The wake-promoting drug modafinil is frequently used off-label to improve cognition in psychiatric and academic populations alike. The domain-specific attentional benefits of modafinil have yet to be quantified objectively in healthy human volunteers using tasks validated for comparison across species. Further, given that modafinil is a low-affinity inhibitor for the dopamine and norepinephrine transporters (DAT/NET respectively) it is unclear if any effects are attributable to a non-specific increase in arousal, a feature of many catecholamine reuptake inhibitors (e.g., cocaine, amphetamine). These experiments were designed to test for domain-specific enhancement of attention and cognitive control by modafinil (200 and 400 mg) in healthy volunteers using the 5-choice continuous performance task (5C-CPT) and Wisconsin Card Sort Task (WCST). An additional cross-species assessment of arousal and hyperactivity was performed in this group and in mice (3.2, 10, or 32 mg/kg) using species-specific versions of the behavioral pattern monitor (BPM). Modafinil significantly enhanced attention (d prime) in humans performing the 5C-CPT at doses that did not affect WCST performance or induce hyperactivity in the BPM. In mice, only the highest dose elicited increased activity in the BPM. These results indicate that modafinil produces domain-specific enhancement of attention in humans not driven by hyperarousal, unlike other drugs in this class, and higher equivalent doses were required for hyperarousal in mice. Further, these data support the utility of using the 5C-CPT across species to more precisely determine the mechanism(s) underlying the pro-cognitive effects of modafinil and potentially other pharmacological treatments.

Posters (Monday) S251consisted of line drawings that depict unusual bodily experiences (eg, autoscopy, feeling of presence, etc.) and common ones (eg, itching, tickling, etc). The drawings were adapted from those used to assess autoscopic or heautoscopic experiences in patients with brain lesions. After viewing each picture, participants were asked whether they have experienced it, and if so, provide frequency, similarity and distress ratings. BODI was tested in relation to established self-report questionnaires of psychosis-proneness (Perceptual Aberration Scale), dissociative experiences (DES-II) and loneliness (UCLA loneliness scale). Furthermore, we examined neuropsychological and proprioceptive correlates of the BODI. Results: The BODI accurately captured bodily self-aberrations in both patients with schizophrenia and healthy controls. Furthermore it distinguished prodromal individuals at risk for psychosis from healthy controls. BODI was associated with increased positive symptoms in patients, and elevated schizotypy in healthy participants. Overall, BODI score was correlated with behavioral signs of temporoparietal abnormalities and increased susceptibility to tactile-proprioceptive illusions. Lastly, social isolation appeared to exacerbate the BODI score across the schizophrenia-spectrum. Conclusion: These findings provide evidence for the hypothesis that weakened sense of body and related self-aberrations may be central to the prodromal stage of schizophrenia, and dissociative experiences may be a latent risk factor for psychosis. M111. THE MISMEASUREMENT OF PSYCHOSIS: PARSING DIFFERENCES IN DISCRIMINATING POWER ACROSS SYMPTOM DIMENSIONSJoshua Mervis* ,1 Nathaniel Helwig, Piper Meyer-Kalos, and Angus MacDonald University of MinnesotaBackground: The purpose of this study is to explore measurement issues related to how differentially well-measuring constructs over time in a large dataset of individuals with first-episode psychosis might impact findings. Methods:In a large dataset of individuals with first-episode psychosis and multiple measurement time points in the context of a clinical trial for a therapeutic intervention, symptom and functioning measures covering multiple domains are examined. The current study seeks to identify where problems develop with differential discriminating power of symptom and functioning measures in a first-episode psychosis population. For the purposes of this study, multiple mathematical definitions of discriminating power will be used, including internal consistency and retest intraclass correlations. Results: Analysis using a hierarchical analysis of variance, as well as parametric and nonparametric regression techniques examines issues at individual time points and across the entire study course. Psychometric assessments examining reliability, validity, and internal consistency are implemented. This additionally serves to address measurement issues that may come up more specifically in the clinical trial environment, like comparison of treatments and showing incrementa...

No abstract

No abstract