First evidence that fear memories can be reduced during sleep

September 22, 2013, Northwestern University
The right hippocampus (shown in the blue box) was one of the brain regions that showed significant changes in activity after fear memory reactivation during sleep. Credit: Dr. Katherina K. Hauner

A fear memory was reduced in people by exposing them to the memory over and over again while they slept. It's the first time that emotional memory has been manipulated in humans during sleep, report Northwestern Medicine scientists.

The finding potentially offers a new way to enhance the typical daytime treatment of phobias through exposure therapy by adding a nighttime component. Exposure therapy is a common treatment for phobia and involves a gradual exposure to the feared object or situation until the fear is extinguished.

"It's a novel finding," said Katherina Hauner, a in neurology at Northwestern University Feinberg School of Medicine. "We showed a small but significant decrease in fear. If it can be extended to pre-existing fear, the bigger picture is that, perhaps, the treatment of phobias can be enhanced during sleep."

Hauner did the research in the lab of Jay Gottfried, associate professor of neurology at Feinberg and senior author of the paper.

The study will be published Sept. 22 in the journal Nature Neuroscience.

Previous projects have shown that spatial learning and motor sequence learning can be enhanced during sleep. It wasn't previously known that emotions could be manipulated during sleep, Northwestern investigators said.

In the study, 15 healthy human subjects received mild electric shocks while seeing two different faces. They also smelled a specific odorant while viewing each face and being shocked, so the face and the odorant both were associated with fear. Subjects received different odorants to smell with each face such as woody, clove, new sneaker, lemon or mint.

Then, when a subject was asleep, one of the two odorants was re-presented, but in the absence of the associated faces and shocks. This occurred during when is thought to occur. Sleep is very important for strengthening , noted Hauner, also a research scientist at the Rehabilitation Institute of Chicago.

"While this particular odorant was being presented during sleep, it was reactivating the memory of that face over and over again which is similar to the process of fear extinction during ," Hauner said.

When the subjects woke up, they were exposed to both faces. When they saw the face linked to the smell they had been exposed to during sleep, their fear reactions were lower than their fear reactions to the other face.

Fear was measured in two ways: through small amounts of sweat in the skin, similar to a lie detector test, and through neuroimaging with fMRI (functional magnetic resonance imaging). The fMRI results showed changes in regions associated with memory, such as the hippocampus, and changes in patterns of brain activity in regions associated with emotion, such as the amygdala. These brain changes reflected a decrease in reactivity that was specific to the targeted face image associated with the presented during sleep.

Explore further: Diminishing fear vicariously by watching others

Related Stories

Diminishing fear vicariously by watching others

September 16, 2013
Phobias—whether it's fear of spiders, clowns, or small spaces—are common and can be difficult to treat. New research suggests that watching someone else safely interact with the supposedly harmful object can help to extinguish ...

People with spider phobia handle tarantulas, have lasting changes in brain after short therapy

May 21, 2012
A single brief therapy session for adults with a lifelong debilitating spider phobia resulted in lasting changes to the brain's response to fear.

Study reveals potential target to better treat, cure anxiety disorders

March 5, 2013
Researchers at Boston University School of Medicine (BUSM) have, for the first time, identified a specific group of cells in the brainstem whose activation during rapid eye movement (REM) sleep is critical for the regulation ...

Changes in patterns of brain activity predict fear memory formation

March 4, 2013
Psychologists at the University of Amsterdam (UvA) have discovered that changes in patterns of brain activity during fearful experiences predict whether a long-term fear memory is formed. The research results have recently ...

Study indicates visual adaptation enhanced by sleep and may be tied to memory

August 28, 2013
(Medical Xpress)—A team of researchers at University College in London has conducted a study that suggests that visual adaptation is enhanced by sleep and might also be tied to memory. In their paper published in Proceedings ...

Giving phobias a rest: Research suggests key role for sleep in treating anxiety, stress

July 24, 2012
Exposure therapy for irrational fear of spiders seems to be more effective if it is followed by sleep, according to a recent study in the Journal of Psychiatric Research. The results have implications for treatment of phobias, ...

Recommended for you

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.