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Effects of the Hallucinogen Psilocybin on Covert Orienting of Visual Attention in Humans

Euphrosyne Gouzoulis‐mayfrank, B. Thelen, Stefanie Maier, Karsten Heekeren, K.‐a. Kovar, Henning Saß, Manfred Spitzer

Neuropsychobiology 2002 DOI: 10.1159/000063672 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Double-blind study Peer reviewed
Sample size 32
Population Healthy volunteers
Interventions Psilocybin 3 4-methylenedioxyethylamphetamine (MDE) d-methamphetamine placebo
Topics LSD Psilocybin Serotonin
Keywords Hallucinogen Methamphetamine Vigilance psychology Inhibition of return Psychosis Placebo Stimulant
Citations 69
Key points Psilocybin and MDE prolonged reaction times and produced attention deficits consistent with those in acute psychotic states, while methamphetamine did not.

Abstract

Hallucinogenic drug-induced states are considered as models for acute schizophrenic disorders (experimental psychoses). In a double-blind study with healthy volunteers we investigated the influence of the serotonergic hallucinogen psilocybin, the ecstasy-like drug 3,4-methylenedioxyethylamphetamine (MDE), the stimulant d- methamphetamine and placebo on covert orienting of spatial attention (n = 8 in each group). Reaction times were prolonged after ingestion of psilocybin > MDE, but not after d-methamphetamine. In addition, subjects on psilocybin exhibited particularly slow reaction times in invalid trials at short cue target intervals and failure of response inhibition in valid trials at long cue target intervals for right visual field targets. Despite some methodological limitations, these results are in line with both bilateral impairment of disengagement of attention and a lateralized impairment of inhibition of return (IOR) in productive psychotic states. Additional investigations with larger samples, different hallucinogenic substances (serotonergic agonists vs. NMDA antagonists) and different dose regimens are needed in order to further explore the suggested relationship between visuospatial attentional dysfunction and acute psychotic conditions.

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