Erasing Fear Memories

Wouldn’t it be nice if you could erase certain undesirable memories? Maybe something you once saw or experienced that you wish you could forget. Dr. Carol Newall, a clinical psychologist at Macquarie University, has explored this idea in regards to fear memories. Perhaps learned fear memories can be erased.

Fear Memories

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When I say fear memories I am talking about some kind of learned fear to something, someone, or some situation (a stimulus). For example, a person may have been bit by a dog that led to a serious fear of dogs. In the movie The Italian Job ‘Left Ear’ explains “I don’t do dogs. I had a bad experience” (click here for movie clip). These bad experiences can lead to severe debilitation and anxiety disorders. As in the dog example, some people may completely avoid dogs, animals in general, or any possible location where dogs could be present.

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A classic example of the development of fear memories is the Little Albert experiment done by John Watson in 1920. This poor infant called Little Albert (approx. 1 year old) was introduced to a variety of objects including a live rabbit, a white rat, masks, etc. Researchers then paired the white rat with a frightening loud noise multiple times, creating a lot of distress for the child. Soon Little Albert was afraid of the rat even when there wasn’t a loud noise. Watson also found that this fear generalized to most furry things like a white rabbit or furry dogs. (click here for video of Little Albert experiment)

Fear Extinction

Treatment for people with severe fear memories often involves fear extinction. This is when the conditioned stimulus is presented multiple times without the situation or item that created the fear. In the case of Little Albert the white rat and furry objects would be presented many times without the loud noise. Over time Little Albert would no longer associate the loud noise (fearful stimuli) with the white rat. Unfortunately this primarily reduces the fear, but the association still remains. For example, if you went through fear extinction and no longer had a fear of dogs, your fear could be reinstated if you got bit again. This reinstatement of the fear demonstrates that fear extinction is not memory erasure.

Developmental Studies

Newall had studied fear extinction and reinstatement with rats. The accelerated development of rats allowed her to look at the differences of fear reinstatement or recovery at different ages. She found that the age at which fear extinction occurs actually determines fear recovery. The next step was to test this with humans and compare fear reinstatement in children and adults.

Woman’s face was paired with the audio of a shrieking scream. Click for source

First, all subjects were fear conditioned by presenting a picture of a frightened woman’s face and a shrieking scream (the screaming lady). After conditioning the fear of the screaming lady the subjects went through fear extinction where the face was presented, but without the scream. Finally, the screaming lady resurrection! The children and adults were then given the same women’s face with the shrieking scream. Through a self-report on the subject’s fear level and scream expectancy, Newall found some interesting results. The fear reinstatement occurred in the adults, but not in the children. Additionally, the children and adults had about the same scream expectancy, but nevertheless the children’s fear level was not very affected.

Can Fear Memories Be Erased?

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Newall’s research suggests that fear extinction may be more permanent with children than adults. Nevertheless, since the children were still able to match the adult’s scream expectancy levels, it is likely the actual fear memory was not erased. True memory erasure seems to still be a long way off. Nevertheless, this research leaves a lot open for further studies on fear erasure beyond conditioned fear, or work on anxious children and fear extinction.

Further Reading

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