It is good to be back. I have just returned from the annual AAN conference, and my mind is now loaded with all the brain facts any person in their right mind should ever hope for, at least in the course of one week. Mastering the mind cannot be done in a lifetime. It is an odd paradox that the neuroscientist lives in. We try to understand why we think the way we do and thus gain the power to artificially change the way we think. But then, what is it that leads us to change the thinking if not our thinking and brains?
There is this odd and mysterious component of will that comes along, or is it just a will of the gaps? If we can understand all thinking, are we really thinking or are we executing a predetermined program? Is it environment, chaos, or some other explanation that leads us to alter thinking through thinking? This of course leads to the most fascinating observation of all (to me), thinking alters our thinking. We have a mind built to learn and grow, change and adapt. The fifty dollar word for it is neuroplasticity The mind is always in the process building itself, making new synaptic connections and breaking old ones. In effect the brain transcends DNA and physiologic programming by actually rewiring itself through conscious thought.
I submit that the mystery is in fact, our spirit, free will, or the part of us that makes us us. It may not be proven, but like gravity to the laws of motion, in spite of our inability to understand the mechanics, it must exist because nothing else makes sense without it, to my thinking anyway, and probably for most non-neuroscientists as well. It is the seductive power of explanation and reductionism that lie behind the occupational hazard of seeing man as machine, or mind as simply matter.
Many are the neurosurgeons and scientists that can no longer believe in a spirit because of their raw, physical interaction and experience with the brain, the very organ of our collective being. Mystery is not conducive to a mechanic’s or surgeons’ job, nor to a scientist in search of description, answers and predictions. Neither is witnessing the soul’s annihilation through brain decay in dementia, stroke, cancer, or other disease.
While the mystery remains, we are learning a lot about thoughts and memory. The line between psychiatry and neurology is blurring. This is evidenced in new knowledge we are gaining about the basal ganglia. This a section deep in the brain known to be responsible for regulating movements, leading to conditions like Huntington’s Chorea, Tourette syndrome, or Parkinson’s disease when it malfunctions. The movement part is easy to unravel because it is an objective measurable function. What has been more mysterious is the psychiatric component of the above disorders. Huntington’s leads to dementia and lack of emotional regulation. Parkinson’s disease is associated with dementia and depression. Tourette’s has long been known to involve attention deficit and obsessive compulsive disorder. It turns out that movement and emotion use the same circuitry, and scientists are learning it is fundamental to learning.
This section of the brain helps us learn complex movements, with a dopamine reward system that helps us to remember and enjoy repetition. In fact, dopamine is central to addiction as drugs like cocaine, alcohol, and amphetamines all cause release of dopamine, encouraging us to repeatedly use again and again. A tic is one of these complex movements that pops out when the basal ganglia is unable to stop them. Once these movements are learned they are transferred into higher, more permanent centers in the brain via the memory circuit, known as the Hippocampus. In this way, a learned movement becomes automatic or learned. It is now a habit.
As something becomes habit the dopamine reward turns off. In Autism and Tourette syndrome it appears that these movements don’t necessarily make the transfer where the reward switches off. This explains why they feel impelled to have Tics. It also seems related to thoughts as both conditions involve obssessive needs to perform ritualistic movements to lead to a better emotional state. This is basically what obsessive compulsive disorder is all about. We can become anxious until we receive the dopamine payoff. At some point it dominates both thoughts and actions.
We are largely creatures of habit. People love routine. In classes, we automatically develop preferred seating. Familiar environments lead to a lowering of anxiety. Good habits can lead to productive and healthy lives. Dysfunctional habits can destroy us. Habit can limit our freedom of response. Remarkably, we can rewire however. We are in control of making new habits. Over time these can replace the old ones. Change isn’t comfortable, but it is doable. We can consciously reprogram our own brain with effort and will and determination. This is the mystery and the miracle of the human brain.