A recent study found that psilocybin, the active compound in magic mushrooms, changes people’s perception of time by making them underestimate the duration of visual events and making them feel like time is moving more slowly. The study, published in the Journal of Psychopharmacology, suggests that these temporal distortions are likely caused by temporary disruptions in attention and memory, rather than hypothetical shifts in the body’s internal clock. These results help elucidate the psychological mechanisms behind psychedelic experiences and provide insight into how the human brain tracks the passage of seconds.
Research into psychedelic substances has expanded rapidly in recent years, with a primary focus on their potential to treat a variety of mental health conditions. As part of this renewed interest, researchers are investigating how these compounds alter basic cognitive functions. One of the most commonly reported effects of psychedelics is severe distortions in time perception. People using these substances frequently report that time seems to stop, stretch, or completely lose its traditional physical meaning.
The human brain tracks time at different scales. We rely on circadian rhythms to manage our daily sleep cycles, which require rapid neural mechanisms that process sensory information in milliseconds. Current research focuses on interval timing, the ability to perceive and track time in the range of seconds to minutes.
Psychologists often use mental models that include the body’s internal pacemaker to explain interval timing. This theoretical pacemaker emits a steady pulse. An internal switch allows these pulses to flow into the accumulator if the duration needs to be estimated. The brain then compares this accumulation of pulses to memories of past durations to make decisions.
Under normal circumstances, this system allows you to accurately estimate how long it will take for the signal to change or how long the fruit has been in the microwave. Certain drugs can alter this system. Stimulants that release dopamine tend to speed up the body’s internal clock, making people feel like time has passed more than in reality. The serotonergic system targeted by psychedelic drugs has a less clear role in this process.
Previous studies on psilocybin and interval timing have yielded mixed results. Past experiments have typically asked participants to recreate a specific time interval by pressing a button for a set amount of time or tapping their finger at a steady pace. These motor tasks require physical coordination, which can also be altered by psychedelics.
First author Petr Scholl, a researcher at the Czech Republic’s National Institute of Mental Health, and his colleagues wanted to see if it was possible to measure time distortions without relying on participants’ ability to perform physical movements. We also wanted to test whether this distortion also held true for visual observations, since past studies have primarily used auditory cues. The researchers designed a study to test whether psilocybin causes universal changes in time perception by changing the type of task and sensory input.
To investigate this, the research team recruited 24 healthy volunteers for a placebo-controlled, double-blind study. On two separate occasions, participants received either a placebo or an effective dose of psilocybin adjusted for body weight. Neither the participant nor the researcher in the room knew which capsule was being administered that day.
The researchers waited four hours after participants ingested the capsules before performing a timing task. This waiting period ensured that the drug’s most powerful visual and cognitive effects began to wear off. The team wanted to ensure that participants could still clearly see the computer screen and understand task instructions.
During the experiment, participants sat at a computer and completed a time bisection task. First, they went through a training phase where they learned to identify a blue circle that appeared on the screen for exactly one second as a brief period. They also learned to identify a blue circle that appeared for exactly 3 seconds as a long duration.
After the training, the actual exam began. The researchers presented blue circles at varying random intervals from 1 second to 3 seconds. For each presentation, participants had to use their computer mouse to classify the circles into short and long circles. By collecting responses across many trials, the researchers calculated specific indicators of how participants judged time intervals.
One of the key metrics the researchers looked at was the bisection point. This is the exact duration at which participants are equally likely to classify a stimulus as short or long. For someone with perfectly accurate time perception, this point would land exactly at 2 seconds, or midway between the 1 and 3 second anchors.
Another indicator was the visible difference. This value represents the smallest change in duration that participants can accurately detect. Lower values indicate higher accuracy, while higher values indicate that a person’s perception of time is fuzzy and less consistent.
Researchers observed changes in the bisection point when participants were under the influence of psilocybin. Participants needed the circle to remain on the screen for a long time before classifying it as long. Essentially, they underestimated how much time had passed during the trial.
If the circle remained on the screen for 2 seconds, participants taking psilocybin acted as if less than 2 seconds had passed. This change indicates that our internal experience of time has slowed down compared to the actual clock hands. In order to feel that normal time had passed, participants needed more actual time to pass.
Additionally, participants showed slightly more significant differences measures increased while taking psilocybin. Their responses became so variable that they lost the ability to accurately distinguish between similar time intervals. This decrease in accuracy was noticeable when the actual duration exceeded 2 seconds.
At the end of the session, the researchers administered a survey to the participants asking about their subjective experiences. Participants rated the extent to which they felt time was passing much slower than usual or faster than usual. Self-reported responses showed a strong preference for the sensation of time slowing down, consistent with the results of the physical task.
When researchers compared subjective survey responses with computer task data, they found a clear relationship. Participants who reported the most drastic changes in their time perception on the questionnaire tended to have the largest changes in their bisection points.
The study authors suggest that these time distortions are likely not the result of the drug directly changing the speed of the body’s mental pacemaker. Instead, they propose that we view results through a framework in which the brain constantly predicts the world based on prior knowledge and incoming sensory data. When a person is trying to track the duration of a few seconds, the brain has to retain incoming sensory information in order to categorize it.
Researchers propose that psychedelic states introduce cognitive noise into this system, impairing working memory and attention, among other things. For long intervals, in the range of a few seconds, this noise becomes overwhelming. The brain has a hard time retaining accumulated time pulses, leading participants to make premature judgments and underestimate the actual passage of time.
The authors note that this study has several limitations. This experiment included a relatively small number of participants and the timing of the study presented methodological challenges. The survey was administered at the end of the session, so participants had to recall their overall experience rather than reporting how they felt at the exact moment of the computer task.
The timing task was also performed during the decline phase of the experience, 4 hours after ingesting the substance. Performing the test when the drug’s effects are at its peak may give you different results, but your vision may be so distorted that you may be unable to complete computer tasks. The researchers did not explicitly check whether participants were silently counting seconds in their heads, even though they were instructed not to do so.
Future studies may investigate these temporal effects using different doses of psychedelics and continuous sliding scales for the study to collect more accurate subjective feedback. The researchers hope to test specific chemical blockers in the brain to see exactly which serotonin receptors are responsible for the disruption in time perception. This could help isolate precisely the cognitive processes that fail when time appears to stand still.
The study “The influence of psilocybin on human time perception: a comparative analysis of subjective and objective measurements” was authored by Petr Schorle, Štěpan Wenke, Tereza Nekovažova, Yulia Zaitseva, Filip Tirsch, Martin Brunovski, Jiří Horáček, Veronika Andraszko, Vlastimir Kudelka, and Michaela. Victorinova, Wojciech Victorin, Kateřina Hajková, Martin Kučas, Tomáš Paleníček.
