Wednesday, July 29, 2009

Mindfulness meditation and neuronal inhibition

Neurons are the cells of our nervous system which process and transmit electrochemical signals. Neuronal connections are either excitatory, when the nerve impulse increases the firing activity of the receiving cell, or inhibitory, the opposite, when the signal reduces the firing activity of the receiving cell. Mindfulness meditation is the workout of our inhibitory connections—the ones that stop us from doing certain things—to keep such connections in good “shape” or restore their capacity if it has deteriorated. Let me explain how this happens and what it is good for.

When people start a meditating session, they go through a wide variety of sensory and perceptual experiences, which originate from the continuous activation and deactivation of their inhibitory connections. As they enter deeper levels of introspection or concentration, they isolate themselves not only from external sensory signals (that is the easy part) but also from mind wandering. At those peak moments, million inhibitory connections turn on, block distracting thoughts and make the meditator undergo very special mental experiences which, in general, are difficult to describe. Still, as any other mental event, such experiences are pure neuronal phenomena and not, by any means, mystical calls.

Neuronal circuits are ensembles of neurons that process specific kinds of information. Excitatory routines prompt events; they are the neuronal circuits that keep data or instructions that are called in when they are needed. Inhibitory routines stop events; they are the blocking circuits that are supposed to restrain further action when the job is complete. The same way as excitatory routines might fade away, this is, they might get weakened and erased—the corresponding data or ability is then forgotten—inhibitory routines might also stop doing their blocking duty and the associated activity, which was supposed to be controlled, is actually overdone.
The purposeful repetition of an “excitatory” physical or mental task reinforces the associated neuronal program; this makes it progressively easier the repetition of the task. Though in a different manner, mindfulness meditation is, from the neuronal point of view, the purposeful repetition of thousands of passivity or stopping routines, this is to say, the workout of inhibitory circuits. Where do these workouts lead to? To the end of suffering, said the Buddha, twenty five centuries ago. But now cognitive sciences are finding now that mindfulness meditation is a very valuable tool to deal with some mental disorders.

Neurologists already knew that several mental disorders, both addictive and repulsive, stem from the malfunctioning of inhibitory mechanisms. The addictive type, such as substance dependence, sexual addiction and eating disorders, are related to pleasure habituation; the repulsive kind, such as phobias, panics, obsessive compulsive disorders or post traumatic stress disorders, are related to pain avoidance.

These disorders are disarrays of natural, normal processes. After pleasurable or painful experiences, the brain builds up automatic neuronal circuits for the conditioned repetition or avoidance of such experiences; the same circuits are triggered when similar circumstances reappear. Eating food is pleasing and stops hunger, therefore seeing or smelling food invites us to eat; touching hot things is painful, therefore avoiding blazing stoves or irons becomes second nature.

But the frequent repetition of an event or the high impact of a single episode might alter inhibitory mechanisms; they fail then to block the conditioned neuronal circuits that urgently demand repetition or avoidance. For instance, if we do many times a pleasing activity or the satisfying impression of one single action is too intense, we might get burning desires to duplicate the circumstances as often as possible, which we will keep doing if the blocking circuits deteriorate and so we become addicts. Or, on the other hand, a very strong negative event might affect the fear blocking signals so badly that phobias, panics or obsessive threats will become automatic in front of imaginary or harmless incidents. As things get worse, the simple thought of the conditioning events triggers cravings for repeating pleasure and dreads for avoiding pain. Either in the addictive or repulsive direction, the whole process becomes an unbearable treadmill. Excessive suffering, the Buddha would say.

When you meditate, you exercise—you force to work— an important fraction of your inhibitory circuits. By isolating physically, a huge number of sensory signals are turned off. When trying to focus your attention onto something (your breath, for instance), your mind switches control between wandering thoughts (involuntarily) and attention focusing (willingly); as this happens, millions of inhibitory neurons turn off and on alternatively. By regularly doing this kind of workout, your day-to-day mindfulness improves and so does your control of addictions and fears.

The rediscovery of this millennial wisdom is very promising; our brain receives so many signals and so much noise today that the pace of our lives does not seem to have a slow lane any more. All kind of mental disorders are on the rise. As the neuronal nature of the uncommon perceptions meditators undergo during meditation and the neuronal workings of the whole mindfulness experience are better understood both the acceptance and the potential of the technique in dealing with mental disorders will grow substantially.




Gustavo Estrada
Author of Hacia el Buda desde el occidente
http://pragmatic-buddha.com/