As with all psychedelics, ayahuasca produces some pretty dramatic effects that can range from trippy hallucinations to full-on ego-death. In most cases this experience lasts for around four to eight hours, although a new study in the Journal of Psychopharmacology reveals that the drug continues to alter connectivity patterns in certain brain regions even once its acute effects have subsided.

Ayahuasca is potent psychedelic brew that is made by boiling the Amazonian vine Banisteriopsis caapi with other jungle plants, and contains DMT as its primary psychoactive ingredient. Recent research has shown that it may have the potential to treat emotional and psychological disorders such as depression and suicidality, though scientists are still trying to figure out exactly how ayahuasca brings about these positive changes.

To get to the bottom of this, researchers have focused much of their attention on ayahuasca’s so-called afterglow effect, whereby people tend to experience prolonged improvements in mood and cognitive flexibility during the days and weeks after drinking the brew.

With this as their starting point, the authors of this latest study used functional magnetic resonance imaging (fMRI) to observe brain connectivity patterns in a group of people drinking ayahuasca for the first time in their lives. Crucially, the researchers scanned participants’ brains one day before they ingested the substance and again one day after their ayahuasca session, thus revealing any sustained changes that outlasted the acute effects of the brew.

Results showed a persistent increase in connectivity within parts of the brain’s salience network 24 hours after drinking ayahuasca. Interestingly, the strength of this effect was correlated with alterations in somesthesia – which refers to the ability to perceive bodily sensations – during the ayahuasca session itself. This, in turn, suggests that people who ingest ayahuasca may experience long-term changes in their physical sensations, though more research is needed to determine the extent of this.

The scans also revealed decreased connectivity within the brain’s default mode network (DMN), which is typically associated with the maintenance of a sense of self. This was correlated with a decrease in volition during the acute phase of the ayahuasca experience, which the study authors define as “the subject’s capacity to willfully interact with his/her ‘self’”.

Finally, an increase in communication between the salience network and the DMN was observed one day after drinking ayahuasca, which was related to alterations in emotional processing during the acute phase.

All in all, these findings suggest that a day after drinking ayahuasca, persisting changes in brain connectivity may continue to influence users’ levels of somesthesia, volition and emotional affect, all of which could help to explain how the substance generates its afterglow.