Regardless of your own drinking habits, having a parent with an alcohol use disorder affects how your brain transitions between active and resting states, according to new research.
The study reveals that the brain reconfigures itself between completing a mentally demanding task and resting. This reconfiguration doesn’t happen in the brain of someone with a family history of an alcohol use disorder, however.
While the missing transition doesn’t seem to affect how well a person performs the mentally demanding task itself, it might be related to larger scale brain functions that give rise to behaviors associated with addiction. In particular, study subjects without this brain process demonstrated greater impatience in waiting for rewards, a behavior associated with addiction.
Like a computer closing programs
How the brain reconfigures between active and resting states is like how a computer closes down a program after you’re finished with it.
“The moment you close a program, a computer has to remove it from memory, reorganize the cache, and maybe clear out some temporary files. This helps the computer to prepare for the next task,” says Joaquín Goñi, an assistant professor in the School of Industrial Engineering and the Weldon School of Biomedical Engineering at Purdue University.
“In a similar way, we’ve found that this reconfiguration process in the human brain is associated with finishing a task and getting ready for what’s next.”
Past research has shown that a family history of alcoholism affects a person’s brain anatomy and physiology, but most studies have looked at this effect only in separate active and quiet resting states rather than the transition between them.
“A lot of what brains do is switch between different tasks and states. We suspected that this task switching might be somewhat lower in people with a family history of alcoholism,” says David Kareken, a professor of neurology at the Indiana University School of Medicine and director of the Indiana Alcohol Research Center.
Alcohol use disorder and the next generation
The study defined a “family history of alcoholism” as someone with a parent who had enough symptoms to constitute an alcohol use disorder. About half of the 54 study participants had this history.
Researchers measured the brain activity of subjects with an MRI scanner as they completed a mentally demanding task on a computer. The task required them to unpredictably hold back from pressing a left or right key. After completing the task, the subjects rested while watching a fixed point on the screen.
A separate task outside of the MRI scanner gauged how participants responded to rewards, asking questions such as if they would like $20 now or $200 in one year.
Enrico Amico, a former postdoctoral researcher who is now a researcher at EPFL in Lausanne, Switzerland, and Goñi processed the data and developed a computational framework for extracting different patterns of brain connectivity between completing the mentally demanding task and entering the resting state. These include when brain areas rose and fell together in activity, or when one brain area rose while another fell at the same time.
The data revealed that these brain connectivity patterns reconfigured within the first three minutes after finishing the task. By the fourth minute of rest, the effect had completely disappeared.
And it’s not a quiet process: Reconfiguration involves multiple parts of the brain at once.
“These brain regions talk to each other and are very strongly implicated in the task even though by this point, the task is already completed. It almost seems like an echo in time of what had been going on,” Kareken says.
Subjects lacking the transition also had the risk factors that researchers have seen to be consistent with developing alcoholism. These include being male, a greater number of symptoms of depression, and reward-impatience.
A family history of alcoholism, however, stood out as the most statistically significant difference in this brain reconfiguration.
“In the past, we’ve assumed that a person who doesn’t drink excessively is a ‘healthy’ control for a study. But this work shows that a person with just a family history of alcoholism may also have some subtle differences in how their brains operate,” Goñi says.
The findings appear in the journal NeuroImage. Funding for the research came from the National Institute on Alcohol Abuse and Alcoholism, the Purdue Discovery Park Data Science Award, and the National Institutes of Health.