A new therapeutic approach is in sight for treatment of traumatic memories, including memories that cause PTSD. Two lines of memory research have converged to produce a treatment, and sometimes even a cure, for the most serious need to forget, PTSD. This may not be generally known or accepted, but at least two research groups have shown there is a blood pressure drug, propranolol, that helps us to forget overwhelmingly stressful memories and thus reduces the stress that goes with those memories. The latest treatment being investigated by some researchers is based on using a common blood pressure drug, propranolol, which has a side effect of blocking the re-consolidation of emotions associated with old memories when those memories are recalled.
One reason it is possible to forget or at least edit memories is that when even well-formed memories are recalled, they are put back on the scratch pad of working memory where they are accessible to “editing” and re-consolidation. As I explained in a previous blog column, each time a memory is retrieved, it can get changed and re-stored in a different way.
While memories reside on the scratch pad of working memory, either for the first time or during any recall episode, they can be changed by drugs. Also relevant here is that memory consolidation is greatly influenced by the impact of the experience, which is magnified by strong emotion and the hormones such emotions release. During re-consolidation, under conditions of proper talk therapy, the emotional impact need not duplicate the original and a more benign version will be stored in memory.
The rationale for testing propranolol was developed in the seminal work by Roger Pitman and colleagues. They noted earlier studies showing that adrenalin (epinephrine), either injected or released naturally under stressful conditions, strengthens memory formation and fear conditioning. Adrenalin helps you to remember the bad event and hopefully you can avoid facing that threat again by being alert and prudent. Adrenaline acts on a class of molecular receptors called beta-adrenergic receptors. Certain drugs, among them propranolol, block beta receptors and thus might theoretically disrupt fear-induced memories. Several groups have confirmed that propranolol does impair fear-conditioned memory in both animals and humans.
Pitman’s group sought to extend this notion to PTSD in a pilot study of 41 patients. They conducted a double-blind, placebo-controlled study in which a single 40 mg oral dose of propranolol was given as soon as possible (within 6 hours) after a traumatic event experienced by patients who had been rushed to a hospital emergency room. Patients then continued the medication four times a day for 10 days followed by a 9 days when the dose was progressively reduced to zero.
One and three months later, patients returned for psychological testing aimed at measuring PTSD. At one month post trauma, the number of patients with PTSD in the propranolol group was almost half that of placebo controls. Not tested was the possibility that a larger dose, especially if given early or prior to the unpleasant experience, might be even more effective, since there probably is a narrow window of opportunity for the drug to be beneficial in impairing the consolidation of bad memories.
A similar result was obtained in a later study by Guillaume Vaiva and colleagues. Their hospital emergency room patients were given propranolol or a placebo 2-20 hours after experiencing an auto accident or physical assault. The patients tested were also selected for having abnormally fast heart rates, because propranolol is a common therapeutic for that condition. Propranolol was given in a dose of 40 mg three times daily for seven days, followed by gradual reduction to zero over 8-12 days.
Under the common situation where emotional trauma has already been consolidated, the obvious treatment approach for PTSD might be to have patients recall the traumatic event later while under the influence of propranolol. The idea is that during recall, the memory and its associated emotion have to be reconsolidated, and this is disrupted by the drug. Indeed, this idea is being hailed in some quarters as a possible major breakthrough in treatment of PTSD. Many positive results are being reported by physicians, and the Army is considering using this approach for combat-related PTSD. The National Institute of Mental Health is now recruiting patients for a Phase IV Clinical trial.
One obvious conclusion is that propranol might be a good PTSD preventive drug if given before an anticipated traumatic event. For example, I wonder if D.O.D. psychiatrists have thought about giving propranolol to combat troops just before they engage in battle.
Another issue that nobody seems to consider is the possibility that people on this kind of blood pressure medication might be suffering impairments of emotional memories that they don't want to lose. Does this drug cause a general dulling of emotions? Could it magnify the failing memories of the elderly?
Copyright 2010, W. R. Klemm. Dr. Bill Klemm is a Professor of Neuroscience at Texas A&M University. Visit his book site and blog at ThankYouBrain.com for more help on improving memory.
Monday, September 13, 2010
Tuesday, September 7, 2010
Zombies Learn Too, But Not Well
I recently had a scholarly paper on free-will research published in a cognitive psychology journal. This experience has caused me to think about the role of free-will in learning and memory. Though it might seem like a stretch, how one approaches learning affects how well it is done. If you learn subconsciously, as in being conditioned like Pavlov's dogs or trained seals, the learning is primitive and limited because it is hidden from consciousness. I call this zombie learning (anybody who has lectured to students has seen this happening throughout the room). On the other hand, when one consciously and freely wills to learn, he becomes engaged as an active learner. Such learning, being mediated in the consciousness, is available for refinement, expansion, application, and integration into other learning, past and future.
Let me explain the point of reference. Ever drive a route so familiar you don’t remember getting there? It is as if your brain was on autopilot. Many scientists think this zombie-like behavior is the norm. They say that even when we are aware of having done something, it was willed subconsciously, and we only became consciously aware after the fact. This has led to a common notion among scholars that free will is an illusion. At least that is the argument promoted long ago by scholars like Darwin, Huxley, and Einstein. Many modern scientists also hold that position and have even performed experiments they say prove it.
These experiments supposedly show that the brain makes a subconscious decision before it is realized consciously. Well, I am not intimidated by science’s giants, past or present. In a paper in the current issue of Advances in Cognitive Psychology (Vol. 6, page 47-65), I challenge a whole series of experiments performed since the 1980s purported to show that intentions, choices, and decisions are made subconsciously, with conscious mind being informed after the fact.
But these experiments do not test what they are intended to test and are misinterpreted to support the view of illusory free will. In the typical experiment, a subject is asked to voluntarily press a button at any time and notice the position of a clock marker when they think they first willed the movement. At the same time, brain activity is monitored over the part of the brain that controls the mechanics of the movement. The startling observation typically is that subjects show brain activity changes before they say they intended to make the movement. In other words the brain issued the command before the conscious mind had a chance to decide to move. All this happens in less than a second, but various scientists have interpreted this to mean that the subconscious mind made the decision to move and the conscious mind only realized the decision later.
Let me explain the point of reference. Ever drive a route so familiar you don’t remember getting there? It is as if your brain was on autopilot. Many scientists think this zombie-like behavior is the norm. They say that even when we are aware of having done something, it was willed subconsciously, and we only became consciously aware after the fact. This has led to a common notion among scholars that free will is an illusion. At least that is the argument promoted long ago by scholars like Darwin, Huxley, and Einstein. Many modern scientists also hold that position and have even performed experiments they say prove it.
These experiments supposedly show that the brain makes a subconscious decision before it is realized consciously. Well, I am not intimidated by science’s giants, past or present. In a paper in the current issue of Advances in Cognitive Psychology (Vol. 6, page 47-65), I challenge a whole series of experiments performed since the 1980s purported to show that intentions, choices, and decisions are made subconsciously, with conscious mind being informed after the fact.
But these experiments do not test what they are intended to test and are misinterpreted to support the view of illusory free will. In the typical experiment, a subject is asked to voluntarily press a button at any time and notice the position of a clock marker when they think they first willed the movement. At the same time, brain activity is monitored over the part of the brain that controls the mechanics of the movement. The startling observation typically is that subjects show brain activity changes before they say they intended to make the movement. In other words the brain issued the command before the conscious mind had a chance to decide to move. All this happens in less than a second, but various scientists have interpreted this to mean that the subconscious mind made the decision to move and the conscious mind only realized the decision later.
My criticisms focus on three main points: 1) timing of when a free-will event occurred requires introspection, and other research shows that introspective estimates of event timing are not accurate, 2) simple finger movements may be performed without much conscious thought and certainly not representative of the conscious decisions and choices required in high-speed conversation or situations where the subconscious mind cannot know ahead of time what to do, and 3) the brain activity measures have been primitive and incomplete.
I identify 12 categories of what I regard as flawed thinking about free will. Some of the more obvious issues that many scientists have glossed over include:
- Decisions are not often instantaneous (certainly not on a scale of a fraction of a second).
- Conscious realization that a decision has been made is delayed from the actual decision, and these may be two distinct processes.
- Decision making is not the only mental process going on in such tasks.
- Some willed action, as when first learning to play a musical instrument or touch type must be freely willed because the subconscious mind cannot know ahead of time what to do.
- Free-will experiments have relied too much on awareness of actions and time estimation of accuracy.
- Extrapolating from such simple experiments to all mental life is not justified.
- Conflicting data and interpretations have been ignored.
In the real world, subconscious and conscious minds interact and share duties. Subconscious mind governs simple or well-learned tasks, like habits or ingrained prejudices, while conscious mind deals with tasks that are complex or novel, like first learning to ride a bike or play sheet music.
We do act like zombies driven by our subconscious when we act out of habit, prejudice, or prior conditioning. But we should and can be responsible for what we make of our brains and for the choices in life we make. In a free-will world, people can choose to extricate themselves from many kinds of misfortune — not to mention make the right choices that can prevent misfortune.
An earlier book of mine on personal responsibility, Blame Game, How To Win It (http://blamegame.us) provided the inspiration to explore why people are not more responsible. It is not that we lack the capacity for free will. Rather, we fail to exercise it.
Relating these ideas to learning, we should strive to become active learners, consciously thinking about what we are learning, not trying to memorize it by rote. Rote memory doesn't work very well anyway, and it puts us in a zombie mode that prevents us from full understanding and capability to use the learned material.
Thursday, August 19, 2010
Traumatic Memories, Part 1
Most of the time, most of us wish we could remember things better. But some of the time all of us have things we wish we could forget. Traumas, emotional upset, grief — all can be more than we can wish to bear.
When anxiety becomes too intense and persistent, the level of stress becomes de-bilitating. There are many negative effects on the adrenal gland and its production of hormones that are designed to cope with stress. Beyond that, the brain is also affected. These effects are the hallmark of what is commonly called “Post-traumatic Stress Syndrome” (PTSD), which seems to be a common and growing problem with American soldiers returning from Iraq and Afghanistan. While older people are in the wrong age bracket to have this problem, they are very likely to know about PTSD in soldiers and may even have children or grandchildren who have PTSD.
You don't have to be a combat soldier to develop anxiety disorders such as PTSD. Everyone has probably had some kind of traumatic experience that caused a serious emotional trauma. Such experiences are always associated with a host of cues, many subconscious, that are part of the original learned traumatic experience. The learned association may be remembered at some unconscious level long after the conscious memory is lost.
Sensory cues, even if not recognized consciously, can trigger recall of disturbing memories or even just the negative emotions that went with the original bad event. Sometimes this is the basis for so-called “anxiety attacks,” which seem to come out of nowhere.
Anxiety disorders are among the most common mental health problems and are often treated with so-called extinction therapies. That is, therapy is geared toward unlearning (extinguishing) our fears by deliberately re-living the disturbing event under safe conditions and thereby learning we can cope.
Modern psychotherapy for phobias, anxiety, and PTSD often involves recalling the original bad event under reassuring conditions. But this has to be done with conscious re-assessment and realization that the original negative emotions and fear are no longer applicable because the re-living is a simulation in a safe environment. One creates a new learning substitute for the original emotional trauma.
The re-living must include dealing with the negative emotions in the light of reason and new emotional experience. Therapy requires critical thinking about thoughts and feelings, especially those that are unhelpful and unrealistic. The patient is gently led to face memories anew and to learn new ways of thinking and behaving. This re-creation of the bad event allows us to extinguish memory of the original bad situation and its negative emotions.
I recently got an up-date in this area of research at a seminar by Gregory Quick from the Department of Psychiatry at the University of Puerto Rico. As Pavlov showed, memory extinction is a basic phenomenon even in simple animals. If you repeatedly ring a bell and then stress a rat, it soon learns to become distressed the next time it hears that bell, even after you stop the stress. In the lab, this is manifested by the rat showing freeze behavior. But, if you repeat the bell enough times without the stress, the conditioned response (CR) (freeze behavior) eventually becomes extinguished.
At first, scientists thought that extinction erases the memory of the CR. But extinction really creates a new memory that competes with memory of the original CR. Both memories co-exist. Over time the extinction memory may be lost, and the CR can return. The implication is that, just as ordinary learning needs rehearsal, so does extinction learning.
Therapy for emotional trauma and PTSD might be more effective if therapy were approached like a conventional learning experience whose memory is affected in all the usual ways. Recall what was said about extinction being a case of new learning. Re-learning of an extinguished response occurs much more readily than it does for an initial extinction learning. This is an example of priming. It’s like re-learning a foreign language. It goes easier the second time and the memory might be even more dependable.
Since memory of an emotional CR learning experience and its extinction can co-exist, these two memories compete for which one is strong enough to survive long-term. Sadly, the CR memory is often stronger. Cues are extremely important to both forming and retrieving all kinds of memory. It seems likely there are many more explicit cues for CR memories than for extinction memories. Therapy should be aimed at enriching the number and variety of cues associated with extinction learning. Rehearsal is likewise important. So far, nobody seems to have given that much thought.
There is another aspect to emotional learning: learning to learn. If you have multiple anxieties, they may generalize and "spread" to facilitate learning new anxieties. The corollary would be that learning how to promote extinction could also generalize and thus increasing the general ability to cope with emotional trauma. Obviously, for one's brain to learn how to do that, one would need to begin with a single relatively easy extinction learning task.
Dr. Bill Klemm is a Professor of Neuroscience at Texas A&M University. Visit his book site and blog at ThankYouBrain.com for more help on improving learning and memory. Copyright 2010, W. R. Klemm
When anxiety becomes too intense and persistent, the level of stress becomes de-bilitating. There are many negative effects on the adrenal gland and its production of hormones that are designed to cope with stress. Beyond that, the brain is also affected. These effects are the hallmark of what is commonly called “Post-traumatic Stress Syndrome” (PTSD), which seems to be a common and growing problem with American soldiers returning from Iraq and Afghanistan. While older people are in the wrong age bracket to have this problem, they are very likely to know about PTSD in soldiers and may even have children or grandchildren who have PTSD.
You don't have to be a combat soldier to develop anxiety disorders such as PTSD. Everyone has probably had some kind of traumatic experience that caused a serious emotional trauma. Such experiences are always associated with a host of cues, many subconscious, that are part of the original learned traumatic experience. The learned association may be remembered at some unconscious level long after the conscious memory is lost.
Sensory cues, even if not recognized consciously, can trigger recall of disturbing memories or even just the negative emotions that went with the original bad event. Sometimes this is the basis for so-called “anxiety attacks,” which seem to come out of nowhere.
Anxiety disorders are among the most common mental health problems and are often treated with so-called extinction therapies. That is, therapy is geared toward unlearning (extinguishing) our fears by deliberately re-living the disturbing event under safe conditions and thereby learning we can cope.
Modern psychotherapy for phobias, anxiety, and PTSD often involves recalling the original bad event under reassuring conditions. But this has to be done with conscious re-assessment and realization that the original negative emotions and fear are no longer applicable because the re-living is a simulation in a safe environment. One creates a new learning substitute for the original emotional trauma.
The re-living must include dealing with the negative emotions in the light of reason and new emotional experience. Therapy requires critical thinking about thoughts and feelings, especially those that are unhelpful and unrealistic. The patient is gently led to face memories anew and to learn new ways of thinking and behaving. This re-creation of the bad event allows us to extinguish memory of the original bad situation and its negative emotions.
I recently got an up-date in this area of research at a seminar by Gregory Quick from the Department of Psychiatry at the University of Puerto Rico. As Pavlov showed, memory extinction is a basic phenomenon even in simple animals. If you repeatedly ring a bell and then stress a rat, it soon learns to become distressed the next time it hears that bell, even after you stop the stress. In the lab, this is manifested by the rat showing freeze behavior. But, if you repeat the bell enough times without the stress, the conditioned response (CR) (freeze behavior) eventually becomes extinguished.
At first, scientists thought that extinction erases the memory of the CR. But extinction really creates a new memory that competes with memory of the original CR. Both memories co-exist. Over time the extinction memory may be lost, and the CR can return. The implication is that, just as ordinary learning needs rehearsal, so does extinction learning.
Therapy for emotional trauma and PTSD might be more effective if therapy were approached like a conventional learning experience whose memory is affected in all the usual ways. Recall what was said about extinction being a case of new learning. Re-learning of an extinguished response occurs much more readily than it does for an initial extinction learning. This is an example of priming. It’s like re-learning a foreign language. It goes easier the second time and the memory might be even more dependable.
Since memory of an emotional CR learning experience and its extinction can co-exist, these two memories compete for which one is strong enough to survive long-term. Sadly, the CR memory is often stronger. Cues are extremely important to both forming and retrieving all kinds of memory. It seems likely there are many more explicit cues for CR memories than for extinction memories. Therapy should be aimed at enriching the number and variety of cues associated with extinction learning. Rehearsal is likewise important. So far, nobody seems to have given that much thought.
There is another aspect to emotional learning: learning to learn. If you have multiple anxieties, they may generalize and "spread" to facilitate learning new anxieties. The corollary would be that learning how to promote extinction could also generalize and thus increasing the general ability to cope with emotional trauma. Obviously, for one's brain to learn how to do that, one would need to begin with a single relatively easy extinction learning task.
Dr. Bill Klemm is a Professor of Neuroscience at Texas A&M University. Visit his book site and blog at ThankYouBrain.com for more help on improving learning and memory. Copyright 2010, W. R. Klemm
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