The role of motivation in clinical presentation, treatment engagement and response in schizophrenia-spectrum disorders: A systematic review.

Schizophrenia, a debilitating psychiatric disorder, has a long-term impact on social and occupational functioning. While negative symptoms, notably amotivation, are recognized as poor prognostic factors, the positive force of patient motivation (autonomous motivation) remains underexplored. This systematic review, guided by Self-Determination Theory (SDT), investigated the impact of motivation on clinical presentation, and treatment engagement and response in schizophrenia-spectrum disorders.

Eye movements and the perceptual span in disordered reading: A comparison of schizophrenia and dyslexia.

Increasing evidence of a common neurodevelopmental etiology between schizophrenia and developmental dyslexia suggests that neurocognitive functions, such as reading, may be similarly disrupted. However, direct comparisons of reading performance in these disorders have yet to be conducted. To address this gap in the literature, we employed a gaze-contingent moving window paradigm to examine sentence-level reading fluency and perceptual span (breadth of parafoveal processing) in adults with schizophrenia (dataset from Whitford et al.

Differential Associations between Cortical Thickness and Striatal Dopamine in Treatment-Naïve Adults with ADHD vs. Healthy Controls.

Alterations in catecholamine signaling and cortical morphology have both been implicated in the pathophysiology of attention deficit/hyperactivity disorder (ADHD). However, possible links between the two remain unstudied. Here, we report exploratory analyses of cortical thickness and its relation to striatal dopamine transmission in treatment-naïve adults with ADHD and matched healthy controls.

Reading deficits in schizophrenia and their relationship to developmental dyslexia: A review.

Although schizophrenia and developmental dyslexia are considered distinct disorders in terms of clinical presentation and functional outcome, they both involve disruption in the processes that support skilled reading, including language, auditory perception, visual perception, oculomotor control, and executive function. Further, recent work has proposed a common neurodevelopmental basis for the two disorders, as suggested by genetic and pathophysiological overlap. Thus, these lines of research suggest that reading may be similarly impacted in schizophrenia and dyslexia.

Perisaccadic perception of visual space in people with schizophrenia.

Corollary discharge signals are found in the nervous systems of many animals, where they serve a large variety of functions related to the integration of sensory and motor signals. In humans, an important corollary discharge signal is generated by oculomotor structures and communicated to sensory systems in concert with the execution of each saccade. This signal is thought to serve a number of purposes related to the maintenance of accurate visual perception.

Amphetamine-induced dopamine release and neurocognitive function in treatment-naive adults with ADHD.

Converging evidence from clinical, preclinical, neuroimaging, and genetic research implicates dopamine neurotransmission in the pathophysiology of attention deficit hyperactivity disorder (ADHD). The in vivo neuroreceptor imaging evidence also suggests alterations in the dopamine system in ADHD; however, the nature and behavioral significance of those have not yet been established. Here, we investigated striatal dopaminergic function in ADHD using [(11)C]raclopride PET with a d-amphetamine challenge.

Effects of methylphenidate on basic and higher-order oculomotor functions.

Eye movements are sensitive indicators of pharmacological effects on sensorimotor and cognitive processing. Methylphenidate (MPH) is one of the most prescribed medications in psychiatry. It is increasingly used as a cognitive enhancer by healthy individuals.

Reading impairments in schizophrenia relate to individual differences in phonological processing and oculomotor control: evidence from a gaze-contingent moving window paradigm.

Language and oculomotor disturbances are 2 of the best replicated findings in schizophrenia. However, few studies have examined skilled reading in schizophrenia (e.g.

Limbic response to psychosocial stress in schizotypy: a functional magnetic resonance imaging study.

Psychological stress causes dopamine release in the striatum and is thought to play a role in susceptibility to psychotic illness. Previous work suggests that an elevated dopaminergic response to stress may index vulnerability to psychosis in certain individuals. With functional magnetic resonance imaging, we measured stress-induced changes in brain activity in healthy individuals at elevated risk of developing psychosis.

Effect of D-amphetamine on inhibition and motor planning as a function of baseline performance.

Rationale: Baseline performance has been reported to predict dopamine (DA) effects on working memory, following an inverted-U pattern. This pattern may hold true for other executive functions that are DA-sensitive.

Objectives: The objective of this study is to investigate the effect of D: -amphetamine, an indirect DA agonist, on two other putatively DA-sensitive executive functions, inhibition and motor planning, as a function of baseline performance.

Smooth pursuit in schizophrenia: a meta-analytic review of research since 1993.

Abnormal smooth pursuit eye-tracking is one of the most replicated deficits in the psychophysiological literature in schizophrenia [Levy, D. L., Holzman, P.

Stress-induced dopamine release in humans at risk of psychosis: a [11C]raclopride PET study.

Drugs that increase dopamine levels in the brain can cause psychotic symptoms in healthy individuals and worsen them in schizophrenic patients. Psychological stress also increases dopamine release and is thought to play a role in susceptibility to psychotic illness. We hypothesized that healthy individuals at elevated risk of developing psychosis would show greater striatal dopamine release than controls in response to stress.

Schizotypy, attention deficit hyperactivity disorder, and dopamine genes.

Previous research has suggested that there may be overlap between schizophrenia and attention-deficit hyperactivity disorder (ADHD). The relationship between schizotypal personality traits, ADHD features and polymorphisms was evaluated in dopamine-related genes. Thirty-one healthy, Caucasian men completed the Rust Inventory of Schizotypal Cognitions (RISC) and the ADHD Self-Report Scale (ASRS).

Smooth pursuit eye movement and schizotypy in the community.

Deficits in smooth pursuit eye movements are well documented in schizophrenia and schizotypic psychopathology. The status of eye tracking dysfunction (ETD) as an endophenotype for schizophrenia liability is relatively robust. However, the relation of ETD to schizophrenia-related deviance in the general population has not been confirmed.

Transcranial magnetic stimulation of frontal oculomotor regions during smooth pursuit.

Both the frontal eye fields (FEFs) and supplementary eye fields (SEFs) are known to be involved in smooth pursuit eye movements. It has been shown recently that stimulation of the smooth-pursuit area of the FEF [frontal pursuit area (FPA)] in monkey increases the pursuit response to unexpected changes in target motion during pursuit. In the current study, we applied transcranial magnetic stimulation (TMS) to the FPA and SEF in humans during sinusoidal pursuit to assess its effects on the pursuit response to predictable, rather than unexpected, changes in target motion.

Executive functions and methylphenidate response in subtypes of attention-deficit/hyperactivity disorder.

Background: Oculomotor tasks are a well-established means of studying executive functions and frontal-striatal functioning in both nonhuman primates and humans. Attention-deficit/hyperactivity disorder (ADHD) is thought to implicate frontal-striatal circuitry. We used oculomotor tests to investigate executive functions and methylphenidate response in two subtypes of ADHD.

Antisaccade and smooth pursuit performance in positive- and negative-symptom schizotypy.

Schizophrenic patients have well-documented abnormalities in smooth pursuit eye movements and antisaccade performance. In populations at risk for schizophrenia, smooth pursuit abnormalities are also well documented. Antisaccade deficits have been replicated in high-risk populations as well, but the findings are more variable and the reasons for the variability are not clear.

Antisaccade performance in biological relatives of schizophrenia patients: a meta-analysis.

Poor performance on the antisaccade (AS) task has been interpreted as a potential indicator of genetic liability that may enhance the power of linkage studies of a multidimensional phenotype for schizophrenia. Every study has replicated the finding of significantly worse performance in schizophrenia patients regardless of which specific antisaccade paradigm was employed. In some studies involving a standard version of the antisaccade task, relatives of schizophrenia patients made an increased number of errors, but in other studies that used this same paradigm, relatives of schizophrenia patients did not differ from controls.

Nicotine and behavioral markers of risk for schizophrenia: a double-blind, placebo-controlled, cross-over study.

We investigated the effect of nicotine on three behavioral markers of risk for schizophrenia: sustained attention (using the Continuous Performance Task (CPT)), antisaccade performance, and smooth pursuit. Smooth pursuit was investigated in two conditions, one in which attention was enhanced (monitoring target changes) and one in which attention was not enhanced (no monitoring). Patients with schizophrenia (n = 15) and controls (n = 14) were given a 14-mg nicotine patch in a double-blind, placebo-controlled, crossover design and plasma nicotine concentrations were monitored.

Neuropsychological impairments in neuroleptic-responder vs. -nonresponder schizophrenic patients and healthy volunteers.

To determine whether two groups of schizophrenic patients representing the two extremes of the neuroleptic response-spectrum (consistent responders vs. consistent nonresponders) differ with respect to their neuropsychological profile. Neuroleptic-responder (R; n=36) and -nonresponder (NR; n=39) schizophrenic patients were recruited according to a priori defined criteria of responsiveness to typical neuroleptics.

Autism and emotion: an ethological theory.

Autistic symptomatology is described as resulting from three processes which have become integrated in clinical presentation. The basic deficit is hypothesized as an inability to participate in information exchange through systems of emotional communication. These systems have been extensively studied in lower animals and a direct phylogenetic line, from posture display to facial expression to human empathy, can be traced in evolutionary advance.