This randomized, double-blinded, crossover trial (n=30) aims to characterise the effects of low doses of LSD on behavioural and neural indicators of feedback and feedforward signalling in perceptual decision-making.
Randomized, double-blind, crossover pharmacological challenge in healthy volunteers comparing 10 µg, 20 µg LSD and placebo across three 5-hour sessions with at least 7 days washout.
Participants perform multiple perceptual decision-making tasks with concurrent EEG to probe behavioural and neural indices of prior beliefs and evidence processing; continuous supervision until ~4.5 hours post-administration.
Single low-dose LSD session (10 µg total) as part of 3-period crossover.
Administered as two 1 ml vials (10 µg + 0 µg) to yield 10 µg total; vials in 20% EtOH; given 0.5 h after session start.
Single low-dose LSD session (20 µg total) as part of 3-period crossover.
Administered as two 1 ml vials (10 µg + 10 µg) to yield 20 µg total; vials in 20% EtOH; given 0.5 h after session start.
Placebo session (0 µg) as part of 3-period crossover.
Two placebo vials (0 µg each) in 20% EtOH; given 0.5 h after session start.