Cannabis is a widely used substance that can have various effects on the brain and behavior. One of the aspects that cannabis may influence is people perceive and respond to emotions, both their own and others’. A new study by researchers at Colorado State University sheds some light on the way cannabis affects the recognition and processing of human emotions like happiness, sadness and anger. The study used an electroencephalogram to measure the brain activity of about 70 volunteers, who themselves as chronic, moderate or non-users of cannabis. The participants were shown faces with different and asked to either identify the emotion or the sex of the face. The researchers found that cannabis users showed more brain activity when they saw negative emotions, anger, than non-users. However, cannabis users also showed less brain activity when they saw positive emotions, such as happiness, than non-users. The researchers concluded that cannabis affects the brain’s ability to process emotion, but that the brain may be able to successfully the effects, depending on whether the emotions are explicitly or implicitly detected.