How Does Neuroscience Research Relate to Psychoanalysis?

Basic neuroscience research is sometimes, but mistakenly, thought to be singularly devoted to finding medications that will treat neurologic and psychiatric diseases. Although some basic neuroscience does suggest new molecular targets for medications, perhaps an even greater proportion of this research has helped us to understand the enduring effects of stress and potential psychosocial remedies. In fact, neuroscience research now appears capable of validating and exploring two of the central pillars of psychoanalytic theory: (1) that much of mental life is unconscious but nevertheless fully capable of affecting waking emotion and behavior and (2) that early life experiences have important implications for adult function and happiness.

An interesting example of a way in which neuroscience research may relate to psychoanalysis is the molecular biology of conditioned fear memory reconsolidation. In the laboratory, rats and mice can fairly easily be conditioned to fear a conditioned stimulus, like a loud tone, if it is paired a few times with an unconditioned stimulus, such as a mild electric shock. After conditioning, the animal responds to the tone by freezing in place, just as it did when given the shock. The process by which fear conditioning becomes part of permanent memory is called consolidation and requires a chain of molecular events, including gene expression and protein synthesis, in the amygdala. Blocking these events during conditioning, such as by administering a protein synthesis inhibitor like anisomycin, prevents the consolidation of fear memory, and no conditioned response can subsequently occur.

The amygdala is also activated in humans when they are presented with fearful stimuli. Patients with anxiety disorders have especially robust amygdala activation when their brain activity is monitored with functional magnetic resonance imaging (fMRI). Conditioned fear in rats responds to selective serotonin reuptake inhibitors (SSRIs) in almost the same temporal pattern as is seen in anxious patients. Thus, conditioned fear in animals is considered by many to be a model of human fear and anxiety.

Conditioned fear responses can be extinguished if the conditioned stimulus is presented multiple times without reinforcement by the unconditioned stimulus. That is, if the tone is presented to the rat over and over again without any electric shock, the animal eventually stops freezing. In this case, it has learned that tone and shock are not paired, a process that involves both the medial prefrontal cortex (mPFC) and the amygdala. But, importantly, the original fear memory is not abolished; rather, the original memory and the new extinction memory exist side by side in a delicate balance. At first, extinction dominates, and the animal does not freeze to the tone, but, after a period of time of no testing, the conditioned fear response can be easily reactivated by a single presentation of the conditioned stimulus.

In 2000, Karim Nader, PhD, and colleagues published a seminal article showing that a reactivated fear memory is temporarily labile and can be blocked from re-entering permanent memory. For the inactive memory to be returned to permanent memory, it must go through the consolidation process all over again. If this reconsolidation is blocked, for example as Nader and colleagues did by administering anisomycin right after memory reactivation, the animal will subsequently not freeze when the tone is presented. What is critically different between extinction and reconsolidation blockade, however, is that in the latter case the fear memory is permanently abolished.

In a 2011 article , Steven P. Roose, MD, and I proposed that psychoanalytic interpretations function in a manner similar to blocking the reconsolidation of fear memory. During psychoanalytic therapy, the patient gradually recovers memory of unconscious conflicts based on early traumatic experiences. When these memories become conscious, we speculated, the memories are labile. Psychoanalytic interpretation reframes them so that, when they are reconsolidated into permanent memory, they are no longer as disturbing and capable of producing negative or aversive emotions and self-destructive behavior. Hence, a successful interpretation should offer patients some measure of permanent relief.

Psychoanalysis is a complex theory, and no single model can ever truly be said to be an adequate model. But the idea that at least one aspect of psychoanalysis may be represented in the laboratory opens up intriguing possibilities for experimental study. I hope the reconsolidation hypothesis stimulates thinking about the neuroscientific basis of psychotherapy.

Financial disclosure:Dr Gorman is a consultant for Care Management Technologies and has received royalties from Oxford University Press.