Functional near infrared spectroscopy detects cortical activation changes concurrent with memory loss in postmenopausal women with Type II Diabetes.

Older adults with Type II Diabetes Mellitus (DM) experience mild cognitive impairment, specifically in the domain of recall/working memory. No consistent causative structural cortical deficits have been identified in persons with DM (PwDM). Memory deficits may be exacerbated in older adult females, who are at the highest risk of cardiovascular decline due to DM. The focus of the current study was to evaluate functional cortical hemodynamic activity during memory tasks in postmenopausal PwDM. Functional Near Infrared Spectroscopy (fNIRS) was used to monitor oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) during memory-based tasks in a cross-sectional sample of postmenopausal women with DM. Twenty-one community-dwelling DM females (age = 65 ± 6 years) and twenty-one age- and sex-matched healthy controls (age = 66 ± 6 years) were evaluated. Working memory performance (via N-back) was evaluated while study participants donned cortical fNIRS. Health state, metabolic data, and menopausal status data were also collected. Deficits in working memory accuracy were found in the DM group as compared to controls. Differences in HbO responses emerged in the DM group. The DM group exhibited altered PFC activity magnitudes and increased functional cortical activity across ROIs compared to controls. HbO and HbR responses were not associated with worsened health state measures. These data indicate a shift in cortical activity patterns with memory deficits in postmenopausal PwDM. This DM-specific shift of HbO is a novel finding that is unlikely to be detected by fMRI. This underscores the value of using non-MRI-based neuroimaging techniques to evaluate cortical hemodynamic function to detect early mild cognitive impairment.

Listening to Remotely Monitored Home-based Preferred Music for Pain in Older Black Adults with Low Back Pain: A Pilot Study of Feasibility and Acceptability.

BACKGROUND: Low back pain (LBP) is a complex condition that is widespread among older Black adults. Nonpharmacologic interventions are recommended as first-line therapy, but their use in practice is limited, possibly due to misunderstanding of their analgesic characteristics. AIM: To determine the feasibility and acceptability of listening to preferred music at home to relieve pain in older Black adults aged 65 years or older with LBP. METHOD: We recruited 20 community-dwelling older adults (≥65 years) with LBP to use noise-isolating headphones to listen to their preferred music for 20 minutes twice daily for four days via the MUSIC CARE® app. Feasibility was determined using enrollment, adherence, and attrition rates, and acceptability was determined using the Treatment Acceptance and Preference (TAP) scale. Average pain scores were self-reported using the Numeric Rating Scale (NRS) after the second intervention of the day. Pain scores were evaluated using paired sample t test and repeated-measures ANOVA. RESULTS: Enrollment, adherence, and attrition rates were 95.25%, 100.00%, and 0.00%, respectively. Most participants rated the TAP scale at ≥3, indicating acceptance. Pain scores decreased significantly from baseline (M = 46.90, SD = 21.47) to post-intervention (M = 35.70, SD = 16.57), t (19) = 2.29, p = .03. Repeated measures ANOVA showed a significant decrease in mean pain scores over time [F (2.36, 44.88) = 5.61, p = .004, η2 = .23]. CONCLUSIONS: Listening to preferred music for 20 minutes twice a day is a feasible and acceptable intervention that can considerably reduce pain in older Black adults with LBP.

Assessing the impact of preferred web app-based music-listening on pain processing at the central nervous level in older black adults with low back pain: An fNIRS study.

BACKGROUND: Low back pain (LBP) disproportionately affects older black adults, often leading to inadequate treatment due to clinician biases. Objective pain measures are imperative, and Functional Near-Infrared Spectroscopy (fNIRS) shows promise for pain detection. AIM: To determine the impact of listening to home-based preferred web app-based music on underlying pain processing mechanisms at the central nervous level in older black adults aged ≥65 with LBP. METHODS: Twenty older black adults with LBP listened to preferred music twice daily for four days using the MUSIC CARE® app. Neuroimaging data were collected using fNIRS. Data were transformed to changes in oxy-hemoglobin and deoxy-hemoglobin concentrations and analyzed. RESULTS: Significant cortical activation pattern differences were observed between pre-and post-intervention scans, particularly in somatosensory regions. Post-intervention scans showed significantly reduced hemodynamic activities. CONCLUSION: Preferred music listening has the potential to alleviate pain, and fNIRS emerges as a promising tool for exploring cortical-level pain-related neural circuits.

Links between socioeconomic disadvantage, neural function, and working memory in early childhood.

Children reared in socioeconomically disadvantaged environments are at risk for academic, cognitive, and behavioral problems. Mounting evidence suggests that childhood adversities, encountered at disproportionate rates in contexts of socioeconomic risk, shape the developing brain in ways that explain disparities. Circuitries that subserve neurocognitive functions related to memory, attention, and cognitive control are especially affected. However, most work showing altered neural function has focused on middle childhood and adolescence. Understanding alterations in brain development during foundational points in early childhood is a key next step. To address this gap, we examined functional near-infrared-spectroscopy-based neural activation during a working memory (WM) task in young children aged 4-7 years (N = 30) who varied in socioeconomic risk exposure. Children who experienced greater disadvantage (lower income to needs ratio and lower Hollingshead index) exhibited lower activation in the lateral prefrontal cortex than children who experienced less to no disadvantage. Variability in prefrontal cortex activation, but not behavioral performance on the WM task, was associated with worse executive functioning in children as reported by parents. These findings add to existing evidence that exposure to early adversity, such as socioeconomic risk, may lead to foundational changes in the developing brain, which increases risk for disparities in functioning across multiple cognitive and social domains.

Local syntactic violations evoke fast mismatch-related neural activity detected by optical neuroimaging.

It remains to be investigated whether syntax-related mismatch activity would be evoked in event-related optical signals by syntactic violations that deviate from our language knowledge and expectations. In the current study, we have employed fast optical neuroimaging with a frequency-domain oximeter to examine whether syntactic violations of English bare infinitives in the non-finite complement clause would trigger syntax-related mismatch effects. Recorded sentences of bare or full infinitive structures (without or with the 'to' infinitival marker) with syntactically correct or incorrect versions and non-syntactic lexical items (verbs) were presented to native speakers of English (n = 8) during silent movie viewing as a passive oddball task. The analysis of source strength (i.e., minimum norm current amplitudes) revealed that the syntactic category violations of bare object infinitives led to significantly more robust optical mismatch effects than the other syntactic violation and non-structural, lexical elements. This mismatch response had a peak latency of 186 ms in the left anterior superior temporal gyrus. In combination with our prior MEG report (Kubota et al. in Neurosci Lett 662:195-204, 2018), the present optical neuroimaging findings show that syntactic marking (unmarked-to-marked) violations of the bare object infinitive against the rule of the mental grammar enhance the signal strength exactly in the same manner seen with MEG scanning, including the peak latency of mismatch activity and the activated area of the brain.

Hemodynamic Function of Forearm Muscle in Postmenopausal Women With Type 2 Diabetes.

Changes in the hemodynamic function of muscle are speculated as a causal mechanism for reduced motor capabilities with aging in Type 2 diabetes mellitus (DM). The focus of this study was to evaluate changes in muscle oxygenation during sustained force production in postmenopausal women with DM compared with controls. Near-infrared spectroscopy was used to monitor deoxyhemoglobin and oxyhemoglobin in the flexor digitorum superficialis. Sensorimotor function and health state covariates were also assessed. Increased deoxyhemoglobin was found during force production, whereas oxyhemoglobin remained constant. Changes were found in the time structure of the hemodynamic data during force production. No between-group differences were found; instead, measures covaried with the health state. Sex-based differences in the manifestation of DM-related sensorimotor dysfunction are likely. These data indicate that basic cardiovascular health measures may be more beneficial to monitoring hyperemic status and muscle function in postmenopausal women with DM, compared with DM diagnosis.

Hemodynamic function during finger force production tasks in healthy adults.

INTRODUCTION: Near-infrared spectroscopy (NIRS) is a noninvasive technique used to measure muscle hemodynamics. The focus of this study was to evaluate changes in muscle oxygenation during sustained maximal force production in young, healthy control individuals to establish baseline function in an ideal population. METHODS: NIRS was used to monitor reduced hemoglobin (HbR) and oxygenated hemoglobin (HbO) in forearm muscles. Hemodynamic responses during force production tasks were monitored in real time. RESULTS: During handgrip exercises, maximal force production declined significantly. Increased HbR was found while HbO remained constant. The correlation between force production and HbO was positive (r = 0.18), while the correlation between force and HbR was negative (r = -0.48). The application of NIRS to monitor the correlation between force production and hemodynamic measures in the forearm was successful. These data set the foundation for future use of NIRS as a diagnostic tool for individuals with peripheral vascular disease: Muscle Nerve 56: 472-478, 2017.

Cortical Activation Patterns Correlate with Speech Understanding After Cochlear Implantation.

OBJECTIVES: Cochlear implants are a standard therapy for deafness, yet the ability of implanted patients to understand speech varies widely. To better understand this variability in outcomes, the authors used functional near-infrared spectroscopy to image activity within regions of the auditory cortex and compare the results to behavioral measures of speech perception. DESIGN: The authors studied 32 deaf adults hearing through cochlear implants and 35 normal-hearing controls. The authors used functional near-infrared spectroscopy to measure responses within the lateral temporal lobe and the superior temporal gyrus to speech stimuli of varying intelligibility. The speech stimuli included normal speech, channelized speech (vocoded into 20 frequency bands), and scrambled speech (the 20 frequency bands were shuffled in random order). The authors also used environmental sounds as a control stimulus. Behavioral measures consisted of the speech reception threshold, consonant-nucleus-consonant words, and AzBio sentence tests measured in quiet. RESULTS: Both control and implanted participants with good speech perception exhibited greater cortical activations to natural speech than to unintelligible speech. In contrast, implanted participants with poor speech perception had large, indistinguishable cortical activations to all stimuli. The ratio of cortical activation to normal speech to that of scrambled speech directly correlated with the consonant-nucleus-consonant words and AzBio sentences scores. This pattern of cortical activation was not correlated with auditory threshold, age, side of implantation, or time after implantation. Turning off the implant reduced the cortical activations in all implanted participants. CONCLUSIONS: Together, these data indicate that the responses the authors measured within the lateral temporal lobe and the superior temporal gyrus correlate with behavioral measures of speech perception, demonstrating a neural basis for the variability in speech understanding outcomes after cochlear implantation.

A multi-layer monitoring system for clinical management of Congestive Heart Failure.

BACKGROUND: Congestive Heart Failure (CHF) is a serious cardiac condition that brings high risks of urgent hospitalization and death. Remote monitoring systems are well-suited to managing patients suffering from CHF, and can reduce deaths and re-hospitalizations, as shown by the literature, including multiple systematic reviews. METHODS: The monitoring system proposed in this paper aims at helping CHF stakeholders make appropriate decisions in managing the disease and preventing cardiac events, such as decompensation, which can lead to hospitalization or death. Monitoring activities are stratified into three layers: scheduled visits to a hospital following up on a cardiac event, home monitoring visits by nurses, and patient's self-monitoring performed at home using specialized equipment. Appropriate hardware, desktop and mobile software applications were developed to enable a patient's monitoring by all stakeholders. For the first two layers, we designed and implemented a Decision Support System (DSS) using machine learning (Random Forest algorithm) to predict the number of decompensations per year and to assess the heart failure severity based on a variety of clinical data. For the third layer, custom-designed sensors (the Blue Scale system) for electrocardiogram (EKG), pulse transit times, bio-impedance and weight allowed frequent collection of CHF-related data in the comfort of the patient's home. We also performed a short-term Heart Rate Variability (HRV) analysis on electrocardiograms self-acquired by 15 healthy volunteers and compared the obtained parameters with those of 15 CHF patients from PhysioNet's PhysioBank archives. RESULTS: We report numerical performances of the DSS, calculated as multiclass accuracy, sensitivity and specificity in a 10-fold cross-validation. The obtained average accuracies are: 71.9% in predicting the number of decompensations and 81.3% in severity assessment. The most serious class in severity assessment is detected with good sensitivity and specificity (0.87 / 0.95), while, in predicting decompensation, high specificity combined with good sensitivity prevents false alarms. The HRV parameters extracted from the self-measured EKG using the Blue Scale system of sensors are comparable with those reported in the literature about healthy people. CONCLUSIONS: The performance of DSSs trained with new patients confirmed the results of previous work, and emphasizes the strong correlation between some CHF markers, such as brain natriuretic peptide (BNP) and ejection fraction (EF), with the outputs of interest. Comparing HRV parameters from healthy volunteers with HRV parameters obtained from PhysioBank archives, we confirm the literature that considers the HRV a promising method for distinguishing healthy from CHF patients.

Correlation between subcutaneous adipose tissue of the head and body mass index in children and young adults aged 8-19 years: implications for functional neuroimaging.

High body mass index (BMI) is presumed to signify high amounts of fat (subcutaneous adipose tissue) distributed across the body. High amounts of fat co-occurring with increased BMI has been cited as a potential neuroimaging barrier. Presence of increased fat may result in high electrical impedance and increased light diffusion-resulting in low signal to noise ratios during electroencepholography (EEG), functional near-infrared spectroscopy (fNIRS), and transcranial direct current stimulation (tDCS) measurements. Examining if subcutaneous fat in the head increases with respect to total body fat percentage and BMI in school-aged children and adolescents is an essential next step in developing possible mathematical corrections for neuroimaging modalities. We hypothesized that percentage of subcutaneous adipose tissue in the head region would increase with respect to both total body fat percentage and BMI. Increased subcutaneous head fat percentage was associated with a positive linear relationship with BMI and a quadratic relationship with total body fat. The data indicate that participant age, sex, and adiposity should be considered in the development of model corrections for neuroimaging signal processing in school-aged children and adolescents. Strength of regression coefficients in our models differed from those in adults, indicating that age-specific models should be utilized.

Self-administered transcranial direct current stimulation treatment of knee osteoarthritis alters pain-related fNIRS connectivity networks.

Significance: Knee osteoarthritis (OA) is a disease that causes chronic pain in the elderly population. Currently, OA is mainly treated pharmacologically with analgesics, although research has shown that neuromodulation via transcranial direct current stimulation (tDCS) may be beneficial in reducing pain in clinical settings. However, no studies have reported the effects of home-based self-administered tDCS on functional brain networks in older adults with knee OA. Aim: We used functional near-infrared spectroscopy (fNIRS) to investigate the functional connectivity effects of tDCS on underlying pain processing mechanisms at the central nervous level in older adults with knee OA. Approach: Pain-related brain connectivity networks were extracted using fNIRS at baseline and for three consecutive weeks of treatment from 120 subjects randomly assigned to two groups undergoing active tDCS and sham tDCS. Results: Our results showed that the tDCS intervention significantly modulated pain-related connectivity correlation only in the group receiving active treatment. We also found that only the active treatment group showed a significantly reduced number and strength of functional connections evoked during nociception in the prefrontal cortex, primary motor (M1), and primary somatosensory (S1) cortices. To our knowledge, this is the first study in which the effect of tDCS on pain-related connectivity networks is investigated using fNIRS. Conclusions: fNIRS-based functional connectivity can be effectively used to investigate neural circuits of pain at the cortical level in association with nonpharmacological, self-administered tDCS treatment.

Multiple levels of contextual influence on action-based timing behavior and cortical activation.

Procedures used to elicit both behavioral and neurophysiological data to address a particular cognitive question can impact the nature of the data collected. We used functional near-infrared spectroscopy (fNIRS) to assess performance of a modified finger tapping task in which participants performed synchronized or syncopated tapping relative to a metronomic tone. Both versions of the tapping task included a pacing phase (tapping with the tone) followed by a continuation phase (tapping without the tone). Both behavioral and brain-based findings revealed two distinct timing mechanisms underlying the two forms of tapping. Here we investigate the impact of an additional-and extremely subtle-manipulation of the study's experimental design. We measured responses in 23 healthy adults as they performed the two versions of the finger-tapping tasks either blocked by tapping type or alternating from one to the other type during the course of the experiment. As in our previous study, behavioral tapping indices and cortical hemodynamics were monitored, allowing us to compare results across the two study designs. Consistent with previous findings, results reflected distinct, context-dependent parameters of the tapping. Moreover, our results demonstrated a significant impact of study design on rhythmic entrainment in the presence/absence of auditory stimuli. Tapping accuracy and hemodynamic responsivity collectively indicate that the block design context is preferable for studying action-based timing behavior.

Introduction to the shared near infrared spectroscopy format.

Significance: Functional near-infrared spectroscopy (fNIRS) is a popular neuroimaging technique with proliferating hardware platforms, analysis approaches, and software tools. There has not been a standardized file format for storing fNIRS data, which has hindered the sharing of data as well as the adoption and development of software tools. Aim: We endeavored to design a file format to facilitate the analysis and sharing of fNIRS data that is flexible enough to meet the community's needs and sufficiently defined to be implemented consistently across various hardware and software platforms. Approach: The shared NIRS format (SNIRF) specification was developed in consultation with the academic and commercial fNIRS community and the Society for functional Near Infrared Spectroscopy. Results: The SNIRF specification defines a format for fNIRS data acquired using continuous wave, frequency domain, time domain, and diffuse correlation spectroscopy devices. Conclusions: We present the SNIRF along with validation software and example datasets. Support for reading and writing SNIRF data has been implemented by major hardware and software platforms, and the format has found widespread use in the fNIRS community.

Designing devices to communicate effectively with intensive care nurses to prevent pressure injuries: A qualitative study.

OBJECTIVES: The aim of this research was to identify "what" key design elements of a device for detecting hospital acquired pressure injuries should do and "how" these elements should function. The goal of the resulting design was to prompt intensive care unit nurses to intervene appropriately to reduce the incidence/severity of pressure injuries, while minimizing workflow disruptions. METHODS: A mixed method study was performed in an intensive care unit, which included shadowing, interviewing, surveying and conducting focus groups with individuals knowledgeable about pressure injuries and related patient care. This study focused on identifying and prioritizing the needs/wants of nurses regarding devices aimed at detecting hospital acquired pressure injuries. These needs were then used as the foundation for designing key elements of such a device. FINDINGS: Intensive care nurses indicated that a device for the early detection of pressure injuries should communicate information as real-time summaries about the severity of a skin issue in an easy-to-understand manner and provide reminders for them to take action when needed without unnecessarily interrupting their workflow. CONCLUSION: The findings regarding nurses' needs will be useful for the future development of technologies/devices that help reduce the incidence/severity of hospital acquired pressure injuries. In turn, nurses may be more likely to use such a device to enhance patient care.

Correlation between subcutaneous adipose tissue of the head and body mass index: Implications for functional neuroimaging.

High body mass index (BMI) is generally assumed to represent overall amounts of body adipose tissue (fat). Increased adipose tissue amounts in persons with increased BMI has been cited as a barrier to assessment of body tissues such as muscle. Significant increases in the amount of adipose tissue between the dermal layer and the skull may result in high electrical impedance and/or increased light diffusion causing a lower signal to noise ratio during use of neuroimaging tools such as electroencepholography (EEG), transcranial direct current stimulation (tDCS), and functional near infrared spectroscopy (fNIRS). Investigating how subcutaneous adipose tissue in the head region increases with respect to total body fat percentage and BMI is an important step in developing mathematical corrections in neuroimaging measurements as BMI increases, as recommended in other measurement modalities such as electromyography (EMG). We hypothesized that percentage of subcutaneous adipose tissue in the head region would increase with respect to both total body fat percentage and BMI. A statistically significant increase in subcutaneous head fat percentage occurred with increased BMI and total body fat percentage. The data investigated in this study indicate that participant age, sex, and BMI are important features to consider in model corrections during data signal processing and analyses for subcutaneous head fat in neuroimaging approaches. The data in this project serve to provide physiological justification for this practice along with regression analyses to be considered for physiologically-based signal to noise correction algorithms.

Optical imaging and spectroscopy for the study of the human brain: status report.

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions.

Information communication networks in severe traumatic brain injury.

In this study we explored the use of coherence and Granger causality (GC) to separate patients in minimally conscious state (MCS) from patients with severe neurocognitive disorders (SND) that show signs of awareness. We studied 16 patients, 7 MCS and 9 SND with age between 18 and 49 years. Three minutes of ongoing electroencephalographic (EEG) activity was obtained at rest from 19 standard scalp locations, while subjects were alert but kept their eyes closed. GC was formulated in terms of linear autoregressive models that predict the evolution of several EEG time series, each representing the activity of one channel. The entire network of causally connected brain areas can be summarized as a graph of incompletely connected nodes. The 19 channels were grouped into five gross anatomical regions, frontal, left and right temporal, central, and parieto-occipital, while data analysis was performed separately in each of the five classical EEG frequency bands, namely delta, theta, alpha, beta, and gamma. Our results showed that the SND group consistently formed a larger number of connections compared to the MCS group in all frequency bands. Additionally, the number of connections in the delta band (0.1-4 Hz) between the left temporal and parieto-occipital areas was significantly different (P < 0.1%) in the two groups. Furthermore, in the beta band (12-18 Hz), the input to the frontal areas from all other cortical areas was also significantly different (P < 0.1%) in the two groups. Finally, classification of the subjects into distinct groups using as features the number of connections within and between regions in all frequency bands resulted in 100% classification accuracy of all subjects. The results of this study suggest that analysis of brain connectivity networks based on GC can be a highly accurate approach for classifying subjects affected by severe traumatic brain injury.

Longitudinal effect of transcranial direct current stimulation on knee osteoarthritis patients measured by functional infrared spectroscopy: a pilot study.

Significance: Knee osteoarthritis (OA) is a common joint disease causing chronic pain and functional alterations (stiffness and swelling) in the elderly population. OA is currently treated pharmacologically with analgesics, although neuromodulation via transcranial direct current stimulation (tDCS) has recently generated a growing interest as a safe side-effect free treatment alternative or a complement to medications for chronic pain conditions. Although a number of studies have shown that tDCS has a beneficial effect on behavioral measures of pain, the mechanistic action of neuromodulation on pain sensitivity and coping at the central nervous system is not well understood. Aim: We aimed at observing longitudinal changes of cortical hemodynamics in older adults with knee OA associated with a two-week-long tDCS self-treatment protocol. Approach: Hemodynamics was measured bilaterally in the motor and somatosensory cortices with functional near-infrared spectroscopy (fNIRS) in response to thermal pain induced ipsilaterally to the knee primarily affected by OA. Results: We found that both oxyhemoglobin- and deoxyhemoglobin-related functional activations significantly increased during the course of the tDCS treatment, supporting the notion that tDCS yields an increased cortical excitability. Concurrently, clinical measures of pain decreased with tDCS treatment, hinting at a potential spatial dissociation between cortically mediated pain perception and suppression and the prevalence of neuromodulatory effects over cortical pain processing. Conclusions: fNIRS is a valid method for objectively tracking pain in an ambulatory setting and it could potentially be used to inform strategies for optimized tDCS treatment and to develop innovative tDCS protocols.

Tracking differential activation of primary and supplementary motor cortex across timing tasks: An fNIRS validation study.

Functional near-infrared spectroscopy (fNIRS) provides an alternative to functional magnetic resonance imaging (fMRI) for assessing changes in cortical hemodynamics. To establish the utility of fNIRS for measuring differential recruitment of the motor network during the production of timing-based actions, we measured cortical hemodynamic responses in 10 healthy adults while they performed two versions of a finger-tapping task. The task, used in an earlier fMRI study (Jantzen et al., 2004), was designed to track the neural basis of different timing behaviors. Participants paced their tapping to a metronomic tone, then continued tapping at the established pace without the tone. Initial tapping was either synchronous or syncopated relative to the tone. This produced a 2 × 2 design: synchronous or syncopated tapping and pacing the tapping with or continuing without a tone. Accuracy of the timing of tapping was tracked while cortical hemodynamics were monitored using fNIRS. Hemodynamic responses were computed by canonical statistical analysis across trials in each of the four conditions. Task-induced brain activation resulted in significant increases in oxygenated hemoglobin concentration (oxy-Hb) in a broad region in and around the motor cortex. Overall, syncopated tapping was harder behaviorally and produced more cortical activation than synchronous tapping. Thus, we observed significant changes in oxy-Hb in direct relation to the complexity of the task.

Functional Near-Infrared Spectroscopy to Assess Central Pain Responses in a Nonpharmacologic Treatment Trial of Osteoarthritis.

BACKGROUND AND PURPOSE: Knee osteoarthritis (OA) is a common source of pain in older adults. Although OA-induced pain can be relieved with analgesics and anti-inflammatory drugs, the current opioid epidemic is fostering the exploration of nonpharmacologic strategies for pain mitigation. Amongs these, transcranial direct current stimulation (tDCS) and mindfulness-based meditation (MBM) hold potential for pain-relief efficacy due to their neuromodulatory effects of the central nervous system, which is known to play a fundamental role in pain perception and processing. METHODS: In this double-blind study, we used functional near-infrared spectroscopy (fNIRS) to investigate the effects of tDCS combined with MBM on underlying pain processing mechanisms at the central nervous level in older adults with knee OA. Nineteen subjects were randomly assigned to two groups undergoing a 10-day active tDCS and MBM regimen and a sham tDCS and MBM regimen, respectively. RESULTS: Our results showed that the neuromodulatory intervention significantly relieved pain only in the group receiving active treatment. We also found that only the active treatment group showed a significant increase in oxyhemoglobin activation of the superior motor and somatosensory cortices colocated to the placement of the tDCS anodal electrode. To our knowledge, this is the first study in which the combined effect of tDCS and MBM is investigated using fNIRS. CONCLUSION: In conclusion, fNIRS can be effectively used to investigate neural mechanisms of pain at the cortical level in association with nonpharmacological, self-administered treatments.