Mahesh Menon

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It is hypothesized that due to an abnormal functioning of the reward system patients with schizophrenia form context-inappropriate associations. It has been shown that the dopamine target regions, especially the ventral striatum, are critical in the formation of reward associations. We wanted to examine how the ventral striatum responds as patients learn(More)
BACKGROUND The prediction error (PE) hypothesized by the temporal difference model has been shown to correlate with the phasic activity of dopamine neurons during reward learning and the blood-oxygen level dependent (BOLD) response during reward and aversive conditioning tasks. We hypothesized that dopamine would modulate the PE related signal in aversive(More)
The incidence rate of an illness is a vital epidemiological measure for investigating etiology. Incidence estimates of schizophrenia from different parts of the world have shown variations, due to differences in the diagnostic criteria, measurement techniques and operational definitions used. In contrast to the prevalence studies in India, incidence surveys(More)
While the majority of cognitive studies on auditory hallucinations (AHs) have been conducted in schizophrenia (SZ), an increasing number of researchers are turning their attention to different clinical and nonclinical populations, often using SZ findings as a model for research. Recent advances derived from SZ studies can therefore be utilized to make(More)
INTRODUCTION A number of studies have suggested that deluded patients show a "jumping to conclusions" reasoning style on probabilistic reasoning tasks. In order to systematically explore the cognitive underpinnings of this task, we compared deluded and nondeluded patients on a number of experimental manipulations to investigate the role of memory and task(More)
INTRODUCTION Previous source monitoring studies on schizophrenia reported an association between external source misattribution and hallucinations, but this is often not replicated. This inconsistency may be attributable to a failure in accounting for guessing parameters when computing source monitoring biases. METHODS Fifty-one patients and 20 healthy(More)
The present article provides a narrative review of empirical studies on metacognitive training in psychosis (MCT). MCT represents an amalgam of cognitive-behavioral therapy (CBT), cognitive remediation (CRT) and psychoeducation. The intervention is available in either a group (MCT) or an individualized (MCT+) format. By sowing the seeds of doubt in a(More)
IMPORTANCE Cognitive interventions increasingly complement psychopharmacological treatment to enhance symptomatic and functional outcome in schizophrenia. Metacognitive training (MCT) is targeted at cognitive biases involved in the pathogenesis of delusions. OBJECTIVE To examine the long-term efficacy of group MCT for schizophrenia in order to explore(More)
BACKGROUND Historical records suggest dyskinesia was observed in severely ill institutionalised patients with schizophrenia in the pre-neuroleptic era. More recent work has not found dyskinesia in never-medicated younger and middle aged patients. The present study complements this recent work and avoids the confounders of severity of illness and(More)
'Jumping to conclusions' (JTC) on probabilistic reasoning tasks has been shown to be related with delusions in schizophrenia. However, whether JTC is merely correlated with, moderate or mediate delusions is not known. Further, it is unclear how antipsychotics affect JTC and its relationship to delusions. We examined the effect of treatment on JTC in a(More)