Cannabis appears to have a significant impact on the recognition and processing of human emotions like happiness, sadness and anger, according to research published in the journal PLOS One.

Share on Pinterest Using marijuana may change how people process emotions.

Scientists are only just starting to understand how cannabis affects the brain.

Cannabis consumption is known to cause immediate, residual and long-term changes in brain activity that can affect appetite and food intake, sleep patterns, executive function and emotional behavior.

Conflicting evidence has suggested that it can intensify both positive and negative mood states.

Lucy Troup, assistant professor of psychology at Colorado State University, and her graduate students wanted to look at how, if at all, cannabis use impacts a person’s ability to process emotions.

For nearly 2 years, the team has been conducting experiments using an electroencephalogram (EEG) to measure the brain activities of about 70 volunteers.

All the participants identified themselves as chronic, moderate or non-users of cannabis. They were all confirmed to be legal users of marijuana under Colorado Amendment 64, either medical marijuana users aged 18 years and above, or as recreational users aged 21 years or older.

An EEG can record a wide variety of generalized brain activity. In this study, the researchers used it to measure the “P3 event-related potential” of the participants.

P3 refers to the electrical activity in the brain that is triggered by noticing something visually. P3 activity is known to be related to attention in emotional processing.