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Transcranial Magnetic Stimulation, The Marshmallow Experiment and Depression by Gary Trotta |
 Transcranial magnetic stimulation is an amazing new tool emerging to neurology now being studied at Columbia University and NYU. It is a procedure that uses magnetic fields to stimulate nerve cells in the brain and has found use in treating depression, chronic pain, tinnitus and some symptoms of schizophrenia. Additionally, this procedure, in conjunction with fMRI (Functional Magnetic Resonance Imaging) is helping us understand and map functionality in the brain. TMS can be used to disable areas of the brain, and through the loss of function, we can pinpoint nuclei in the brain responsible for that various cortical function.
Newsweek (November 7 & 14 Editions) lead with an article which talked about TMS being used to locate areas of the brain responsible for impulsive buying. Just in time for the Christmas shopping frenzy. It appears that some of us are more prone to immediate gratification than others. In 1960, a very famous experiment was performed by Walter Mischel called The Marshmallow Experiment. Four year old children, with a marshmallow sitting in front of them, were presented with a simple proposition. "If you wait, and don't eat the marshmallow before I return" said Mischel, "I'll give you a second marshmallow when I return". What was fascinating about this experiment was the follow up which occurred, and is on-going, many years later. It turns out that those that were able to resist the temptation to eat the single marshmallow (many years later) scored higher on their SATs, were less likely to be obese, and were less likely to become addicted to drugs or to become divorced. Imagine the marshmallow test, so simple, but an astoundingly accurate predictor of future success.
In later years, B.J. Casey of Weill Cornell Medical College gathered 59 of these marshmallow kids together and again tested their ability to delay immediate gratification, but this time using fMRI to sneak a peek at their brain. Those better able to resist immediate gratification showed more activity in their frontal lobes as well as their inferior frontal gyrus, which inhibits the "I want it now" impulse. In a recent study at NYU, TMS was deployed to disable the area of the brain (Dorsolateral Pre-Frontal Cortex) that sends calming signals to the mid brain's "I want it now" circuits, and amazingly participants became more impulsive.
With transcranial magnetic stimulation, a large electromagnetic coil is placed against your scalp near your forehead. The electromagnet used in transcranial magnetic stimulation creates electric currents that stimulate nerve cells in the region of your brain involved in mood control and depression.
But transcranial magnetic stimulation's greatest potential use may be in the treatment of depression. More studies, however, are needed to determine how effective it is. For more than 50 years, electroconvulsant therapy (ECT) has been the last resort option for the depressed patient. It is effective although it sounds somewhat extreme. I remember many years ago as a milieu therapist at Buffalo Psychiatric Center assisting with this procedure on a patient. I say assisting, but for the most part, I was just standing in the same room. The patient is anesthetized and convulsions are limited to some slight twitching of the toes. As I've said, ECT appears to work very well for many patients. It is obviously, expensive and is typically followed by memory loss.
The advantages of TMS therapy over ECT treatment are that there's no need to administer an anesthetic and there is no memory loss. However, TMS is also expensive and can take up to six weeks to show positive results.
Regardless, the science appears to be progressing and carries with it a great potential for not only safely improving our knowledge of the brain but also our health and well being. |
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