Eureka! The neuroscience of creative insights
/“If the brain is recalling a flash bulb memory, what would the average firing rate of neurons be in a human?”
What is the firing rate of the brain while a human remembers a flash bulb? Or perhaps you mean the experience of a "light-bulb going off in the brain, ah ha!" moment?
In both cases, the answer is: more than zero, (probably) less than a grand mal seizure.
The problem with the question is twofold. First, there is just no way (yet?) to measure the activity of every neuron in a human brain. And given the complexity memory/conscious perception/the brain, it's hard (read: pointless) to even try to come up with a ballpark figure. More importantly, this question ... isn't really the right question to ask in the first place. Important information isn't encoded in the brain as a factor of average firing rate of the entire brain. In my opinion, the only thing the average firing rate of the whole brain might tell you with any degree of specificity is whether you were brain dead or not. Even brain activity during an epileptic seizure is characterized more by an unusual degree of synchrony (neurons firing at the same time), rather than a total increase in the number of neurons firing.
A more meaningful reinterpretation of this question might be:
What is the neural process that underlies an "ah ha!" moment? Or, in other words, what is our brain doing when we leap out of our baths yelling "eureka"?
For insight (heh) into this process, we should turn to Dr. Mark Beeman, a professor at Northwestern University. Dr. Beeman studies the cognition of insight and creativity, and gives a lecture titled, "Where Ideas Come From: The Cognitive and Brain Bases of Eureka! Moments". A lecture that you can watch online.
Where Ideas Come From: The Cognitive and Brain Bases of Eureka! Moments Mark Beeman, Neuroscience Northwestern University How does the brain produce those sudden moments of creative insight? Most creativity occurs over extended periods of time, making it difficult to elucidate the critical cognitive and neural processes. But sometimes, while at an impasse about how to solve a problem - Eureka! - a sudden insight emerges. Such moments of sudden insight can signal and isolate some of the critical components of creative cognition. Although insight seems to occur suddenly, the Eureka! moment is the culmination of cognitive processes and internal states that facilitate the insight - from rapidly changing preparatory states to relatively stable individual differences in brain states that influence problem solving style. Furthermore, the processes and neural activity that lead to insight solutions are modulated by mood and attention. Based on these results, I present a framework of cognitive and neural mechanisms supporting insight and at least some aspects of creative cognition. Background Review Article: Kounios, J., & Jung-Beeman, M. (2009). Aha! The cognitive neuroscience of insight. Current Directions in Psychological Science, 18,210-216.
For a general-readership-friendly profile on Dr. Beeman and his work, check out this New Yorker article.
