Why you forget to drop off clothes at dry cleaners

Washington, Oct 21 : Do you often forget to drop off the clothes at the dry cleaner? Well, then you are suffering from what the Yale researchers call the "dry cleaning effect," which they say is the result of clashing of brain systems.

Such duelling in brain system also points to ways by which substance abusers and people with obsessive-compulsive disorder can overcome bad habits.

Led by Christopher J. Pittenger, M.D., researchers have described a sort of competition between areas of the brain involved in learning that results in "dry cleaning effect."

An area of the brain called the striatum helps record cues or landmarks that lead to a familiar destination. It is the area of the commuter's brain that goes on autopilot and allows people to get to work, often with little memory of the trip.

However, when driving to an unfamiliar place, the brain engages a second area called the hippocampus, which is involved in a more flexible system called spatial learning. The commuter must employ this system if he or she wants to run an errand before work.

"When you have driven the same route many times and are doing it on autopilot, it can be really difficult to change. This is why I cannot, for the life of me, remember to drop off my dry cleaning on the way to work. If I'm not paying enough attention right at that moment, if I am thinking about something else, I just sail right on by," said Pittenger.

The researchers developed a way to study how these two modes of learning might be interconnected in mice.

When the researchers disrupted areas of the striatum in mice in one group, it was discovered that the mice's ability to complete landmark navigation tasks was impaired. However, these mice actually improved on tasks that involved spatial learning.

On the other hand, when an area of the hippocampus involved in spatial learning was disrupted, the animals could no longer navigate spatially but learned landmark tasks more quickly.

The researchers hypothesised that the interactions between these two systems may be important for understanding certain mental illnesses in which patients have destructive, habit-like patterns of behavior or thought. Obsessive-compulsive disorder,

Tourette syndrome, and drug addiction involve abnormal function of the striatum and may also involve disruption of the interactions between the two learning systems, which may make habits stronger and less flexible.

"This is part of what we are doing in cognitive-behavioral therapy when we teach patients to recognize their destructive habits, to take a step back, and to learn to do things differently. What we're really asking them to do is to use one of these systems to overcome and, ultimately, to re-train the other," said Pittenger.

In time, Pittenger hopes his studies will lead to more effective treatments for psychiatric disease - and, maybe, help him drop off his dry cleaning.

The study is published in Proceedings of the National Academy of Sciences.

ANI