Prefrontal Cortical Areas Research Articles

Brain Functional Connectivity in the Resting State and the Exercise State in Elite Tai Chi Chuan Athletes: An fNIRS Study.

This study aimed to reveal the characteristics of multi-circuit brain synergy between elite tai chi chuan athletes in resting and exercise states and to provide neuroimaging evidence of improvements in brain function by motor skill training. Functional near-infrared spectroscopy (fNIRS) was used to compare the brain activity of professional tai chi chuan athletes (expert group) and beginners (novice group) in resting and exercise states, and to assess functional connectivity (FC) between the prefrontal lobe and the sensorimotor zone. In the resting state, the FC between the left prefrontal lobe and the right sensorimotor area in the expert group was significantly lower than that in the novice group (P < 0.05). In the exercise state, the patterns of FC between the left prefrontal lobe and right sensorimotor area, the right prefrontal lobe and left sensorimotor area, and the left and right sensorimotor areas in the expert group were significantly lower than that in the novice group (P < 0.05). From the resting state to the locomotor state, the expert group experienced a greater absolute value of functional connection increment between the left prefrontal cortex and right sensorimotor area, and between the left sensorimotor area and right sensorimotor area (P < 0.05). This was positively correlated with the self-evaluation results of motor performance behavior. Under sports conditions, professional athletes’ multi-circuit brain FC strength is significantly reduced, and their elite motor skill performance supports the neural efficiency hypothesis. This may be related to the high adaptation of the brain to specific tasks and the improvement of the integration of somatic perception processing and motor function.

Extracurricular sports activities modify the proprioceptive map in children aged 5–8 years

The Chinese government has recently issued the strictest ever guideline to improve the compulsory education system. The new policy aims at reducing the burden of excessive homework and supplementary tutoring, whilst promoting extracurricular activities, including sports and arts, for primary and junior middle school students. To examine the impact that this reform might have on sensory development—which is critical for higher-order cognitive functions—we assessed proprioceptive abilities in children from 5 to 8 years of age. Proprioception refers to sensations of position and motion of the body in space and is mediated by activity in somatosensory and prefrontal cortical areas. By asking participants to perform position matching tasks in the forward–backward directions, we were able to compare the proprioceptive maps of children with and without regular sports training. We demonstrate that extracurricular sports activities can modify the proprioceptive map and improve proprioceptive acuity and stability in school-aged children.

Using fNIRS to study Mother-Child Brain-to-Brain Synchrony in Typical and Atypical Contexts

A potential avenue of investigating the caregiver-infant relationship lies in caregiver-infant synchrony, which refers to the coordinated interplay of behavioural and physiological signals reflecting the bi-directional attunement of one individual to the other’s psychophysiological, cognitive, emotional and behavioural state. Here, we aim to study how early naturalistic caregiver-infant interactions give raise to caregiver-infant attachment, which influences physiological and psychological processes by modulating brain sensitivity. Furthermore, we aim to study how caregiver-infant bond shapes neural pathways involved in socio-emotional regulation in typical and atypical contexts. We present new evidence from fNIRS hyperscanning studies, where we measured simultaneous caregiver (mothers, N=30 and fathers N=38) and child brain activity (N=70). From the mother-child hyperscanning study (Azhari et al., 2019; 2020; 2021), we have found that higher levels of parenting stress are correlated to lower mother-child brain-to-brain synchrony, especially in the areas of the medial left prefrontal cortex. Additionally, maternal anxious attachment (Azhari et al., 2020a) also correlated in lower mother-child synchrony in the frontal and medial left prefrontal regions. These areas contain structures implicated in the inference of mental states and social cognition, highlighting the role of psychological factors such as parenting stress and attachment style in the influence of caregiver-infant bond formation during naturalistic interactions. From the combined mother- and father-child free play sessions (Azhari et al., 2020b), behavioural data revealed that parenting stress and caregivers’ recall of their past bonding experiences their own parents interact with each other to influence the eventual quality of dyadic interaction with their child. Disclosure No significant relationships.

P.161 Spatiotemporal dynamics of neuronal ensembles in the primate prefrontal cortex during virtual reality navigation tasks

Background: Brain-machine-interface research has utilized multichannel single neuron recordings to decode movement intention. However, the prefrontal cortex (PFC) contains mental representations of more abstract task and goal elements which may be utilized as important signals in a brain-machine-interface. We therefore utilized virtual reality to simulate a real-world task while recording from ensembles of primate PFC neurons. Methods: Two male rhesus macaques (macaca mulatta) were trained to navigate a virtual reality environment using a joystick and learn a context-object association rule. We implanted each monkey with two 96-channel Utah arrays (Blackrock Microsystems) in the lateral PFC (areas 9/46 and 8a) and simultaneously recorded from multiple single neurons. Results: A linear support-vector-machine decoded task elements (context, target location and chosen direction of movement) with significantly greater than chance accuracy. This information was decoded in a sequential manner as the primates made a rule-based decision, with context information appearing first, followed by target location, and chosen side. Conclusions: We found that different neuronal ensembles encode the elements needed for implementing the context rule, and that such ensembles are activated sequentially. Brain-machine-interface systems may benefit by integrating neural data from the PFC, providing salient goal-related information such as the content of the goal and its spatial location.

Level of mRNA of orexin receptors of second type (ORXR2) in conditions of chronic alcoholation in structures of the rat brain

BACKGROUND: Orexin and its receptors are involved in the mechanisms of pathological craving for alcohol, but there is no unambiguous answer about the expression of the OX2R gene in the rat brain under conditions of alcohol addiction.&#x0D; AIM: The aim of this study was to determine the level of OX2R mRNA in brain structures in rats under conditions of prolonged alcoholization and during the period of abstinence.&#x0D; MATERIALS AND METHODS: Adult male Wistar rats were alcoholized with 15% ethanol as the only source of liquid for 6 months. The rats were decapitated after chronic alcoholization, as well as on the 1st and 7th days of alcohol withdrawal. Samples of brain structures (prefrontal cortex, hippocampus, ventral tegmental area) were frozen in liquid nitrogen and stored at 80C. Determination of the level of OX2R mRNA was carried out using the method of PCR-analysis.&#x0D; RESULTS: The level of ORXR2 gene expression significantly increased in the hippocampus on the 7th day of abstinence in relation to the group of intact animals and in relation to the group of chronically alcoholized rats. The level of OX2R mRNA in the prefrontal cortex and ventral tegmental area in animal groups of abstinence (1st and 7th days) did not change in relation to both alcohol and the intact animals.&#x0D; CONCLUSIONS: It is concluded that the orexin brain system may represent a new potential therapeutic target for the prevention of relapse in alcohol withdrawal. Together with the previously obtained data it was concluded that orexin receptor antagonists can be used to reduce the pathological craving for alcohol.

Stress management using fNIRS and binaural beats stimulation.

In this study, we investigate the effectiveness of binaural beats stimulation (BBs) in enhancing cognitive vigilance and mitigating mental stress level at the workplace. We developed an experimental protocol under four cognitive conditions: high vigilance (HV), vigilance enhancement (VE), mental stress (MS) and stress mitigation (SM). The VE and SM conditions were achieved by listening to 16 Hz of BBs. We assessed the four cognitive conditions using salivary alpha-amylase, behavioral responses, and Functional Near-Infrared Spectroscopy (fNIRS). We quantified the vigilance and stress levels using the reaction time (RT) to stimuli, accuracy of detection, and the functional connectivity metrics of the fNIRS estimated by Phase Locking Values (PLV). We propose using the orthogonal minimum spanning tree (OMST) to determine the true connectivity network patterns of the PLV. Our results show that listening to 16-Hz BBs has significantly reduced the level of alpha amylase by 44%, reduced the RT to stimuli by 20% and increased the accuracy of target detection by 25%, (p < 0.001). The analysis of the connectivity network across the four different cognitive conditions revealed several statistically significant trends. Specifically, a significant increase in connectivity between the right and left dorsolateral prefrontal cortex (DLPFC) areas and left orbitofrontal cortex was found during the vigilance enhancement condition compared to the high vigilance. Likewise, similar patterns were found between the right and left DLPFC, orbitofrontal cortex, right ventrolateral prefrontal cortex (VLPFC) and right frontopolar PFC (prefrontal cortex) area during stress mitigation compared to mental stress. Furthermore, the connectivity network under stress condition alone showed significant connectivity increase between the VLPFC and DLPFC compared to other areas. The laterality index demonstrated left frontal laterality under high vigilance and VE conditions, and right DLPFC and left frontopolar PFC while under mental stress. Overall, our results showed that BBs can be used for vigilance enhancement and stress mitigation.

Shape and Rule Information Is Reflected in Different Local Field Potential Frequencies and Different Areas of the Primate Lateral Prefrontal Cortex.

The lateral prefrontal cortex (LFPC) plays a crucial role in executive function by adaptively storing behavior-relevant information as working memory. Neural mechanisms associated with local field potentials (LFPs) may underlie the adaptive properties of the LFPC. Here, we analyzed how LFPs recorded from the monkey LFPC are modulated by the crucial factors of a shape manipulation task. In this task, the test shape is transformed by manipulating a lever to match the size and orientation of the sample shape. The subject is required to temporarily memorize the rules such as the arm-movement-manipulation relationship and the sample shape to generate the sequential behavior of operations. In the present study, we focused on task variables about shape and rules, and examined among which aspects distinguish the ventral and dorsal sides of the LFPC. We found that the transformed shape in the sample period strongly affected the theta and delta waves in the delay period on the ventral side, while the arm-manipulation assignment influenced the gamma components on the dorsal side. These findings suggest that area- and frequency-selective LFP modulations are involved in dynamically recruiting different behavior-relevant information in the LFPC.

Asymmetric Prefrontal Cortex Activation Associated with Mutual Gaze of Mothers and Children during Shared Play

Mother–child shared play provides rich opportunities for mutual symmetrical interactions that serve to foster bond formation in dyads. Mutual gaze, a symmetrical behaviour that occurs during direct eye contact between two partners, conveys important cues of social engagement, affect and attention. However, it is not known whether the prefrontal cortical areas responsible for higher-order social cognition of mothers and children likewise exhibit neural symmetry; that is, similarity in direction of neural activation in mothers and children. This study used functional Near-infrared Spectroscopy (fNIRS) hyperscanning on 22 pairs of mothers and their preschool-aged children as they engaged in a 10-min free-play session together. The play interaction was video recorded and instances of mutual gaze were coded for after the experiment. Multivariate linear regression analyses revealed that neural asymmetry occurred during mother–child mutual gaze, where mothers showed a deactivation of prefrontal activity whereas children showed an activation instead. Findings suggest that mothers and children may employ divergent prefrontal mechanisms when engaged in symmetrical behaviours such as mutual gaze. Future studies could ascertain whether the asymmetric nature of a parent–child relationship, or potential neurodevelopmental differences in social processing between adults and children, significantly contribute to this observation.

Frontal asymmetry as a core feature of major depression: a functional near-infrared spectroscopy study.

Background:Frontal asymmetry plays a major role in depression. However, patients with treatment-resistant depression (TRD) have widespread hypofrontality. We investigated whether patients with TRD have a characteristic frontal activation pattern in functional near-infrared spectroscopy (fNIRS) findings and how the frontal cortex responds to different levels of cognitive tasks.Methods:We enrolled 27 right-handed patients with TRD, 27 patients without TRD and 27 healthy controls. We used multichannel fNIRS to evaluate activation of the bilateral dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC) and left motor area in response to 3 tasks: finger tapping, a low cognitive–load motor task; verbal fluency, a moderate cognitive–load task; and a dual task involving simultaneous finger tapping and verbal fluency, a high cognitive–load task.Results:We found significant between-group differences in left DLPFC activation for all 3 tasks. The healthy controls had cortical activation in the left motor area during finger tapping and the bilateral frontal cortex during the dual task. However, patients without TRD had right VLPFC activation during finger tapping and left DLPFC activation during the dual task. Patients with TRD had bilateral DLPFC activation during finger tapping but exhibited increased bilateral VLPFC and left motor area activation during verbal fluency and increased left motor area activation during the dual task. In healthy controls and patients without TRD, we found that the right VLPFC was positively correlated with depression severity.Limitations:Our cohort included only patients with late-onset depression.Conclusion:We found different patterns of abnormal frontal activation between patients with and without TRD. In patients without TRD, the right prefrontal cortex (PFC) was recruited during simple motor tasks. However, in patients with TRD, the bilateral PFC was recruited during simple tasks and motor cortical resources were used compensatorily during PFC-demanding complex cognitive tasks.

Revision and Validity Test for Experimental Tasks Related to Risky Social Decision-Making

&lt;p&gt;近年來，學者認為，行為決策的偏差導因於情緒-認知歷程間的失衡，哥倫比亞卡片任務(CCT)因此 被提出用以測量個人在風險決策中的情緒和認知歷程，但至今該任務測量的建構效度如何，仍不清楚， 並且原任務設計除了在實施上較為複雜且耗時外，在決策歷程中也僅考量分數的得失變化，未考量社會 因素(如:同儕與社會酬賞)對青少年風險決策歷程的影響。本研究主要目的在於，參考與修正(簡 化)原CCT任務設計，並增加同儕決策的社會參照與同儕認同的社會酬賞情境設計於修正版的CCT風險 決策任務中，衡鑑該社會風險決策任務的建構效度。本研究以269位八年級學生為對象，採多層次驗證 性因素分析考量資料巢套結構對分析結果的影響。研究結果顯示:(1)簡化後的原CCT任務可有效激 發情緒與認知歷程。(2)融入社會因素的CCT任務亦能有效激發社會參照與社會酬賞對決策的影響。 (3)本研究編修的社會風險決策任務具有良好的建構效度。根據研究結果，未來研究可運用該測量工 具，理解青少年行為的風險決策對認知與行為表現的影響。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Risky decisions increase with age and reach peaks in adolescence and early adulthood before declining again during adulthood. Although risky decisions are commonly made by adolescents, it may have long-term negative impacts on life later. The Iowa Gambling Task (IGT), proposed about three decades ago, is the most common task used to investigate risky decision-making. It was developed based on the somatic marker hypothesis, which assumed that individuals’ behaviors are implicitly influenced by reward and punishment experiences, and these experiences would send emotional information to drive individuals’ decision-making behaviors toward beneficial long-term directions. However, only the emotional decision-making process was addressed in IGT, which may not sufficiently account for adolescents’ risky decision processes. Recently, cognitive neuroscience research suggested that risky decision-making involves two systems in the brain. Risky decision-making increases between childhood and adolescence as a result of changes around the time of puberty of the brain’s socio-emotional system that leads to increased reward-seeking, especially when peers are present. The socio-emotional system has been shown to rely on the ventral tegmentum area, subcortical structures (ventral striatum and amygdala) and cortical structures (the insular and medial/orbital frontal cortex). This system is operated automatically based on similarity and contiguity, and behavior is influenced by emotional impulse. Risky decision-making decreases between adolescence and adulthood because of changes in the brain’s cognitive-control system &amp;ndash; changes which improve individuals’ ability for self-control, which occur gradually and over the course of adolescence and young adulthood. The cognitive-control system is assumed to rely on the dorsal and ventral area of the lateral prefrontal cortex and posterior parietal cortex. The differing timetables of these two brain systems make mid-adolescence a time of heightened vulnerability to make risky decisions. Consequently, researchers tended to argue that biased behavioral decision making was due to an imbalance between emotion and cognition processes. The Columbia Card Task (CCT) was proposed to measure individuals’ emotion and cognition processes in decision making. However, the construct validity of this measurement was unclear, and it was not only complex and time- consuming in the implementation of the original task design but also considered the changes of scores instead of including the effects of social factors (i.e., peers and social reward) on decision making processes. The main purpose of this study was referring and revising (simplifying) the original design of CCT and adding other tasks that incorporated social reference of peers’ decisions and social rewards of recognition into a revised CCT task to evaluate the construct validity of this social risky decision-making task. There were 269 eighth graders who consented to participate in this study, and multilevel confirmatory factor analysis was conducted to take into account nesting structure. The results showed: (1) The original design of CCT with minor revisions (reducing decision options from three to two) was effective in eliciting emotion and cognition processes. (2) Simplified CCT tasks incorporating social factors were also effective in eliciting the effects of social reference and social reward. (3) The social risky decision-making task held good construct validity. Future studies are encouraged to utilize this measurement to understand the effects of adolescents’ risky decision-making on cognition and behavior. For guidance and counseling practices, it is encouraged to understand the extent of risky decision-making for adolescents through present tasks to identify adolescents who are vulnerable to make risky decisions as early as possible and to regularly show care and help through guidance and counseling. Moreover, clarifying which adolescents are more likely to make risky decisions because of the presence of peers or social rewards helps to understand the potential impacts of risky decisions under different decision conditions. This study is beneficial for guidance and counseling practitioners to provide more precise interventions.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Immune Phenotypes of Oligodendroglial‐Lineage Cells in MDD and in Response to Chronic Stress‐Induced Microglial Inflammation

BackgroundMajor Depressive Disorder (MDD) is a complex and heterogenous psychiatric disorder affecting more than 300 million people worldwide. Though the mechanisms underlying MDD are not fully understood, a subset of depressive patients can manifest chronic neuroinflammatory responses. In addition, brain‐imaging studies in MDD patients have provided evidence of white matter reductions and such changes are hypothesized to lead to disruption of Oligodendroglial‐Lineage cells (OLN) homeostatic mechanisms, resulting in destabilization of emotional/cognitive circuitry. The present goal of the study is to investigate whether these histopathological alterations are linked with chronic inflammation through single‐nucleus transcriptomics of MDD patients and in a depression mouse model.MethodsBioinformatics: Raw counts were downloaded from GEO (GSE144136), and expression objects created using Seurat. OLN were subsetted, clustered (using UMAP), and annotated based on their expression of early and late OLN markers. Pseudotime trajectory analysis was conducted using Moncle3. In vivo: The Repeated Social Defeat Stress (RSDS) paradigm (10 days) was used to induce depressive‐like behavior in 8–12‐week‐old male CX3CR1‐GFP+ and CSPG4‐EGFP+ mice. Behavioral tasks (BH) were performed to stratify the defeated mice to susceptible (S; depressive‐like) and resilient (R; non‐depressive) to stress groups. The study focuses on the MDD‐affected prefrontal cortex (mPFC) area (Fig).ResultsSeparate clustering of MDD and Control samples yielded four similar clusters labeled based on their gene expression as: OPCs, Committed OPCs, Immature Oligodendrocytes (OLs), and Mature OLs. One MDD‐specific cluster was also obtained and labeled as Immune OLs (ImOL), given its expression of immune genes, such as: ARGHAP24, ADAM28, LPAR6, C3, CD74, and P2RY12. Further analysis of the ImOL cluster revealedexpression of markers associated with later phases of OLN progeny. Finally, a predictive model of pseudotime trajectory revealed alterations in the progression of OLN progeny in MDD samples. We then sought to identify this novel subset of ImOL in the RSDS model of depression. MHCII, C3 and P2RY12 were examined in conjunction with OLN markers (CSPG4, O4, CNP), with significant changes observed in S groups. Interestingly, microglial phagocytosis of myelin elements (CX3CR1‐GFP, MHCII, CNP), was significantly increased in S groups post RSDS, rendering the ImOL populations as potential recruiters of innate immunity.ConclusionsTogether, our computational data in MDD patients and depression mouse model, show that OLN can swiftly respond to chronic stress, and adopt an immune‐like phenotype, potentially contributing to the white matter disturbances observed in MDD.

The effect of acute mental stress on the exchange of monoamines in the mesocortical and nigrostriatal systems of the rat brain

Background. Мesocortical and nigrostriatal dopaminergic systems are highly sensitive to stressful events. One of the most adequate models of acute psychogenic stress in animals is the death of a partner upon presentation of a predator.&#x0D; Aim. To study the content of dopamine (DA), serotonin and their metabolites: dioxyphenylacetic (DOPAC), homovanillic and 5-hydroxyindoleacetic (5-HIAA) acids in the prefrontal cortex, striatum, and ventral tegmental area in rats on days 3, 7, and 14 after the acute psychogenic stress of the death of a partner upon presentation of a predator.&#x0D; Materials and methods. 28 male Wistar rats were studied. Acute single psychotraumatic situation was used. A group of rats was placed in a tiger python terrarium. One animal died as a result of its nutritional needs, the rest of the rats experienced the death of a partner. The content of monoamines in the brain structures was carried out by high performance liquid chromatography with electrochemical detection.&#x0D; Results. Changes in the content of monoamines in the prefrontal cortex, striatum, and ventral tegmental area were found on the 7 and 14 days after the presentation of the predator. In the ventral tegmental area on the 7 day, there was an increase in the DOPAC/DA ratio and an increase in the serotonin metabolite 5-HIAA, which reflects an increase in the activity of dopamine and serotonin. In the prefrontal cortex on the 14 day, the DOPAС content and the DOPAС/DA index decreased. The 5-HIAA content in the prefrontal cortex and the 5-HIAA/5-HT value also significantly decreased.&#x0D; Conclusions. Changes in the metabolism of monoamines after presentation of a predator develop gradually: increase of the dopamine and serotonin activity in the ventral tegmental area was noted on the 7 day after presentation of the predator, decrease in their activity in the striatum and prefrontal cortex only on the 14 day, reflecting the development of depressive states and post-traumatic stress disorder.

Multiarea Brain Activation and Gait Deterioration During a Cognitive and Motor Dual Task in Individuals With Parkinson Disease.

In people with Parkinson disease (PD), gait performance deteriorating during dual-task walking has been noted in previous studies. However, the effects of different types of dual tasks on gait performance and brain activation are still unknown. The purpose of this study was to investigate cognitive and motor dual-task walking performance on multiarea brain activity in individuals with PD. Twenty-eight participants with PD were recruited and performed single walking (SW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT) at their self-selected speed. Gait performance including walking speed, stride length, stride time, swing cycle, temporal and spatial variability, and dual-task cost (DTC) was recorded. Brain activation of the prefrontal cortex (PFC), premotor cortex (PMC), and supplementary motor areas (SMA) were measured using functional near-infrared spectroscopy during walking. Walking performance deteriorated upon performing a secondary task, especially the cognitive task. Also, a higher and more sustained activation in the PMC and SMA during WCT, as compared with the WMT and SW, in the late phase of walking was found. During WMT, however, the SMA and PMC did not show increased activation compared with during SW. Moreover, gait performance was negatively correlated with PMC and SMA activity during different walking tasks. Individuals with mild to moderate PD demonstrated gait deterioration during dual-task walking, especially during WCT. The SMA and PMC were further activated in individuals with PD when performing cognitive dual-task walking.Supplemental Digital Content is Available in the Text.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A383 ).

Изучение функциональной коннективности головного мозга у пациентов с асимптомным каротидным стенозом

Purpose: To explore functional connectivity in patients with asymptomatic internal carotid arteries stenosis of more than 60% when using hirudotherapy. Materials and methods: The analysis of the results of the examination of 15 patients aged 60 to 82 years with asymptomatic stenosis of the carotid arteries in the range of 60‒75 % was carried out. The patients underwent a course of hirudotherapy, consisting of 10 sessions. All patients underwent structural and functional magnetic resonance imaging with analysis of statistical data at rest, complaints and neurological status were assessed ‒ before and after the course of hirudotherapy. Results: When using a course of hirudotherapy in patients with asymptomatic internal carotid arteries tenosis, when analyzing the neurological status and complaints, a significant improvement in well-being was noted. During functional magnetic resonance imaging, differences in functional connectivity between the medial prefrontal cortex and other areas of the brain were determined. Activation was noted in the main structures of the network of managerial control and identification of significance. Connectivity between the leading regions of the brain increased, which is a sign of improved brain activity. Conclusion: Connectivity research can be used to study the functioning of brain networks and to determine the effectiveness of therapy. The course of hirudotherapy significantly changed the functional connectivity of the brain regions, the changes correlated with a decrease in the number of complaints. This work is a pilot and will be continued for the further development of treatment-and-prophylactic strategies with the inclusion of hirudotherapy in patients with a high risk of vascular accidents in a treatment.

Simple Coordination and Cognitive Stimulation Activities for Cognitive Function Assessments using Functional Near-Infrared Spectroscopy

Functional near-infrared spectroscopy (fNIRS) is a non-invasive and high-density imaging device used for the evaluation of cognitive functions by measuring the oxygenated haemoglobin (HbO) and deoxygenated haemoglobin (HHb) levels in the prefrontal cortex. The present study determined the utilisation of fNIRS in detecting cerebral haemoglobin oxygenation level during coordination and simple cognitive stimulation activities in healthy young volunteers. Thirty subjects comprising equally of both genders were recruited. Subjects were tasked with coordination tests (plate tapping and block transfer tests) and cognitive stimulation activities (ruler drop test and MRAVLT) while the fNIRS system was attached to their prefrontal cortex area. The HbO and HHb levels were recorded and analysed using Repeated Measures ANOVA. The HbO levels during coordination tests differ significantly from resting state (p&lt;0.05) in all but channel 2. All coordination tests elevated HbO levels compared to resting state except during block transfer test in channel 1. No significant difference was observed in HHb levels between coordination tests and resting state in all channels (p&gt;0.05), except channel 3. All cognitive stimulation activities increased HbO levels compared to resting state; this change was significant in channels 3 and 4 (p&lt;0.05). In contrast, HHb levels during all cognitive tests were lower compared to the resting state and was found to be significant in channels 2 and 3 (p&lt;0.05). These findings suggested that coordination and cognitive stimulation activities activate prefrontal cortex in healthy young adults and could be potentially utilised as a valid screening tool for cognitive function assessments via fNIRS.

Reward and loss incentives improve spatial working memory by shaping trial-by-trial posterior frontoparietal signals

Integrating motivational signals with cognition is critical for goal-directed activities. The mechanisms that link neural changes with motivated working memory continue to be understood. Here, we tested how externally cued and non-cued (internally represented) reward and loss impact spatial working memory precision and neural circuits in human subjects using fMRI. We translated the classic delayed-response spatial working memory paradigm from non-human primate studies to take advantage of a continuous numeric measure of working memory precision, and the wealth of translational neuroscience yielded by these studies. Our results demonstrated that both cued and non-cued reward and loss improved spatial working memory precision. Visual association regions of the posterior prefrontal and parietal cortices, specifically the precentral sulcus (PCS) and intraparietal sulcus (IPS), had increased BOLD signal during incentivized spatial working memory. A subset of these regions had trial-by-trial increases in BOLD signal that were associated with better working memory precision, suggesting that these regions may be critical for linking neural signals with motivated working memory. In contrast, regions straddling executive networks, including areas in the dorsolateral prefrontal cortex, anterior parietal cortex and cerebellum displayed decreased BOLD signal during incentivized working memory. While reward and loss similarly impacted working memory processes, they dissociated during feedback when money won or avoided in loss was given based on working memory performance. During feedback, the trial-by-trial amount and valence of reward/loss received was dissociated amongst regions such as the ventral striatum, habenula and periaqueductal gray. Overall, this work suggests motivated spatial working memory is supported by complex sensory processes, and that the IPS and PCS in the posterior frontoparietal cortices may be key regions for integrating motivational signals with spatial working memory precision.

Sensorimotor Synchronization in Healthy Aging and Neurocognitive Disorders.

Sensorimotor synchronization (SMS), the coordination of physical actions in time with a rhythmic sequence, is a skill that is necessary not only for keeping the beat when making music, but in a wide variety of interpersonal contexts. Being able to attend to temporal regularities in the environment is a prerequisite for event prediction, which lies at the heart of many cognitive and social operations. It is therefore of value to assess and potentially stimulate SMS abilities, particularly in aging and neurocognitive disorders (NCDs), to understand intra-individual communication in the later stages of life, and to devise effective music-based interventions. While a bulk of research exists about SMS and movement-based interventions in Parkinson’s disease, a lot less is known about other types of neurodegenerative disorders, such as Alzheimer’s disease, vascular dementia, or frontotemporal dementia. In this review, we outline the brain and cognitive mechanisms involved in SMS with auditory stimuli, and how they might be subject to change in healthy and pathological aging. Globally, SMS with isochronous sounds is a relatively well-preserved skill in old adulthood and in patients with NCDs. At the same time, natural tapping speed decreases with age. Furthermore, especially when synchronizing to sequences at slow tempi, regularity and precision might be lower in older adults, and even more so in people with NCDs, presumably due to the fact that this process relies on attention and working memory resources that depend on the prefrontal cortex and parietal areas. Finally, we point out that the effect of the severity and etiology of NCDs on sensorimotor abilities is still unclear: More research is needed with moderate and severe NCD, comparing different etiologies, and using complex auditory signals, such as music.

Prefrontal cortex hemodynamic response to acute high intensity intermittent exercise during executive function processing

We investigated prefrontal cortex (PFC) hemodynamic response, through functional near infrared spectroscopy (fNIRS) during executive function (EF) processing in response to acute high intensity intermittent exercise (HIIE) in young adults. We also assessed the associated sex differences in the cognitive scores and related PFC hemodynamic functions in response to HIIE. 49 young healthy adult participants (32 women, 17 men) were randomly assigned to either control or HIIE intervention groups. HIIE group participants performed 4 × 4 minutes of HIIE on cycle ergometer with 3 minutes of active recovery between the bouts; control group relaxed for the time equivalent to intervention. fNIRS data was collected during the performance of the EF tests including Color Word Stroop Test (CWST) and Trail Making Test (TMT) in pre and post sessions in both the groups. Results indicated a significant change in the hemodynamic response in the form of increased oxygenated and decreased deoxygenated hemoglobin in the PFC areas specific to the EF tasks, with improved CWST and TMT scores in response to HIIE intervention. PFC activation was different in men and women in response to HIIE, however similar scores of task performance were observed in men and women during the performance of executive functions in response to HIIE. The study concludes that an acute HIIE session improves executive function which is associated with an increase activation of PFC. Sex differences exist in the activation of PFC in response to HIIE during EF processing. Our study adds to the current evidence regarding exercise and cognition.

Neurochemical and functional interactions for improved perceptual decisions through training.

Learning and experience are known to improve our ability to make perceptual decisions. Yet, our understanding of the brain mechanisms that support improved perceptual decisions through training remains limited. Here, we test the neurochemical and functional interactions that support learning for perceptual decisions in the context of an orientation identification task. Using magnetic resonance spectroscopy (MRS), we measure neurotransmitters (i.e., glutamate, GABA) that are known to be involved in visual processing and learning in sensory [early visual cortex (EV)] and decision-related [dorsolateral prefrontal cortex (DLPFC)] brain regions. Using resting-state functional magnetic resonance imaging (rs-fMRI), we test for functional interactions between these regions that relate to decision processes. We demonstrate that training improves perceptual judgments (i.e., orientation identification), as indicated by faster rates of evidence accumulation after training. These learning-dependent changes in decision processes relate to lower EV glutamate levels and EV-DLPFC connectivity, suggesting that glutamatergic excitation and functional interactions between visual and dorsolateral prefrontal cortex facilitate perceptual decisions. Further, anodal transcranial direct current stimulation (tDCS) in EV impairs learning, suggesting a direct link between visual cortex excitation and perceptual decisions. Our findings advance our understanding of the role of learning in perceptual decision making, suggesting that glutamatergic excitation for efficient sensory processing and functional interactions between sensory and decision-related regions support improved perceptual decisions.NEW & NOTEWORTHY Combining multimodal brain imaging [magnetic resonance spectroscopy (MRS), functional connectivity] with interventions [transcranial direct current stimulation (tDCS)], we demonstrate that glutamatergic excitation and functional interactions between sensory (visual) and decision-related (dorsolateral prefrontal cortex) areas support our ability to optimize perceptual decisions through training.

Role of Amygdala-Infralimbic Cortex Circuitry in Glucocorticoid-induced Facilitation of Auditory Fear Memory Extinction.

The basolateral amygdala (BLA) and infralimbic area (IL) of the medial prefrontal cortex (mPFC) are two interconnected brain structures that mediate both fear memory expression and extinction. Besides the well-known role of the BLA in the acquisition and expression of fear memory, projections from IL to BLA inhibit fear expression and have a critical role in fear extinction. However, the details of IL-BLA interaction have remained unclear. Here, we investigated the role of functional reciprocal interactions between BLA and IL in mediating fear memory extinction. Using lidocaine (LID), male rats underwent unilateral or bilateral inactivation of the BLA and then unilateral intra-IL infusion of corticosterone (CORT) prior to extinction training of the auditory fear conditioning paradigm. Freezing behavior was reported as an index for conditioned fear. Infusions were performed before the extinction training, allowing us to examine the effects on fear expression and further extinction memory. Experiments 1-3 investigated the effects of left or right infusion of CORT into IL and LID unilaterally into BLA on fear memory extinction. Intra-IL infusion of CORT in the right hemisphere reduced freezing behavior when administrated before the extinction training. Auditory fear memory extinction was impaired by asymmetric inactivation of BLA and CORT infusion in the right IL; however, the same effect was not observed with symmetric inactivation of BLA. IL-BLA neural circuit may provide additional evidence for the contribution of this circuit to auditory fear extinction. This study demonstrates dissociable roles for right or left BLA in subserving the auditory fear extinction. Our finding also raises the possibility that left BLA-IL circuitry may mediate auditory fear memory extinction via underlying mechanisms. However, further research is required in this area. Corticosterone infusion in the right (but not the left) infralimbic area facilitates auditory fear memory extinction.Corticosterone infusion in the right infralimbic area following symmetric basolateral amygdala inactivation has no effect on auditory fear memory extinction.Asymmetric basolateral amygdala inactivation prior to corticosterone infusion into the right infralimbic area impairs auditory fear memory extinction. Previous studies have established that glucocorticoids, which are released in stressful conditions, enhance fear memory extinction. In this study, we found that corticosterone infusion into the right infralimbic area, but not the left one, facilitates auditory fear memory extinction. The effect of corticosterone infusion in the infralimbic area was not blocked by the intra-basolateral amygdala injections of lidocaine when administrated in the ipsilateral hemisphere. However, asymmetric basolateral amygdala inactivation and corticosterone infusion into the right infralimbic area impairs auditory fear memory extinction.