It has been long known that smoking marijuana affects peoples' impulsivity, attention, memory, cognition and decision-making abilities. Now, a recent research has scientifically proved that marijuana affects the brains of chronic users, especially the decision-making process.
In the study, lead author Michael J. Wesley, department of Physiology and Pharmacology at Wake Forest Baptist Medical Center and his co-researchers observed that marijuana users performed poorly on the Iowa Gambling Task (IGT), which is a complex decision-making task in which participants make choices under ambiguous conditions and win or lose money based on their choices.
The IGT goal is to use the feedback of the wins and losses to guide future choices towards safe options that result in winning more and losing less. The early phase of the IGT is particularly important because early exposure to wins and losses aid the development of decision-making strategies that are exploited in later phases of the task.
Sixteen chronic marijuana users and 16 controls, or non users, performed a modified IGT in an MRI scanner.
"The marijuana users appear to have a blunted response to losing. They don't figure out a strategy to avoid monetary losses and this is associated with a decreased functional brain response to the early, negative information that guides the other group to safer choices," said Wesley.
"The bottom line is that it looks like they don't care as much if they lose," added Wesley.
Wesley and his co-researchers on the study will present the study results at the annual meeting of the College on Problems of Drug Dependence (CPDD) this week in Florida.