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Continuous theta burst stimulation (cTBS) is a form of noninvasive repetitive brain stimulation that, when delivered over the contralesional hemisphere, can influence the excitability of the ipsilesional hemisphere in individuals with stroke. cTBS applied prior to skilled motor practice interventions may augment motor learning; however, there is a high degree of variability in individual response to this intervention. The main objective of the present study was to assess white matter biomarkers of response to cTBS paired with skilled motor practice in individuals with chronic stroke. We tested the effects of stimulation of the contralesional hemisphere at the site of the primary motor cortex (M1c) or primary somatosensory cortex (S1c) and a third group who received sham stimulation. Within each stimulation group, individuals were categorized into responders or nonresponders based on their capacity for motor skill change. Baseline diffusion tensor imaging (DTI) indexed the underlying white matter microstructure of a previously known motor learning network, named the constrained motor connectome (CMC), as well as the corticospinal tract (CST) of lesioned and nonlesioned hemispheres. Across practice, there were no differential group effects. However, when categorized as responders vs. nonresponders using change in motor behaviour, we demonstrated a significant difference in CMC microstructural properties (as measured by fractional anisotropy (FA)) for individuals in M1c and S1c groups. There were no significant differences between responders and nonresponders in clinical baseline measures or microstructural properties (FA) in the CST. The present study identifies a white matter biomarker, which extends beyond the CST, advancing our understanding of the importance of white matter networks for motor after stroke.

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Choosing one's preferred hypothesis requires multiple brain regions to work in concert as a functionally connected network. We predicted that a stronger network signal would underlie cognitive coherence between a hypothesis and the available evidence. In order to identify such functionally connected networks in magnetoencephalography (MEG) data, we first localized the generators of changes in oscillatory power within three frequency bands, namely alpha (7-13 Hz), beta (18-24 Hz), and theta (3-7 Hz), with a spatial resolution of 5mm and temporal resolution of 50 ms. We then used principal component analysis (PCA) to identify functionally connected networks reflecting co-varying post-stimulus changes in power. As predicted, PCA revealed a functionally connected network with a stronger signal when the evidence supported accepting the hypothesis being judged. This difference was driven by beta-band power decreases in the left dorsolateral prefrontal cortex (DLPFC), ventromedial prefrontal cortex (VMPFC), posterior cingulate cortex (PCC), and midline occipital cortex.

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BACKGROUND: It has been previously demonstrated that a cognitive bias against disconfirmatory evidence (BADE) is associated with delusions. However, small samples of delusional patients, reliance on difference scores and choice of comparison groups may have hampered the reliability of these results. In the present study we aimed to improve on this methodology with a recent version of the BADE task, and compare larger groups of schizophrenia patients with/without delusions to obsessive-compulsive disorder (OCD) patients, a population with persistent and possibly bizarre beliefs without psychosis. METHOD: A component analysis was used to identify cognitive operations underlying the BADE task, and how they differ across four groups of participants: (1) high-delusional schizophrenia, (2) low-delusional schizophrenia, (3) OCD patients and (4) non-psychiatric controls. RESULTS: As in past studies, two components emerged and were labelled 'evidence integration' (the degree to which disambiguating information has been integrated) and 'conservatism' (reduced willingness to provide high plausibility ratings when justified), and only evidence integration differed between severely delusional patients and the other groups, reflecting delusional subjects giving higher ratings for disconfirmed interpretations and lower ratings for confirmed interpretations. CONCLUSIONS: These data support the finding that a reduced willingness to adjust beliefs when confronted with disconfirming evidence may be a cognitive underpinning of delusions specifically, rather than obsessive beliefs or other aspects of psychosis such as hallucinations, and illustrates a cognitive process that may underlie maintenance of delusions in the face of counter-evidence. This supports the possibility of the BADE operation being a useful target in cognitive-based therapies for delusions.

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Metacognitive training (MCT) for patients with schizophrenia is a novel psychological group treatment targeting cognitive biases putatively involved in the pathogenesis of schizophrenia (e.g. jumping to conclusions, overconfidence in errors). Its eight modules are available cost-free online in many languages. In the present study, 36 subacute or remitted patients were randomly allocated to either the MCT or a wait-list group who received treatment-as-usual (TAU). Baseline and post assessments were 8 weeks apart and were performed blind to group status. MCT showed significantly greater improvement on the following parameters relative to the TAU group: delusion distress (PSYRATS), memory and social quality of life. In the MCT group, the rate of jumping to conclusions bias was reduced after training. No differences occurred on the PANSS. The present study confirms prior reports that MCT exerts beneficial effects on some cognitive and symptomatic parameters.

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BACKGROUND: Although antipsychotic medication still represents the treatment of choice for schizophrenia, its objective impact on symptoms is only in the medium-effect size range and at least 50% of patients discontinue medication in the course of treatment. Hence, clinical researchers are intensively looking for complementary therapeutic options. Metacognitive training for schizophrenia patients (MCT) is a group intervention that seeks to sharpen the awareness of schizophrenia patients on cognitive biases (e.g. jumping to conclusions) that seem to underlie delusion formation and maintenance. The present trial combined group MCT with an individualized cognitive-behavioural therapy-oriented approach entitled individualized metacognitive therapy for psychosis (MCT+) and compared it against an active control. METHOD: A total of 48 patients fulfilling criteria of schizophrenia were randomly allocated to either MCT+ or cognitive remediation (clinical trial NCT01029067). Blind to intervention, both groups were assessed at baseline and 4 weeks later. Psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS) and the Psychotic Symptom Rating Scales (PSYRATS). Jumping to conclusions was measured using a variant of the beads task. RESULTS: PANSS delusion severity declined significantly in the combined MCT treatment compared with the control condition. PSYRATS delusion conviction as well as jumping to conclusions showed significantly greater improvement in the MCT group. In line with prior studies, treatment adherence and subjective efficacy was excellent for the MCT. CONCLUSIONS: The results suggest that the combination of a cognition-oriented and a symptom-oriented approach ameliorate psychotic symptoms and cognitive biases and represents a promising complementary treatment for schizophrenia.

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BACKGROUND: Cognitive biases, especially jumping to conclusions (JTC), are ascribed a vital role in the pathogenesis of schizophrenia. This study set out to explore motivational factors for JTC using a newly developed paradigm. METHOD: Twenty-seven schizophrenia patients and 32 healthy controls were shown 15 classical paintings, divided into three blocks. Four alternative titles (one correct and three lure titles) had to be appraised according to plausibility (0-10). Optionally, participants could decide for one option and reject one or more alternatives. In random order across blocks, anxiety-evoking music, happy music or no music was played in the background. RESULTS: Patients with schizophrenia, particularly those with delusions, made more decisions than healthy subjects. In line with the liberal acceptance (LA) account of schizophrenia, the decision threshold was significantly lowered in patients relative to controls. Patients were also more prone than healthy controls to making a decision when the distance between the first and second best alternative was close. Furthermore, implausible alternatives were judged as significantly more plausible by patients. Anxiety-evoking music resulted in more decisions in currently deluded patients relative to non-deluded patients and healthy controls. CONCLUSIONS: The results confirm predictions derived from the LA account and assert that schizophrenia patients decide hastily under conditions of continued uncertainty. The fact that mood induction did not exert an overall effect could be due to the explicit nature of the manipulation, which might have evoked strategies to counteract their influence.

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BACKGROUND: In previous studies we suggested that liberal acceptance (LA) represents a fundamental cognitive bias in schizophrenia and may explain why patients are more willing to accept weak response alternatives and display overconfidence in incorrect responses. The aim of the present study was to test a central assumption of the LA account: false alarms in schizophrenia should be particularly increased when the distractor-target resemblance is weak relative to a control group. METHOD: Sixty-eight schizophrenia patients were compared to 25 healthy controls on a visual memory task. At encoding, participants studied eight complex displays, each consisting of a unique pairing of four stimulus attributes: symbol, shape, position and colour. At recognition, studied items were presented along with distractors that resembled the targets to varying degrees (i.e. the match between distractors and targets ranged from one to three attributes). Participants were required to make old/new judgements graded for confidence. RESULTS: The hypotheses were confirmed: false recognition was increased for patients compared to controls for weakly and moderately related distractors only, whereas strong lure items induced similar levels of false recognition for both groups. In accordance with prior research, patients displayed a significantly reduced confidence gap and enhanced knowledge corruption compared to controls. Finally, higher neuroleptic dosage was related to a decreased number of high-confident ratings. CONCLUSIONS: These data assert that LA is a core mechanism contributing to both enhanced acceptance of weakly supported response alternatives and metamemory deficits, and this may be linked to the emergence of positive symptomatology.

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One of the main challenges in working memory research has been to understand the degree of separation and overlap between the neural systems involved in encoding and maintenance. In the current study we used a variable load version of the Sternberg item recognition test (two, four, six, or eight letters) and a functional connectivity method based on constrained principal component analysis to extract load-dependent neural systems underlying encoding and maintenance, and to characterize their anatomical overlap and functional interaction. Based on the pattern of functional connectivity, constrained principal component analysis identified a load-dependent encoding system comprising bilateral occipital (Brodmann's area (BA) 17, 18), bilateral superior parietal (BA 7), bilateral dorsolateral prefrontal (BA 46), and dorsal anterior cingulate (BA 24, 32) regions. For maintenance, in contrast, constrained principal component analysis identified a system that was characterized by both load-dependent increases and decreases in activation. The structures in this system jointly activated by maintenance load involved left posterior parietal (BA 40), left inferior prefrontal (BA 44), left premotor and supplementary motor areas (BA 6), and dorsal cingulate regions (BA 24, 32), while the regions displaying maintenance-load-dependent activity decreases involved bilateral occipital (BA 17, 18), posterior cingulate (BA 23) and rostral anterior cingulate/orbitofrontal (BA 10, 11, 32) regions. The correlation between the encoding and maintenance systems was strong and negative (Pearson's r = -.55), indicting that some regions important for visual processing during encoding displayed reduced activity during maintenance, while subvocal rehearsal and phonological storage regions important for maintenance showed a reduction in activity during encoding. In summary, our analyses suggest that separable and complementary subsystems underlie encoding and maintenance in verbal working memory, and they demonstrate how constrained principal component analysis can be employed to characterize neuronal systems and their functional contributions to higher-level cognition.

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BACKGROUND: The present study attempted to extend previous research on source monitoring deficits in schizophrenia. We hypothesized that patients would show a bias to attribute self-generated words to an external source. Furthermore, it was expected that schizophrenic patients would be overconfident regarding false memory attributions. METHOD: Thirty schizophrenic and 21 healthy participants were instructed to provide a semantic association for 20 words. Subsequently, a list was read containing experimenter- and self-generated words as well as new words. The subject was required to identify each item as old/new, name the source. and state the degree of confidence for the source attribution. RESULTS: Schizophrenic patients displayed a significantly increased number of source attribution errors and were significantly more confident than controls that a false source attribution response was true. The latter bias was ameliorated by higher doses of neuroleptics. CONCLUSIONS: It is inferred that a core cognitive deficit underlying schizophrenia is a failure to distinguish false from true mnestic contents.

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Previous research has suggested that high doses of conventional neuroleptics may induce neurocognitive deficits when assessed with standard tasks. However, little is known about the effects of high doses of neuroleptics (conventional or atypical) on subjective cognitive dysfunction. Recent research stresses the putative importance of self-reported cognitive deficits for both symptomatic outcome and medication compliance. The aim of the present study was to investigate the impact of neuroleptic medication on subjective cognition in patients treated with either conventional or atypical agents (clozapine, risperidone, olanzapine). Patients were asked to endorse the items of a questionnaire entitled 'Subjective Well-Being under Neuroleptic Treatment' prior to discharge. Subjective impairment, as assessed with the subscale 'mental functioning', was significantly correlated with greater conventional neuroleptic dosage after controlling for psychopathology (P<0.05). The difference between patients medicated with higher doses of conventional neuroleptics and those with lower doses was highly significant (P<0.001). In contrast, higher atypical neuroleptic doses were not associated with impairment.

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The purpose of this study was to provide the psychologist with base-rate tables for the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Verbal IQ-Performance IQ difference scores in 1593 psychiatric inpatients. Subtables also were provided for each of three primary psychiatric diagnoses (schizophrenia spectrum disorders, bipolar disorders, and depression). The base rates of VIQ-PIQ splits in the full inpatient sample, and those for the subsamples based on primary psychiatric diagnosis, were very similar to those reported in the WAIS-R standardization sample. Consistent with past research on the standardization sample, the VIQ-PIQ split was correlated positively with Full Scale IQ (FSIQ), indicating that larger splits are more common at the higher IQ levels. Therefore, base-rate tables also were provided for the total inpatient sample split into five IQ groupings.

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A recent theoretical account delineated the role of the anterior cingulate cortex (ACC) in cognitive control as the detection of conflict between competing information streams. Using functional magnetic resonance imaging, we examined the activity of this brain structure during different forms and degrees of conflict between the word and the color dimensions of Stroop stimuli. Overall, our results showed a dissociation between the degree of conflict and ACC activation. More specifically, although ACC activation was very extensive when print color interfered with word reading performance, the level of conflict, as measured by reaction time costs, was only moderate compared to other conditions. These results suggest that either the ACC is differentially sensitive to various types of conflict or its function should be extended to include other cognitive constructs, such as resolution of prior inhibition.

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The Behavioural Assessment Scale (BAS) was administered to a sample of 95 inpatients with neuropsychiatric conditions. The total scores in the sample ranged from 26 to 145 (maximum possible score is 163), without any evidence of the "floor effect" encountered with other tests used with this population. Investigation into the psychometric structure of the BAS revealed three factors interpreted as Daily Living Skills, Communication/Social Skills, and Problem Behavior. The high intercorrelation between the two dominant factors was interpreted as general sensitivity of the BAS to global decline in functioning associated with severity of illness. These results confirm a previous psychometric investigation carried out on an elderly psychiatric sample. A recommendation is made for interpreting subscales based on these factor domains when specific abilities are of interest and using a Global Functioning subscale as a measure of overall adaptive behavior for both adult and geriatric inpatient neuropsychiatry patients.

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The Behavioural Assessment Scale (BAS) was developed to assess adaptive functioning in older persons with severe cognitive impairment. Previous research has demonstrated that BAS items can be rescored as 3 factor-based subscales entitled Daily Living Skills, Communication and Social Skills, and Problem Behavior, or as a global functioning aggregate. Normative information on these subscales is most helpful when based on a severely impaired sample because very little variation is present in an unimpaired population. In accordance with this goal, regression-predicted age- and mental-status-corrected percentile ranks are presented for these 4 subscales, and for the total score of the BAS.

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The purpose of this study was to evaluate the reliability and concurrent validity of 2 short forms of the Visual Form Discrimination Test, referred to as first half (FH) and front-back (FB). Participants were a mixed sample of 225 patients seen for neuropsychological evaluations. The mean difference score between both short forms and the full form was less than 1 point. The short-total correlations were .85 and .86 for the FH and FB forms, respectively. A binary clinical decision rule, used to classify patients as normal or impaired, resulted in a 93.3% correct and a 94.7% correct classification rate for the FH and FB forms, respectively. It is concluded that the short form of the test, used in conjunction with a clinical decision rule, results in a very minor loss of accuracy.

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The subscales of the Behavioural Assessment Scale (BAS) (Language, Mobility, Physical Independence, Occupation and Orientation, and Social Integration) were designed to measure specific areas of functioning. The purpose of this investigation was to assess the psychometric structure of the BAS in a sample of 275 geriatric psychiatry inpatients. This psychometric assessment was carried out using 2 methods: measures of internal consistency and exploratory factor analysis. The measures of internal consistency suggested that only the Language and Physical Independence subscales measured a unified construct. The subsequent factor analysis revealed 3 highly correlated factors that accounted for 65% of the item variance. These factors were interpreted as Daily Living Skills, Communication/Social Skills, and Problem Behavior. The high intercorrelations between the factors were interpreted as a general sensitivity of the BAS to global decline in functioning associated with dementia (i.e., severity of illness). The computation of factor-based subscales and a general functioning aggregate were recommended for clinical use of the BAS.

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