Left Dorsal Lateral Prefrontal Cortex Research Articles

Abnormal structure and function of white matter in obsessive-compulsive disorder

BackgroundAbnormal structure and function of gray matter (GM) have been discovered in the cortico-striatal-thalamic-cortical (CSTC) circuit in obsessive-compulsive disorder (OCD). The GM structure and function may be influenced by the structure and function of the white matter (WM). Therefore, it is crucial to explore the characteristics of WM in OCD. MethodsDiffusion tensor imaging and resting-state functional magnetic resonance imaging data of 52 patients with OCD and 39 healthy controls (HCs) were collected. The tract-based spatial statistics, amplitude of low-frequency fluctuations (ALFF), and structural-functional coupling approaches were utilized to explore the WM structure and function. Furthermore, the relationship between the abnormal WM structure and function and clinical symptoms of OCD was investigated using Pearson's correlation. Support vector machine was performed to evaluate whether patients with OCD could be identified with the changed WM structure and function. ResultsCompared to HCs, the lower fractional anisotropy (FA) values of four clusters including the superior corona radiata, anterior corona radiata, right superior longitudinal fasciculus, corpus callosum, left posterior corona radiata, fornix, and the right anterior limb of internal capsule, reduced ALFF/FA ratio in the left anterior thalamic radiation (ATR), and the decreased functional connectivity between the left ATR and the left dorsal lateral prefrontal cortex within CSTC circuit at rest were observed in OCD. The decreased ALFF/FA ratio in the left ATR negatively correlated with Yale-Brown Obsessive-Compulsive Scale obsessive thinking scores and Hamilton Anxiety Rating Scale scores in OCD. Furthermore, the features that combined the abnormal WM structure and function performed best in distinguishing OCD from HCs with the appropriate accuracy (0.80), sensitivity (0.82), as well as specificity (0.80). ConclusionCurrent research discovered changed WM structure and function in OCD. Furthermore, abnormal WM structural-functional coupling may lead to aberrant GM connectivity within the CSTC circuit at rest in OCD.Trial Registration: Study on the mechanism of brain network in obsessive-compulsive disorder with multi-model magnetic resonance imaging (ChiCTR-COC-17013301).

Bilingual Language Control in the Brain: Evidence from Structural and Effective Functional Brain Connectivity.

Experience in bilingual language control is often accompanied by changes in the structure and function of the brain. Brain structural changes are also often closely related to changes in functions. Previous studies, however, have not directly explored the relationship between structural connectivity and effective functional connectivity of the brain during bilingual language control, and whether the two types of connectivity are associated with behavioral performance of language control. Using behavioral performance, functional, and diffusion imaging techniques, we found that: (1) during language control, the left dorsal lateral prefrontal cortex (dlPFC), left caudate nucleus (CN), inferior parietal lobe, precuneus, and dorsal anterior cingulate cortex (dACC)/pre-SMA were significantly activated. (2) In the language control model with left dlPFC, dACC/pre-SMA, and left CN as ROIs (selected based on activation results and language control models from previous studies), stimuli first enter dACC/pre-SMA and then to left CN. At the left CN, a bidirectional effective connectivity is formed with left dlPFC. (3) There is a nonlinear relationship between effective connectivity during language control and the structural connectivity of the second language learners' brains. Specifically, the fiber density between dACC/pre-SMA and left dlPFC has a positive influence on the bidirectional effective connectivity between left dlPFC and left CN. Findings of the present study contribute evidence toward functional effective connectivity during bilingual language control; toward structural connectivity in the brains of second language learners; as well as toward nonlinear relationships between functional effective connectivity, structural connectivity, and behavioral performance in relation to bilingual language control.

TRANSCRANIAL DIRECT CURRENT STIMULATION MODULATES BRAIN ACTIVITY DURING DUAL-TASK STANDING IN OLDER ADULTS

Abstract In older adults, performing an attention-demanding cognitive task while standing comes with a ‘cost’ (i.e., decrement) to postural control. Transcranial direct current stimulation (tDCS) designed to facilitate the excitability of the left dorsal-lateral prefrontal cortex (L-DLPFC) and motor cortex (M1) mitigates this dual-task cost (DTC). The effects of tDCS on underlying brain activity measured by electroencephalography (EEG) during dual-tasking, however, is unknown. We hypothesized that tDCS would decrease the DTC of EEG-measured alpha and gamma power, as these frequencies have been linked to attentional processing and their attenuation is believed to reflect more efficient and/or effective postural control. Thirty participants received 20-minutes of tDCS targeting the L-DLPFC and M1, or sham (i.e., control) stimulation, in random order, on two separate visits. Before and immediately after each stimulation, EEG and postural sway area were recorded as participants completed trials of standing with and without verbalized serial subtractions. EEG alpha and gamma power were derived from channels corresponding to the L-DLPFC and M1 areas. The DTC (absolute change from single to dual-tasking) for both EEG and sway outcomes were calculated. tDCS, compared to sham, decreased the DTC to gamma power (p=0.04) and sway area (p=0.04). No pre-to-post stimulation changes were observed for alpha power (p=0.42). Participants who demonstrated a greater decrease in the DTC to gamma power after tDCS exhibited a greater reduction (improvement) in the DTC to sway area (r=0.66, p=0.002). The results suggest that the tDCS-induced changes in gamma-frequency activity were associated with improved dual-task standing balance in older adults.

FC2: The effect of Maintenance phase of Transcranial Direct Current Stimulation (tDCS) in Alzheimer’s Dementia

Introduction:Transcranial direct current stimulation (tDCS) has been proposed to affect long-term synaptic plasticity through LTP and LTD, thereby improving cognitive ability. In pathology, the amyloid deposits in AD disrupts the balance between long-term potentiation (LTP) and long-term depression (LTD) of neuronal cells and synaptic plasticity. An increasing number of studies have been concluded a positive therapeutic effect on cognition in AD. In brain stimulation, dorsolateral prefrontal cortex (DLPFC) was associated with improvements in memory enhancement, language, processing speed, global cognitive symptoms, and apathy over a period of treatment. Theoretically, the aftereffect of tDCS would need to be re-stimulated by tDCS to maintain its delayed plastic response benefits. In this pilot study, we investigate the maintenance effects of continuing tDCS at three different times, weekly, every two weeks, and every four weeks, for 12 weeks.Method:Twenty-eight AD participants aged 55-90 years were enrolled (mean age 72.7, 77.3, and 76.2 in the three groups - maintained weekly (7 cases), biweekly (9 cases) and every 4 weeks (12 cases)). The anodal electrode was placed over the left dorsal lateral prefrontal cortex and the cathodal electrode was placed over the right supraorbital area. In each active session, we applied a current intensity of 2 mA and an electrode size of 25 cm2 for 30 min. All subjects received a series of neuropsychological assessments including CDR, MMSE, CASI and WCST at (1) baseline, (2) post-10sessions of tDCS (in 2weeks), and (3) post-maintenance phase (total of 12 weeks). Chi-square tests, Wilcoxon signed rank tests and Mann-Whitney U tests were used to assess differences in participant demographic characteristics and to compare differences in test scores between groups.Results:After 10 sessions of tDCS stimulations, the total CASI scores in the 1-week group improved significantly from baseline to 2 weeks. However, there are no significant difference in MMSE, CASI or WCST between baseline and after maintain phase stimulations in each group.Conclusion:Although tDCS has a positive effect in AD, it is recommended to prolong the number of tDCS stimulations, such as 20 sessions in 4 weeks.

Multisite rTMS combined with cognitive training modulates effective connectivity in patients with Alzheimer's disease.

To investigate the effective connectivity (EC) changes after multisite repetitive transcranial magnetic stimulation (rTMS) combined with cognitive training (COG). We selected 51 patients with mild or moderate Alzheimer's disease (AD) and delivered 10 Hz rTMS over the left dorsal lateral prefrontal cortex (DLPFC) and the lateral temporal lobe (LTL) combined with COG or sham stimulation for 4 weeks. The selected AD patients were divided into real (real rTMS+COG, n = 11) or sham (sham rTMS+COG, n = 8) groups to undergo neuropsychological assessment, resting-state fMRI, and 3D brain structural imaging before (T0), immediately at the end of treatment (T4), and 4 weeks after treatment (T8). A 2 × 3 factorial design with "time" as the within-subjects factor (three levels: T0, T4, and T8) and "group" as the between-subjects factor (two levels: real and sham) was used to investigate the EC changes related to the stimulation targets in the rest of the brain, as well as the causal interactions among seven resting-state networks based on Granger causality analysis (GCA). At the voxel level, the EC changes from the left DLPFC out to the left inferior parietal lobe and the left superior frontal gyrus, as well as from the left LTL out to the left orbital frontal cortex, had a significant group × time interaction effect. At the network level, a significant interaction effect was identified in the increase in EC from the limbic network out to the default mode network. The decrease in EC at the voxel level and the increase in EC at the network level were both associated with the improved ability to perform activities of daily living and cognitive function. Multisite rTMS combined with cognitive training can modulate effective connectivity in patients with AD, resulting in improved ability to perform activities of daily living and cognitive function.

Effect of Repetitive Transcranial Magnetic Stimulation on the Working Memory of Patients with Alzheimer’s Disease

Background and Aims Alzheimer’s disease (AD) is a common neurological disorder that begins with mild memory loss and progresses to severe impairment of executive and cognitive functions. This study aims to investigate the effect of repeated transcranial magnetic stimulation (rTMS) on the working memory of patients with AD. Methods In this quasi-experimental study with a pre-test/post-test design, 30 patients with AD aged 55-75 years referred to neurology clinics in Yazd, Iran participated, who were selected using a convenience sampling method and divided into two groups of intervention (n=15) and control (n=15). Active memory was measured by a computerized n-back test, both in terms of reaction time and percentage of accuracy before and after treatment. In the control group, each patient received 10 sessions of inactive rTMS for 20 minutes, while the intervention group received 10 sessions of active rTMS for 20 minutes at a frequency of 10 Hz over the left dorsal lateral prefrontal cortex. Data analysis was performed using analysis of covariance. Results Data analysis results showed that the reaction time significantly decreased, and the percentage of accuracy significantly increased in the n-back test in the intervention group after receiving rTMS compared to the control group (P= 0.001). Conclusion It seems that rTMS over the left dorsal lateral prefrontal cortex can improve the working memory in patients with AD.

Feasibility and Safety of Sequential Transcranial Direct Current Stimulation and Physical Therapy in Older Adults at Risk of Falling: A Randomized Pilot Study

ObjectiveTo establish the feasibility and safety of administering transcranial direct current stimulation (tDCS) immediately prior to physical therapy (PT) sessions in older adults at risk of falls. DesignA pilot randomized controlled study. SettingOutpatient geriatric physical therapy clinic. ParticipantsTen older adults living within supportive housing facilities (86.8±7.9 y/o, 8F) were enrolled in the study. InterventionsParticipants received tDCS or sham stimulation targeting the left dorsal lateral prefrontal cortex for 20 minutes, immediately prior to up to 10 of their PT visits. Main Outcome MeasuresFeasibility, safety, and functional outcomes were reported to inform the design of a larger and more definitive trial. ResultsSix fallers (88.8±5.0 y/o, 5F) completed the study and received 82.3% of the possible stimulation sessions, suggesting adding a 20-minute session of stimulation immediately prior to PT training sessions, along with pre- and post-assessments is feasible. The blinding strategy was successful and all reported side effects were expected and transient. While feasible and safe, the trial was met with numerous challenges, including selection bias, time and energy commitment, and large variation in functional performance, that must be considered when designing and implementing larger more definitive trials. ConclusionThis study provides preliminary evidence about the feasibility, safety, and challenges to combine PT and tDCS in very frail older adults.

Excitatory Dorsal Lateral Prefrontal Cortex Transcranial Magnetic Stimulation Increases Social Anxiety.

Social exclusion refers to the experience of rejection by one or more people during a social event and can induce pain-related sensations. Cyberball, a computer program, is one of the most common tools for analyzing social exclusion. Regions of the brain that underlie social pain include networks linked to the dorsal lateral prefrontal cortex (DLPFC). Specifically, self-directed negative socially induced exclusion is associated with changes in DLPFC activity. Direct manipulation of this area may provide a better understanding of how the DLPFC can influence the perception of social exclusion and determine a causal role of the DLPFC. Transcranial magnetic stimulation (TMS) was applied to both the left and right DLPFC to gauge different reactions to the Cyberball experience. It was found that there were elevated exclusion indices following right DLPFC rTMS; participants consistently felt more excluded when the right DLPFC was excited. This may relate to greater feelings of social pain when the right DLPFC is manipulated. These data demonstrate that direct manipulation of the DLPFC results in changes in responses to social exclusion.

Association of Changes in Neural Targets and Dietary Outcomes among Patients with Comorbid Obesity and Depression: Post hoc Analysis of ENGAGE-2 Mechanistic Clinical Trial

BackgroundDisruptions in brain circuits that regulate cognition and emotion can hinder dietary change and weight loss among individuals with obesity and depression. ObjectiveThe study aimed to investigate whether changes in brain targets in the cognitive control, negative affect, and positive affect circuits after 2-mo problem-solving therapy (PST) predict changes in dietary outcomes at 2 and 6 mo. MethodsAdults with obesity and depression from an academic health system were randomly assigned to receive PST (7-step problem-solving and behavioral activation strategies) over 2 mo or usual care. Seventy participants (mean age = 45.9 ± 11.6 y; 75.7% women, 55.7% Black, 17.1% Hispanic, 20.0% White; mean BMI = 36.5 ± 5.3 kg/m2; mean Patient Health Questionnaire-9 depression score = 12.7 ± 2.8) completed functional MRI and 24-h food recalls. Ordinary least square regression analyses were performed. ResultsAmong intervention participants, increased left dorsal lateral prefrontal cortex (dLPFC) activity of the cognitive control circuit at 2 mo was associated with increased diet quality (β: 0.20; 95% CI: −0.02, 0.42) and decreased calories (β: −0.19; 95% CI: −0.33, −0.04), fat levels (β: −0.22; 95% CI: −0.39, −0.06), and high-sugar food intake (β: −0.18; 95% CI: −0.37, 0.01) at 6 mo. For the negative affect circuit, increased right dLPFC–amygdala connectivity at 2 mo was associated with increased diet quality (β: 0.32; 95% CI: −0.93, 1.57) and fruit and vegetable intake (β: 0.38; 95% CI: −0.75, 1.50) and decreased calories (β: −0.37; 95% CI: −1.29, 0.54), fat levels (β: −0.37; 95% CI: −1.50, 0.76), sodium concentrations (β: −0.36; 95% CI: −1.32, 0.60), and alcohol intake (β: −0.71; 95% CI: −2.10, 0.68) at 2 but not at 6 mo. The usual care group showed opposing associations. The 95% CIs of all between-group differences did not overlap the null, suggesting a significant treatment effect. ConclusionsAmong adults with obesity and depression who underwent PST compared with those under usual care, improved dLPFC–amygdala regulation of negative affective brain states predicted dietary improvements at 2 mo, whereas improvements in dLPFC-based cognitive control predicted dietary improvements at 6 mo. These findings warrant confirmatory studies.This trial was at clinicaltrials.gov as NCT03841682.

Evaluating the treatment outcomes of repetitive transcranial magnetic stimulation in patients with moderate-to-severe Alzheimer's disease.

The repetitive transcranial magnetic stimulation (rTMS) shows great potential in the treatment of Alzheimer's disease (AD). However, its treatment efficacy for AD patients in moderate to severe stage is relatively evaluated. Here, we proposed a randomized, sham-controlled, clinical trial of rTMS among 35 moderate-to-severe AD patients. A high frequency (10 Hz) stimulation of the left dorsal lateral prefrontal cortex (DLPFC), 60-session long treatment lasting for 3 months procedure was adopted in the trial. Each participant completed a battery of neuropsychological tests at baseline and post-treatment for evaluation of the rTMS therapeutic effect. Twelve of them completed baseline resting-state functional magnetic resonance imaging (fMRI) for exploration of the underlying neural contribution to individual difference in treatment outcomes. The result showed that the rTMS treatment significantly improved cognitive performance on the severe impairment battery (SIB), reduced psychiatric symptoms on the neuropsychiatric inventory (NPI), and improved the clinician's global impression of change (CIBIC-Plus). Furthermore, the result preliminarily proposed resting-state multivariate functional connectivity in the (para) hippocampal region as well as two clusters in the frontal and occipital cortices as a pre-treatment neuroimaging marker for predicting individual differences in treatment outcomes. The finding could brought some enlightenment and reference for the rTMS treatment of moderate and severe AD patients.

Task switching involves working memory: Evidence from neural representation.

It is generally assumed that task switching involves working memory, yet some behavioral studies question the relationship between working memory and task switching ability. This debate can be resolved by directly comparing the brain activity pattern in task switching and working memory processes. If the task switching involves working memory, the neural activity patterns evoked by such two tasks would exhibit higher similarity. Here, we employed the task switching task and working memory to investigate the characteristic of the neural representation in such two cognitive processes. A conjunction analysis showed that the bilateral superior parietal lobule (SPL), bilateral insula, bilateral middle frontal gyrus (MFG), bilateral dorsal lateral prefrontal cortex (DLPFC) and pre-supplementary motor area (pre-SMA) were commonly and significantly activated in both task switching and working memory task. Critically, we found that task switching and working memory processing elicited similar activity patterns in bilateral SPL, right insula, left MFG, left DLPFC and pre-SMA, consistent with common neural processes for both tasks. These results not only suggest that the task switching process involves working memory from the perspective of neural representation, but also provide major new insights into the neurocognitive links between task switching and working memory.

The analgesic effect of different interactive modes of virtual reality: A prospective functional near-infrared spectroscopy (fNIRS) study.

This study primarily aimed at investigating the analgesic effect of different VR interactive modes via functional near-infrared spectroscopy (fNIRS) and exploring its correlations with the subjectively reported VR experience through a self-rating questionnaire. Fifteen healthy volunteers (Age: 21.93 ± 0.59 years, 11 female, 4 male) were enrolled in this prospective study. Three rounds of interactive mode, including active mode, motor imagery (MI) mode, and passive mode, were successively facilitated under consistent noxious electrical stimuli (electrical intensity: 23.67 ± 5.69 mA). Repeated-measures of analysis of variance (ANOVA) was performed to examine its pain relief status and cortical activation, with post hoc analysis after Bonferroni correction performed. Spearman's correlation test was conducted to explore the relationship between VR questionnaire (VRQ) items and cortical activation. A larger analgesic effect on the active (-1.4(95%CI, -2.23 to -0.57), p = 0.001) and MI modes (-0.667(95%CI, -1.165 to -0.168), p = 0.012) was observed compared to the passive mode in the self-rating pain score, with no significant difference reported between the two modes (-0.733(95%CI, -1.631 to.165), p = 0.131), associated with diverse activated cortical region of interest (ROI) in charge of motor and cognitive functions, including the left primary motor cortex (LM1), left dorsal-lateral prefrontal cortex (LDLPFC), left primary somatosensory cortex (LS1), left visual cortex at occipital lobe (LOL), and left premotor cortex (LPMC). On the other hand, significant correlations were found between VRQ items and different cortical ROIs (r = -0.629 to 0.722, p < 0.05) as well as its corresponding channels (r = -0.599 to 0.788, p < 0.05). Our findings suggest that VR can be considered as an effective non-invasive approach for pain relief by modulating cortical pain processing. A better analgesic effect can be obtained by exciting and integrating cortical ROIs in charge of motor and cognitive functions. The interactive mode can be easily tailored to be in line with the client's characteristics, in spite of the diverse cortical activation status when an equivalent analgesic effect can be obtained.

Quantitative description of the relationship between the enhancement of distraction-suppression and brain local state alteration after transcranial direct current stimulation.

Anodal transcranial direct current stimulation (tDCS) over the left dorsal lateral prefrontal cortex (lDLPFC) can improve distraction suppression ability, possibly by distantly regulating the connection properties of several large-scale brain networks and local brain state changes. However, little is known about the local state alteration that tDCS can induce in distant but task-related regions and the relationship between performance enhancement and local state alteration in potentially related regions, resulting in inefficient and uncertain tDCS regulation. We aimed to examine the alteration of brain local state before and after tDCS and its relationship with performance enhancement. With the within-subject design, the participants received anodal (1.5 mA) and sham tDCS at F3 (lDLPFC) for 20 min. The visual search task and resting-state functional magnetic resonance imaging (rsfMRI) were performed before and after stimulation. Anodal tDCS significantly enhanced distraction suppression. The amplitude of low-frequency fluctuation (ALFF) in the left parietal region significantly decreased, the decrement significantly positively correlated with performance enhancement after anodal tDCS. As well, the regional homogeneity (ReHo) in the left precuneus significantly increased, and the increasement significantly positively correlated with performance enhancement. Anodal tDCS over the lDLPFC can distantly modulate the local state of the brain and improve the distraction suppression ability. These two aspects are closely related and provide a direct and efficient approach to enhancing performance.

The role of associative learning in healthy and sustainable food evaluations: An event-related potential study

Individuals in industrialized societies frequently include processed foods in their diet. However, overconsumption of heavily processed foods leads to imbalanced calorie intakes as well as negative health consequences and environmental impacts. In the present study, normal-weight healthy individuals were recruited in order to test whether associative learning (Evaluative Conditioning, EC) could strengthen the association between food-types (minimally processed and heavily processed foods) and concepts (e.g., healthiness), and whether these changes would be reflected at the implicit associations, at the explicit ratings and in behavioral choices. A Semantic Congruency task (SC) during electroencephalography recordings was used to examine the neural signature of newly acquired associations between foods and concepts. The accuracy after EC towards minimally processed food (MP-food) in the SC task significantly increased, indicating strengthened associations between MP-food and the concept of healthiness through EC. At the neural level, a more negative amplitude of the N400 waveform, which reflects semantic incongruency, was shown in response to MP-foods paired with the concept of unhealthiness in proximity of the dorsal lateral prefrontal cortex (DLPFC). This implied the possible role of the left DLPFC in changing food representations by integrating stimuli’s features with existing food-relevant information. Finally, the N400 effect was modulated by individuals’ attentional impulsivity as well as restrained eating behavior.

Improved Regional Homogeneity in Chronic Insomnia Disorder After Amygdala-Based Real-Time fMRI Neurofeedback Training.

BackgroundChronic insomnia disorder (CID) is a highly prevalent sleep disorder, which influences people's daily life and is even life threatening. However, whether the resting-state regional homogeneity (ReHo) of disrupted brain regions in CID can be reshaped to normal after treatment remains unclear.MethodsA novel intervention real-time functional magnetic resonance imaging neurofeedback (rtfMRI-NF) was used to train 28 CID patients to regulate the activity of the left amygdala for three sessions in 6 weeks. The ReHo methodology was adopted to explore its role on resting-state fMRI data, which were collected before and after training. Moreover, the relationships between changes of clinical variables and ReHo value of altered regions were determined.ResultsResults showed that the bilateral dorsal medial pre-frontal cortex, supplementary motor area (SMA), and left dorsal lateral pre-frontal cortex had decreased ReHo values, whereas the bilateral cerebellum anterior lobe (CAL) had increased ReHo values after training. Some clinical scores markedly decreased, including Pittsburgh Sleep Quality Index, Insomnia Severity Index, Beck Depression Inventory, and Hamilton Anxiety Scale (HAMA). Additionally, the ReHo values of the left CAL were positively correlated with the change in the Hamilton depression scale score, and a remarkable positive correlation was found between the ReHo values of the right SMA and the HAMA score.ConclusionOur study provided an objective evidence that amygdala-based rtfMRI-NF training could reshape abnormal ReHo and improve sleep in patients with CID. The improved ReHo in CID provides insights into the neurobiological mechanism for the effectiveness of this intervention. However, larger double-blinded sham-controlled trials are needed to confirm our results from this initial study.

The Common and Different Neural Bases of Distraction and Reinterpretation: A Meta-Analysis of fMRI Studies.

Distraction and reinterpretation have been recognized as two different tactics of emotion regulation. As a tactic of attention deployment, distraction involves shifting attention to neutral information or performing a secondary task to distract attention from emotion stimuli of the primary task. Reinterpretation, a representative tactic of cognitive change, was defined as changing the meaning of a situation to enhance or reduce its emotional impact. Thus, there are significant differences between the two processes. We wondered if the neural mechanisms underlying distraction and reinterpretation are different. Even though their neural correlates have been widely studied with functional magnetic resonance imaging (fMRI), few studies were conducted to compare the two tactics directly. Here we conducted an activation likelihood estimation (ALE) meta-analyses to investigate the common or different neural bases of distraction and reinterpretation. Moreover, we also used the meta-analytic connectivity modeling (MACM) to identify the emotion regulation network of distraction and reinterpretation. Overall, we found that the left dorsal lateral prefrontal cortex (DLPFC) was consistently activated during distraction and reinterpretation, whereas the left amygdala and inferior frontal gyrus/ventrolateral prefrontal cortex (VLPFC) were specifically activated during reinterpretation alone. The results indicate that the neural basis of distraction and reinterpretation are similar but not identical. The MACM results showed that distraction and reinterpretation share a common emotion regulation network, including the bilateral DLPFC, the dorsal medial prefrontal cortex, the inferior parietal lobule, the insula, the left (pre) supplementary motor area, the left middle temporal gyrus, and the right superior temporal gyrus. However, that network may subserve different functions when adopting various emotion regulation strategies. In addition, we suggest that the emotion regulation network of the left VLPFC may be a specific regulatory network for reinterpretation.

Attention Control in Children With ADHD: An Investigation Using Functional Near Infrared Spectroscopy (fNIRS)

ABSTRACT Attention problems are a predominant contributor to near- and far-term functional outcomes in attention-deficit/hyperactivity disorder (ADHD); however, most interventions focus on improving the alerting attentional network, which has failed to translate into improved learning for a majority of children with ADHD. Comparatively less is known regarding the executive attentional network and its overarching attention control process, which governs the ability to maintain relevant information in a highly active, interference-free state, and is intrinsic to a broad range of cognitive functions. This is the first study to compare attention control abilities in children with ADHD and typically developing (TD) children using the Visual Array Task (VAT) and to simultaneously measure hemodynamic functioning (oxyHb) using functional Near-Infrared Spectroscopy (fNIRS). Nineteen children with ADHD Combined type and 18 typically developing (TD) children aged 8 to 12 years were administered the VAT task while prefrontal activity was monitored using fNIRS. Results revealed that children with ADHD evinced large magnitude deficits in attention control and that oxyHb levels in the left dorsal lateral prefrontal cortex (dlPFC) were significantly greater in children with ADHD relative to TD children. These findings suggest that poor attention control abilities in children with ADHD may be related to increased left dlPFC activation in response to an underdeveloped and/or inefficient right dlPFC. The need to design interventions that target and strengthen attention control and its corresponding neural network is discussed based on the likelihood that attention control serves as the potential quaesitum for understanding a wide array of ADHD-related deficits.

Impact of Transcranial Direct Current Stimulation with Psychological Effects of Color on Stroke-Induced Depression

Background and Aims: Depression is a common psychiatric disorder after a stroke. These patients often experience defective recovery despite intensive medication and psychotherapy. Transcranial Direct Current Stimulation (tDCS) of the brain is a technique used to stimulate different areas of the brain in neurological and psychiatric patients. One of the aims of this study was to investigate the psychological effects of color along with cerebral transduction direct electrical stimulation on stroke-induced depression. Methods: This was a quasi-experimental study. Fifteen stroke patients hospitalized in the Shahid Sadoughi Hospital in Yazd (nine males and six females with a mean age of 55.76 years and mean post-stroke of 47.4 years) were selected and randomly divided into three groups of A, B, and C. Their Beck Depression Scale scores were compared in three occasions after treatment, after sham, and two months after the treatment. Each patient received ten sessions of sham electrical stimulation (20 minutes) with white, ten sessions of anodic stimulation and cathodic stimulation (2 mA-20 min) with white, and ten sessions of anodic stimulation and cathodic stimulation (2 mA-20 min) with green in left and right dorsal lateral prefrontal cortex, respectively. Data analysis was performed in two levels of descriptive (mean &amp; standard deviation) and inferential (ANOVA with repeated measures) using SPSS software v. 21. Results: The findings of (ANOVA with repeated measures demonstrated that compared with a white color treatment, depression declined immediately after treatment with green and white color (P&lt;0.001) and a follow-up period (P&lt;0.001). Conclusion: In line with the findings of this study, direct electrical stimulation with the green color can be utilized in the rehabilitation of stroke patients. However, electrical stimulation with the color green had a superior recovery than the white color.

419 - Effect of Transcranial Direct Current Stimulation (tDCS) in Dementia with Lewy Bodies

AbstractIntroduction:Dementia with Lewy Bodies (DLB), this second most common form of degenerative dementia, presents more functional disability, more potentially fatal complication, more impaired quality of life than Alzheimer’s dementia. There is no FDA-proved medication can slow, stop or improve the progression of cognitive declines in DLB. Identifying effective treatments is a critical issue for DLB. In neuropathology, extracelluar α-syn oligomers interfere with the expression of long-term potentiation, and influence memory and learning. Transcranial direct current stimulation (tDCS) has been proposed to affect long-term synaptic plasticity through LTP and LTD, thereby improving cognitive ability. So far, only two researches assess the effect of tDCS in DLB. In this pilot study, we investigate the effects of tDCS in DLB.Method:Using a double-blind, randomized, sham- controlled and crossover trial design, 11 DLB aged 55-90 years (mean age 77.8) were included in the study. DLB diagnostics is according to DSM-5 criteria. The CDR ratings of DLB participants ranged from 0.5 to 2. The active tDCS (or sham) process includes consecutive daily sessions of active tDCS (or sham) for 10 days. The anodal electrode was over the left dorsal lateral prefrontal cortex (DLPFC) and the cathodal electrode on the right supraorbital area. In each session, we applied a current intensity of 2 mA and an electrode size of 25 cm2 for 30 min in the active group. All subjects received a series of neuropsychological tests, which included CDR, MMSE, CASI, NPI and WCST, before and after these treatment sessions. Chi-square tests, Wilcoxon signed rank tests and Mann-Whitney U tests were used to assess the differences in participant demographic characteristics and to compare the differences among groups.Results:On CASI, MMSE, NPI and WCST, there were no statistically significant differences between pre- and post the 10-session course for the active and the sham groups. No side effects reported during or immediately after active tDCS stimulation.Conclusion:These results suggest that left DLPFC anodal, and right deltoid cathodal tDCS, do not improve cognition, behavioral and psychological symptoms in DLB. Larger-scale trials are needed to confirm the effect of tDCS in DLB.

418 - Long-term Effect of Transcranial Direct Current Stimulation (tDCS) in Alzheimer’s

AbstractIntroduction:To explore and develop effective treatments is crucial for patients with Alzheimer’s dementia (AD). In pathology, the amyloid deposits of AD result in disruption of the balance between long-term potentiation (LTP) and long-term depression (LTD) of neuronal cells and synaptic plasticity. Transcranial direct current stimulation (tDCS) has been proposed to affect long-term synaptic plasticity through LTP and LTD, thereby improving cognitive ability. Although an increasing number of studies have been concluded a positive therapeutic effect on cognition in AD, tDCS studies to date are limited on exploring the duration of its efficacy. In this pilot study, we investigate the effects of tDCS in AD and verify its extending beneficial effects for 3 months follow-up period after the end of stimulation.Method:34 AD participants aged 55-90 years (mean age 75.9 (66-86)) were included in a double-blind, randomized, sham-controlled crossover study. All participants were randomly assigned to receive 10 consecutive daily sessions of active tDCS (or sham) and switched groups 3 months later. The anodal electrode was on the left dorsal lateral prefrontal cortex and the cathodal electrode was on the right supraorbital area. In each active session, we applied a current intensity of 2 mA and an electrode size of 25 cm2 for 30 min in the active group. All subjects received a series of neuropsychological assessments including CDR, MMSE, CASI and WCST at baseline and in 2 weeks, 4 weeks, and 12 weeks post-tDCS (or sham) 10 sessions. Chi-square tests, Wilcoxon signed rank tests and Mann-Whitney U tests were used to assess the differences in participant demographic characteristics and to compare the differences of test scores between groups.Results:The active tDCS group showed significant improvements on CASI total scores from baseline to 2-weeks, 1-month and 3-months after active stimulations, though the improvement declined over time. There are also different presentations in total correct items, conceptual level responses, failure to maintain sets of WCST between active tDCS and sham groups. There is no difference in MMSE, CASI and WCST scores in the sham groups.Conclusion:These results suggest a long term-beneficial effects of tDCS in AD.