-MCI patients showed reduced cortical activation relative to PDD, they exhibited extensive connectivity across cortical regions, suggesting an expanded cortical network as compensation. In PDD, the mPFC, left OFC, and left DLPFC displayed the highest cortical activation and alongside reduced functional connectivity, which may reflect widespread atrophy across multiple brain regions. These findings highlight fNIRS as a potential tool for characterizing cognitive impairment stages in PD.

Chronic post-surgical pain (CPSP) poses significant socioeconomic and humanitarian challenges. This study investigated relationships between resting-state neural activation in the somatosensory cortex (SMC) and emotional functioning outcomes (depression, anxiety, perceived stress), and between prefrontal cortex (PFC) activation and chronic stress, measured by hair cortisol concentration (HCC); and whether pain intensity moderates these relationships in females with CPSP. Twenty-nine females with CPSP reported baseline pain, completed emotional functioning questionnaires, underwent functional Near-Infrared Spectroscopy, and provided hair samples for HCC analysis. Pearson's correlation examined associations between emotional functioning and SMC activation, and between HCC and PFC activation. Benjamini-Hochberg correction adjusted for multiple comparisons. Significant correlations were further tested using moderation analyses to assess whether pain intensity influenced these associations. Left SMC activation was positively correlated with depressive symptoms (r = 0.505, pFDR = 0.036) and anxiety(r = 0.705, pFDR = 0.039). Right lateral PFC activation showed a negative correlation with HCC (r = -0.475, pFDR = 0.048). Pain intensity did not significantly moderate these relationships. Findings suggest associations between brain activity and emotional functioning in females with CPSP, highlighting potential neural targets for future interventions. This study supports the utility of multimodal approaches to further phenotype CPSP and inform precision medicine strategies.

Early detection of mild cognitive impairment (MCI) is crucial for preventing Alzheimer's disease (AD). This study aims to explore alterations in brain co-functional connectivity between cognitively healthy individuals and those with cognitive impairment during a verbal fluency task (VFT) using functional near-infrared spectroscopy (fNIRS). The investigation examines changes in brain activation patterns in both MCI patients and healthy controls during the VFT and 1-back task, and identifies correlations between cognitive function and brain activation areas using fNIRS technology.

This study evaluated markers for screening MCI by performing the VFT and 1-back task using a 67-channel fNIRS to measure changes in oxyhemoglobin (HbO) levels in the bilateral prefrontal and temporal lobes of 108 healthy controls (HC) and 103 participants with MCI. The severity of patients' symptoms was assessed using the Montreal Cognitive Assessment (MoCA) scale, neuropsychiatric symptoms were evaluated with the Symptom Checklist-90 (SCL-90), and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI).

Compared with the HC group, the MCI group showed a significant reduction in MoCA scores, with no significant differences in education level, PSQI, and SCL-90 scores. There was no significant difference in brain activation levels between the MCI and HC groups during the VFT. However, during the 1-back task, the MCI group exhibited significantly reduced activation levels in channels 33, 54, 49, and 47, as well as in the dorsolateral prefrontal cortex (DLPFC) and frontal eye fields (FEF). Moreover, the mean HbO levels in these channels, DLPFC, and FEF during the 1-back task were found to be significantly correlated with MoCA scores.

When performing the VFT and 1-back task, our study found that patients with MCI exhibited reduced brain activity levels in the DLPFC and FEF only during the 1-back task. This diminished task-induced brain activity was significantly positively correlated with MoCA scores and was less influenced by mental health and sleep quality. The 1-back task may be a more optimal paradigm for the early detection of MCI compared to the VFT.

Attention plays a vital part in the cognitive process, where different kinds of attention are associated with separate brain mechanisms. The objective of this research was to investigate the patterns of brain activation and functional connectivity in middle-aged and elderly individuals, while they were engaged in various attentional tasks, with the intention of establishing a reference foundation for the clinical treatment of attention disorders.

A total of 44 healthy middle-aged and elderly persons (47.1% women) aged over 40 were enrolled in this study. The digital cancellation test (DCT), the paced auditory serial addition test (PASAT), the Stroop colour-word test, and the trail making test (TMT) are, respectively, associated with four types of attention tasks: sustained attention, divided attention, selective attention, and attention shifting. Functional near-infrared spectroscopic imaging was employed to measure the concentration of brain oxyhaemoglobin in the subjects, while they were performing these four attention tasks.

In this study, we found distinct activation patterns in brain areas, such as BA-3, BA-4, BA-6, and others. Functional connectivity analysis revealed that the frontal and right parietal lobes consistently showed higher density and strength of connections across tasks, with the PASAT task exhibiting the highest number of connections exceeding the threshold. Notably, the DCT task demonstrated significant correlations in oxygen fluctuations among several brain regions, while the TMT-B task highlighted strong functional connectivity within the bilateral frontal and parietal lobes.

This research provides evidence that middle-aged and elderly people have different brain activation and functional connectivity patterns in different attentional tasks, suggesting individualized treatment for attention disorder patients based on impairment type and location.

This study has been registered through the Chinese Clinical Trial Registry (ChiCTR2400087755).

Classroom teaching is essential for cognitive development and cultural evolution, yet its neurocognitive mechanisms remain unclear. Here, this is explored in a university graduate course by combining wearable functional near-infrared spectroscopy (fNIRS) and machine learning models. The results show that blended teaching involving both students' recalling and teachers' lecturing leads to better learning outcomes than lecturing alone. Moreover, during the same lecturing phase, blended teaching induces knowledge construction in the middle frontal cortex (MFC), while lecturing alone induces knowledge representation in the right temporoparietal junction (TPJ), with the former significantly correlating with the final learning outcomes. Additionally, the MFC's construction begins during earlier recalling but is significantly facilitated by later lecturing. Finally, when teacher's TPJ activity precedes that of students' MFC, significant teacher-student neural synchronization is observed during lecturing of blended teaching and is correlated with learning outcomes. These findings suggest that, in the real classroom teaching, the MFC serves as a hub of a rapid cortical learning process, supporting knowledge construction through a projection from the teacher's TPJ.

Empirical studies have shown immediate detrimental effects of TV viewing on children's executive functions (EFs). Existing theories of TV viewing have proposed that such depletion could occur due to fantastical cartoons triggering an attention bias towards salient features of the stimuli (e.g., stimulus-driven exogenous attention). However, a co-occurrence of salient visual features known to drive attention exogenously in fantastical cartoons means it is unclear which aspect of the content is problematic. In the present study, we matched clips on visual saliency to isolate and test the short-term impact of fantastical content. Specifically, we tested (1) performance on an inhibitory control (IC) task (a gaze-contingent anti-saccade task) as a measure of EF depletion, whilst 36 toddlers (18 months) viewed cartoons with and without fantastical events (7-min viewing duration), and (2) whether differences in IC are associated with increased stimulus-driven exogenous attention. Results confirmed an immediate detrimental effect of fantastical cartoons on toddlers' endogenous control (indexed by anti-saccade behaviours), with toddlers less able to inhibit looks to a distractor to make anticipatory looks to a target. However, fixation durations (FDs) during cartoon viewing and speed of orienting to a distractor on the anti-saccade task did not differ between the two viewing conditions, suggesting no effects on exogenously driven attention. These results point to a detrimental impact of fantastical cartoons on endogenous control mechanisms, which may have arisen from cognitive processing difficulties.

Short-term memory poses a significant challenge, involving complex processes of image perception, memory formation, and execution. However, the mechanisms underlying the formation, storage, and execution of short-term memory remain poorly understood.

In this study, 41 healthy college students participated in a memory challenge test designed to investigate these processes. Functional near-infrared spectroscopy (fNIRS) was employed to measure dynamic changes in hemoglobin concentrations in specific cortical regions, while facial expressions and vital signs were recorded in real-time during the tests.

The results revealed heightened activity in the inferior prefrontal gyrus, visual association cortex, pre-motor cortex, and supplementary motor cortex. Functional connectivity between these regions was significantly enhanced during the tasks, and inter-group differences decreased over time. Participants with superior short-term memory exhibited lower levels of negative emotional expressions and higher heart rates compared to those with weaker memory performance. These findings suggest that cortical interconnectivity and adequate cerebral blood oxygenation play critical roles in enhancing short-term memory capacity. This has important implications for education, as it highlights strategies for cultivating attention, training memory skills, and improving memory integration abilities.

Simultaneous eye tracking and cerebral hemodynamic monitoring contribute to the understanding of neural responses to stimuli in infants. However, exploring the impact of complex socioeconomic and environmental adversities on neurodevelopment requires transitioning this tool from research laboratories into clinical practice to evaluate its feasibility in outpatient contexts.

This study aimed to present a protocol for simultaneously integrating functional near-infrared spectroscopy (fNIRS) with eye tracking (ET) in infants at risk for neurodevelopmental disorders in a clinical setting with limited resources, during a cognitive task.

The protocol was applied to infants in their first 12 months of life. The infants were exposed to tasks involving the processing of social and non-social stimuli, while their brain signals were monitored using fNIRS and their eyes were tracked with ET. The protocol included three main stages: (1) pre-collection, involving the preparation and habituation of the infants and equipment setup (fNIRS and ET); (2) cognitive function monitoring, using social and non-social stimuli to assess preferential processing via fNIRS and ET; and (3) post-collection, with guidelines for data pre-processing and analysis.

The application of the protocol allowed for the identification of technical challenges and the adaptation of procedures for clinical use. The main methodological challenges were difficulty using the conventional cap, excessive movement, synchronization issues between fNIRS and ET, and difficulties calibrating both devices across different age groups.

The standardization proposed in this protocol enables healthcare professionals to explore different neurocognitive aspects in pediatric clinical settings and expands the scope of neurodevelopmental assessments.

This study aimed to investigate age-related changes in brain functional connectivity during various motor and cognitive tasks, providing evidence for evaluating and intervening in brain aging.

15 elderly participants (ELD) and 30 young controls (YOU) were assessed. fNIRS haemodynamic responses were recorded during the Purdue nail board motor task, continuous minus 7 cognitive task, and motor-cognitive dual task. Differences in brain activation, functional connectivity, integral values, and barycentre values between the groups were compared using oxygenated haemoglobin (HbO) concentrations over time.

The ELD group performed significantly worse than the YOU group (p < 0.05). ELD participants showed significantly lower activation in the LSMA during motor tasks (p < 0.05), the RDLPFC and LDLPFC during cognitive tasks (p < 0.05), and both RSMA and LSMA during dual tasks (p < 0.05). Functional connectivity between LDLPFC, RSMA, LSMA, and RDLPFC-LDLPFC, LSMA-RSMA in the ELD group was significantly lower than in the YOU group (p < 0.05). The ELD group also had lower connectivity in RSMA, RDLPFC-LDLPFC, and LSMA-RSMA during cognitive tasks (p < 0.05). The centre of gravity for the ELD group was significantly lower during dual tasks compared to the YOU group (p < 0.05). In cognitive tasks, the ELD group showed significantly lower RSMA centre of gravity and integral values compared to dual tasks (p = 0.05).

Elderly individuals exhibit lower cortical brain connectivity than young people across various tasks. fNIRS-based cerebral haemodynamics provide a useful quantitative measure for evaluating age-related brain changes.

Occupational workload can contribute to significant health problems such as chronic stress, fatigue and burnout. To investigate the underlying mechanisms, it is necessary to monitor brain activity in real work environments. Functional near-infrared spectroscopy (fNIRS) is a portable, non-invasive neuroimaging method that captures neural correlates of occupational workload under natural conditions. However, despite its increasing application, a comprehensive overview of fNIRS-based research in this field is lacking. Therefore, this systematic review examines how fNIRS can be utilized to investigate occupational workload.

Following PRISMA 2020 guidelines, we conducted our systematic review by searching Web of Science, PubMed, and Scopus between November 15, 2023 and March 20, 2025. We included all studies published in English or German at any date, as long as they examined healthy adult professionals performing occupational tasks with functional near-infrared spectroscopy (fNIRS). Extracted data included study characteristics, workload details, signal processing methods, main fNIRS findings, and study quality, assessed using the JBI Critical Appraisal Tool.

We included 41 studies. Of these, 23 reported a significant increase in oxygenated hemoglobin (HbO) concentration and functional connectivity in the prefrontal cortex (PFC) under higher occupational workload conditions. Only five studies examined typical office tasks. Nine studies analyzed differences in cortical activation between experts and novices, with experts showing increased HbO concentration in the PFC than novices. Regarding methodology, 26 studies used standardized optode placements, while only 17 applied systemic and extracerebral artifact correction. Small sample sizes and the absence of randomized controlled trials limited the reliability and reproducibility of the findings.

Functional near-infrared spectroscopy effectively detects neural correlates of occupational workload and provides objective insights into cognitive demands in real-world work settings. Standardizing optode placement, harmonizing signal-processing methods, and increasing sample sizes would enhance the validity and comparability of future research. Expanding investigations to typical office environments is also crucial for understanding daily workload and for developing interventions that promote employee well-being and productivity. Overall, fNIRS represents a promising tool for establishing evidence-based workplace health promotion strategies across diverse occupational settings.

Subjective evaluation of a sport event in real time is normally assessed using self-report measures, but neural indices of evaluative processing may provide new insights. The extent of evaluative processing of a sporting event at the neural level may depend on the degree of emotional investment by the viewer, as well as the key moment of the game play being observed. Those with high ego involvement might show more activation within evaluative processing nodes, and this pattern may be most pronounced during critical moments of game play. In the current study, we examined neural activations within the medial and lateral prefrontal cortex during game play as a function of ego involvement, using video clips featuring key moments in a European league ice hockey game. A total of 343 participants were pre-screened to identify high (n = 11) and low (n = 9) ego-involved individuals. These subgroups then viewed a game segment containing 12 key play moments, while undergoing neuroimaging using functional near-infrared spectroscopy (fNIRS). Findings indicated more engagement of the dorsomedial prefrontal cortex (dmPFC) throughout all key moments for high ego-involved participants, but particularly during critical game moments. Overall, findings suggest that neural indices of evaluative processing might contribute meaningfully to understanding when emotionally invested individuals are most engaged in an action sequence during a sporting event.

Functional near-infrared spectroscopy (fNIRS) has become a well-established tool for neuroscience research and been suggested as a potential biomarker during clinical assessment in individuals with mental disorders. Biomarker need to be objective indications of biological processes which can be measured accurately and reproducibly. Despite various applications in clinical research, test-retest reliability of the fNIRS signal has not yet been evaluated sufficiently. To assess reliability of the fNIRS signal during tasks of executive functions, a group of 34 healthy subjects (13 male, 21 female) were tested twice for inhibitory control and working memory. On a group level results show a specific activation pattern throughout the two sessions, reflecting a task-related frontal network associated with the assessed cognitive functions. On the individual level the retest reliability of the activation patterns were considerably lower and differed strongly between participants. In conclusion, the interpretation of fNIRS signal on a single subject level is partially hampered by its low reliability. More studies are needed to optimize the retest reliability of fNIRS and to be applied on a routine basis in developmental research.

Individuals' risk preferences have been shown to influence their decision-making in various contexts. However, the neural mechanisms underlying the relationship between risk preference and decision-making in a social setting remain unclear. This study utilized functional near-infrared spectroscopy (fNIRS) to investigate the neural correlates of dyadic decision-making under risk and the modulating effect of individual risk preference.

This study examined the impact of risk preference on group decision-making using a two-phase experimental design. Based on G-power software calculations, 168 right-handed participants (62 males, 106 females, mean age 21.26±1.70) were recruited. Participants first completed a single-player Sequential Risk Task to measure risk preference, followed by group classification into three groups: Risky&Risky, Risky&Safe, and Safe&Safe. Task performance and decision-making behavior were recorded. Functional Near-Infrared Spectroscopy (fNIRS) was employed to measure cortical activation in the prefrontal cortex, focusing on inter-brain synchrony and coupling directionality using wavelet coherence and Granger causality(GC) analyses. Data were preprocessed to remove noise, and statistical analyses included repeated measures ANOVAs, Support Vector Regression and multiple regression analyses.

The study investigated dyadic risky decision-making among different paired groups, and the "Risky&Risky" group showed the highest risk-seeking behavior, with a significant main effect (F(2,81) = 7.438, P = 0.001). Inter-brain synchrony showed significance during outcome periods characterized by positive feedback, notably being higher within the "Risky&Risky" group. Granger causality analysis unveiled unique brain connectivity patterns, indicating that the GC values of "Risky&Safe" pairs increased during the diversion condition and decreased during the cooperation condition in comparison to other pairs, albeit without reaching statistical significance. Regression analysis indicated that OFC-mdlPFC GC values and personality traits were significant predictors of risk-taking, with the moderation of these effects by group membership (R²adjusted = 0.173 and 0.191).

This study employed fNIRS hyperscanning to investigate how individual differences in risk preference impact decision-making in dyadic contexts. The results indicated that variations in connectivity and information transfer between the orbitofrontal and medial prefrontal cortices underlie the distinct risk-taking behaviors exhibited by dyadic pairs. These findings underscore the pivotal role of affective and cognitive control mechanisms and individual risk personality traits in cooperative decision-making under conditions of uncertainty.

Reinvestment is a psychological phenomenon during which people consciously engage in controlling their movements (i.e., movement-specific reinvestment) or decision making (i.e., decision-specific reinvestment). This can result in performance deterioration and can have detrimental consequences for individuals in various sports.

This systematic review aimed to identify psychophysiological correlates of reinvestment to tackle the need for more objective measurements of reinvestment and to develop interventions to counteract performance-related decrements in the future. Considering brain, parasympathetic and oculomotor activity, jointly adds a holistic perspective on mechanisms underlying reinvestment.

We conducted a systematic literature search using the PRISMA guidelines in three electronic databases (Pubmed, Web of Science and SportDiscus) on 20th of November 2024. The included studies assessed reinvestment together with psychophysiological parameters. The risk of bias of the included studies was assessed by the authors using "The Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross Sectional Studies" (Moola et al., 2020).

A total of N = 21 studies containing a total of 791 participants were included. Of these, twelve studies considered brain activity, five considered parasympathetic cardiac activity, and two considered heart rate. Finally, two studies considered gaze behavior.

The findings indicate potential relationships between reinvestment and the considered psychophysiological parameters, but methods and findings appear heterogeneous in terms of task variability, population groups, and study design. To be able to draw more accurate conclusions, more systematic research programs are required to move towards a better holistic understanding of the psychophysiological correlates of reinvestment.

Flow is the state of optimal experience which can lead to outstanding performance. Our study demonstrates the feasibility of detecting and monitoring flow using wearable devices. Twenty-eight Hungarian adults participated in the experiment. They played a game at different levels to induce flow and anti-flow states, which was tested with questionnaires. We measured electroencephalography (EEG), heart rate (HR), blood oxygen saturation (SpO2) and galvanic skin response (GSR) signals as well as head and hand motion. We isolated EEG delta, theta, alpha and beta band power, HR, SpO2 and GSR average and standard deviation, as well as acceleration and angular velocity standard deviation. In flow condition, alpha and theta power were the dominant components, in accordance with the transient hypofrontality hypothesis. We also replicated the U-shaped characteristic of the heart rate variability; in addition, we propose an inverse U-shaped and a U-shaped characteristic for SpO2 and SpO2 variability, respectively. On the basis of motion tracking, subjects were the least physically active in flow, signifying a focused state, and the most active in boredom. Our results support the applicability of lightweight, wearable devices for monitoring mental state that can be utilized to improve well-being at work or in everyday situations.

A shared understanding of terminology is essential for clear scientific communication and minimizing misconceptions. This is particularly challenging in rapidly expanding, interdisciplinary domains that utilize functional near-infrared spectroscopy (fNIRS), where researchers come from diverse backgrounds and apply their expertise in fields such as engineering, neuroscience, and psychology.

The fNIRS Glossary Project was established to develop a community-sourced glossary covering key fNIRS terms, including those related to the continuous-wave (CW), frequency-domain (FD), and time-domain (TD) NIRS techniques.

The glossary was collaboratively developed by a diverse group of 76 fNIRS researchers, representing a wide range of career stages (from PhD students to experts) and disciplines. This collaborative process, structured across five phases, ensured the glossary's depth and comprehensiveness.

The glossary features over 300 terms categorized into six key domains: analysis, experimental design, hardware, neuroscience, mathematics, and physics. It also includes abbreviations, symbols, synonyms, references, alternative definitions, and figures where relevant.

The fNIRS glossary provides a community-sourced resource that facilitates education and effective scientific communication within the fNIRS community and related fields. By lowering barriers to learning and engaging with fNIRS, the glossary is poised to benefit a broad spectrum of researchers, including those with limited access to educational resources.

The influence of hypoxia - a condition where tissues are under oxygen deficiency - on the human brain under functional load has not been fully understood yet. This study aims to analyse the effects of hypoxia on the brain's haemodynamic response under visual stimulation, using the in-house developed functional near-infrared spectroscopy system and to quantify the hemodynamic response. Our results (median, 25th and 75th percentile) demonstrate the amplitude of the oxygenated haemoglobin functional response during hypoxia 0.30 µM (0.27, 0.41) was lower compared with the normoxia 0.63 µM (0.54, 0.93) and hyperoxia 0.73 µM (0.43, 1.09). No statistical significance is observed for the deoxygenated haemoglobin changes. The hypoxia has a statistically significant effect on the amplitude of the haemodynamic response (p < 0.001).

A fundamental characteristic of social exchanges is the synchronization of individuals' behaviors, physiological responses, and neural activity. However, the association between how individuals communicate in terms of emotional content and expressed associative knowledge and interpersonal synchrony has been scarcely investigated so far. This study addresses this research gap by bridging recent advances in cognitive neuroscience data, affective computing, and cognitive data science frameworks. Using functional near-infrared spectroscopy (fNIRS) hyperscanning, prefrontal neural data were collected during social interactions involving 84 participants (i.e., 42 dyads) aged 18-35 years. Wavelet transform coherence was used to assess interpersonal neural synchrony between participants. We used manual transcription of dialogues and automated methods to codify transcriptions as emotional levels and syntactic/semantic networks. Our quantitative findings reveal higher than random expectations levels of interpersonal neural synchrony in the superior frontal gyrus (q = .038) and the bilateral middle frontal gyri (q< .001, q< .001). Linear mixed models based on dialogues' emotional content only significantly predicted interpersonal neural synchrony across the prefrontal cortex (Rmarginal2=3.62%). Conversely, models relying on syntactic/semantic features were more effective at the local level, for predicting brain synchrony in the right middle frontal gyrus (Rmarginal2=9.97%). Generally, models based on the emotional content of dialogues were not effective when limited to data from one region of interest at a time, whereas models based on syntactic/semantic features show the opposite trend, losing predictive power when incorporating data from all regions of interest. Moreover, we found an interplay between emotions and associative knowledge in predicting brain synchrony, providing quantitative support to the major role played by these linguistic components in social interactions and in prefrontal processes. Our study identifies a mind-brain duality in emotions and associative knowledge reflecting neural synchrony levels, opening new ways for investigating human interactions.

Repetitive transcranial magnetic stimulation (rTMS) emerges as a promising non-invasive neuromodulation technique for the treatment of patients with disorders of consciousness (DOC). The selection of rTMS parameters significantly influences the clinical therapeutic effects. However, the differences in spatiotemporal responsiveness of the brain under different rTMS stimulation frequencies remain unclear. In this pilot study, functional near-infrared spectroscopy (fNIRS) was used to evaluate the spatiotemporal differences in hemodynamic responses elicited by rTMS at different frequencies (1, 5, 10, 15, and 20 Hz) over left dorsolateral prefrontal cortex (F3). The results showed that the distribution patterns of the rTMS-evoked hemodynamic responses varied across different frequencies, indicating that rTMS frequency influences the hemodynamic responses in patients with DOC. Specifically, 10 Hz rTMS evoked strong positive hemodynamic responses over the frontal cortex, particularly in the right dorsolateral prefrontal cortex (R-DLPFC). Additionally, 20 Hz rTMS produced largepositive hemodynamic responses over the motor-related cortex, especially the right premotor cortex (R-PreM) and right primary sensorimotor cortex (PSMC). The current findings suggested that fNIRS can be used as a promising tool for evaluating the effects of rTMS in patients with DOC. Moreover, it provides useful guidance for the personalized design of rTMS parameters in a clinical environment.