The cognitive bias task (CBT) in healthy controls: a replication study

Contextual processing is the selection and bringing "on-line" of internal representations of a task that can be used in planning and mediating goal-appropriate behavioral responses and is a relevant issue that probably is involved in many neurological and psychiatric conditions. The Cognitive Bias Task is a measure of context-dependent responding, is sensitive to quadrant-lesion effects, and interacts with gender. The goal of this study was to replicate and detail more completely the method of context-dependent processing for healthy control patients on the Cognitive Bias Task. The results show the presence of three different cognitive patterns that could biases the response of control patients: context-independent, context-dependent, and mixed. Gender, but not handedness, significantly influences contextual processing, with more females than males producing a context-independent pattern of responding. Test results and the relation of contextual processing in psychiatric disorders were discussed.     

Context-dependent reasoning in a cognitive bias task Part II. SPECT activation study

A cognitive bias task (CBT) delineates two different cognitive selection mechanisms in the prefrontal cortex. To identify functional anatomy of context-dependent reasoning, we used technetium-99mhexamethyl- propyleneamine oxime (99mTc HM-PAO) single photon emission computed tomography (SPECT) and statistical parametric mapping. Twelve right-handed men 20-24 years old were instructed to look at a target card and then select the choice card (among two) that they preferred (modified CBT; mCBT). They also selected a choice card 2 weeks later without prior presentation of a target card (control task). In both tasks, 99mTc HM-PAO was injected intravenously about 15 s after initiation of the mCBT or control task. Brain images were obtained using a gamma camera and reconstructed by a UNIX-based workstation. Statistical analysis compared all activated images to control images. Results associated with P values of less than 0.01 (Z score > 2.36) were depicted on T1-weighted magnetic resonance images. All subjects preferred choices more similar to the target. SPECT activation occurred bilaterally in the dorsolateral prefrontal cortices and middle temporal gyri during performance of the CBT. Additionally, the left inferior prefrontal cortex and left fusiform gyrus showed significant activation compared with the control task. A neural network linking the temporal and prefrontal cortices prominently seen in the left hemisphere participates in context-dependent reasoning. Knowledge of such neural systems is essential for understanding prefrontal lobe function and dysfunction.     

Schizophrenic patients with polydipsia and water intoxication more often have a form of schizophrenia first described by Kraepelin

Polydipsia and water intoxication (PWI) seem to be associated with a particular form of schizophrenia, first described by Kraepelin, involving negative symptoms, disorganization and poor outcome. In this study, a group of 20 schizophrenic patients with PWI was selected and matched for age, duration of illness and gender with a group of 20 schizophrenic controls with no PWI. For these patients the following measure were obtained: clinical and demographic data, Keefe's criteria for Kraepelinian schizophrenia, the Positive and Negative Syndrome Scale score and the score on Fagerstr?m's Nicotine Dependence Scale. The group of schizophrenic patients with PWI presents significantly higher levels of negative symptoms, disorganized symptoms and general symptoms of psychopathology, and it is composed of a significantly higher percentage of Kraepelinian patients. These results show an association of polydipsia and water intoxication with Kraepelinian schizophrenia suggesting physiological hypotheses for a specific pathogenic pathway.     

Schizophrenic subjects activate dorsolateral prefrontal cortex during a working memory task, as measured by fMRI.

BACKGROUND: Neuroimaging studies of schizophrenic subjects performing working memory (WM) tasks have demonstrated a relative hypoactivity of prefrontal cortex compared with normal subjects. METHODS: Using functional magnetic resonance imaging (fMRI), we compared dorsolateral prefrontal cortex (DLPFC) activation in 12 schizophrenic and 10 normal subjects during rewarded performance of a WM task. Subjects performed a modified version of the Sternberg Item Recognition Paradigm (SIRP), a continuous performance, choice reaction time (RT) task that requires WM. We compared a high WM load condition with a nonWM choice RT condition and with a low WM load condition. RESULTS: Schizophrenic subjects performed the tasks better than chance but worse than normal subjects. They showed greater activation than normal subjects in the left DLPFC but did not differ in the right DLPFC or in the control region. In the schizophrenic group, left DLPFC activation was inversely correlated with task performance, as measured by errors. CONCLUSIONS: These findings contrast with previous studies that demonstrated task-related hypofrontality in schizophrenia. Task parameters that may contribute to this difference are discussed. We hypothesize that the performance and activation differences we observed are also manifestations of prefrontal dysfunction in schizophrenia. They reflect inefficient functioning of the neural circuitry involved in WM.     

The efficacy of integrated cognitive behavioral therapy (CBT) and acupressure versus CBT for insomnia: a three-arm pilot randomized controlled trial

ObjectivesThis pilot study aimed to examine the efficacy of integrated cognitive behavioral therapy (CBT) and acupressure in treating insomnia and its daytime impairments in a Chinese adult population.Methods40 eligible participants with insomnia were randomly assigned to either the integrated CBT and acupressure (CBTAcup) group (n = 14), the CBT group (n = 13), or the waitlist control (WL) group (n = 13). Participants in the CBTAcup group attended a 2-hour integrated CBT and self-administered acupressure group treatment once per week for six consecutive weeks, while participants in the CBT group attended six weekly 2-hour CBT for insomnia. Sleep, mood, daytime impairments, quality of life, and treatment credibility and adherence were assessed at baseline, immediate post-treatment (Week 7), and 4-week post-treatment (Week 11).ResultsLinear mixed-effects models showed that both the CBTAcup and CBT groups had significantly lower insomnia severity (d = −1.74 and d = −2.61), dysfunctional beliefs related to sleep (d = −2.17 and −2.76), and mental fatigue (d = −1.43 and −1.60) compared with the WL group at Week 7. The CBTAcup group provided additional benefits in reducing total fatigue (d = −1.43) and physical fatigue (d = −1.45). Treatment credibility was found to be improved in the CBTAcup group from baseline to Week 7.ConclusionsIntegrated CBT and acupressure demonstrated comparable efficacy to pure CBT in treating insomnia symptoms, with additional advantages to improve fatigue symptoms and acceptability in the Chinese population. Further methodologically rigorous studies on a larger scale and longer follow-up are warranted to confirm these findings.     

Lateralization of the frontal lobe functions elicited by a cognitive bias task is a fundamental process. Lesion study

Cognitive neuroscience researchers have hypothesized that context-dependent and context-independent response selection is associated with the left and right frontal lobe, respectively, in right-handed adult males. Patients with left frontal lobe lesions show context-independent reasoning in a cognitive bias task (CBT), while those with right frontal lesions show context-dependent reasoning. Young children show more context-independent responses in a modified CBT (mCBT), while adolescents and adults show more context-dependent responses. We investigated the cognitive bias of right-handed children with unilateral frontal lobe lesions/epileptic foci to explore the plasticity of lateralization in the frontal lobes. The study included eight children with left frontal lobe lesions/epileptic foci (LLF) and four children with right frontal lobe lesions/epileptic foci (RLF). Twenty-three right-handed age-matched males served as controls. A computer presented version of the original card-choice task that was simplified and modified for children was used (mCBT). Simple visual stimuli differed dichotomously in shape, color, number, and shading. A target object presented alone was followed by two choices from which subjects made selection based on preference. Considering all four characteristics, the degree of similarity between the target and the subjects' choice was scored for 30 trials. A high score indicated a context-dependent response selection bias and a low score indicated a context-independent bias. The RLF subjects had a higher converted score (mean: 26.8+/-2.2), while LLF subjects showed a lower converted score (mean: 7.75+/-6.3). There were highly significant differences between LLF subjects and the other groups (P<0.001 vs. controls or RLF subjects). No significant correlations were observed between the converted scores and the age at onset, time since insult, or IQ in either LLF or RLF subjects. These findings suggest that the lateralization of frontal lobe function elicited by mCBT is fundamental and independent of language lateralization, rather than secondary to it. Furthermore, these findings also indicate that the timetable for the development of lateralized frontal lobe functions depends upon biologic factors.     

Cognitive behavioural therapy (CBT) for carers of patients with Parkinson's disease: a preliminary randomised controlled trial

OBJECTIVE: Most individuals with Parkinson's disease live in their own homes cared for by a family member. Providing such long term care can be a source of significant stress, with many carers experiencing sleep difficulty, depression, anxiety, loneliness, and other symptoms of psychological strain. Cognitive behavioural therapy (CBT) is one of the most widely used psychological treatments in clinical use today, with applications across the full range of clinical conditions. It has been previously used in the management of other carer groups. The present study sought to evaluate the efficacy of CBT in treating psychological distress in a group of Parkinson's disease carers. METHOD: A total of 30 carers scoring at caseness level on the 28 item General Health Questionnaire (GHQ-28) were randomised to receive either a course of 12-14 sessions of CBT or to a no-treatment control group. RESULTS: Although some change was observed in both groups, significantly greater improvement on the GHQ-28 was observed after three months in the CBT treated group. Similar findings were observed in measures of caregiver strain and subjective burden, with the benefits being maintained over a subsequent three month follow up period. CONCLUSIONS: These results offer preliminary support to the value of a CBT approach in the management of psychological morbidity in Parkinson's disease carers. Further larger scale research is needed in the future to examine the generalisability of the findings to a broader range of carers, assess the longer term impact on outcome in carers and those with Parkinson's disease, and explore how CBT can be best delivered in the most cost effective manner.     

Age shifts frontal cortical control in a cognitive bias task from right to left: part I. Neuropsychological study

Two functionally and neurally distinct cognitive selection mechanisms involve the prefrontal lobes: those based on internal representations (context dependent) and those involving exploratory processing of novel situations (context independent). We used a cognitive bias task (CBT) representing contextual reasoning to correlate lateralization with age in the frontal lobes. Subjects included 37 healthy right-handed male children and adolescents (age range, 5–18 years). Controls were 19 right-handed men from 20 to 30 years old. A computer-presented version of the original card-choice task simplified, modified for children was used (modified CBT; mCBT). Simple visual stimuli differed dichotomously in shape, color, number, and shading. A target object presented alone was followed by two choices from which subjects selected according to preference. Considering all four characteristics, similarity between target and subject choice was scored for 30 trials. A high score implied a context-dependent response selection bias and a low score, a context-independent bias. Similarity increased significantly with age. The youngest children (5–7 years) scored lower than ages from 11 years to adulthood. Between 7 and 9 years, scores began to increase with age to reach an adult level by age 13–16. Young children showed context-independent responses representing right frontal lobe function, while adolescents and adults showed context-dependent responses implicating left frontal lobe function. The locus of frontal cortical control in right-handed male subjects thus shifts from right to left as cognitive contextual reasoning develops.     

Bilaterally reduced frontal activation during a verbal fluency task in depressed patients as measured by near-infrared spectroscopy

The present study investigated functional changes of brain oxygenation in prefrontal brain areas of nine depressed patients and nine age- and sex-matched healthy comparison subjects by using near-infrared spectroscopy. During a verbal fluency task, the healthy subjects exhibited the typical activation pattern, with a significant increase in oxyhemoglobin and a decrease in deoxyhemoglobin, as compared to a resting baseline condition. Patients had significantly lower activation bilaterally during the cognitive task, with no significant differences in behavioral performance. The results underscore the hypothesis of a functional deficit in prefrontal cortex in depression and confirm the feasibility of near-infrared spectroscopy in measuring functional brain activation.     

Frontotemporal cognitive function in X-linked spinal and bulbar muscular atrophy (SBMA): a controlled neuropsychological study of 20 patients

A cross-sectional neuropsychological study of cognitive functions in 20 male patients with genetically proven spinal and bulbar muscular atrophy (SBMA) was performed, with a comparison of their cognitive performance with that of 20 age- and education-matched control subjects. Neuropsychological assessment covered executive functioning, memory, and attentional control. The SBMA patients revealed deficits in verbal and non-verbal fluency as well as concept formation. Additionally, they showed significant memory deficits in all of the investigated domains of working memory, short-term and long-term memory. With respect to attentional control, the SBMA patients underperformed in relevant subtests, although performance differences did not reach significance overall. We conclude that fronto-temporal cognitive functions are impaired in SMBA, although at a subclinical level. Thus, functional deficits in SBMA are not confined to motor neurons but also affect extramotor networks.     

Building a clinically relevant cognitive task: case study of the AX paradigm

Tasks developed for basic cognitive neuroscience are often ill suited for experimental psychopathology. The development of the expectancy variant of AX continuous performance task to test theories about context processing in schizophrenia is used as an illustration of how this has been done in one research program. Four design principles are recommended: tasks should (1) have a foundation in existing literature and therefore stay as close as possible to an existing task; (2) be simple, which is frequently accomplished by paring down a task to evaluate the function of interest; (3) probe a mechanism of interest, with conditions that selectively manipulate this mechanism; and (4) have the potential to distinguish a specific deficit on the mechanism of interest from a generalized impairment. Data from a number of studies support several aspects of context-processing theory; however unpredicted results have also been reported. The development of the expectancy AX paradigm continues, and future developments that may enhance its usefulness are also described.     

The effects of 7-week cognitive training in patients with vascular cognitive impairment,no dementia (the Cog-VACCINE study): A randomized controlled trial

IntroductionEvidence for the efficacy of cognitive training in patients with subcortical vascular cognitive impairment no dementia is still lacking.MethodsA randomized, active controlled design using multidomain, adaptive, computerized cognitive training for 30 minutes, 5 days/week for 7 weeks. Assessments included global cognitive function and executive function (primary outcomes) and brain functional connectivity and structural changes (secondary outcomes).ResultsSixty patients were randomized across three medical centers in Beijing. At the end of the intervention, the cognitive training group showed significant improvement in Montreal Cognitive Assessment relative to the active control group (P = .013) and significantly increased functional connectivity between the left dorsolateral prefrontal cortex and medial prefrontal cortex, which was significantly correlated with Montreal Cognitive Assessment change (P = .017).DiscussionComputerized cognitive training significantly improved global cognitive function, which was supported by the improved brain plasticity. Incorporation of biomarkers should be implemented in cognitive training trials.     

认知矫正治疗慢性精神分裂症患者认知功能缺陷的随机对照研究

目的 探讨认知矫正治疗(CRT)和计算机认知矫正治疗(CCRT)对精神分裂症患者认知缺陷的疗效.方法 180例慢性期病情稳定的精神分裂症患者随机分成3组,CCRT组、CRT组和工娱治疗(WAT)组.CCRT组108例,治疗以自主开发的计算机认知矫正治疗系统为工具,每周4次,每次45 min,持续3个月;CRT组36例,以Ann Delahunty和Rodney Morice等制定的神经认知矫正手册(汉化)为治疗工具,在治疗师的指导下进行认知矫正治疗;WAT组36例,接受相同时间的工娱治疗.3组在治疗频度和治疗持续时间上完全一致.治疗前后及治疗结束后第3个月分别进行临床症状和认知功能评定,内容包括阳性和阴性症状量表(PANSS)、精神分裂症认知功能成套测验(MCCB)、威斯康星卡片分类测验(WCST).结果 治疗结束后及随访第3个月时,CCRT组和CRT组在改善WCST完成分类数、连线测验、空间广度方面显著优于WAT组(P均＜0.05);CCRT组在空间广度方面明显优于CRT组(P＜0.05),CRT组在符号编码方面则优于CCRT组(P＜0.05);3组的临床症状在治疗结束及随访阶段无明显变化.结论 CCRT和CRT均能显著改善慢性精神分裂症患者的认知功能,主要表现在记忆、执行功能、精神运动速度方面;CCRT在空间记忆方面较CRT有优势,CRT在精神运动方面较CCRT有优势,CCRT和CRT在执行功能、记忆、精神运动速度等方面的疗效能持续3个月.     

Mechanism of action in CBT (MAC): methods of a multi-center randomized controlled trial in 369 patients with panic disorder and agoraphobia

Cognitive behavioral therapy (CBT) is efficacious for panic disorder with agoraphobia (PD/A). Nevertheless, the active ingredients of treatment and the mechanisms through which CBT achieves its effects remain largely unknown. The mechanisms of action in CBT (MAC) study was established to investigate these questions in 369 patients diagnosed with PD/A. The MAC study utilized a multi-center, randomized controlled design, with two active treatment conditions in which the administration of exposure was varied, and a wait-list control group. The special feature of MAC is the way in which imbedded experimental, psychophysiological, and neurobiological paradigms were included to elucidate therapeutic and psychopathological processes. This paper describes the aims and goals of the MAC study and the methods utilized to achieve them. All aspects of the research design (e.g., assessments, treatment, experimental procedures) were implemented so as to facilitate the detection of active therapeutic components, and the mediators and moderators of therapeutic change. To this end, clinical, behavioral, physiological, experimental, and genetic data were collected and will be integrated.

     

ApoE4-positive multiple sclerosis patients are more likely to have cognitive impairment: a cross-sectional study

Neurological Sciences - Multiple sclerosis (MS) presents with a wide variety of symptoms, including cognitive dysfunction. Previous studies in terms of the possible function of the ApoE4 allele as...     

Augmenting atypical antipsychotics with a cognitive enhancer (donepezil) improves regional brain activity in schizophrenia patients: a pilot double-blind placebo controlled BOLD fMRI study

Cognitive impairments are cardinal features of schizophrenia and predictors of poor vocational and social outcome. Imaging studies with verbal fluency tasks (VFT) lead some to suggest that in schizophrenia, the combination of a failure to deactivate the left temporal lobe and a hypoactive frontal lobe reflects a functional disconnectivity between the left prefrontal cortex and temporal lobe. Others have theorized that an abnormal cingulate gyrus modulates such fronto-temporal connectivity. Thus addition of a cognitive enhancing medication to current antipsychotic therapy might improve functionality of networks necessary in working memory and internal concept generation. To test this hypothesis, we serially measured brain activity in 6 subjects on stable atypical antipsychotics performing a VFT, using BOLD fMRI. Measurements were made at baseline and again after groups were randomized to receive 12 weeks of donepezil (an acetylcholinesterase inhibitor) and placebo in a blind cross-over design. Donepezil addition provided a functional normalization with an increase in left frontal lobe and cingulate activity when compared to placebo and from baseline scans. This pilot study supports the cingulate's role in modulating cognition and neuronal connectivity in schizophrenia.     

A controlled study into the (cognitive) effects of exposure treatment on trauma therapists

Several researchers have reported on therapists’ symptoms as a result of trauma treatment, such as disruptions in cognitive schemata and symptoms resembling PTSD-symptoms. Thus far, however, no studies compared the symptoms of trauma therapists and non-trauma therapists. In the present study, both trauma therapists (n=20) and non-trauma therapists (n=19) were included. During semi-structured interviews, both therapist groups reported negative and positive effects of their work with patients on their personal and professional functioning. Trauma therapists reported more often changes of cognitions due to trauma work. Results from questionnaires, however, showed that compared with norm-standards and compared with non-trauma therapists, trauma therapists did not show enhanced psychopathology nor distorted cognitive schemata. It is concluded that although exposure treatments with trauma patients are associated with therapists’ distress, therapists seem able to cope with it in a healthy way.