4AM, Kinshasa, Zaire, 1974. The bell rings. Round 1 is over. The most anticipated bout between two undefeated giants has begun. If you want to know what fear is, look at Muhammad Ali's eyes as he gasps in his corner. See him engrossed by the unassailable man on the other side of the ring, breathless, while the feeling of terror disseminates within. Who is the greater nemesis -- George Foreman across the ring or the petrifying feeling of fear?
Seeing Muhammad Ali, the greatest boxer of all times, afraid, vehemently reveals the power of fear. Even if subdued, it is always there, lurking. Waiting for the right moment to erupt and take over your will. But fear was there just for a moment, as if a cold breeze blew across Ali's face and quickly disappeared. What happened in Ali's mind during those crucial seconds between Round 1 and Round 2? Scientists do not know. But they do know what happened in his brain.
The core of our defense mechanism is a deep structure in the brain, the amygdala (Greek for "almond," its shape). Like almost every part of the brain, there are two of them, one at each side, roughly behind the eyes, aligned with the ears. Information about imminent threat travels through our sensory organs into the amygdala. The amygdala then stimulates motor and hormonal systems, thus triggering an instinctive response of defense. The importance of the amygdala is beyond the ability to react, though. It is in the ability to predict.
Have you ever experienced profound fear? If you have, you probably remember not only what scared you but also a few other things that stood out. Perhaps the color of a shirt, the view of a shadow, or the clicking sound of metal. Innocent cues that up until now stood for nothing, but from now on, their mere presence is a cause for alert. The amygdala is the key focal point where information about threat and the cues that predict it, converge.
This association, between a naive cue and a harmful outcome, is classical conditioning. If this rings a bell, you are probably thinking of Pavlov. The amygdala is the production site of these Pavlovian associations. It does a good job of it, as these are typically long lasting and strong. What it means is that whenever you encounter such a conditioned cue, you are not only reminded of the frightening event, you actually feel it, here and now, although you did not yet encounter the threat.
Still, something is missing in this picture. It doesn't make sense that we go about life learning these associations and then reacting whenever they pop up. What if we are in a different situation? What if a long time has passed? Sometimes our predictions about threat are no longer relevant simply because things have changed.
To overcome such hard-wired defense responses, we need to engage another part of the brain, the prefrontal cortex, resting behind our forehead. The prefrontal cortex controls the amygdala by overriding its projections to the brainstem and the hypothalamus, the regions that bring about the defensive reaction to threat.
There is a constant battle between these two parts of the brain. The prefrontal cortex takes into consideration the current situation and new knowledge, and chooses the appropriate course of action amongst several ways. But, to gain control over our automatic defensive behavior, should our prefrontal cortex be perpetually astir? Maybe not. Scientists may have found a way to circumvent the entire thing.
Memory becomes fragile when it is active in our brain. Say you put something precious in a box and each time you take it out, it changes a little bit. Memory, as it turns out, is the same. We think we remember exactly the way things went about. But scientists now discover that the act of retrieval itself makes the memory vulnerable. When you store it again, it would go in slightly different. The next time you retrieve it, it will be a different version of the memory, with this delicate change.
For science and medicine, this is a golden opportunity. There is a short time window to target an old memory and prevent us from storing it again. This is where fiction becomes reality. There might be a real opportunity for memory transformation. With the right drug or the right manipulation, memory can change in a deliberate way. This sounds a little troubling, to be honest, do we really want to meddle with what essentially is our core being?
Let's look at it from the perspective of George Foreman, who lost the fight in Zaire. Suppose he could have taken a drug that erased the memory of this devastating loss, and spare him the fear of going back to the ring. But then, he would have not been the fighter he is, regaining his title after 20 years.
It could have turned out differently, however, if Foreman would have lost the courage to go back in. He might have stopped fighting altogether, hardly function in everyday life, and react agilely to any bell ring. A traumatic memory, such as this, is beyond the jurisdiction of the prefrontal cortex. The normal defense systems of the brain, in this case, go awry. These circumstances, where an adaptive defense response is now dysfunctional and counterproductive, might justify a 'memory pill.' It is not a matter of ethics -- just as we would fix a broken jaw, a broken memory we could fix as well.
Science tells us that memory is dynamic, but what does this mean? Maybe memory is not about memory. Perhaps it is not about an accurate documentation or an organized filing scheme. Maybe the true function of memory is to help us make sense of the present and better predict what happens next. We are better off with an up-to-date memory, even if not accurate, if this indeed is the case. If memory is like clay at the hands of a pottery maker, then it is not bestowed upon us. We change the story of our lives just by telling it, again and again.