N,N-Dimethyltryptamine (DMT) is an endogenous substance, and in humans, it is found mainly in the lungs, thyroid, adrenal gland, and in lower concentrations, in the brain. In our previous studies with ayahuasca, a DMT-based indigenous formulation, we have found increased brain activity in a number of neural networks related to vision, salience, and introspection. Based on our previous results, this study aims to evaluate the acute and subacute effects of inhaled DMT. We investigate the safety and tolerability of this route of administration as well as the changes in behavior and the neurophysiology of mental imagery in healthy people. We hypothesize that changes in perception and cognition correspond to changes in neural response patterns. To investigate these changes, we use electroencephalography (EEG) to record the event-related potentials (ERPs) of 25 healthy participants during two dosing sessions conducted on the same day, 2 hours apart: one with a high dose of DMT and the other with a placebo (a very low dose of DMT), in random order. We also measure the phenomenology of the experience by assessing subjective perception and the influence of the substance on different cognitive constructs.