The important thing to understand is that these two memory systems are separate, even if they generally operate in tandem.
Patients in whome the hippocampal system is damaged have poor conscious memory. [There is a] famous case of a woman who had severe amnesia. Each day when her doctor walked into her room, he would have to reintroduce himself because the woman never remembered having seen him the day before. In fact, if he left the room for even just a few minutes, she wouldn’t remember him when he returned. One day the doctor walked in and extended his hand to shake hers. But this time he held a pin in the palm of his hand. When their hands met, hers was pricked and she withdrew it immediately. The doctor left the room, and when he came back a few minutes later … she wouldn’t shake hands with him. She had no conscious memory of being pricked by the doctor, but … her amygdala remembered [to] protect herself.
By contrast, patients whos hippocampus is intact but who have amygdala damage are unable to do this kind of pinprick learning, this kind of fear conditioning. They know all the details – that the doctor was in the room, that they were pricked – but they don’t withdraw their hand when the doctor tries to shake. … the amygdala and the hippocampus systems mediate different kinds of memory. Normally, they work together so that emotional memories … and memories of emotion … are fused in our conscious experience so immediately and so tightly that we cannot dissect them by introspection. …
A traumatic [or stressful] situation … has separate consequences for these two memory systems. When … stress hormones [are released] into the body, the hormones (especially cortisol) tend to inhibit the hippocampus, but they excite the amygdala. In other words, the amygdala will have no trouble forming an emotional, unconscious memories of the event – and, in fact, will form even stronger memories because of the stress hormones. But these same hormones can interfere with … and prevent formation of a conscious memory of the event. (pp. 140–142)
This has a strong bearing on our early childhood programming. It is thought that the hippocampus is not fully formed and functional in early childhood, and, as a result, we are unable to develop long-term, conscious memories before that time.
Yet, the amygdala is fully formed and functioning. And it is for this reason that abused children form very strong emotional memories that cause them to react strongly to many things, while having no access at all to any conscious understanding of why they feel as they do.
Unconscious emotional memories affect us all our lives, powerfully, and it is extremely difficult to work through them without conscious recall. The mere sight of anything that is associated with an early traumatic or stressful event can activate the emotional response, whether it is of a positive or negative nature.
More than this, these unconscious memories can generalize as we have already described in an earlier section.
Now, all animals have the fear-learning mechanism that enables them to survive. They can detect danger and respond to it appropriately. However, they do not have fearful feelings, the way we do when our basic “fear program” is activated in a brain which also has self-consciousness. Here, a new phenomenon occurs: subjective feelings.
Feelings of fear … are what happen in consciousness when the activity generated by the subcortical neural system involved in detecting danger is perceived … by certain systems in the cortex, especially the working memory system …
A conscious feeling of fearfulness is not necessary to trigger an emotional fear response. The low road can take care of this just fine. That is, we can produce responses to danger without being consciously afraid, as when we jump back up onto the curb to avoid being hit by a car. In a situation like that, as people so often say, we don’t “have time to be afraid.” … At other times we will first have some kind of response in our body and only later be able to name what the feeling was: anxious, sad or angry. In many cases, though, even if we can say that we feel anxious, we don’t know what generated those feelings. Indeed, we see this again and again in the various disorders of the fear system, such as panic attacks and phobias. …
Why is it so difficult to eliminate such fears? Once the amygdala is turned on, it can influence information processing in the cortex from the earliest stages onward, but only the later stages of cortical processing affect the amygdala. In other words, even though communication goes two ways, it’s not equally effective in both directions. In general, the projections from the amygdala to the cortex are much stronger than vice versa. If we think of the routes from the amygdala to the cortex as superhighways, then those from the cortex to the amygdala are narrow back roads. Once the emotions are activated, they can influence the entire working of the cortex, whereas the cortex is very inefficient at controlling the amygdala. So, using thinking to overcome emotion is like using a back road or side street from the cortex, while the amygdala is bombarding the cortex with input via the superhighways. (LeDoux 1999, 144–145)
But thinking with the cortex, it turns out, is basically a way to rewire your brain. It is like working on the back roads to develop them into the commanding interstate system of the brain they were meant to be. Research shows that changes in the brain are the result of learning experiences, and it seems that learning – acquiring knowledge – is the path of rewiring the synaptic connections in the brain.
The key to this is the fact that learning, hard thinking and pondering, requires that certain brain chemicals – usually acetylcholine – be squirted out at just the right place and in the right quantities. It is becoming clear that the molecules of memory are blind to the kind of memory – whether it is conscious or unconscious – that is occurring. What determines the quality of different kinds of memories is not the molecules that do the storing but the systems in which those molecules act. If they act in the hippocampus, the memories that get recorded are factual and accessible to our consciousness. If the chemicals are acting in the amygdala, they are emotional and mostly inaccessible to conscious awareness.
So, even if we don’t know what has triggered a given emotional response until after the fact, we do have an awareness that we are feeling a certain way. This awareness is called our “working memory.”
Working memory, or awareness, involves the frontal lobes of the brain just above and behind the eyebrows. This is what we use when we want to remember a new phone number just long enough to dial it, or to remember what we went to the kitchen for long enough to get it. It is also the place where many different kinds of information are held simultaneously while we are comparing one thing to another. We can have all kinds of things going on there at once. We can look at something and hold this image in working memory along with the memory of something we have pulled from long-term memory that we wish to compare it to. Sounds, smells, and even the ongoing physiological input from our system. And while we do this, we are considering: does it make us feel peaceful, happy, sad, afraid?
All of these elements come together simultaneously. However, this working memory can only do one thing at a time, even if that one task is multi-factored. A classic example is when you try to remember a new phone number and someone asks you a question before you get to dial it. The number flies out the window as you answer the question and you have to go back and look it up again.
It seems that this “working memory” or awareness is – if not consciousness itself – at least a window to it. It is in working memory that conscious feelings occur. In working memory, three things come together to create conscious feeling: present stimuli, activation of the amygdala in some way and activation of conscious memory in the hippocampus.
Present stimuli might include standing inside a church. This would arouse the amygdala so that the unconscious memories of the many experienced in church – the flooding of the receptors with neurochemicals; and this would activate conscious memory of the last time you were in church, or several memorable times will pass through the mind. When all these things come together in working memory, with the body now activated with chemistry and past history, this is perceived as “feeling.”
The same thing can occur in any kind of encounter as we have already described. Something that is present now will turn on the chemicals, which will arouse conscious memories that are related to those chemicals, and then the present moment will be interpreted in those same terms.
Since what we are looking at here is the fact that unconscious, chemical imprints have a much greater ability to influence thinking than vice versa, we realize that we are face to face with an age-old debate between reason and emotion, logic and passion, knowledge and faith.
When you are aroused emotionally, whether by fear or pleasure or sexual attraction, it is a cold hard fact that emotion dominates thinking.
Philosophers going all the way back to Plato have endlessly analyzed this fundamental schism. The body fills us with passions and desires and fears and fancies and foolishness and fairy tales made up to justify these chemical reactions. Plato opined that the true philosopher was one who could master his emotions by the use of reason. Socrates said, “Know thyself,” by which he meant that we had to understand our emotions in order to be able to control them.
The vast majority of philosophers and philosophical writers throughout man’s recorded history have believed that in order to be truly human – as opposed to just an animal – we must activate reason. Descartes didn’t say, “I feel, therefore I am.” Thinking seems to be the distinctly human thing that humans do which separates them from animals. But, as Theodore Dreiser said, “Our civilization is still in the middle stage, scarcely beast in that it is no longer guided by instinct, scarcely human in that it is not yet wholly guided by reason.”
The prime example of this is, of course, Star Trek’s Dr. Spock. Captain Ahab, the hero of Melville’s Moby Dick was just the opposite. Melville wrote: “Ahab never thinks, he just feels, feels, feels.” Perhaps the mindless pursuit of a white whale is a good metaphor for the result of living by emotion.
However, I am not advocating domination of cognition; merely balance. There is, at present, such an imbalance between the amygdala’s input to the cortex and the very sparse control of the cortex over the amygdala. Even though thoughts can readily trigger emotions by activating the amygdala, it is very difficult to willfully turn off emotions.
As it happens, the cortical connections to the amygdala are actually far greater in primates than in other animals. It seems that more balanced cortical pathways are the evolutionary trend. It is my opinion that we will develop them or perish. A more harmonious integration of emotion and thinking would allow us to both know our true feelings, and why we have them, and to be able to use them more effectively.
The key is in learning. Knowledge protects. And if you haven’t already begun to put the pieces of the puzzle together with the advantages of expanding and working the frontal cortex, perhaps what we are going to look at next will finally make the whole thing clear.
Let’s take a walk into the back roads of the frontal cortex.