Cognitive Control In Patients Research Articles

Exploring expected reward and efficacy in enhancing cognitive control in patients with depression

ABSTRACT Background Depression is associated with impairments in cognitive control. Considering the lack of mechanistic models accounting for cognitive control deficits in depression, the expected value of control (EVC) theory offers a mechanistic view for allocating cognitive control emphasizing motivational components (efficacy, value). Efficacy refers to the possibility that an effort leads to a special outcome and reward refers to the value (amount) associated with the outcome. This study aimed to examine the role of the EVC in depression. Method This study used a within-between-subject design. Participants with depression (n = 36) and healthy controls (n = 31) completed a clinical diagnostic interview, the Beck Depression Inventory-II, the General Health Questionnaire-12, and a computer-based incentivized Stroop Color-Word Paradigm in which levels of efficacy (high vs. low) and the amount of rewards (high vs. low) were presented as cues before target stimuli. Results We found significant interaction effects of group × efficacy and efficacy × reward in terms of reaction time in the Stroop Paradigm. Follow-up analyses indicated the Depressed group were significantly slower than Controls on high efficacy trials, but the two groups did not differ significantly on low efficacy trials. Additionally, on high efficacy trials, reward did not influence performance, but on low efficacy trials, high reward improved performance in both groups. Limitation Lack of neurological measures and eye tracking techniques. Conclusion Overall, our findings suggest that reward and efficacy may jointly improve cognitive control allocation and highlight the need for further research examining EVC theory as a mechanistic account of cognitive control deficits in depression.

EEG microstate changes during hyperbaric oxygen therapy in patients with chronic disorders of consciousness.

Hyperbaric oxygen (HBO) therapy is an effective treatment for patients with disorders of consciousness (DOC). In this study, real-time electroencephalogram (EEG) recordings were obtained from patients with DOC during HBO therapy. EEG microstate indicators including mean microstate duration (MMD), ratio of total time covered (RTT), global explained variance (GEV), transition probability, mean occurrence, and mean global field power (GFP) were compared before and during HBO therapy. The results showed that the duration of microstate C in all patients with DOC increased after 20 min of HBO therapy (p < 0.05). Further statistical analysis found that the duration of microstate C was longer in the higher CRS-R group (≥8, 17 cases) than in the lower group (<8, 24 cases) during HBO treatment. In the higher CRS-R group, the transition probabilities from microstate A to microstate C and from microstate C to microstate A also increased significantly compared with the probability before treatment (p < 0.05). Microstate C is generally considered to be related to a salience network; an increase in the transition probability between microstate A and microstate C indicates increased information exchange between the auditory network and the salience network. The results of this study show that HBO therapy has a specific activating effect on attention and cognitive control in patients and causes increased activity in the primary sensory cortex (temporal lobe and occipital lobe). This study demonstrates that real-time EEG detection and analysis during HBO is a clinically feasible method for assessing brain function in patients with DOC. During HBO therapy, some EEG microstate indicators show significant changes related to the state of consciousness in patients with chronic DOC. This will be complementary to important electrophysiological indicators for assessing consciousness and may also provide an objective foundation for the precise treatment of patients with DOC.

The Effect of Physical Activity on Neurotrophin Concentrations and Cognitive Control in Patients With a Depressive Episode.

BackgroundCognitive deficits occur in most patients with affective disorders. The role of neurotrophic factors (e.g., BDNF) as modulators of brain plasticity affecting neurocognitive abilities has been emphasized. Neurotrophin concentrations may change under the influence of various interventions, including physical activity. Selected studies have shown that cognitive function may also be affected by exercise.AimThe aim of the study was to determine whether physical activity changes the concentration of neurotrophins and their receptors in patients with an episode of depression. It was also examined how one session of aerobic exercise affects cognitive control.MethodsThe study included 41 participants. The subjects were asked to exercise on a cycloergometer for 40 min with individually selected exercise loads (70% VO2max). Before and shortly after the exercise blood samples were acquired to perform blood assays (proBDNF, BDNF, TrkB, NGFR). The participants also performed a Stroop test twice—before the exercise and 10 min after its cessation.ResultsThe single bout of physical exercise did not cause any significant changes in the concentration of neurotrophic factors. The SCWT results: both the mean reading time (29.3 s vs. 47.8 s) and the color naming time (36.7 s vs. 50.7 s) increased. The patients made more mistakes after physical exercise, both in part A (0.2 vs. 1.5) and B (0.6 vs. 1.5). The so-called interference effect decreased—the difference between naming and reading times was smaller after exercise (6.2 s vs. 2.4 s). No significant correlations were found between the concentrations of the studied neurotrophic factors and the Stroop test results.ConclusionsThe results did not confirm changes in neurotrophin concentration under the influence of a single session of physical activity. The shortening of the interference time after exercise may be caused by practice effects. A significant limitation of the study is the use of the Stroop test twice in short intervals.

Impaired cognitive control in patients with brain tumors

Though the assessment of cognitive functions is proven to be a reliable prognostic indicator in patients with brain tumors, some of these functions, such as cognitive control, are still rarely investigated. The objective of this study was to examine proactive and reactive control functions in patients with focal brain tumors and to identify lesioned brain areas more at “risk” for developing impairment of these functions. To this end, a group of twenty-two patients, candidate to surgery, were tested with an AX-CPT task and a Stroop task, along with a clinical neuropsychological assessment, and their performance was compared to that of a well-matched healthy control group. Although overall accuracy and response times were similar for patients and control groups, the patient group failed more on the BX trials of the AX-CPT task and on the incongruent trials of the Stroop task, specifically. Behavioral results were associated with the damaged brain areas, mostly distributed in right frontal regions, by means of a lesion-symptom mapping multivariate approach. This analysis showed that a white matter cluster in the right prefrontal area was associated with lower d’-context values on the AX-CPT, which reflected the fact that these patients rely more on later information (reactive processes) to respond to unexpected and conflicting stimuli, than on earlier contextual cues (proactive processes). Taken together, these results suggest that patients with brain tumors present an imbalance between proactive and reactive control strategies in high interfering conditions, in association with right prefrontal white matter lesions.

Ameliorating cognitive control in patients with binge eating disorder by electrical brain stimulation: study protocol of the randomized controlled ACCElect pilot trial

BackgroundThe current first-line treatment for binge eating disorder (BED), which is psychotherapy, is moderately effective in terms of abstinence from binge-eating. Neurobiological evidence suggests that people affected by BED show difficulties along the spectrum of impulsivity, including inhibitory control impairments and highlights the potential of novel treatment approaches directly targeting inhibitory control, including cognitive training approaches and non-invasive brain stimulation.MethodsACCElect is a prospective, randomized controlled pilot trial investigating a novel, food-related inhibitory control training combined with transcranial direct current stimulation (tDCS). 40 patients with BED will be randomly assigned to receive the training either combined with verum or with sham stimulation (control condition). The inhibitory control training is based on principles of the antisaccade paradigm and comprises six training sessions over two weeks. Core aims are the investigation of feasibility and clinically relevant effects of a tDCS-enhanced inhibitory control training in BED patients and the establishment of a data basis for a larger efficacy trial. The primary clinical endpoint is binge-eating (BE) frequency in terms of changes in BE episodes four weeks after treatment termination as compared to baseline. Key secondary outcomes comprise ED pathology and general psychopathology, inhibitory control capacities, quality of life as well as acceptability and satisfaction with the intervention.DiscussionThe results of the present trial will contribute to the development of novel neurobiologically informed treatment approaches for patients suffering from BED.Trial registration The ACCElect trial was prospectively registered on October 1, 2020, under the registration number NCT04572087 at ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT04572087).

Two-Hour Tobacco Abstinence Has No Effect on Cognitive Control in Male Patients With Nicotine Dependence: An ERP Study.

The average nicotine half-life in body tissues is 2 h. Understanding the influence of pure nicotine abstinence on cognitive control may be helpful in eliminating nicotine dependence (ND) and preventing smoking relapse. This study was to investigate the effects of 2-h tobacco abstinence on cognitive control in patients with ND. Twenty-five patients with ND completed event-related potential (ERP) P300 measurements at the normality state and the abstinence state. Twenty-five healthy controls (HCs) were measured with P300 twice with a 2-h time interval. HAMD and HAMA were used to assess the emotional state. Results showed that there were significant differences in Carbon monoxide (CO) levels between the abstinence state and the normality state in the ND group. There were no significant differences in HAMD and HAMA scores for the abstinence state in the ND group or the normality state in the ND group and the HC group. For P3a, P3b amplitude, and P3a latency, the main effect for ND group was significant. For P3a, P3b amplitude, and latency, the interaction effect for group × time point was not significant, and the main effect for time point was not significant. It concluded that patients with ND present cognitive control deficits, and 2-h tobacco abstinence has no effect on cognitive control deficits in male patients with ND. Our findings may be helpful in eliminating nicotine dependence and preventing smoking relapse.

Transcranial Direct Current Stimulation to the Left Dorsolateral Prefrontal Cortex Improves Cognitive Control in Patients With Attention-Deficit/Hyperactivity Disorder: A Randomized Behavioral and Neurophysiological Study

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder associated with significant morbidity and mortality that may affect over 5% of children and approximately 2.8% of adults worldwide. Pharmacological and behavioral therapies for ADHD exist, but critical symptoms such as dysexecutive deficits remain unaffected. In a randomized, sham-controlled, double-blind, crossover mechanistic study, we assessed the cognitive and physiological effects of transcranial direct current stimulation (tDCS) in 40 adult patients with ADHD in order to identify diagnostic (cross-sectional) and treatment biomarkers (targets). MethodsPatients performed three experimental sessions in which they received 30 minutes of 2 mA anodal tDCS targeting the left dorsolateral prefrontal cortex, 30 minutes of 2 mA anodal tDCS targeting the right dorsolateral prefrontal cortex, and 30 minutes of sham. Before and after each session, half the patients completed the Eriksen flanker task and the other half completed the stop signal task while we assessed behavior (reaction time, accuracy) and neurophysiology (event-related potentials). ResultsAnodal tDCS to the left dorsolateral prefrontal cortex modulated cognitive (reaction time) and physiological (P300 amplitude) measures in the Eriksen flanker task in a state-dependent manner, but no effects were found in the stop signal reaction time of the stop signal task. ConclusionsThese findings show procognitive effects in ADHD associated with the modulation of event-related potential signatures of cognitive control, linking target engagement with cognitive benefit, proving the value of event-related potentials as cross-sectional biomarkers of executive performance, and mechanistically supporting the state-dependent nature of tDCS. We interpret these results as an improvement in cognitive control but not action cancellation, supporting the existence of different impulsivity constructs with overlapping but distinct anatomical substrates, and highlighting the implications for the development of individualized therapeutics.

Dynamic Functional Connectivity Patterns in Schizophrenia and the Relationship With Hallucinations.

There is a wealth of evidence showing aberrant functional connectivity (FC) in schizophrenia but with considerable variability in findings across studies. Dynamic FC is an extension of traditional static FC, in that such analyses allow for explorations of temporal changes in connectivity. Thereby they also provide more detailed information on connectivity abnormalities in psychiatric disorders such as schizophrenia. The current study investigated dynamic FC in a sample of 80 schizophrenia patients and 80 matched healthy control subjects, replicating previous findings of aberrant dwell times in specific FC states, and further supporting a role for default mode network (DMN) dysfunction. Furthermore, relationships with hallucinations, a core symptom of schizophrenia, were explored. Two measures of hallucinations were used, one measure of current hallucination severity assessed on the day of scanning, and one trait-measure where hallucinations were assessed repeatedly over the course of 1 year. Current hallucination severity did not show a significant relationship with dynamic FC. However, the trait-measure of hallucination proneness over 1 year showed a significant relationship with dynamic FC. Patients with high hallucination proneness spent less time in connectivity states characterized by strong anti-correlation between the DMN and task-positive networks. The findings support theoretical models of hallucinations which have proposed an instability of the DMN and impaired cognitive control in patients with hallucinations. Furthermore, the results point to hallucination proneness as a potential marker for identifying distinct subgroups of schizophrenia patients.

Capacity of cognitive control in patients with cerebral small vessel disease

Objective To evaluate the capacity of cognitive control(CCC) in patients with cerebral small vessel disease(CSVD) and explore the relationship between CCC and cognitive function in CSVD, and to assess the predict value of CCC on the occurrence of CSVD. Methods Twenty-two patients with CSVD and twenty-three healthy controls were enrolled.All of them completed the majority function task-masked (MFT-M) and a set of neuropsychological tests.Neuropsychological test was performed by Montreal cognitive assessment (MoCA), verbal fluency test (VFT), Chinese auditory learning test (CAVLT), symbol digit modalities test (SDMT), digital span (DS), Stroop color word test (SCWT), color trail test (CTT) and Modified Boston naming test (Modified BNT). The predict value of CCC for the occurrence of CSVD was assessed with logistic regression analysis. Results CCC of patients with CSVD was lower than that of healthy control ((2.97±0.72)bps vs (3.53±0.62)bps, t=-2.704, P=0.01). Between patients with CSVD and healthy control, there were significant differences in MoCA ((22.24±4.58 vs (24.86±2.42), t=-2.334, P=0.026), VFT-animal (12(6) vs 15(6), Z=-2.965, P=0.003), VFT-vegetables and fruits ((13.79±3.81) vs (18.27±4.13), t=-3.592, P=0.001), CAVLT-immediate ((7.45±2.18) vs (9.11±2.08), t=-2.502, P=0.017), CAVLT-short term delay ((7.20±3.32) vs (10.76±3.08), t=-3.564, P=0.001), CAVLT-long term delay ((7.30±3.16) vs (10.29±3.18), t=-3.012, P=0.005), SDMT ((15.95±5.49) vs (23.41±12.73), t=-2.513, P=0.018), CTT-A (85.17(42.60) vs 55.50(52.65), Z=-2.965, P=0.003), CTT-B ((200.69±71.35) vs (132.44±53.66), t=3.556, P=0.001), and CTT-B-A ((104.13±53.31) vs (65.20±35.98), t=2.819, P=0.007). But there was no significant difference in VFT-word begin with Chinese characterwater((3.68±2.63) vs (5.44±2.71), t=-1.940, P=0.061), CAVLT-recognition (14(3) vs 14(4), Z=-0.524, P=0.601), DS-forward (7.0(3.0) vs 5.5(2.0), Z=-0.152, P=0.880), DS-backward (4(1) vs 4(2), Z=-1.044, P=0.297), SCWT ((9.50±9.28) vs (5.94±10.47), t=1.123, P=0.268), Modified BNT (14.0(3.0) vs 13.5(3.0), Z=-0.727, P=0.467) between CSVD patients and healthy controls.In patients with CSVD, CCC was positively correlated with scores of MoCA (r=0.551, P=0.010) and also with DS-forward (r=0.532, P=0.013) and SCWT (r=-0.487, P=0.040). Logistic regression analysis showed that CCC was an important variable in predicting the possibility of CSVD (B=-1.318, P=0.019, OR=0.268, 95%CI (0.089-0.808)). Conclusion Compared with the healthy control, CCC in patients with CSVD decreases significantly and CCC is related to the cognitive impairment.CCC can predict the possibility of CSVD. Key words: Cognitive control capacity; Cerebral small vessel disease; Cognitive function

Impairments to Cognitive Control in Patients with Somatoform Disorders and Their Treatment

Objectives. To study impairments to cognitive control in patients with somatoform dysfunction of the autonomic nervous system (somatoform disorder – SFD) and to assess the efficacy of the use of Recognan in the treatment of this pathology. Materials and methods. A total of 46 patients aged 18–45 years with SFD were studied. Histories were taken from all patients, who also underwent neurological examination and assessment of autonomic impairments. The severity of asthenic and emotional disorders were quantified using a subjective asthenia assessment scale (Multidimensional Fatigue Inventory, MFI-20), the Hamilton Anxiety Rating Scale (HARS), and the Cognitive Emotional Regulation Questionnaire (CERQ). Attention and impulsivity were quantified by the TOVA psychophysiological test. Patients of the study group were treated using Recognan (citicoline). The control group consisted of 30 essentially healthy people aged 18–45 years. Results. Patients with SFD were characterized by cognitive domain features which were most marked in the form of impaired attention. Psychological investigations demonstrated an increase level of anxiety. In addition, patients with SFD had lower levels of cognitive control of the emotions than members of the control group. The results of follow-up studies after courses of treatment indicated that the use of Recognan in the treatment of SFD was highly effective (improvements occurred in 67.4% of patients). Courses of treatment were followed by significant decreases in the severity of autonomic impairments and decreases in measures characterizing asthenia.

Impairments of cognitive control in patients with somatoform disorders and their treatment

To study impairments of cognitive control in patients with somatoform disorders (SD) and to evaluate the efficacy of recognan in the treatment of this pathology. Forty-six patients with SD, aged from 18 to 45 years, were studied. A clinical history, neurological examination, and assessment of autonomic disorders were collected from all patients. For the objectification of the severity of asthenic and emotional disorders, the Subjective Scale of Asthenia (MFI-20), the Hamilton Anxiety Scale (HARS), the Cognitive Emotion Regulation Questionnaire (CERQ were used. A quantitative assessment of impaired attention and impulsivity was performed using the psychophysiological test TOVA. Patients were treated with recognan (citicoline). The control group consisted of 30 healthy people aged from 18 to 45 years. Patients with SD had specific characteristics of the cognitive sphere, most pronounced in the form of attention disorders. The psychological study showed the higher level of anxiety. In addition, patients with SD were characterized by the low levels of emotional intelligence and cognitive control of emotions compared with the control group. The results of the follow-up study after treatment suggest the high efficacy of recognan in the treatment of SD (improvement was noted in 67.4% of patients). A significant decrease in the severity of autonomic disorders and in indicators characterizing asthenia was established after the treatment.

The impact of white matter hyperintensities on the structural connectome in late-life depression: Relationship to executive functions.

BackgroundWhite matter hyperintensities (WMH) represent ischemic white matter damage in late-life depression (LLD) and are associated with cognitive control dysfunction. Understanding the impact of WMH on the structural connectivity of gray matter and the cognitive control correlates of WMH-related structural dysconnectivity can provide insight into the pathophysiology of LLD.MethodsWe compared WMH burden and performance on clinical measures of cognitive control in patients with LLD (N = 44) and a control group of non-depressed older adults (N = 59). We used the Network Modification (NeMo) Tool to investigate the impact of WMH on structural dysconnectivity in specific gray matter regions, and how such connectivity was related to cognitive control functions.ResultsCompared to the control group, LLD participants had greater WMH burden, poorer performance on Trail Making Test (TMT) A & B, and greater self-reported dysexecutive behavior on the Frosntal Systems Behavior Scale-Executive Function subscale (FrSBe-EF). Within the LLD group, disrupted connectivity in the left supramarginal gyrus, paracentral lobule, thalamus, and pallidum was associated with psychomotor slowing (TMT-A). Altered connectivity in the left supramarginal gyrus, paracentral lobule, precentral gyrus, postcentral gyrus, thalamus, and pallidum was associated with poor attentional set-shifting (TMT-B). A follow-up analysis that isolated set-shifting ability (TMT-B/A ratio) confirmed the association with dysconnectivity in the bilateral paracentral lobule, right thalamus, left precentral gyrus, postcentral gyrus, and pallidum; additionally, it revealed associations with dysconnectivity in the right posterior cingulate, and left anterior cingulate, middle frontal cortex, and putamen.ConclusionsIn LLD, WMH are associated with region-specific disruptions in cortical and subcortical gray matter areas involved in attentional aspects of cognitive control systems and sensorimotor processing, which in turn are associated with slower processing speed, and reduced attentional set-shifting.Clinical trials registrationhttps://clinicaltrials.gov/ct2/show/NCT01728194

The Time Course of Dorsal and Rostral-Ventral Anterior Cingulate Cortex Activity in the Emotional Stroop Experiment Reveals Valence and Arousal Aberrant Modulation in Patients with Schizophrenia

This paper aims to investigate the temporal dynamics within the dorsal anterior cingulate cortex (dACC) and the rostral-ventral (rv) ACC during the interaction of emotional valence and arousal with cognitive control in patients with Schizophrenia (SZ). Although cognitive deficits in SZ are highly relevant and emotional disturbances are common, the temporal relationship of brain regions involved in the interaction of emotional and cognitive processing in SZ is yet to be determined. To address this issue, the reaction time (RT), event-related potential (ERP) and temporal dynamics of the dACC and rvACC activity were compared between SZ subjects and healthy controls (HC), using a modified emotional Stroop experiment (with factors namely congruence, arousal and valence). EEG was recorded with 64 channels and source localisation was performed using the sLORETA software package. We observed slower initial increase and lower peaks of time course activity within the dACC and rvACC in the SZ group. In this particular group, the dACC activity during late negativity was negatively correlated with a significantly higher RT in the high arousal conflict condition. In contrast to HC subjects, at the N450 window, there was no significant valence (ERP and rvACC ROI) modulation effect in the SZ subjects. Using high density EEG and source localisation, it was possible to distinguish various disturbances within the dACC and rvACC in patients with SZ, during emotion–cognition processing.

Cognitive control in patients with alcohol use disorder: testing a three-function model

Aim of the studyThe aim of the current study is to test cognitive control models for explaining cognitive dysfunctions in patients with AUD.Subject or material and methods53 participants with AUD undergoing detoxification inpatient treatment were assessed using Brief Assessment of Cognition in Affective disorder battery (BAC-A), Continuous Performance Test – Identical Pair (CPT-IP), and the Stroop test.ResultsA model of patients’ cognitive control dysfunction is developed using principal component analysis. It includes response inhibition and working memory components and explains 87.3% of cognitive control variance. The comparison between “low” and “high” cognitive control groups yielded significant differences in verbal and working memory (p&lt;0.001), processing speed (p=0.006), and emotional processing (p&lt;0.01) tasks. When compared to the normative data, the «low» cognitive control group exhibited deficits in working memory, motor skills, processing speed, planning and decision making, and emotional processing (all at the p&lt;0.001 level). No other significant differences were observed.DiscussionThe cognitive control model, which includes working memory and response inhibition, might be more accurate in explaining cognitive deficits in AUD. The clinically and demographically equal groups differed in cognitive control abilities, motor skills, processing speed and emotional interference control.ConclusionsThis is one the first studies examining cognitive control in Russian patients with AUD. The findings suggest the diversity of premorbid cognitive functioning or differences in vulnerability to neurotoxic effects of alcohol intake among patients with AUD with varying levels of cognitive control.

Frontal lobe functioning during a simple response conflict task in first-episode psychosis and its relationship to treatment response.

Prior functional magnetic resonance imaging (fMRI) studies have investigated the neural mechanisms underlying cognitive control in patients with psychosis with findings of both hypo- and hyperfrontality. One factor that may contribute to inconsistent findings is the use of complex and polyfactorial tasks to investigate frontal lobe functioning. In the current study we employed a simple response conflict task during fMRI to examine differences in brain activation between patients experiencing their first-episode of psychosis (n = 33) and age- and sex-matched healthy volunteers (n = 33). We further investigated whether baseline brain activation among patients predicted changes in symptom severity and treatment response following 12weeks of controlled antipsychotic treatment. During the task subjects were instructed to press a response button on the same side or opposite side of a circle that appeared on either side of a central fixation point. Imaging data revealed that for the contrast of opposite-side vs. same-side, patients showed significantly greater activation compared with healthy volunteers in the anterior cingulate cortex and intraparietal sulcus. Among patients, greater baseline anterior cingulate cortex, temporal-parietal junction, and superior temporal cortex activation predicted greater symptom reduction and therapeutic response following treatment. All findings remained significant after covarying for task performance. Intact performance on this relatively parsimonious task was associated with frontal hyperactivity suggesting the need for patients to utilize greater neural resources to achieve task performance comparable to healthy individuals. Moreover, frontal hyperactivity observed using a simple fMRI task may provide a biomarker for predicting treatment response in first-episode psychosis.

Cognate effects and cognitive control in patients with parallel and differential bilingual aphasia.

Until today, there is no satisfying explanation for why one language may recover worse than another in differential bilingual aphasia. One potential explanation that has been largely unexplored is that differential aphasia is the consequence of a loss of language control rather than a loss of linguistic representations. Language control is part of a general control mechanism that also manages non-linguistic cognitive control. If this system is impaired, patients with differential aphasia could still show bilingual language activation, but they may be unable to manage activation in non-target languages, so that performance in another language is hindered. To investigate whether a loss of cognitive control, rather than the loss of word representations in a particular language, might underlie differential aphasia symptoms. We compared the performance of seven bilinguals with differential and eight bilinguals with parallel aphasia with 19 control bilinguals in a lexical decision and a flanker task to assess bilingual language co-activation and non-linguistic control respectively. We found similar cognate effects in the three groups, indicating similar lexical processing across groups. Additionally, we found a larger non-linguistic control congruency effect only for the patients with differential aphasia. The present data indicate preserved language co-activation for patients with parallel as well as differential aphasia. Furthermore, the results suggest a general cognitive control dysfunction, specifically for differential aphasia. Taken together, the results of the current study provide further support for the hypothesis of impaired cognitive control abilities in patients with differential aphasia, which has both theoretical and practical implications.

Abnormal interaction between cognitive control network and affective network in patients with end-stage renal disease.

End-stage renal disease (ESRD) is a common complicated disorder that is generally associated with an altered central nervous system and cognitive impairment. Neuroimaging studies have recorded aberrant brain circuits in patients with ESRD that were closely associated with abnormal clinical manifestations. However, whether the altered interaction was within and/or between these circuits is largely unclear. We investigated brain topological organization and/or module interaction by employing resting-state functional magnetic resonance imaging (rs-fMRI) and modularity network analysis in 24 patients with ESRD and 20 age- and gender-matched healthy control (HC) subjects. Stroop task was used to evaluate the performance of cognitive control in all subjects. At the global level, ESRD patients exhibited significantly decreased global and local efficiency which were mainly related to abnormal functional connectivity of the amygdala and inferior frontal gyrus (IFG). Stepwise regression analysis was applied to estimate the relationships between network efficiency and blood biochemistry level (urea, creatine, phosphate, Ca2+, hematocrit, cystatin, hemoglobin levels, parathyroid hormone, K+ and Na+), and only the hematocrit level was significantly associated with global efficiency in patients with ESRD. At the modular level, we discovered an aberrant brain interaction between the amygdala- and IFG-related circuits in the ESRD group, and the regional efficiency of the amygdala was observably relative to the performance of cognitive control in patients with ESRD. Our results suggested that ESRD exhibited aberrant brain functional topological organization and module-level interaction between the affective and cognitive control circuits, providing crucial insights into the pathophysiological mechanism of ESRD patients.

Increased recruitment of cognitive control in the presence of traumatic stimuli in complex PTSD.

A neurocircuitry model of post-traumatic stress disorder (PTSD) suggests increased amygdala responses to emotional stimuli, coupled with hypoactivation of prefrontal regions associated with cognitive control. However, results are heterogenous across different subsamples of PTSD as well as different paradigms. We investigated cognitive control in a classic and emotional Stroop task in 28 female patients with complex PTSD (cPTSD), 28 female trauma-exposed healthy controls (TCs) and 28 female non-trauma-exposed healthy controls (HCs) using functional neuroimaging. Afterwards, we assessed memory function in a spontaneous free recall and recognition task. Patients with cPTSD displayed significantly greater Stroop interference with trauma-related words (as reflected in slower reaction times and increased errors) compared to the other conditions and compared to the TC and HC groups. Moreover, patients with cPTSD showed increased activation in the context of trauma-related words in brain regions associated with cognitive control (dlPFC, vmPFC, dACC) compared to both control groups, and a trend for increased activation in the insula compared to the HC group. Increased recruitment of regions contributing to cognitive control in patients with cPTSD, together with a lack of amygdala response may point to efforts to compensate for emotional distraction caused by the trauma-related words.

Altered neural mechanisms of cognitive control in patients with primary progressive multiple sclerosis: An effective connectivity study.

Primary progressive multiple sclerosis (PPMS) leads to physical and cognitive disability. Specifically, cognitive deficits in PPMS have been explained by both grey matter atrophy and white matter lesions. However, existing research still lacks in the understanding of how the brain of a patient with PPMS functions under cognitive control demands. Thus, the aim of the current study was to examine information integration in patients with PPMS using a search-based effective connectivity method. Fourteen patients with PPMS and 22 age- and gender-matched healthy controls (HC) performed the Stroop task, a cognitively demanding interference task that taxes neural resources required for cognitive control and response inhibition. Results showed that compared to HC, PPMS patients exhibited poor behavioral performance and alterations in information flow, manifested in the form of the loss of top-down connections, reversal of connections, and hyperconnectivity. Significant correlations were observed between connection strengths and behavioral measures. The connection between the posterior parietal cortex (PCC) and left posterior parietal lobule, which was present in both groups, showed a negative correlation with performance accuracy on incongruent trials. The connection between the left dorsolateral prefrontal cortex and PCC showed a positive correlation with performance accuracy on incongruent trials. However, the adaptive nature of this connection was not significant on a behavioral level as the PPMS group performed significantly worse compared to the HC group during the Stroop task. Thus, the current study provides important evidence about effective connectivity patterns that can be characterized as maladaptive cerebral re-organization in the PPMS brain. Hum Brain Mapp 38:2580-2588, 2017. © 2017 Wiley Periodicals, Inc.

Conflict monitoring and adaptation as reflected by N2 amplitude in obsessive-compulsive disorder.

Feelings of doubt and perseverative behaviours are key symptoms of obsessive-compulsive disorder (OCD) and have been linked to hyperactive error and conflict signals in the brain. While enhanced neural correlates of error monitoring have been robustly shown, far less is known about conflict processing and adaptation in OCD. We examined event-related potentials during conflict processing in 70 patients with OCD and 70 matched healthy comparison participants, focusing on the stimulus-locked N2 elicited in a flanker task. Conflict adaptation was evaluated by analysing sequential adjustments in N2 and behaviour, i.e. current conflict effects as a function of preceding conflict. Patients with OCD showed enhanced N2 amplitudes compared with healthy controls. Further, patients showed stronger conflict adaptation effects on reaction times and N2 amplitude. Thus, the effect of previous compatibility was larger in patients than in healthy participants as indicated by greater N2 adjustments in change trials (i.e. iC, cI). As a result of stronger conflict adaptation in patients, N2 amplitudes were comparable between groups in incompatible trials following incompatible trials. Larger N2 amplitudes and greater conflict adaptation in OCD point to enhanced conflict monitoring leading to increased recruitment of cognitive control in patients. This was most pronounced in change trials and was associated with stronger conflict adjustment in N2 and behaviour. Thus, hyperactive conflict monitoring in OCD may be beneficial in situations that require a high amount of control to resolve conflict, but may also reflect an effortful process that is linked to distress and symptoms of OCD.