TY - JOUR T1 - Dexamphetamine widens temporal and spatial binding windows in healthy participants JF - Journal of Psychiatry and Neuroscience JO - JPN SP - E90 LP - E98 DO - 10.1503/jpn.220149 VL - 48 IS - 2 AU - Faiz M. Kassim AU - Samra Krakonja Lahooti AU - Elizabeth Ann Keay AU - Rajan Iyyalol AU - Jennifer Rodger AU - Matthew A. Albrecht AU - Mathew T. Martin-Iverson Y1 - 2023/03/14 UR - http://jpn.ca/content/48/2/E90.abstract N2 - Background: The pathophysiology of psychosis is complex, but a better understanding of stimulus binding windows (BWs) could help to improve our knowledge base. Previous studies have shown that dopamine release is associated with psychosis and widened BWs. We can probe BW mechanisms using drugs of specific interest to psychosis. Therefore, we were interested in understanding how manipulation of the dopamine or catecholamine systems affect psychosis and BWs. We aimed to investigate the effect of dexamphetamine, as a dopamine-releasing stimulant, on the BWs in a unimodal illusion: the tactile funneling illusion (TFI).Methods: We conducted a randomized, double-blind, counterbalanced placebo-controlled crossover study to investigate funnelling and errors of localization. We administered dexamphetamine (0.45 mg/kg) to 46 participants. We manipulated 5 spatial (5–1 cm) and 3 temporal (0, 500 and 750 ms) conditions in the TFI.Results: We found that dexamphetamine increased funnelling illusion (p = 0.009) and increased the error of localization in a delay-dependent manner (p = 0.03). We also found that dexamphetamine significantly increased the error of localization at 500 ms temporal separation and 4 cm spatial separation (pinteraction = 0.009; p500ms|4cm v. baseline = 0.01).Limitations: Although amphetamine-induced models of psychosis are a useful approach to understanding the physiology of psychosis related to dopamine hyperactivity, dexamphetamine is equally effective at releasing noradrenaline and dopamine, and, therefore, we were unable to tease apart the effects of the 2 systems on BWs in our study.Conclusion: We found that dexamphetamine increases illusory perception on the unimodal TFI in healthy participants, which suggests that dopamine or other catecholamines have a role in increasing tactile spatial and temporal BWs. ER -