Search Results (121)

Background: This study examined the impact of amnestic mild cognitive impairment (aMCI) on dynamic changes in cerebrocortical oxygen saturation (ScO₂) and O₂ extraction during acute, moderately intense, normobaric hypoxia and reoxygenation in elderly adults (71 ± 6 years old). Methods: Thirty-two aMCI and thirty-five control subjects participated. Inspired and expired fractions of O₂ and CO₂ (mass spectrometry), arterial O₂ saturation (SaO₂) and prefrontal ScO₂ (near-infrared spectroscopy), heart rate, tidal volume and breathing frequency were monitored while subjects breathed hypoxic air (fractional inspired O₂ 0.10) for 3–5 min (aMCI: 4.5 ± 0.7 min; control: 4.5 ± 0.6 min) and recovered on room air. Values at the pre-hypoxia baseline, the first and last min of hypoxia and the first min of recovery were compared within and between groups using two-factor ANOVA. Results: Despite a similar baseline SaO₂ in aMCI (97.2 ± 1.6%) and control (97.3 ± 1.3%) subjects, prefrontal ScO₂ was lower (p < 0.05) in the aMCI subjects in both the left (67.0 ± 1.7% vs. 69.6 ± 4.5%) and right (66.8 ± 4.6% vs. 69.4 ± 4.1%) hemispheres. Hypoxia similarly decreased SaO₂ and ScO₂ in both groups (last min hypoxia, aMCI vs. control subjects: SaO₂ 76.6 ± 5.3% vs. 77.4 ± 6.1%, left prefrontal ScO₂ 54.0 ± 4.9% vs. 55.2 ± 6.4%, right prefrontal ScO₂ 56.0 ± 4.3% vs. 58.2 ± 4.4%). Upon the resumption of room-air breathing, ScO₂ recovered at similar rates in aMCI and control subjects. Conclusions: Although it produced a greater deoxygenation in the left vs. the right prefrontal cortex, acute, normobaric, moderate hypoxia was well tolerated by elderly adults, even those with aMCI. Dynamic changes in cerebral oxygenation during hypoxia and recovery were unaltered by aMCI. Brief, moderate hypoxia does not impose more intense cerebrocortical oxygen depletion in elderly adults with aMCI, despite pre-hypoxic cerebrocortical oxygenation below that of their non-MCI counterparts. Full article

Background/Objectives: This study aimed to investigate the effects of low and high glycemic index (LGI and HGI) breakfasts on post-exercise cognitive functions and prefrontal hemodynamic responses. Methods: Ten male athletes aged 18–22 years participated in this study. The athletes conducted two laboratory visits in a randomized manner. Athletes were given different glycemic index (GI) levels (low and high) for pre-exercise meals on different days, with the same calorie values, carbohydrate, and fat content. A total of 90 min after breakfast, a 30 min submaximal exercise was performed using a cycling ergometer. During the laboratory visits, blood glucose measurements were performed at the 0th (fasting), 90th (pre-exercise), and 120th (post-exercise) min. Additionally, the “3-Back test” was performed pre- and post-exercise to assess working memory and their prefrontal hemodynamic responses were monitored via functional Near-Infrared Spectroscopy. The collected data were evaluated in the SPSS 22 statistical program. Results: The HGI breakfast led to higher blood glucose levels at the 90th (pre-exercise) and 120th min (post-exercise) than LGI breakfast (p < 0.05). No difference was observed between HGI and LGI breakfasts in the results of the “3-Back Test” performed pre- and post-exercise. In terms of prefrontal hemodynamic responses, no difference was observed in post-exercise oxy-hemoglobin responses between the conditions. Conclusions: The findings of the study indicate that an increase in the glycemic index of breakfast has the potential to affect prefrontal oxygenation responses during cognitive tasks. However, no effect of glycemic index level was observed on cognitive and hemodynamic values at the end of the exercise. Full article

Background/Objectives: Movement during attention-demanding tasks may help compensate for cortical under-arousal in pediatric ADHD patients. However, the influence of medication during movement is unknown. This study assessed the impact of concurrent movement during executive functioning tasks on dorsolateral prefrontal cortex (DLPFC) activation and inhibitory control, with a particular focus on the influence of medication status. Methods: Twenty-six children with ADHD (15 medicated; 11 unmedicated) and 24 children without ADHD performed a Stroop task under two conditions: while remaining seated (Stationary condition) and while pedalling on a desk cycle (Movement condition). Functional near-infrared spectroscopy (fNIRS) was used to measure changes in oxygenated and deoxygenated hemoglobin levels in the left DLPFC. Results: Sixty-four percent of unmedicated children with ADHD showed greater left DLPFC activity while desk-cycling compared to remaining stationary. Only 37% of medicated children with ADHD showed the same pattern, with 63% showing greater left DLPFC activation when remaining stationary during executive functioning. Children without ADHD had similar DLPFC patterns as unmedicated ADHD children, with 65% showing increased activation during movement. Unmedicated ADHD children who were able to desk-cycle during the Stroop task had higher overall and incongruent accuracy scores; no Stroop differences were found between conditions for children with ADHD who were medicated or for controls. Conclusions: Medicated ADHD children did not benefit from physical activity during tasks requiring executive control, yet unmedicated ADHD children showed significantly greater DLPFC activation and inhibitory control when engaging in movement. If medication is not suitable for children with ADHD due to adverse side effects, movement during executive functioning may help mimic the benefit of medications and similarly support attention. Full article

Although clomipramine (CLO) is widely used as a serotonin reuptake inhibitor, its subchronic administration during the early stages of brain development leads to depressive-like behaviors in adulthood. High doses of CLO have been linked to mitochondrial impairment and increased reactive oxygen species in cells and adult animals. It is unknown whether subchronic administration of this drug at early ages can induce oxidative stress (OS) in adulthood. The objective of this study was to evaluate OS and cellular damage in the prefrontal cortex and limbic system (hippocampus and amygdala) of rats exposed to CLO neonatally. Methods: Forty male Wistar rats were divided into experimental (EXP) and control (CTRL) groups. The EXP animals received CLO (15 mg/kg, twice daily, subcutaneously, postnatal days 5–35); the CTRL animals received saline. At 55 and 85 days of age, the brains were collected for biochemical assays and histological analysis. Results: Rats exposed to neonatal CLO presented significant reductions in reduced glutathione (GSH) and increases in oxidized glutathione (GSSG) and malondialdehyde in both studied regions, especially on day 85. The GSH/GSSG ratio decreased, indicating persistent OS. Histology revealed neuronal degeneration, pyknotic nuclei, cell shrinkage, and disorganized tissue, which progressed from days 55 to 85. Conclusions: Early exposure to CLO can cause long-lasting neurochemical and structural alterations in the brain regions associated with the regulation of emotions and some behavioral responses that can persist over time and affect behavior in adulthood. Full article

Background: Hemiplegic cerebral palsy (HCP) is a motor dysfunction disorder resulting from perinatal developmental brain injury, predominantly impairing upper limb function in children. Nonetheless, there has been insufficient research on the brain activation patterns and inter-brain coordination mechanisms of HCP children when performing motor control tasks, especially in contrast to children with typical development(CD). Objective: This cross-sectional study employed functional near-infrared spectroscopy (fNIRS) to systematically compare the cerebral blood flow dynamics and brain network characteristics of HCP children and CD children while performing upper-limb mirror training tasks. Methods: The study ultimately included 14 HCP children and 28 CD children. fNIRS technology was utilized to record changes in oxygenated hemoglobin (HbO) signals in the bilateral prefrontal cortex (LPFC/RPFC) and motor cortex (LMC/RMC) of the subjects while they performed mirror training tasks. Generalized linear model (GLM) analysis was used to compare differences in activation intensity between HCP children and CD children in the prefrontal cortex and motor cortex. Finally, conditional Granger causality (GC) analysis was applied to construct a directed brain network model, enabling directional analysis of causal interactions between different brain regions. Results: Brain activation: HCP children showed weaker LPFC activation than CD children in the NMR task (t = −2.032, p = 0.049); enhanced LMC activation in the NML task (t = 2.202, p = 0.033); and reduced RMC activation in the MR task (t = −2.234, p = 0.031). Intragroup comparisons revealed significant differences in LMC activation between the NMR and NML tasks (M = −1.128 ± 2.764, t = −1.527, p = 0.025) and increased separation in RMC activation between the MR and ML tasks (M = −1.674 ± 2.584, t = −2.425, p = 0.031). Cortical effective connectivity: HCP group RPFC → RMC connectivity was weaker than that in CD children in the NMR/NML tasks (NMR: t = −2.491, p = 0.018; NML: t = −2.386, p = 0.023); RMC → LMC connectivity was weakened in the NMR task (t = −2.395, p = 0.022). Conclusions: This study reveals that children with HCP exhibit distinct abnormal characteristics in both cortical activation patterns and effective brain network connectivity during upper limb mirror training tasks, compared to children with CD. These characteristic alterations may reflect the neural mechanisms underlying motor control deficits in HCP children, involving deficits in prefrontal regulatory function and compensatory reorganization of the motor cortex. The identified fNIRS indicators provide new insights into understanding brain dysfunction in HCP and may offer objective evidence for research into personalized, precision-based neurorehabilitation intervention strategies. Full article

The present study aimed to investigate sex differences in the hemodynamic response of the cerebral cortex during interactive and passive tasks using functional near-infrared spectroscopy fNIRS. Ninety-seven healthy adults (63 women, 34 men) participated in the study. Participants performed two tasks: an interactive motor game and a passive hand movement, and activation was measured in five cortical regions. Statistically significant differences in the amplitude of the hemodynamic response of oxygenated haemoglobin ΔHbO levels were observed, particularly in the parietal cortex, where men showed higher activation levels. The differences remained significant in the parietal, prefrontal, left hemisphere, and visual cortex. The differences were more pronounced in the passive task, which may indicate different processing strategies in women and men. Although no significant group differences were found in the latency time of maximum reaction t_max, men tended to have longer times in the visual cortex. Additionally, a moderate positive correlation between ΔHbO and t_max was observed among men, particularly in the prefrontal cortex. These results highlight the importance of considering biological sex in neuroimaging studies and suggest directions for further analysis. Full article

Functional near-infrared spectroscopy (fNIRS) allows non-invasive assessment of cortical activity during naturalistic tasks. This study aimed to compare cortical activation dynamics—specifically the latency (t_max) and amplitude (ΔoxyHb) of oxygenated haemoglobin changes—in passive observation and an interactive task using the Nefroball system. A total of 117 healthy adults performed two tasks involving rhythmic hand movements: a passive protocol and an interactive game-controlled condition. fNIRS recorded signals from the visual, parietal, motor, and prefrontal cortices of the left hemisphere. The Mann–Whitney test revealed significantly shorter t_max in all areas during the interactive task, suggesting faster recruitment of cortical networks. ΔoxyHb amplitude was significantly higher only in the visual cortex during the interactive task, indicating increased visual processing demand. No significant ΔoxyHb differences were observed in the motor, prefrontal, or parietal cortices. Weak but significant positive correlations were found between tmax and ΔoxyHb in the motor and prefrontal regions, but only in the passive condition. These findings support the notion that interactive tasks elicit faster, though not necessarily stronger, cortical responses. The results have potential implications for designing rehabilitation protocols and brain–computer interfaces involving visual–motor integration. Full article

Introduction: Chewing gum is a widespread, seemingly mundane behaviour that has been linked to diverse benefits such as improved cognitive performance, reduced stress, and enhanced alertness. While animal and human research indicate that mastication engages extensive sensorimotor networks and may also modulate higher-order cognitive and emotional processes, questions remain about the specific neural mechanisms involved. This review combines findings from neuroimaging studies—including fMRI, fNIRS, and EEG—that investigate how chewing gum alters brain activity in humans. Methods: Using a targeted search strategy, we screened the major databases (PubMed/Medline, Scopus, ResearchGate, Google Scholar, and Cochrane) from January 1980 to March 2025 for clinical studies published in English. Eligible studies explicitly measured brain activity during gum chewing using EEG, fNIRS, or fMRI. Results: After a title/abstract screening and a full-text review, thirty-two studies met the inclusion criteria for this review: 15 utilising fMRI, 10 using fNIRS, 2 using both fNIRS and EEG, and 5 employing EEG. Overall, the fMRI investigations consistently reported strong activation in bilateral motor and somatosensory cortices, the supplementary motor area, the insula, the cerebellum, and the thalamus, during gum chewing, with several studies also noting involvement of higher-order prefrontal and cingulate regions, particularly under stress conditions or when participants chewed flavoured gum. The fNIRS findings indicated that chewing gum increased oxygenated haemoglobin in the prefrontal cortex, reflecting heightened cortical blood flow; these effects were often amplified when the gum was flavoured or when participants were exposed to stressful stimuli, suggesting that both sensory and emotional variables can influence chewing-related cortical responses. Finally, the EEG studies documented transient increases in alpha and beta wave power during gum chewing, particularly when flavoured gum was used, and reported short-lived enhancements in vigilance or alertness, which tended to subside soon after participants ceased chewing. Conclusions: Neuroimaging data indicate that chewing gum reliably engages broad sensorimotor circuits while also influencing regions tied to attention, stress regulation, and possibly memory. Although these effects are often short-lived, the range of outcomes—from changes in cortical oxygenation to shifts in EEG power—underscores chewing gum’s capacity to modulate brain function beyond simple oral motor control. However, at this time, the neural changes associated with gum chewing cannot be directly linked to the positive behavioural and functional outcomes observed in studies that measure these effects without the use of neuroimaging techniques. Future research should address longer-term impacts, refine methods to isolate flavour or stress variables, and explore potential therapeutic applications for mastication-based interventions. Full article

Background/Objectives: Attention-Deficit Hyperactivity Disorder (ADHD) is an immensely heterogeneous developmental disorder, uniquely impacting each individual. Physical movement is a promising adjunct behavioral treatment that can promote executive functioning in children with ADHD. The current study used neuroimaging and behavioral techniques to investigate the impact of movement during executive functioning on dorsolateral prefrontal cortical (DLPFC) activity and inhibitory control in children with ADHD, with particular focus on key individual difference factors in ADHD, such as subtype, severity, and gender. Methods: Twenty-eight children with ADHD completed a Stroop task while remaining stationary (stationary condition) and while desk cycling (movement condition). Simultaneous functional near-infrared spectroscopy (fNIRS) recorded oxygenated and deoxygenated changes in hemoglobin within the left DLPFC. Participants were categorized into ADHD subtype (hyperactive/impulsive, inattention, combined), ADHD severity (low, moderate, high), and gender (male, female). Results: Those with the hyperactive and combined ADHD subtypes, those with high ADHD severity, and males with ADHD showed greater DLPFC activation when engaging in movement during executive functioning compared to remaining stationary. In contrast, those with the inattentive ADHD subtype, those with low-to-moderate ADHD severity, and females with ADHD showed greater DLPFC activation when remaining stationary during executive functioning compared to engaging in movement. Inhibitory control improved in the stationary condition for females who were predominantly inattentive. Conclusions: This work underscores the importance of considering individual difference factors in ADHD when designing physical activity interventions, as treatment efficacy may vary. Full article

Oxidative stress due to increased reactive oxygen species (ROS) formation and/or inflammation is considered to play an important role in ischemic stroke injury. Leukemia inhibitory factor (LIF) has been shown to protect both oligodendrocytes and neurons from ischemia by upregulating endogenous anti-oxidants, though the effect of ischemia and the protective role of LIF treatment in mitochondrial function have not been studied. The goal of this study was to determine whether LIF protects ischemia-induced altered mitochondrial bioenergetics in reproductively senescent aged rats of both sexes (≥18 months old), approximately equivalent to the average age of human stroke patients. Animals were euthanized at 3 days after permanent middle cerebral artery occlusion (MCAO) surgery. We found that MCAO surgery significantly reduced mitochondrial oxidative phosphorylation in both the ipsilateral striatum and prefrontal cortex in male aged rats compared to their respective contralateral regions of the brain. MCAO injury showed mitochondrial bioenergetic dysfunction only in the striatum in female rats; however, the prefrontal cortex remained unaffected to the injury. LIF-treated rats significantly prevented mitochondrial dysfunction in the striatum in male rats compared to their vehicle-treated counterparts. Collectively, MCAO-induced mitochondrial dysfunction and LIF’s potential as a therapeutic biomolecule exhibited sex- and tissue-specific effects, varying between the striatum and prefrontal cortex in male and female rats. Full article

This study investigated prefrontal cortex activity during the viewing and evaluation of pictures depicting scenarios with varying levels of danger, with a focus on the modulatory effects of personality traits and decision-making styles. The study sample included 120 male participants (44.4 ± 12.9 years) and 87 female participants (38.9 ± 10.5 years). Functional Near-Infrared Spectroscopy (fNIRS) was used to measure prefrontal oxygenation during the period of looking at pictures and the subsequent period of judging how dangerous they looked. Psychometric assessments included the Zuckerman–Kuhlman–Aluja Personality Questionnaire (ZKA-PQ) and the Melbourne Decision-Making Questionnaire (MDMQ). The results revealed significant time-by-region (F = 2.9, p = 0.013) and danger level by region interactions (F = 2.8, p = 0.021) during the viewing period. During the evaluation period, a significant time-by-region interaction was observed (F = 8.7, p < 0.001). High sensation seekers exhibited reduced oxygenation levels in specific right prefrontal regions, reflecting a differential neural response to varying danger levels. Similarly, individuals with higher Aggressiveness and Extraversion displayed distinct oxygenation patterns during the evaluation phase, suggesting that personality traits influence prefrontal activity. However, no significant effects of decision-making styles were detected in either phase. These findings emphasise the pivotal role of the prefrontal cortex in assessing scene safety and highlight how neural responses are modulated by personality traits, rather than by decision-making styles. Full article

Driver distraction remains a critical factor in road accidents, necessitating intelligent systems for real-time detection. This study introduces a novel fNIRS-based method to to classify varying levels of driver distraction across diverse simulated scenarios, including cognitive, visual–manual, and auditory sources of inattention. Unlike previous work, we evaluated multiple neurophysiological metrics—including oxygenated, deoxygenated, and combined haemoglobin—to identify the most reliable biomarker for distraction detection. Neurophysiological data were collected, and three multi-class classifiers (SVM, KNN, decision tree) were applied across different fNIRS metrics. Our results show that oxygenated haemoglobin outperforms other signals in distinguishing distracted from non-distracted states, while the combined signal performs best in differentiating distraction from baseline. The proposed SVM model achieved ≈ 77.9% accuracy in detecting distracted and relaxed driving states based on brain oxygen levels. Our findings also show that increased distraction correlates with elevated activity in the dorsolateral prefrontal cortex and premotor cortex, whereas driving without distraction exhibits lower neurovascular engagement. This study contributes to affective computing and intelligent transportation systems and could support the development of future driver distraction monitoring systems for safer and more adaptive vehicle control. Full article

Background/Objectives: This study explores variations in brain activity between individuals with dementia of the Alzheimer’s type (DAT) and healthy older adults during a resting state using functional near-infrared spectroscopy (fNIRS). Methods: FNIRS measured brain activity in ten AD patients and six healthy individuals. A device with 16 channels was placed on each participant’s forehead to measure oxygenation levels while they kept their eyes closed. The data were analyzed using a support vector machine (SVM) model. Results: The results indicated differences in oxygenated hemoglobin (HbO) levels between the two groups. Specifically, HbO levels were generally higher in the dementia group in the left hemisphere, with a sharp increase after 26 s. Conversely, HbO levels were consistently lower in the right hemisphere of the dementia group. The SVM analysis demonstrated high accuracy in differentiating between the AD and healthy groups based on HbO levels. Conclusions: The study indicates that differences in brain activity during resting state can potentially distinguish people with DAT from healthy individuals. We found relatively reduced hemoglobin activity in the prefrontal areas of those with DAT. Furthermore, the concentration changes in the HbO in the left lateral prefrontal and right medial brain regions emerged as the most informative in distinguishing individuals with DAT from healthy individuals. The results of the current study show that this method could improve current DAT diagnostic practices due to its efficiency. Full article

Background/Objectives: Art-based interventions have been shown to enhance communication skills in children with autism spectrum disorder (ASD), yet their impact on prefrontal hemodynamics remains unclear. Methods: This study employed functional near-infrared spectroscopy (fNIRS) to examine hemoglobin oxygenation (HbO) changes in the prefrontal cortex of school-age children with ASD, providing empirical support for its therapeutic efficacy. Sixty age-matched children participated in a 9-week art therapy program, including twenty ASD children and forty typically developing peers. Assessments included self-portrait drawing (SPD), the Diagnostic Drawing Series (DDS), and the General Quality of Life Inventory (GQOL-74). In addition, we performed fNIRS measurements in the ASD participants and observed changes in prefrontal HbO at rest and while drawing. Results: The drawing intervention significantly enhanced drawing ability, emotional expression, and cognitive skills, with the intervention group outperforming the controls. ASD participants exhibited distinct prefrontal connectivity patterns with visual, motor, and language-related regions, including the dorsolateral prefrontal cortex, frontal eye field, and Broca’s area. Task-based painting interventions indirectly influenced the frontal lobe’s hemodynamic characteristics, indicating drawing intervention as an effective intervention for ASD. Full article

This study investigates how the sound of a hair dryer influences users’ perceptions of its quality, using functional near-infrared spectroscopy (fNIRS) to measure prefrontal cortex (PFC) activation. Eighteen participants were involved in a within-subject evaluation experiment where they assessed the perceived quality of hair dryers with three different sound levels: no sound, low sound, and high sound. The results show that hair dryers with high sound levels were rated as having higher quality and caused greater increases in oxygenated hemoglobin (HbO) concentration in the dorsolateral prefrontal cortex (DLPFC) compared to soundless hair dryers. In contrast, when participants evaluated low-sound hair dryers, differential activation between the left and right hemispheres was observed, with increased left-brain activity. These findings highlight the significant role of multisensory factors, such as sound, in shaping product perception. Moreover, DLPFC activity, especially in the left hemisphere, emerges as a potential marker for evaluating product quality, contributing new insights to the understanding of sensory-driven decision-making in product evaluation. Full article