Sunday, September 27, 2009

The Scent of the Virtual Bong

A standard laboratory method in addiction research is the “cue exposure” experiment. People are shown pictures of drug paraphernalia or read descriptions of drug use. Addicts respond more strongly to these scenarios than to neutral photos and descriptions because their cravings have become conditioned to drug-related cues such as needles or lines of coke. Cue exposure data have been used to argue that heavy marijuana use creates psychophysiological dependency. It’s also been proposed that cue reactivity “may provide treatment professionals with valuable information on tailoring therapy sessions” for potheads looking to kick the habit.

In an effort to ramp up the realism of the cue exposure paradigm, a group of social workers has teamed up with a company in Decatur, Georgia that manufactures virtual reality devices. The result is the Virtual Reality Cannabis Cue Reactivity Assessment or VR-CCRAS. The system “integrates a visual head mounted display, tracking device, and directional audio, vibrotactile, and olfactory stimuli.” The smells are courtesy of the Envirodine Studios Scent Palette™ system. The results of their first study—comparing two neutral virtual environments with two pot-related ones—have just been published.

So what sort of experience does the VR-CCRAS provide? Well, the two neutral conditions consist of boring rooms with nature films playing on wall-panel TV screens while vanilla scent wafts past. Snore. The drug-cue conditions are a little juicier. One is a room full of drug paraphernalia. The other is a “party room”:
The party environment provided exposure to complex social cues. The party consisted of indoor and outdoor areas of a home in which people were eating, drinking, and smoking cannabis on a patio. During the party, participants observed a person rolling a joint. Participants were encouraged to interact with the virtual environment. An offer to smoke a joint or “take a hit” on a marijuana pipe (based on the participants preferred method of smoking) was initiated by other party guests. Olfactory cannabis cues were presented when participants encountered people smoking cannabis at a table with pizza and popcorn.

The VR-CCRAS system provided smells of “raw cannabis (buds), cannabis smoke, pizza, incense-frankincense, beer, popcorn, and outdoors (pine/dirt).”


Not surprisingly, under these conditions heavy pot smokers have higher craving levels than in the neutral, nature-film room. And by “heavy” I mean twenty adults who smoked an average of 3.5 times a day and for 25.8 out of the past 30 days.


Where this all leads is a little unclear. The study, published in the Journal of Psychoactive Drugs, didn’t compare these heavy smokers to occasional users or non-users. The craving measure consisted of a single self-rating—no independent physiological measures such as heart rate were obtained. But the party room helmet sounds like a blast, even though I’m not sure it will be on Nintendo Wii any time soon.

Oh, and thanks to all you American taxpayers for making it possible through the National Institute of Drug Abuse Small Business Innovative Research Awards program. The tab: $144,526.



Olfacta said...

3.5 times a day?

Avery Gilbert said...


Yup: 3.5 ± 2.8 times per day. On average they began smoking at age 16; their average age at testing was 26. That’s a lot of blunts (preferred over joints 45% to 30%).

Another gem from the methods section: While they all met DSM-IV-TR diagnostic criteria for cannabis abuse or dependence, none of the volunteers was seeking treatment.