ABSTRACT Cannabis is one of the most widely used substances. As the legalization of both medical and recreational cannabis sweeps across the country, the use and misuse of cannabis is expected to increase, likely related to a decreasing perception of risk. Also, the concentration of the psychoactive component of cannabis, delta-9- tetrahydrocannabinol (THC), has been on the rise in recreationally available cannabis over recent decades, and of consequence, cannabis, especially high in THC, has been associated with detrimental cognitive and mental health outcomes. THC is thought to disrupt cognitive function by altering the brain’s ability to transfer and process information in cortical networks critical for perception, learning, and memory. Thus, there is an urgent need to understand the psychophysiology of THC exposure. The objective of this study is to evaluate acute effects of THC on proximal (magnetoencephalography / electroencephalography; MEG/EEG) and distal (cognition) measures of brain function. This 2-test day, double-blind, placebo-controlled, cross-over study will use advanced source analyses for multimodal MEG/EEG signals to determine the changes in the activity and connectivity of cognitive neural networks induced by THC in non-users of cannabis (n = 20). To our knowledge, this proof of concept study will be the first to use MEG/EEG to examine the acute effects of THC on brain activity and connectivity and their relation to cognition.