• Explain memory consolidation and how it can be manipulated using concepts from conditioning
• Describe how reconsolidation can be used to treat anxiety or PTSD

You’ve learned about treatment methods in broad terms—now we’ll take a closer look at a relatively new treatment method that relies on principles of behavioral therapy.

Memory and Mental Disorders

Problems with memory are at the core of many psychological disorders. For example, people suffering from both clinical-level depression and posttraumatic stress disorder (PTSD) often have difficulty remembering the details of specific memories, especially for happy experiences. This is called overgeneralized autobiographical memory (OGM). A therapist might ask a depressed person showing OGM to recall a recent happy experience. The depressed person might answer, “When I was visiting my friends last weekend,” but then be unable to recall or describe any particular events or interactions during that visit that were enjoyable or rewarding. For another example, people suffering from obsessive-compulsive disorder (OCD) experience less confidence in the accuracy of memories they retrieve than people without the disorder. This uncertainty about memory can lead to obsessive thoughts about whether they turned off the stove or paid the electric bill when it was due.

You may also have learned by now that remembering and thinking about past events—either recent or long ago—is the basis of most forms of psychotherapy. The psychodynamic therapy developed by Sigmund Freud is almost entirely based on remembering actual experiences or recent dreams. Even newer forms of therapy, like Cognitive-Behavioral Therapy (CBT), involve a great deal of memory work.

It may seem that research laboratories in universities and medical centers are a long way from psychotherapists’ offices, but professional therapists keep up with new developments in basic research and they often collaborate with researchers in bridging the gap between new theories and the application of those theories in the real world. A great example of the basic research-applied research connection is the development of therapies that can change the emotional impact of some memories without erasing or otherwise distorting them.

Memory Consolidation

consolidation

The neural processes that occur between an experience and the stabilization of the memory for that experience is called consolidation. Consolidation is complex, with some consolidation processes taking minutes to hours and other consolidation processes taking weeks, months, or even years. For the rest of this reading, we will concern ourselves with the quick part of consolidation that occurs in the hours and days immediately after an experience.

Old Views: Memory is Like a Book

The idea of consolidation does not rule out forgetting. Memories can fade—that is, lose details—or become impossible to retrieve. In the reading on memory, you also learned that misinformation that a person hears shortly after an event can be incorporated into the memory. But the idea is that the final version of the memory is essentially fixed once it has consolidated within a few hours. This late-20th-century theory says that memory is like a book. When it is first printed, the ink must dry (the consolidation process that takes up to a few hours), but when that has occurred, the contents of the book don’t change. The ink may fade over time or you may have trouble finding it in your library, but the contents of the book never change, no matter how often you pull it out to read it.

New Views: Memory is Like Saving a Computer File

Around the beginning of the current century, our understanding of memory was shaken by new research, first in animal labs, but later with humans.^[1] The study that initially caught the attention of memory scientists was a study using rats as subjects by Karim Nader, Glenn Schafe, and Joseph Le Doux of New York University in the year 2000. They taught their animals a fear memory by pairing a particular sound with a mild, but unpleasant shock using classical conditioning. The researchers found that they could change a memory that had already been consolidated if they did just the right things at just the right time.

reconsolidation

What Nader and his colleagues found was that memories become open to changes for a brief period of time when they are retrieved. For a few hours, the changed memories can be disrupted (e.g., by trauma to the brain, by drugs, and by other means), but once they have RE-consolidated, they become a new version of the memory.

This newer theory of memory says that our memories are not like books with print that dries, but memory is more like a computer file that is updated without saving the original. You originally create the memory (consolidation) and store it away. When you retrieve the memory, you can change some information in the file, but this new version now becomes the memory. Many researchers believe we don’t have a backup version of the original memory. All we have is the new, modified memory of the event.

Reconsolidation: In the Basic Research Lab

The theory of reconsolidation has changed the way we think about the stability and accuracy of memories. How do you think that “rewriting” a memory might be able to help someone experiencing a specific phobia of spiders?

Let’s look at some research conducted by Dr. Elizabeth Phelps, a highly respected psychologist who is one of the leaders on modern neuroscience of emotion and cognition, Daniella Schiller (an associate professor of psychiatry at Mt. Sinai Hospital in New York), and some of their colleagues.

Dr. Phelps and her colleagues classically conditioned volunteer research participants to fear a shock. They allowed this learning (i.e., the conditioned fear response) to consolidate, and then figured out the way to eliminate the fear response.

To start, we are going to look at what happened in one of the control conditions, which will give you an idea about what normally happens with this kind of fear learning.

DAY 1 – Control Group

On Day 1 for the control group, we create a memory for participants so that they come to “fear” a yellow box. Click through the slides to see how the participants were conditioned.

Day 1 is successful when classical conditioning of the fear response to the yellow box is complete. The participant now shows a fear response to the yellow box.

Note: we used emoticons in the exercise above, but the actual dependent variable in the study was a physiological measure of fear: skin conductance. When we are scared, our sweat glands respond by producing sweat, sometimes a lot, sometimes a little, but always some. This moisture on our skin changes the way that electricity moves across the skin, and these changes can be detected and measured, even if the changes are very subtle. This is the skin conductance response (called SCR). Detection of changes in skin conductance is simple, requiring only some detectors on your fingers, and it is painless.

DAY 2 – Control Group

For the control group, Day 2 involves extinction, which is the process of unlearning the fear response. Extinction is simple. You repeatedly show the person the yellow box, but there are no shocks. Over time, the person learns a new association: the yellow box means no shock. But this takes some time.

Day 2 has been successful. The person is no longer afraid of the yellow box. But, we’re still not quite done. We need to test for spontaneous recovery. Let’s go to Day 3.

DAY 3 – Control Group

What is shown above is what typically happens. Despite the fact that the person learned on Day 2 that the yellow box does not signal a shock, if you wait a while (hours or, as in this case, 24 hours), the fear response has returned. This is called spontaneous recovery of the fear response.

Spontaneous recovery is one of the big problems with extinction training. You can get rid of a response for a while, but the response can return over and over again.

According to the researchers—Dr. Phelps and Dr. Schiller—the problem may be that the person has two memories: one where the yellow box means a shock is coming, and another that means the yellow box equates to no shock. These two memories are both available, so when a yellow box happens to retrieve the first memory (yellow box = shock), the fear response returns.

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