Near-infrared Spectroscopy Study Research Articles

Supplementary and Premotor Cortical Activation During Manual Dexterity Involving Motor Imagery in Multiple Sclerosis: A Functional Near-Infrared Spectroscopy Study

Background Investigating brain activation during motor imagery (MI) tasks in people with multiple sclerosis (pwMS) can increase the knowledge of the neural mechanisms underlying motor dysfunction in MS and, hopefully, aid in developing improved rehabilitation strategies. Objective To investigate brain activation in the supplementary motor area and premotor cortex via functional near-infrared spectroscopy (fNIRS) during a hand manipulation task, and comparing MI with actual practice (AP) in pwMS. Methods Each subject completed a sequence of 4 consecutive manual dexterity trials wearing an fNIRS device. The tasks included the following conditions: AP dominant hand, MI dominant hand, AP non-dominant hand, and MI non-dominant hand. Results Twenty pwMS (mean Expanded Disability Status Scale = 4.75 [3.0-6.5]) and 20 healthy controls (HC) participated in the study. According to the fNIRS timeline course, a similar increase (compared with baseline) was observed in the relative oxygenated hemoglobin (HbO) concentration during the MI and AP tasks, which was immediately followed by a decrease (for either hand) in the pwMS and the HC groups. A difference in the relative HbO concentration between the HC and pwMS was detected solely when the 2 groups mentally replicated the manual dexterity task movements in the MI condition (dominant hand). The increase was higher in the HC group ( P = .030). Conclusions Despite exhibiting manual dexterity difficulties, pwMS demonstrated comparable neural activation patterns as the HCs during MI tasks in regions associated with motor planning and complex movement control, thus, suggesting that deficits in manual dexterity among pwMS may not solely originate from impairments in the motor planning processes.

Cerebral baseline optical and hemodynamic properties in pediatric population: a large cohort time-domain near-infrared spectroscopy study

Cerebral baseline optical and hemodynamic properties in pediatric population: a large cohort time-domain near-infrared spectroscopy study

The Role of the Bilateral Inferior Frontal Gyrus in Non-suicidal Self-injury (NSSI) among Depressed Adolescents: A Functional Near-infrared Spectroscopy (fNIRS) Study during Verbal Fluency Tasks

BackgroundThe diagnosis and treatment of adolescents engaging in non-suicidal self-injury (NSSI) have been a clinical focus. We examined the hemodynamic changes in verbal fluency tasks (VFT) of adolescents with depression and NSSI, and its association with NSSI indexes. MethodsSeventy-three adolescents with depression and NSSI and sixty-nine healthy controls (HCs) were employed. The VFT was performed by functional near-infrared spectroscopy (fNIRS). Independent-sample t-test, correlation analysis, and liner regression were measured. ResultsIn the VFT, reduced hemodynamic changes were found in the NSSI group, including thirteen channels. Totally seven ROIs were defined according to which brain region these channels had the largest coverage and other channels that also belonged to it. They are the right inferior frontal gyrus (RIFG, t = -2.53, FDR corrected p = 0.02), right middle frontal gyrus (RMFG, t = -3.47, FDR corrected p = 0.002), right superior frontal gyrus (RSFG, t = -2.98, FDR corrected p = 0.005), left middle frontal gyrus (LMFG, t = -3.26, FDR corrected p = 0.002), left inferior frontal gyrus (LIFG, t = -2.80, FDR corrected p = 0.001), left precentral gyrus (LPrCG, t = -2.22, FDR corrected p = 0.03), and left supramarginal gyrus (LSMG, t = -2.20, FDR corrected p = 0.03). Negative correlations were found between the frequency of NSSI and the bilateral IFG (RIFG, r = -0.28, p = 0.01; LIFG, r = -0.26, p = 0.03). BDI and BAI have positive correlations with the frequency of NSSI (BDI: r = 0.42, FDR corrected p < 0.001; BAI: r = 0.41, FDR corrected p < 0.001), but results of liner regression showed that both of them do not affect the association between the frequency of NSSI and hemodynamic changes in bilateral IFG (RIFG, p = 0.01; LIFG, p = 0.04). ConclusionAdolescents with depression and NSSI have worse performance in the VFT, and lower activation in the bilateral IFG may represent a higher frequency of NSSI. These results help physicians enhance the understanding of adolescents with depression and NSSI.

Network-based statistics reveals an enhanced subnetwork in prefrontal cortex in mild cognitive impairment: a functional near-infrared spectroscopy study

Network-based statistics reveals an enhanced subnetwork in prefrontal cortex in mild cognitive impairment: a functional near-infrared spectroscopy study

Decrease in walking ability with increased functional connectivity between multiple brain areas in Parkinson's disease: a functional near-infrared spectroscopy study.

Gait disturbances significantly impact the mobility and quality of life of individuals with Parkinson's disease (PD). This study aims to delve into the cortical mechanisms underlying gait disorders in PD, specifically focusing on the prefrontal cortex (PFC), premotor cortex (PMC), and primary somatosensory cortex (PSC). To compare the functional connectivity of the PFC, PMC, and PSC regions during walking between individuals with PD and healthy controls. The study included 30 individuals with PD (mean age 62.40 ± 7.16 years) and 22 healthy older adults (mean age 60.95 ± 6.34 years). All participants were requested to walk back and forth at a comfortable pace for 30 s over a 10-meter course three times. A mobile functional near-infrared spectroscopy (fNIRS) system was employed to evaluate the oxyhemoglobin concentration change (∆HbO2). To assess the interactions between the PFC, PMC, and PSC, the connectivity strength between different fNIRS channels was computed. Individuals with PD in the off-state exhibited significantly decreased walking speed and shorter stride length compared to the healthy controls. For six brain regions including the left (L) and right (R) PFC, PMC, and PSC, no significant differences in functional connectivity within each region were found between the PD and control groups. However, when it comes to the functional connectivity between every two regions, the PD group exhibited stronger functional connectivity than the control group in the LPFC-LPMC, LPFC-RPMC, LPFC-LPSC, RPFC-LPMC, RPFC-LPSC, LPMC-LPSC, LPMC-RPSC, and RPMC-RPSC. Positive correlations were found between gait performance (speed and stride length) and functional connectivity within the RPMC as well as between the RPMC and the RPSC. Individuals with PD exhibit notable gait disturbances and increased functional connectivity in brain regions responsible for sensorimotor integration and motor function in their off-state. Strengthening the functional connectivity within the RPMC and between the RPMC and the RPSC could be a potential target for future treatments of gait impairments in PD.

Characteristic activation pattern and network connectivity of prefrontal cortex in patients with type 2 diabetes mellitus and major depressive disorder during a verbal fluency task: A functional near-infrared spectroscopy study based on network-based statistic prediction.

Type 2 diabetes (T2DM) and major depressive disorder (MDD) together occur frequently among the elderly population. However, the inconsistency in assessments and limited medical resources in the community make it challenging to identify depression in patients with T2DM. This cross-sectional study aimed to investigate the activation pattern and network connectivity of prefrontal cortex (PFC) during a verbal fluency task (VFT) in patients with T2DM and MDD using functional near-infrared spectroscopy (fNIRS). Three parallel groups (T2DM with MDD group, T2DM group, and healthy group) with 100 participants in each group were included in the study. Recruitment took place from August 1, 2020, to December 31, 2023. Due to the close association between the PFC and depressive emotions, fNIRS was used to monitor brain activation and network connectivity of PFC in all participants during a task of Chinese-language phonological VFT. Network-based statistic prediction (NBS-predict) was adopted as data analysis method. Patients in the T2DM with MDD group showed characteristic activation pattern and network connectivity in contrast with patients with T2MD and healthy controls, including decreased activation in PFC, and decreased network connectivity of right dorsolateral prefrontal cortex (DLPFC). Furthermore, the network connectivity of the right DLPFC in patients with T2DM and MDD was negatively correlated with scores of Hamilton Depression Scale-24 (HAMD-24). There was a distinctive activation pattern and network connectivity of the prefrontal cortex in patients with T2DM and MDD. The right DLPFC could serve as a potential target for the diagnosis and intervention of MDD in patients with T2DM.

Brain networks in newborns and infants with and without sensorineural hearing loss: A functional near-infrared spectroscopy study.

Understanding the impact of early sensory deficits on brain development is essential for understanding developmental processes and developing potential interventions. While previous studies have looked into the impact of prenatal experiences on language development, there is a lack of research on how these experiences affect early language and brain function development in individuals with sensorineural hearing loss (SNHL). To investigate SNHL effects on early brain development and connectivity in 4-month-olds vs healthy newborns and controls. The research involved analyzing the functional brain networks of 65 infants, categorized into three groups: 28 healthy newborns, 22 4-month-old participants with SNHL, and 15 age-matched healthy participants. The resting-state functional connectivity was measured and compared between the groups using functional near-infrared spectroscopy and graph theory to assess the brain network properties. Significant differences were found in resting-state functional connectivity between participants with SNHL and age-matched controls, indicating a developmental lag in brain connectivity for those with SNHL. Surprisingly, SNHL participants showed better connectivity development compared to healthy newborns, with connectivity strengths of 0.13 ± 0.04 for SNHL, 0.16 ± 0.08 for controls, and 0.098 ± 0.04 for newborns. Graph theory analysis revealed enhanced global brain network properties for the SNHL group, suggesting higher communication efficiency at 4 months. No significant differences were noted in network properties between 4-month-old SNHL participants and neonates. A unique pattern of central hubs was observed in the SNHL group, with 2 hubs in the left hemisphere compared to 6 in controls. 4-month-old infants with SNHL have a distinct brain network pattern with efficient long-distance information transmission but less effective local communication compared to age-matched controls.

Age-related cerebral changes during different n-back tasks: a functional near-infrared spectroscopy study.

The n-back task is a widely used paradigm to assess working memory and is commonly applied in research on age-related cognitive decline. However, studies utilizing functional near-infrared spectroscopy (fNIRS) to explore this area are limited. This study aims to investigate age-related differences in brain activation during the n-back task using fNIRS. fNIRS data were collected from 18 elderly and 19 young participants while performing different n-back tasks. Brain activation patterns and peripheral performance were compared between the two groups. Significant differences in brain activation patterns were observed between elderly and young participants. Under the 3-back condition, the older group exhibited reduced activation in brain regions adjacent to prefrontal cognitive areas compared to the younger group. Additionally, the older group's performance plateaued at the 2-back level, along with a decline in prefrontal activation. These findings may suggest potential markers for cognitive decline, providing a new target for future screening.

Association of Exercise with Better Olfactory Performance and Higher Functional Connectivity Between the Olfactory Cortex and the Prefrontal Cortex: A Resting-State Functional Near-Infrared Spectroscopy Study.

Background: Olfactory deterioration is suggested to be a predictor of some neurodegenerative diseases. Recent studies indicate that physical exercise has a positive relationship with olfactory performance, and a subregion in the prefrontal cortex (PFC) may play an important role in olfactory processing. The PFC is not only related to olfactory function but it also engages in complex functions such as cognition and emotional processing. Methodology: Our study compared the functional connectivity between the olfactory cortex and the PFC in healthy individuals who exercised regularly and healthy persons who did not. Those who exercised more than three times/week for at least 30 min each time were considered the exercise group, and those who did not meet this exercise criteria were considered the nonexercise group. We also assessed their odor threshold. Participants were aged 55 years or older, and the two groups were balanced for age, sex, body mass index, and educational level. Results: We found that compared with individuals who did not exercise, exercisers had a significantly lower threshold for detecting odors. In addition, the olfactory cortex had stronger connectivity with the PFC in exercisers than in nonexercisers. More specifically, when the PFC was grouped into three subregions, namely, the ventrolateral prefrontal cortex (VLPFC), dorsolateral prefrontal cortex (DLPFC), and frontopolar cortex (FPA), Pearson correlation analysis revealed stronger connectivity between the VLPFC and the orbitofrontal cortex (OFC), between the OFC and the FPA, and between the left and right OFC hemispheres in the exercisers. In addition, Granger causality indicated higher directional connectivity from the DLPFC to the OFC in exercisers than in nonexercisers. Conclusion: Our findings indicated that the exercise group not only had better olfactory performance but also had stronger functional connectivity between the olfactory cortex and the PFC than nonexercise group.

Electrophysiological and hemodynamic mechanisms underlying load modulations in visuospatial working memory: A functional near-infrared spectroscopy (fNIRS) and electroencephalogram (EEG) study.

The n-back task has been widely used to study working memory. Previous studies investigating the electrophysiological (electroencephalogram [EEG]) and hemodynamic correlates (functional near-infrared spectroscopy [fNIRS]) of the n-back task have been generally based on verbal stimuli and only investigated EEG frequency bands. We simultaneously acquired the EEG and fNIRS in 35 participants (16 males; age = 26.4 ± 4.3 years; educational attainment = 18 ± 2 years) during a visuospatial n-back task. The task encompassed a control condition and a low (requiring to recall one previous stimulus) and a high (requiring to recall two previous stimuli) working memory load experimental conditions. Accuracy decreased and reaction times slowed in the high compared to both low load and control conditions. Regarding EEG, P3a showed higher amplitude in the experimental conditions compared to the control one, and P3b exhibited higher amplitude in the low compared to the high load condition. Regarding fNIRS, the high load condition showed higher deoxygenated hemoglobin compared to the control one. Moreover, the central frontopolar cortex showed higher activation compared with the left frontal cortex. Our study showed that working memory load during a visuospatial n-back task influenced behavioral and electrophysiological indices. Even if the load effect was only observed for deoxygenated hemoglobin on hemodynamic data, this was in line with previous studies and coherent with its electrophysiological correlates. Thus, our study confirms that EEG and fNIRS can be successfully used in multimodal acquisitions, but also highlights that future studies are needed to develop a novel version of the task. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Atypical prefrontal neural activity during an emotional interference control task in adolescents with autism spectrum disorder: A functional near-infrared spectroscopy study

Atypical prefrontal neural activity during an emotional interference control task in adolescents with autism spectrum disorder: A functional near-infrared spectroscopy study

Characteristic Changes of Prefrontal and Motor Areas in Patients with Type 2 Diabetes and Major Depressive Disorder During a Motor Task of Tai Chi Chuan: A Functional Near-Infrared Spectroscopy Study.

This cross-sectional study aims to identify the characteristic changes of prefrontal and motor areas during a tai chi chuan task in patients with Type 2 diabetes mellitus (T2DM) and major depressive disorder (MDD) using wearable functional near-infrared spectroscopy (fNIRS). Three parallel groups (T2DM with DD group, T2DM group, and healthy group) were recruited from December 10, 2022, to May 31, 2023. Participants in three groups conducted a motor task of tai chi chuan designed by Eprime 3.0, and fNIRS was used to monitor the brain activation, functional connectivity (FC), and lateralization of prefrontal and motor areas. Correlation analyses were performed to examine the relationship between depressive symptoms and the function of prefrontal and motor areas. Ninety elder adults (aged ≥ 60), including 30 patients with T2DM and MDD, 30 patients with T2DM, and 30 healthy subjects, were enrolled. In contrast with the patients with T2DM and healthy subjects, the patients with T2DM and MDD had decreased activation and abnormal lateralization in prefrontal and motor areas and decreased FC among supplementary motor area, motor area, and dorsolateral prefrontal cortex (DLPFC). Furthermore, the oxyhemoglobin (HbO2) concentration value of DLPFC in patients with T2DM and MDD was negatively associated with scores of Hamilton Depression Scale-24 (HAMD-24). Patients with T2DM and MDD had characteristic functional changes in prefrontal and motor areas. DLPFC may be a potential target of diagnosis and intervention for patients with T2DM and MDD.

Resting-state brain network analysis and applied evaluation of global developmental delay in preterm infants: A functional near-infrared spectroscopic study

Global developmental delay (GDD) is a common neurodevelopmental disorder in children under 5 years of age. This study assessed the potential of functional Near-Infrared Spectroscopy (fNIRS) technology aiding diagnosis of GDD in premature infants and explored brain pathogenesis of GDD. This prospective cohort study was conducted between December 2020 and June 2023 among preterm infants in five hospitals in China. The primary outcome was the diagnosis of GDD. A 5-min fNIRS brain scan was performed in preterm infants at 4-, 8-, and 12-month corrected age in two hospitals. A diagnostic model based on fNIRS brain network and an integrated diagnostic model built on fNIRS data as well as birth head circumference was developed. Diagnostic models were assessed using the area under the curve (AUC) from receiver operating characteristic curves. Brain network analysis revealed significantly worse left-sided functional connectivity in GDD preterm infants. The fNIRS technique had satisfactory diagnostic value for GDD in all age groups. The diagnostic accuracy of the combined diagnostic model significantly improved. This study suggested that fNIRS could be considered for early screening and late auxiliary diagnosis of GDD in preterm infants. Furthermore, it can also be used to explore GDD brain pathogenesis.

Cortical activity during online motor control in children with and without developmental coordination disorder: a cross-sectional functional near-infrared spectroscopy study

BackgroundChildren with developmental coordination disorder (DCD) have impaired online motor control. Researchers posit that this impairment could be due to a deficit in utilizing the internal model control process. However, there is little neurological evidence to support this view because few neuroimaging studies have focused specifically on tasks involving online motor control. Therefore, the aim of this study was to investigate the differences in cortical hemodynamic activity during an online movement adjustment task between children with and without DCD.MethodsTwenty children with DCD (mean age: 9.88 ± 1.67 years; gender: 14M/6F) and twenty age-and-gender matched children with typical development (TD) (mean age: 9.87 ± 1.59 years; gender: 14M/6F) were recruited via convenience sampling. Participants performed a double-step reaching task under two conditions (with and without online adjustment of reaching). Cortical hemodynamic activity during task in ten regions of interest, including bilateral primary somatosensory cortex, primary motor cortex, premotor cortex, superior parietal cortex, and inferior parietal cortex was recorded using functional near-infrared spectroscopy. In the analyses, change in oxyhemoglobin (ΔHbO) concentration was used to characterize hemodynamic response. Two-way analyses of variance were conducted for each region of interest to compare hemodynamic responses between groups and conditions. Additionally, Pearson’s r correlations between hemodynamic response and task performance were performed.ResultsOutcome showed that children with DCD required significantly more time to correct their reaching movements compared to the control group (t = 3.948, P < 0.001). Furthermore, children with DCD have a significantly lower ΔHbO change in the left superior parietal cortex during movement correction, compared to children with TD (F = 4.482, P = 0.041). Additionally, a significant negative correlation (r = − 0.598, P < 0.001) was observed between the difference in movement time of reaching and the difference in ΔHbO between conditions in the left superior parietal cortex.ConclusionsThe findings of this study suggest that deficiencies in processing real-time sensory feedback, considering the function of the superior parietal cortex, might be related to the impaired online motor control observed in children with DCD. Interventions could target this issue to enhance their performance in online motor control.

Association of Compensatory Mechanisms in Prefrontal Cortex and Impaired Anatomical Correlates in Semantic Verbal Fluency: A Functional Near-Infrared Spectroscopy Study.

Semantic verbal fluency (SVF) engages cognitive functions such as executive function, mental flexibility, and semantic memory. Left frontal and temporal lobes, particularly the left inferior frontal gyrus (IFG), are crucial for SVF. This study investigates SVF and associated neural processing in older adults with mild SVF impairment and the relationship between structural abnormalities in the left IFG and functional activation during SVF in those individuals. Fifty-four elderly individuals with modest level of mild cognitive impairment whose global cognition were preserved to normal but exhibited mild SVF impairment were participated. Prefrontal oxyhemoglobin (HbO2) activation and frontal cortical thickness were collected from the participants using functional near-infrared spectroscopy (fNIRS) and brain MRI, respectively. We calculated the β coefficient of HbO2 activation induced by tasks, and performed correlation analysis between SVF induced HbO2 activation and cortical thickness in frontal areas. We observed increased prefrontal activation during SVF task compared to the resting and control task. The activation distinct to SVF was identified in the midline superior and left superior prefrontal regions (p<0.05). Correlation analysis revealed an inverse relationship between SVF-specific activation and cortical thickness in the left IFG, particularly in pars triangularis (r(54)=-0.304, p=0.025). The study contributes to understanding the relationship between reduced cortical thickness in left IFG and increased functional activity in cognitively normal individuals with mild SVF impairment, providing implications on potential compensatory mechanisms for cognitive preservation.

Vibrational Features of Oxyamines: A Comparative Study of N,N-Diethylhydroxylamine and N,N-Diethylacetyloxyamine.

The ability of oxyamines to undergo homolytic cleavage of the O-C bond, leading to the formation of stable radicals, is widely used in polymerization processes and to prevent oxidative stress in materials. We present a mid and near-infrared spectroscopy study on two model compounds, N,N-diethylhydroxyloxyamine (C4H11NO) and its acetyl derivative N,N-diethylacetyloxyamine (C6H13NO2) in the liquid phase. The analysis of the spectra is based on a complete exploration of the conformational space, coupled to harmonic and anharmonic calculations performed using the generalized second-order vibrational perturbation theory (GVPT2) formalism at the B3LYP-D3(BJ)/Def2-TZVP level of calculation and potential energy distribution analysis. In the most stable species out of 25, the three amine chains present an all-anti arrangement, with the carbonyl oxygen atom pointing towards the nitrogen lone pair. The simulated spectra are in overall good agreement with the experimental ones, and suitable for the assignment of the main observed bands. Furthermore, similarities and divergences between the two molecules are discussed.

Near-Infrared Spectroscopic Study of Secondary Minerals in the Oxidation Zones of Copper-Bearing Deposits

This study measured the infrared spectra of secondary minerals in the oxidation zones of three types of copper ores: dioptase, malachite, and azurite, and assigned the peak positions of OH stretching vibrations and the origins of OH combination vibrations. Dioptase contains three types of water molecules with different orientations within its ring channels, which exhibit six kinds of OH stretching vibrations in the 3000–3600 cm−1 range; the bond length range is 2.652 to 2.887 Å. Among them, the 3443 cm−1 band shows strong near-infrared activity and combines with Si–O vibrations or OH bending vibrations in the structure, resulting in five combination vibration peaks in the 4000–5000 cm−1 range. Malachite contains two inequivalent hydroxyls in its structure, leading to two OH stretching vibrations in the high-frequency region located at 3314 and 3402 cm−1, respectively. Azurite contains only one type of hydroxyl, and thus only one characteristic OH stretching vibration is present at 3424 cm−1. The OH stretching vibrations of malachite and azurite mainly combine with [CO3]2− vibrations or OH bending vibrations, leading to six and five combination peaks in the OH combination vibration region, respectively. By analyzing the combination of peak positions at 4341 cm−1 in the near-infrared spectrum, the merged OH bending vibration at 921 cm−1 in azurite was discovered. Spectroscopic research on secondary minerals can better provide a basis for ore exploration and geological remote sensing.

Borderline personality trait is associated with neural differentiation of self-other processing: A functional near-infrared spectroscopy study

BackgroundIndividuals with borderline personality traits are known to have disturbed representations of self and others. Specifically, an unstable self-identity and difficulties distinguishing between self and others can impair their mentalizing abilities in interpersonal situations. However, it is unclear whether these traits are linked to differences in neural representation of self and others. MethodsIn this study involving 156 young adults, changes in neural function during self-other processing were measured using a Functional Near-Infrared Spectroscopy (fNIRS) task and a self-report survey. During the fNIRS task, participants were asked about their own traits, others' traits, how they believed others perceived them, and the basic meaning of words. The study aimed to determine whether the degree of neural differentiation between the task conditions was related to borderline personality traits. ResultThe study found that traits indicative of identity instability could be predicted by similarities in task-dependent connectivity. Specifically, the neural patterns when individuals estimated how others perceived them were more similar to the patterns when they judged their own traits. ConclusionsThese findings suggest that borderline personality traits related to identity issues may reflect difficulties in distinguishing between neural patterns when processing self and other information.

(Interfering) Cortical mechanisms of standing balance and cognition in old-age depression: A functional near-infrared spectroscopy (fNIRS) study

Major depressive disorder in old age can cause changes in the cerebral cortex that might lead to postural imbalance and thus increase fall risk. We aim to examine cortical activation during standing balance in depressed older patients compared to healthy controls and to determine how an additional cognitive task affects this activation. Eleven older patients (age ≥65 years) diagnosed with major depressive disorder and sixteen age-matched healthy controls participated in the study. Functional near-infrared spectroscopy (fNIRS) was used to assess cortical activation of the prefrontal (PFC) and motor (MC) cortex during standing balance with eyes closed under single and dual task (counting backwards). The present study generally revealed tendencies in the MC – and partly the PFC too – for more activation whilst balancing compared to baseline. Also, in the MC, patients tended to show more cortical activation compared to controls and dual task tended to elicit more activation. The results suggest that depressed older patients, to compensate for their illness, may require increased cortical activation to perform motor and cognitive tasks than healthy controls. The absence of PFC activation in the main analyses may be related to the small participant number and possibly to too simple task conditions.

Gender Differences in Prefrontal Cortex Response to Negative Emotional Stimuli in Drivers.

Road safety improvement is a governmental priority due to driver-caused accidents. Driving style variation affects safety, with emotional regulation being pivotal. However, functional near-infrared spectroscopy (fNIRS) studies show inconsistent prefrontal cortex activity during emotion processing. This study examines prefrontal cortex response to negative emotional stimuli, particularly traffic accident images, across drivers diverse in age and gender. The study involved 118 healthy males (44.38 ± 12.98 years) and 84 females (38.89 ± 10.60 years). The Multidimensional Driving Style Inventory (MDSI) was used to assess driving behavior alongside fNIRS recordings. Participants viewed traffic accident and neutral images while prefrontal oxygenation was monitored. Women rated traffic accidents (t-test = 2.43; p < 0.016) and neutral images (t-test = 2.19; p < 0.030) lower in valence than men. Arousal differences were significant for traffic accident images (t-test = -3.06; p < 0.002). correlational analysis found an inverse relationship between Dissociative scale scores and oxygenation (all p-values ≤ 0.013). Greater prefrontal oxygenation occurred with neutral images compared to traffic accidents. Left hemisphere differences (t-test = 3.23; p < 0.001) exceeded right hemisphere differences (t-test = 2.46; p < 0.015). Subgroup analysis showed male participants to be driving these disparities. Among adaptive drivers, significant oxygenation differences between neutral and accident images were evident in both hemispheres (left: t-test = 2.72, p < 0.009; right: t-test = 2.22, p < 0.030). Male drivers with maladaptive driving styles, particularly dissociative ones, exhibit reduced prefrontal oxygenation when exposed to neutral and traffic accident images. This response was absent in female drivers, with no notable age-related differences.