The Journal of Cognitive Neuroscience published a study by the U.S. Department of Energy’s Brookhaven National Laboratory concluding that the more gray matter you have in the decision-making, thought-processing part of your brain, the better your ability to evaluate rewards and consequences. The study shows this link between structure and function in healthy people — and the impairment of both structure and function in people addicted to cocaine.

Differences in gray matter volume — the amount of brain matter made up of nerve cell bodies, as opposed to the "white matter" axons that form the connections between cells — have been observed in a range of neuropsychiatric diseases when compared with healthy states.

The test utilized MRI, EEG and P300 studies. To explore this structure-function relationship, the scientists performed magnetic resonance imaging (MRI) brain scans to measure brain volume in 17 healthy people and 22 cocaine users.

The implications are important for understanding the potential loss of control and disadvantageous decision-making that can occur in people suffering from drug addiction.  There are still questions about whether these changes in brain structure and function are a cause or a consequence of addiction. But the use of multimodal imaging techniques, as illustrated by this study, may open new ways to address these and other questions relevant to understanding human motivation in both health and disease states, with particular relevance to treating drug addiction.