Clinical Assessment of Prefrontal Lobe Functions

Altered Subcortical Brain Volume and Cortical Thickness Related to Insulin Resistance in Type 2 Diabetes Mellitus

PURPOSE

The objective of this study is to examine the alterations in subcortical brain volume and cortical thickness among individuals diagnosed with Type 2 diabetes mellitus (T2DM) through the application of morphometry techniques and, additionally, to investigate the potential association between these modifications and insulin resistance (IR).

MATERIALS AND METHODS

The present cross-sectional study comprised a total of 121 participants (n = 48 with healthy controls [HCs] and n = 73 with T2DM) who were recruited and underwent a battery of cognitive testing and structural magnetic resonance imaging (MRI). FreeSurfer was used to process the MRI data. Analysis of covariance compared discrepancies in cortical thickness and subcortical brain volume between T2DM and HCs, adjusting for the potential confounding effects of gender, age, education, and body mass index (BMI). Exploratory partial correlations investigated links between IR and brain structure in T2DM participants.

RESULTS

Compared with HCs, individuals with T2DM demonstrated a cortical thickness decrease in the right caudal middle frontal gyrus, right pars opercularis, left precentral gyrus, and bilateral superior frontal gyrus. Furthermore, this study for T2DM found that the severity of IR was inversely related to the volume of the left putamen and left hippocampus, as well as the thickness of the left pars orbitalis, left pericalcarine, right entorhinal area, and right rostral anterior cingulate gyrus.

CONCLUSION

The evidence for structural brain changes in T2DM was observed, and alterations in cortical thickness were concentrated in the frontal lobes. Correlations between IR and frontal cortical thinning may serve as a potential neuroimaging marker of T2DM and lead to various diabetes-related brain complications.

Substantial parallel mediation contribution by cognitive domains in the relationship between adolescents' physical fitness and academic achievements: the Cogni-Action Project

Objective

To determine how cognitive domains mediate the link between fitness components, their global score (GFS), and adolescents' academic achievement (ACA) across various school subjects.

Methods

In this study, 1,296 adolescents aged 10-14 participated. GFS was computed by three fitness components (strength, muscular, and cardiorespiratory fitness) through the ALPHA-fitness test battery. ACA was determined by five school subjects (Language, English, Mathematics, Science, and History) and two academic scores (a) "Academic Average" (five subjects) and (b) "Academic-PISA" (Language, Mathematics, and Science). A principal component analysis was performed to establish four factors (working memory [WM], cognitive flexibility [CF], inhibitory control [IC], and fluid reasoning [FR]). A parallel mediation approach was implemented with 5,000 bootstrapped samples controlled for sex, maturity, central obesity, having breakfast before cognitive tasks, schools, and school vulnerability. Total, direct, indirect effects, and mediation percentages were estimated.

Results

Overall, the finding showed a full parallel mediation effect for Language (92.5%) and English (53.9%), while a partial mediation for Mathematics (43.0%), Science (43.8%), History (45.9%), "Academic Average" (50.6%), and "Academic-PISA" (51.5%). In particular, WM, IC, and FR mediated all school subjects except mathematics, where IC was not significant. CF has not mediated any relationship between GF and academic performance.

Conclusion

This study underscores the pivotal role of cognitive domains, specifically WM, IC, and FR, in mediating the link between physical fitness and academic performance in adolescents. These insights have relevant implications for educational and public health policies.

Aberrant functional hubs and related networks attributed to cognitive impairment in patients with anti‑N‑methyl‑D‑aspartate receptor encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis results in severe neuropsychiatric symptoms and persistent cognitive impairment; however, the underlying mechanism is still not fully understood. The present study utilized the degree centrality (DC), functional connectivity (FC) and multivariate pattern analysis (MVPA) to further explore neurofunctional symptoms in patients with anti-NMDAR encephalitis. A total of 29 patients with anti-NMDAR encephalitis and 26 healthy controls (HCs) were enrolled for neuropsychological assessment and resting-state functional MRI (rs-fMRI) scans. DC, FC and MVPA were examined to investigate cerebral functional activity and distinguish neuroimaging characteristics between the patient and HC groups based on the rs-fMRI data. Compared with the HCs, the patients exhibited cognitive deficits, anxiety and depression. In the DC analysis, the patients exhibited significantly decreased DC strength in the left rectus gyrus, left caudate nucleus (LCN) and bilateral superior medial frontal gyrus, as well as increased DC strength in the cerebellar anterior lobe, compared with the HCs. In the subsequent FC analysis, the LCN showed decreased FC strength in the bilateral middle frontal gyrus and right precuneus. Furthermore, correlation analysis indicated that disrupted cerebral functional activity was significantly correlated with the alerting effect and Hamilton Depression Scale score. Using DC maps and receiver operating characteristic curve analysis, the MVPA classifier exhibited an area under curve of 0.79, and the accuracy classification rate was 76.36%, with a sensitivity of 79.31% and a specificity of 78.18%. The present study revealed that the disrupted functional activity of hub and related networks in the cerebellum, including the default mode network and executive control network, contributed to deficits in cognition and emotion in patients with anti-NMDAR encephalitis. In conclusion, the present study provided imaging evidence and primary diagnostic markers for pathological and compensatory mechanisms of anti-NMDAR encephalitis, with the aim of improving the understanding of this disease.

The contribution of executive functions to the process of return to work after brain injury: A systematic review

Acquired brain injury (ABI) is a worldwide public health issue for its high prevalence rate and the disability it produces. The consequences of ABI, including cognitive deficits, may impact return to work. This review focuses on the association between executive functions (EFs) and return to work after ABI. A systematic review of the literature between 1998 and 2023 was conducted following PRISMA guidelines. The articles were retrieved from the Pubmed, Medline and Web of Science databases. A total of 49 studies were finally selected. Impairments of EF were consistently shown to have a negative impact on return to work after an ABI. There is evidence that specific executive functions and neurobehavioral variables may affect return to work Studies showed a significant theoretical and methodological heterogeneity, representing an important limitation to understand the relation between EFs and work. There is a robust association between EFs and return to work after brain injury. Findings in this systematic review raise the need for further research on the role of specific EF profiles in the process of returning to work after brain damage.

Altered resting-state functional connectivity and its association with executive function in adolescents with borderline personality disorder

Adolescents with borderline personality disorder (BPD) may have impaired executive functions. There are few functional MRI (fMRI) studies in adolescents with BPD and the neuroimaging markers of this disorder are unknown. The aim of this study was to investigate the functional connectivity (FC) of BPD in adolescents, and to explore the relationship between FC changes and executive function in adolescents with BPD. 50 adolescents aged 12 to 17 years with BPD and 21 gender-and-age matched healthy controls (HC) were enrolled into the study. Brain MRI scan including a 3D-T1 weighted structural sequence and a resting-state fMRI was acquired. A seed-based FC analysis was performed. We used the Stroop color-word test (SCWT) and the trail making test (TMT) to evaluate the executive function of the participants. Correlative analysis of FC alterations with executive function and clinical symptoms was also performed. Compared to the HCs, adolescents with BPD showed increased FC in the limbic-cortical circuit, such as the FC between the left hippocampus and right parahippocampal gyrus, between the right middle occipital gyrus and the left middle temporal gyrus, and between the left medial superior frontal gyrus and the right inferior temporal gyrus. FC in the default mode network (DMN) was decreased between the left angular gyrus and the left precuneus but increased between the left angular gyrus and the right anterior cingulate cortex (voxel P < 0.001, cluster P < 0.05, FWE corrected). The BPD group demonstrated significantly lower cognitive testing scores than the HC group on the SCWT-A (P < 0.001), SCWT-B (P < 0.001), and SCWT-C (P = 0.034). The FC alterations between limbic system and cortical regions were associated with SCWT and TMT (P < 0.05). FC alterations were noted in both limbic-cortical circuit and DMN in adolescents with BPD, which were associated with impaired executive function. This study implicated the FC alterations as the neural correlates of executive functioning in adolescents with BPD.

Role of the prefrontal cortical protease TACE/ADAM17 in neurobehavioral responses to chronic stress during adolescence

INTRODUCTION

Chronic adolescent stress profoundly affects prefrontal cortical networks regulating top-down behavior control. However, the neurobiological pathways contributing to stress-induced alterations in the brain and behavior remain largely unknown. Chronic stress influences brain growth factors and immune responses, which may, in turn, disrupt the maturation and function of prefrontal cortical networks. The tumor necrosis factor alpha-converting enzyme/a disintegrin and metalloproteinase 17 (TACE/ADAM17) is a sheddase with essential functions in brain maturation, behavior, and inflammatory responses. This study aimed to determine the impact of stress on the prefrontal cortex and whether TACE/ADAM17 plays a role in these responses.

METHODS

We used a Lewis rat model that incorporates critical elements of chronic psychosocial stress, such as uncontrollability, unpredictability, lack of social support, and re-experiencing of trauma.

RESULTS

Chronic stress during adolescence reduced the acoustic startle reflex and social interactions while increasing extracellular free water content and TACE/ADAM17 mRNA levels in the medial prefrontal cortex. Chronic stress altered various ethological behavioral domains in the observation home cages (decreased ingestive behaviors and increased walking, grooming, and rearing behaviors). A group of rats was injected intracerebrally either with a novel Accell™ SMARTpool TACE/ADAM17 siRNA or a corresponding siRNA vehicle (control). The RNAscope Multiplex Fluorescent v2 Assay was used to visualize mRNA expression. Automated puncta quantification and analyses demonstrated that TACE/ADAM17 siRNA administration reduced TACE/ADAM17 mRNA levels in the medial prefrontal cortex (59% reduction relative to control). We found that the rats that received prefrontal cortical TACE/ADAM17 siRNA administration exhibited altered eating patterns (e.g., increased food intake and time in the feeding zone during the light cycle).

CONCLUSION

This study supports that the prefrontal cortex is sensitive to adolescent chronic stress and suggests that TACE/ADAM17 may be involved in the brain responses to stress.

Trail making test - black & white (TMT B&W): Normative study for the Chilean population

The trailmaking test (TMT) has an educational bias that makes it inapplicable to people with low levels of education due to its dependence on the alphabet. The TMT standardization is the only one available in Chile, and there is a need for alternative ways of using the TMT that do not depend on the level of education for its applicability. To determine the normative scores of the TMT - black & white (TMT B&W), considering sociodemographic factors in adult and elderly Chilean population. A total sample of 227 participants (133 healthy, 94 cognitively impaired) from the Ageing Mets cohort were recruited from three areas in Chile (Antofagasta, Santiago, and Puerto Montt). The TMT B&W was administered to all participants. A multiple regression model was used to generate normative data only in the cognitively healthy group, considering the effect of age, education and sex. A significant effect of age was found in the score of the TMT B&W Parts A and B. The level of education influenced the part B of the test; however, the completion rate of the TMT B&W parts A and B was over 90% in cognitively healthy people. Norms for the number of errors were obtained, and differences between groups were found after controlling for the effect of age and education. This study is the first to provide normative data for the Chilean version of the TMT B&W and will benefit clinical neuropsychologists by improving the procedures for more accurately assessing executive functions and its impairments.

Self-reported symptoms of everyday executive dysfunction, daytime sleepiness, and fatigue and health status among adults with congenital aniridia: a descriptive study

Background

Congenital aniridia is a rare genetic disorder of the eye characterized by visual impairment and progressive vision loss. While prior research has focused on ocular manifestations in individuals with aniridia, there is a dearth of research on impacts on cognition and mental health. The aims of this study were to describe subjective symptoms of everyday executive functioning, fatigue and sleepiness in adults with aniridia and to compare self-reported health status with that of a normative reference group.

Methods

Twenty-nine adults (aged 18-79 years) with congenital aniridia were included in this online survey, of whom 52% were females. Participants completed self-report measures of executive functioning (The Behavior Rating Inventory of Executive Function-Adult Version), sleepiness, fatigue, and health status (EQ-5D-5L).

Results

Participants reported relatively few problems in everyday executive functioning, with only 14% experiencing impaired executive functioning. Scores on the five EQ-5D-5L domains (mobility, self-care, usual activities, pain, and anxiety/depression) did not differ from those of the normative reference group. The frequencies of excessive daytime sleepiness and severe fatigue were 17% and 38%, respectively. Ocular pain was experienced by 62% of participants.

Conclusions

The findings show that cognitive problems are related to and reflect self-reported health status and extent of fatigue. Moreover, those who suffered from ocular pain reported more difficulties with executive functioning, sleepiness and fatigue. These findings are important for understanding this disorder and supporting patients.

Online physical exercise program with music improves working memory

Objective

The spread of coronavirus disease (COVID-19) has limited the implementation of face-to-face non-pharmacological treatment for the prevention of dementia. As a result, online non-pharmacological treatment has become increasingly important. In this study, we used an online conferencing system to implement an online version of a physical exercise program with music, and examined its effect on cognitive function.

Methods

The participants were 114 healthy older adults [63 men and 51 women; mean age of 70.7 years (standard deviation = 4.6)]. Seventy-five participants were allocated to the physical exercise with music group (60 min, once a week, total 20 sessions), while the remaining 39 participants were assigned to the control group, and only underwent the examinations. In the physical exercise with music group, we performed neuropsychological examinations and brain tests both before and after the exercise program. Neuropsychological tests included the Mini-Mental State Examination, Raven's Colored Progressive Matrices (RCPM), the Rivermead Behavioral Memory Test, graphic imitation, word fluency (WF) (animal names and initial sounds), and the Trail Making Test-A/B. As an assessment of brain function, we developed an online examination of subtle cognitive decline, including tests of number and word memory, spatial grasp, the N-back task, and change inference.

Results

In the N-back task, the physical exercise with music group improved significantly relative to the control group (p = 0.008).

Discussion

The present findings suggest that the online version of the physical exercise with music program improved working memory, which mainly involves the frontal lobe.

Cerebral hypoperfusion in post-COVID-19 cognitively impaired subjects revealed by arterial spin labeling MRI

Cognitive impairment is one of the most prevalent symptoms of post Severe Acute Respiratory Syndrome COronaVirus 2 (SARS-CoV-2) state, which is known as Long COVID. Advanced neuroimaging techniques may contribute to a better understanding of the pathophysiological brain changes and the underlying mechanisms in post-COVID-19 subjects. We aimed at investigating regional cerebral perfusion alterations in post-COVID-19 subjects who reported a subjective cognitive impairment after a mild SARS-CoV-2 infection, using a non-invasive Arterial Spin Labeling (ASL) MRI technique and analysis. Using MRI-ASL image processing, we investigated the brain perfusion alterations in 24 patients (53.0 ± 14.5 years, 15F/9M) with persistent cognitive complaints in the post COVID-19 period. Voxelwise and region-of-interest analyses were performed to identify statistically significant differences in cerebral blood flow (CBF) maps between post-COVID-19 patients, and age and sex matched healthy controls (54.8 ± 9.1 years, 13F/9M). The results showed a significant hypoperfusion in a widespread cerebral network in the post-COVID-19 group, predominantly affecting the frontal cortex, as well as the parietal and temporal cortex, as identified by a non-parametric permutation testing (p < 0.05, FWE-corrected with TFCE). The hypoperfusion areas identified in the right hemisphere regions were more extensive. These findings support the hypothesis of a large network dysfunction in post-COVID subjects with cognitive complaints. The non-invasive nature of the ASL-MRI method may play an important role in the monitoring and prognosis of post-COVID-19 subjects.

Prefrontal cortical protease TACE/ADAM17 is involved in neuroinflammation and stress-related eating alterations

Childhood traumatic stress profoundly affects prefrontal cortical networks regulating top-down control of eating and body weight. However, the neurobiological mechanisms contributing to trauma-induced aberrant eating behaviors remain largely unknown. Traumatic stress influences brain immune responses, which may, in turn, disrupt prefrontal cortical networks and behaviors. The tumor necrosis factor alpha-converting enzyme / a disintegrin and metalloproteinase 17 (TACE/ADAM17) is a sheddase with essential functions in brain maturation, behavior, and neuroinflammation. This study aimed to determine the role of TACE/ADAM17 on traumatic stress-induced disruption of eating patterns. We demonstrate a novel mechanistic connection between prefrontal cortical TACE/ADAM17 and trauma-induced eating behaviors. Fifty-two (52) adolescent Lewis rats (postnatal day, PND, 15) were injected intracerebrally either with a novel Accell™ SMARTpool ADAM17 siRNA or a corresponding siRNA vehicle. The RNAscope Multiplex Fluorescent v2 Assay was used to visualize mRNA expression. Observation cages were used to monitor ethological behaviors in a more naturalistic environment over long periods. We found that traumatic stress blunts startle reactivity and alter eating behaviors (increased intake and disrupted eating patterns). We also found that the rats that received prefrontal cortical TACE/ADAM17 siRNA administration exhibited decreased eating and increased grooming behaviors compared to controls. These changes were associated with decreased AIF-1 expression (a typical marker of microglia and neuroinflammation). This study demonstrates that prefrontal cortical TACE/ADAM17 is involved in neuroinflammation and may play essential roles in regulating feeding patterns under stress conditions. TACE/ADAM17 represents a promising target to ameliorate inflammation-induced brain and behavior alterations.

Natural products regulate mitochondrial function in cognitive dysfunction-A scoping review

Medicines from natural products can not only treat neurodegenerative diseases but also improve the cognitive dysfunction caused by treatments with western medicines. This study reviews the literature related to the regulation of mitochondrial participation in cognitive function by natural products. In this study, we focused on English articles in PubMed, Web of Science, and Google Scholar, from 15 October 2017, to 15 October 2022. Fourteen studies that followed the inclusion criteria were integrated, analyzed, and summarized. Several studies have shown that natural products can improve or reduce cognitive dysfunction by ameliorating mitochondrial dysfunction. These results suggest that natural products may serve as new therapeutic targets for neurodegenerative diseases.

Cognitive impairment, childhood trauma, sedentary behaviour, and elevated C-reactive protein levels in major affective disorders

Elevated C-reactive protein (CRP) levels were associated with cognitive decline, sedentary behaviour, and childhood trauma in patients with major affective disorders. This study aims to examine the association of peripheral CRP levels, cognitive function, childhood trauma, sedentary behaviour, and quality of life in individuals with major affective disorders, including bipolar disorder (BD), major depressive disorder (MDD), and individuals without mood disorders (controls). We included outpatients with BD (n = 42), MDD (n = 27), and healthy controls (n = 40). All participants were assessed by a questionnaire, structured clinical interview, and the following scales: international physical activity questionnaire, childhood trauma questionnaire, 17-item Hamilton Depression Rating Scale (HDRS₁₇), and World Health Organization Quality of Life instrument, brief version (WHOQOL-BREF). Other measures were included: hs-CRP levels, anthropometric measures, and cognitive tests (Trail-making test part A and part B, Stroop test, phonemic verbal fluency test, and semantic verbal fluency test). Our results indicated that BD outpatients were less significantly physically active on leisure domain than controls. Levels of hs-CRP ≥ 5 mg/L were significantly linked with a history of childhood sexual abuse and childhood physical abuse, as well as worse neurocognitive performance in major depressive disorders, mainly in BD. There was a significant negative correlation between Trail-making part B score and WHOQOL-BREF total score. The findings support the hypothesis that levels of hs-CRP ≥ 5 mg/L may be a possible predictor of cognitive dysfunction, childhood sexual abuse and sedentary behaviour in major affective disorders.

Recognition of Emotion by Brain Connectivity and Eye Movement

Simultaneous activation of brain regions (i.e., brain connection features) is an essential mechanism of brain activity in emotion recognition of visual content. The occipital cortex of the brain is involved in visual processing, but the frontal lobe processes cranial nerve signals to control higher emotions. However, recognition of emotion in visual content merits the analysis of eye movement features, because the pupils, iris, and other eye structures are connected to the nerves of the brain. We hypothesized that when viewing video content, the activation features of brain connections are significantly related to eye movement characteristics. We investigated the relationship between brain connectivity (strength and directionality) and eye movement features (left and right pupils, saccades, and fixations) when 47 participants viewed an emotion-eliciting video on a two-dimensional emotion model (valence and arousal). We found that the connectivity eigenvalues of the long-distance prefrontal lobe, temporal lobe, parietal lobe, and center are related to cognitive activity involving high valance. In addition, saccade movement was correlated with long-distance occipital-frontal connectivity. Finally, short-distance connectivity results showed emotional fluctuations caused by unconscious stimulation.

Self-Enhancement and the Medial Prefrontal Cortex: The Convergence of Clinical and Experimental Findings

Self-enhancement (SE) is often overlooked as a fundamental cognitive ability mediated via the Prefrontal Cortex (PFC). Here, we present research that establishes the relationship between the PFC, SE, and the potential evolved beneficial mechanisms. Specifically, we believe there is now enough evidence to speculate that SE exists to provide significant benefits and should be considered a normal aspect of the self. Whatever the metabolic or social cost, the upside of SE is great enough that it is a core and fundamental psychological construct. Furthermore, though entirely theoretical, we suggest that a critical reason the PFC has evolved so significantly in Homo sapiens is to, in part, sustain SE. We, therefore, elaborate on its proximate and ultimate mechanisms.

Differential Cognitive Functioning and Benefit From Surgery in Patients Undergoing Coronary Artery Bypass Grafting and Carotid Endarterectomy

Background

Stenosing atherosclerosis in both coronary and carotid arteries can adversely affect cognition. Also their surgical treatments, coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA), are associated with cognitive changes, but the mechanisms of cognitive decline or improvement may not be the same. This study was designed to compare the cognitive profile and outcome in patients undergoing surgical treatment for coronary or carotid disease.

Methods

A total of 100 CABG patients and 44 CEA patients were recruited in two previously reported studies. They were subjected to a comprehensive neuropsychological examination prior to surgery and in the acute (3-8 days) and stable (3 months) phase after operation. A group of 17 matched healthy controls were assessed with similar intervals. We used linear mixed models to compare cognitive trajectories within six functional domains between the CABG, CEA and control groups. Postoperative cognitive dysfunction (POCD) and improvement (POCI) were determined with the reliable change index method in comparison with healthy controls.

Results

Before surgery, the CEA patients performed worse than CABG patients or healthy controls in the domains of executive functioning and processing speed. The CABG patients exhibited postoperative cognitive dysfunction more often than the CEA patients in most cognitive domains in the acute phase but had regained their performance in the stable phase. The CEA patients showed more marked postoperative improvement in executive functioning than the CABG group in the acute phase, but the difference did not reach significance in the stable phase.

Conclusion

Our findings suggest that anterior cerebral dysfunction in CEA patients impairs preoperative cognition more severely than global brain dysfunction in CABG patients. However, CEA may have more beneficial effects on cognition than CABG, specifically in executive functions mainly operated by the prefrontal lobes. In addition, the results underline that POCD is a heterogeneous condition and dependent on type of revascularization surgery.

Segmentation of Prefrontal Lobe Based on Improved Clustering Algorithm in Patients with Diabetes

Diabetics are prone to postoperative cognitive dysfunction (POCD). The occurrence may be related to the damage of the prefrontal lobe. In this study, the prefrontal lobe was segmented based on an improved clustering algorithm in patients with diabetes, in order to evaluate the relationship between prefrontal lobe volume and COPD. In this study, a total of 48 diabetics who underwent selective noncardiac surgery were selected. Preoperative magnetic resonance imaging (MRI) images of the patients were segmented based on the improved clustering algorithm, and their prefrontal volume was measured. The correlation between the volume of the prefrontal lobe and Z-score or blood glucose was analyzed. Qualitative analysis shows that the gray matter, white matter, and cerebrospinal fluid based on the improved clustering algorithm were easy to distinguish. Quantitative evaluation results show that the proposed segmentation algorithm can obtain the optimal Jaccard coefficient and the least average segmentation time. There was a negative correlation between the volume of the prefrontal lobe and the Z-score. The cut-off value of prefrontal lobe volume for predicting POCD was <179.8, with the high specificity. There was a negative correlation between blood glucose and volume of the prefrontal lobe. From the results, we concluded that the segmentation of the prefrontal lobe based on an improved clustering algorithm before operation may predict the occurrence of POCD in diabetics.

Dengzhanxixin Injection Ameliorates Cognitive Impairment Through a Neuroprotective Mechanism Based on Mitochondrial Preservation in Patients With Acute Ischemic Stroke

Acute ischemic stroke (AIS) is a global health burden and cognitive impairment is one of its most serious complication. Adequate interventions for AIS may have the potential to improve cognitive outcomes. In the present study, we selected Erigeron breviscapus (Vaniot) Hand.-Mazz. injection (Dengzhanxixin injection, DZXI), a widely used Chinese herbal injection, in contrast to edaravone as the positive control drug to test its potential to ameliorates neurological and cognitive impairments caused by AIS. We performed a 2-week randomized trial with these two drugs in AIS patients presenting mild to moderate cognitive impairments. Neuropsychological tests and MRI examinations showed that DZXI attenuated the neurological and cognitive impairments of patients and protected the grey matter in specific regions from ischemic damage. Notably, DZXI exerted better effects than edaravone in some neuropsychological tests, probably due to the protective effect of DZXI on grey matter. To explore the therapeutic mechanisms, we carried out an experiment with a middle cerebral artery occlusion rat model. We found that DZXI decreased the infarct volume and increased the survival of neuronal cells in the ischemic penumbra; furthermore, DZXI modulated the mitochondrial respiratory chain process and preserved the mitochondrial structure in the brain tissue. Overall, our data suggested that the administration of DZXI is effective at ameliorating neurological and cognitive impairments in AIS, and the underlying mechanisms are related to the protective effects of DZXI on cerebral neurons and neuronal mitochondria.

The Anterior Attentional-Intentional System in Patients with Parkinson's Disease-A Pilot and Feasibility Study

(1) Background: This study compared anterior attentional–intentional system performance between three groups: Parkinson’s disease (PD) patients with normal cognition (PD-NC), with mild cognitive impairment (PD-MCI), and a comparison group (CG). It also evaluated the feasibility of the recruitment and study procedures; (2) Methods: From 45 participants recruited, 39 were allocated (mean age 65.31; 43.59% men) to PD-NC, PD-MCI and CG (13 per group). To assess attention, we used three tasks from the ROtman–Baycrest Battery for Investigating Attention: Simple Reaction time (RT), Choice RT, and Prepare RT. We conducted a mixed-model analysis of variance with a 3 (groups) × 4 (tasks) design to compare reaction times; (3) Results: PD-MCI had slower reaction times than PD-NC (p = 0.028) and the CG (p = 0.052); there was no difference between PD-NC and CG. PD-MCI might perform worse on monitoring tasks than PD-NC, Z = −1.68, p = 0.092. Nearly half the volunteers from the CG and 87% of all eligible patients were enrolled in the study and completed all neuropsychological procedures; (4) Conclusions: General cognitive decline appears related to partial deficits in energization and tends to impair attentional monitoring. Furthermore, PD-NC exhibited similar reaction times to the CG. Results from the feasibility study contributed to the definitive study.

Tractography-Guided Anterior Capsulotomy for Major Depression and Obsessive-Compulsive Disorder: Targeting the Emotion Network

BACKGROUND

Bilateral anterior capsulotomy (BAC) is an effective surgical option for patients with treatment-resistant major depression (TRMD) and treatment-resistant obsessive-compulsive disorder (TROCD). The size of the lesion and its precise dorsal-ventral location within the anterior limb of the internal capsule (ALIC) remain undefined.

OBJECTIVE

To present a method to identify the trajectories of the associative and limbic white matter pathways within the ALIC for targeting in BAC surgery.

METHODS

Using high-definition tractography, we prospectively tested the feasibility of this method in 2 patients with TRMD and TROCD to tailor the capsulotomy lesion to their limbic pathway.

RESULTS

The trajectories of the associative and limbic pathways were identified in the ALIC of both patients and we targeted the limbic pathways by defining the dorsal limit of the lesion in a way to minimize the damage to the associative pathways. The final lesions were smaller than those that have been previously published. This individualized procedure was associated with long-term benefit in both patients.

CONCLUSION

Tractography-guided capsulotomy is feasible and was associated with long-term benefit in patients with TRMD and TROCD.

Does the Prefrontal Cortex Play an Essential Role in Consciousness? Insights from Intracranial Electrical Stimulation of the Human Brain

A central debate in philosophy and neuroscience pertains to whether PFC activity plays an essential role in the neural basis of consciousness. Neuroimaging and electrophysiology studies have revealed that the contents of conscious perceptual experience can be successfully decoded from PFC activity, but these findings might be confounded by postperceptual cognitive processes, such as thinking, reasoning, and decision-making, that are not necessary for consciousness. To clarify the involvement of the PFC in consciousness, we present a synthesis of research that has used intracranial electrical stimulation (iES) for the causal modulation of neural activity in the human PFC. This research provides compelling evidence that iES of only certain prefrontal regions (i.e., orbitofrontal cortex and anterior cingulate cortex) reliably perturbs conscious experience. Conversely, stimulation of anterolateral prefrontal sites, often considered crucial in higher-order and global workspace theories of consciousness, seldom elicits any reportable alterations in consciousness. Furthermore, the wide variety of iES-elicited effects in the PFC (e.g., emotions, thoughts, and olfactory and visual hallucinations) exhibits no clear relation to the immediate environment. Therefore, there is no evidence for the kinds of alterations in ongoing perceptual experience that would be predicted by higher-order or global workspace theories. Nevertheless, effects in the orbitofrontal and anterior cingulate cortices suggest a specific role for these PFC subregions in supporting emotional aspects of conscious experience. Overall, this evidence presents a challenge for higher-order and global workspace theories, which commonly point to the PFC as the basis for conscious perception based on correlative and possibly confounded information.

Cognitive and Emotional Mapping With SEEG

Mapping of cortical functions is critical for the best clinical care of patients undergoing epilepsy and tumor surgery, but also to better understand human brain function and connectivity. The purpose of this review is to explore existing and potential means of mapping higher cortical functions, including stimulation mapping, passive mapping, and connectivity analyses. We examine the history of mapping, differences between subdural and stereoelectroencephalographic approaches, and some risks and safety aspects, before examining different types of functional mapping. Much of this review explores the prospects for new mapping approaches to better understand other components of language, memory, spatial skills, executive, and socio-emotional functions. We also touch on brain-machine interfaces, philosophical aspects of aligning tasks to brain circuits, and the study of consciousness. We end by discussing multi-modal testing and virtual reality approaches to mapping higher cortical functions.

Development and initial validation of the Generalized Tracking Questionnaire

The concept of rule-governed behavior (RGB) has been used in the behavior-analytic literature as a way to analyze complex human behavior, including thinking and problem-solving. Relational frame theory suggests the existence of two main functional types of RGB termed pliance and tracking. In this paper, we describe the development of the Generalized Tracking Questionnaire (GTQ) and the preliminary evaluation of its psychometric properties and validity through three studies, with a total of 1155 participants. In Study 1, a pool of items describing the main characteristics of generalized tracking was designed and evaluated by experts on the RFT account of RGB. The resulting 11 items were administered to 460 undergraduates to examine the understandability and psychometric quality of the items. The exploratory factor analysis indicated that the GTQ can be seen as a unidimensional scale, with all items exhibiting high factor loadings and corrected item-total correlations. In Study 2, the GTQ was administered online to a sample of 464 non-clinical participants and a clinical sample of 125 participants. The one-factor model of the GTQ obtained a good fit in the conducted confirmatory factor analysis. The GTQ showed measurement invariance across gender and clinical and nonclinical participants. It also obtained excellent internal consistency and correlated in theoretically coherent ways with other constructs. In Study 3, the GTQ and a neuropsychological battery of executive functions were administered to 105 participants. The GTQ showed statistically significant, medium-size correlations with working memory tests, verbal fluency, planning, and behavioral inhibition. In conclusion, the GTQ seems to be a promising measure to advance in the empirical analysis of functional classes of RGB.

Executive Function in Autism Spectrum Disorder: History, Theoretical Models, Empirical Findings, and Potential as an Endophenotype

This review presents an outline of executive function (EF) and its application to autism spectrum disorder (ASD). The development of the EF construct, theoretical models of EF, and limitations in the study of EF are outlined. The potential of EF as a cognitive endophenotype for ASD is reviewed, and the Research Domain Criteria (RDoC) framework is discussed for researching EF in ASD given the multifaceted factors that influence EF performance. A number of executive-focused cognitive models have been proposed to explain the symptom clusters observed in ASD. Empirical studies suggest a broad impairment in EF, although there is significant inter-individual variability in EF performance. The observed heterogeneity of EF performance is considered a limiting factor in establishing EF as a cognitive endophenotype in ASD. We propose, however, that this variability in EF performance presents an opportunity for subtyping within the spectrum that can contribute to targeted diagnostic and intervention strategies. Enhanced understanding of the neurobiological basis that underpins EF performance, such as the excitation/inhibition hypothesis, will likely be important. Application of the RDoC framework could provide clarity on the nature of EF impairment in ASD with potential for greater understanding of, and improved interventions for, this disorder.