In an amazing study it was revealed that we get back even remotest and long-forgotten tragic events back to our memory on occasion when pushed to the corner or in utmost fear called the emotional implicit response. It means people forget tragic events of the past but maintain similar emotional reaction during post-traumatic events.
The study undertaken by the Cognition and Brain Plasticity group of the Bellvitge Biomedical Research Institute (IDIBELL) and the University of Barcelona shows how in case of fear, human brain encodes contextual memory of a negative event with more details of the place, what we saw and related details sharply into memory and prompts our emotional response.
The study findings said that in the context of fearful events, the electrodermal activity and the emotional implicit response was the same and much higher than in the neutral or unconnected context.
The study measures electrodermal activity of eighty-six individuals in a fearful context generated in the laboratory and in a neutral context in which they have to learn a list of words. One week and two weeks after the experiment they were tested to see which words they remembered.
Author Pau Packard said that there is a portion of memory that is erased or people do not have access in our memory lanes and they almost forget the details but during the contexts of fear and emotion, these memories are accessed instantly by the brain.
“In both contexts, forgetting curve was normal. Over time, they forgot all the words, the explicit trace. Moreover, in the fearful context the electrodermal activity —the emotional implicit response— was exactly the same, much higher than in the neutral context,” said Packard.
In traumatic events, it seems that, over time, there is a portion of memory that is erased or inaccesible. We forget the details but still maintain the emotional reaction. The imprint is divided into two separate paths and Packard says, “the brain dissociates the explicit memory of a negative event from the emotional response”.
This may help us to understand why in pathological situations of post-traumatic stress disorders, the uncontrolled emotional response linked to the negative event is generated without knowing what causes it.
Lluís Fuentemilla, project coordinator, emphasises that “the study helps to explain how the processing of fearful memories can lead to post-traumatic stress disorder”. Furthermore, it opens the door to the investigation of new therapeutic strategies for these disorders because “the implicit memory trace in a fearful context does not loose over time and can be detected through electrodermal measures”.
The study is published in the journal Neurobiology of Learning and Memory.