QUOTE(karenws @ May 06, 2010, 08:48 PM)
It seems to me that the most stressful events are those that both influence your evolutionary fitness and were unpredicted. If something important and unpredicted happened, that's a sign that you need to correct a prediction error to safeguard yourself in the future. What if correcting this prediction error involved demolition of the neuronal material that mediated the erroneous prediction? This could explain the microdamage that has been seen in the brain with stress. Interestingly, the hippocampus and prefrontal cortex are extremely vulnerable to stress-induced microdamage and both regions have been suggested to mediate detection of aversive prediction errors. Any thoughts?
While contributing to stress, the unpredicted can actually contribute to the evolutionary development of the brain. The brain itself is continually going through a process of natural selection as neurons compete for resources. Gerald Edelman's work on neuronal natural selection suggests that the brain is a microcosm of evolution.