Cannabis and how it effects the brain is still being studied and understood a bit better, little by little. With that in mind, Lucy Troup at Colorado State University's College of Natural Sciences set out to find out how the substance impacts a person's ability to process emotions.
The resulting study concluded that cannabis does have an effect on the user's ability to see or recognize, understand and empathize with other humans' emotions, including sadness, anger and happiness. On the other hand, the findings include evidence that the brain may counteract those effects. That all depends, though, on whether the stoned or affected person is detecting the emotions explicity or implicitly.
"We're not taking a pro or anti stance, but we just want to know, what does it do? It's really about making sense of it," Troup said.
In the nearly two-year study, Troup and her team used an electroencephalogram (EEG) to monitor about 70 human volunteer subjects' brain movements. The volunteers had self-identified as moderate, chronic or non-users of cannabis. Because they live in Colorado, they were all established as legal users of marijuana under that state's Amendment 64.
The study subjects were asked - while connected to an EEG - to identify faces that showed four possible expressions: happy, neutral, fearful and angry. Those who were under the influence of cannabis responded more strongly to the negative expressions, particularly those that showed anger, than the controls. They had a lesser response to happy and other positive expressions than the controls, though. In further testing, the users of cannabis showed a lesser ability to empathize with others' emotions.
The emotions study was published in the journal PLOS ONE.
On the lighter side, in a study last year about cannabis and the munchies, researchers at Yale University found that brain neurons that usually busy themselves suppressing hunger are activated by using cannabis.
While it has been well-known for a long time that people who use marijuana end up hungry even when they may be full, it is also established that activating something called the cannabinoid receptor 1 (CB1R) can result in overeating. Nerve cells in a bunch called pro-opiomelanocortin (POMC) neurons are thought to be key drivers to reduce eating when full.
"This event is key to cannabinoid-receptor-driven eating," lead author Tamas Horvath said. He noted that the eating that is stimulated by these neurons is simply one action mode connected with CB1R signaling. "More research is needed to validate the findings."
That study may turn out to be useful in helping cancer patients who often lose their appetite during treatment.
