Probing deeper into how such memories form, researchers at the University of Wisconsin-Madison have found that the mere anticipation of a fearful situation can fire up two memory-forming regions of the brain - even before the event has occurred.
That means the simple act of anticipation may play a surprisingly important role in how fresh the memory of a tough experience remains.
The findings of the brain-imaging study, which appear in the current issue of the Proceedings of the National Academy of Sciences, have important implications for the treatment of psychological conditions such as post-traumatic stress disorder (PTSD) and social anxiety, which are often characterized by flashbacks and intrusive memories of upsetting events.
"The main motivation for this study was a clinical one, in terms of understanding and applying knowledge about memory so that we can better inform the treatment of disorders that have a large memory component, like PTSD," says lead author Kristen Mackiewicz, a graduate student at the University of Colorado who worked on the anticipation study while a student at UW-Madison.
The project also builds on a relatively new body of work on the role of anticipation in emotion and clinical disorders, says senior author Jack Nitschke, a UW-Madison assistant professor of psychiatry and psychology.
"Our study illustrates how the power of expectancy can extend to memory formation as well," says Nitschke, also an associate of UW-Madison's Waisman Laboratory for Brain Imaging and Behavior. "Just the expectation of seeing something bad can enhance the memory of it after it happens."
A teacher who struggles with stage fright, for example, might feel anxious before every class she has to teach. The UW-Madison work suggests that the longer she spends dreading her next lecture, the stronger her memory of the uncomfortable experience is likely to be when it is over. Unfortunately, that sets a vicious cycle in motion, because the stronger her memory of discomfort, the worse her performance anxiety is likely to get.
The UW-Madison scientists found that two key regions of the brain - the amygdala and the hippocampus - become activated when a person is anticipating a difficult situation. Scientists think the amygdala is associated with the formation of emotional memories, while the hippocampus helps the brain form long-term recollections, Nitschke says.
The researchers studied the brain activity of 36 healthy volunteers using a technique known as functional magnetic resonance imaging, which produces high-contrast images of human tissue. They began by showing the volunteers two kinds of signals. One was neutral, but the other indicated that some type of gruesome picture was soon to follow, such as explicit photos of bloody, mutilated bodies. Thirty minutes after the researchers had shown dozens of violent images, they quizzed study participants on how well they remembered the pictures they had just seen.
"We found that the more activated the amygdala and hippocampus had been during the anticipation [of the pictures], the more likely it was that a person would remember more of them right away," says Nitschke.
Two weeks after the experiment, scientists met with the study subjects again to measure how well they remembered the same disturbing images. This time, they found that people who best remembered them had shown the greatest amygdala and hippocampus activity during the picture-viewing exercise two weeks before. That suggested that those subjects' brains had already started converting short-term memories of the images into longer-lasting ones.
Mackiewicz says the anticipation of an uncomfortable situation probably kick-starts a kind of "arousal or fear circuitry" in the brain, which in turn helps to reinforce old memories.
"In the future, we could look for ways to dampen that arousal response in patients so that they do not evoke negative memories so easily," she adds.
Jack Nitschke | EurekAlert!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy