Affiliation:
1. Pharmacology School of Biomedical Sciences the University of Western Australia Crawley Western Australia Australia
2. Department of Psychology University of Wuppertal Düsseldorf Germany
3. Department of Psychology Humboldt University Berlin Berlin Germany
4. Psychiatry School of Medicine The University of Western Australia Crawley Western Australia Australia
5. Graylands Hospital The University of Western Australia (M708) Crawley Western Australia Australia
Abstract
AbstractObjectivesStimuli that are separated by a short window of space or time, known as spatial and temporal binding windows (SBW/TBWs), may be perceived as separate. Widened TBWs are evidenced in schizophrenia, although it is unclear if the SBW is similarly affected. The current study aimed to assess if dexamphetamine (DEX) may increase SBWs in a multimodal visuo‐tactile illusion, potentially validating usefulness as an experimental model for multimodal visuo‐tactile hallucinations in schizophrenia, and to examine a possible association between altered binding windows (BWs) and working memory (WM) suggested by previous research.MethodsA placebo‐controlled, double‐blinded, and counter‐balanced crossover design was employed. Permuted block randomisation was used for drug order. Healthy participants received DEX (0.45 mg/kg, PO, b.i.d.) or placebo (glucose powder) in capsules. The Rubber Hand Illusion (RHI) and Wechsler Adult Intelligence Scale Spatial Span was employed to determine whether DEX would alter SBWs and WM, respectively. Schizotypy was assessed with a variety of psychological scales.ResultsMost participants did not experience the RHI even under normal circumstances. Bi‐directional and multimodal effects of DEX on individual SBWs and schizotypy were observed, but not on WM.ConclusionsBidirectional multimodal effects of DEX on the RHI and SBWs were observed in individuals, although not associated with alterations in WM.