In 2007, the Journal of Psychopharmacology published a study that investigated the effect of psilocybin on time perception.
The authors of the study recruited six male and six female participants. These participants randomly received a medium or high dose of psilocybin or a placebo on three different days, each day separated by two weeks.
After being administered psilocybin (or placebo), the participants completed three tasks used to examine the perception of time. The first task assessed the ability of the participants to reproduce the duration of a sound. The second task involved listening to a consistent set of sounds that the participants had to synchronize with by tapping their index finger. In the third task, participant were asked to tap their finger at a tempo of their choosing and also asked to tap as rapidly as they could.
The authors found that psilocybin negatively effected individuals ability to reproduce durations of sounds longer than three seconds and also impaired their ability to synchronize to regular auditory beats.
Psilocybin also slowed down the preferred tapping tempo of participants, but did not seem to have any effect on their maximum tapping rate.
Reference:
Wittmann, M., Carter, O., Hasler, F., Cahn, B.R., Grimberg, U., Spring, P., Hell, D., Flohr, H. & Vollenweider, F.X. (2007). Effects of psilocybin on time perception and temporal control of behaviour in humans. Journal of Psychopharmacology, Vol 21, No 1: 50-64.