Research Identifies Relationship Between Emotional Events And Memory
When we are asked about everyday events such as, for example, what we had for lunch the day before or what television programs we watched last weekend, we do not always have the answer at our fingertips. However, when the question involves events of great emotional importance, such as passing college or the birth of a child, our memories tend to be more vivid.
Considering this, an article published in the journal Nature Human Behavior, in January of this year, associated the memorization of events with emotions through high-frequency neuronal activities. The study, developed by a group of scientists at Columbia University, in the USA, also suggested that patients suffering from post-traumatic disorders, depression and other mental disorders may have greater difficulty storing and creating new memories.
According to Rafael Ruggiero, a researcher in the area of Neurosciences, with a focus on psychiatry, and a collaborating professor at the Faculty of Medicine of Ribeirão Preto (FMRP) at USP, it is already known that “we tend to keep memories that have a more relevant emotional content much easier and for much longer.” However, the novelty behind the international study was “to indicate a mechanism that could underlie this formation of emotional memory”.
With the help of human patients, the scientists carried out a series of tests. “The tests they did basically involved a list of words to memorize. Both words with emotional salience, such as, for example, ‘wedding’, ‘knife’, ‘dog’ and more neutral words, such as ‘bag’, ‘suitcase’, ‘watch’, which do not evoke so many emotions”, illustrates Ruggiero, who did not participate in the research. He says that, in the sequence, a mathematical task was applied to distract the patients and, a few seconds after its execution, the patients needed to remember the words. “What they noticed was a strong correlation between the emotional content of the word and the likelihood that it would be remembered.”
During the course of the study, the scientists analyzed data from memory tests that were conducted with volunteers with epilepsy who underwent direct intracranial brain recording for the location and treatment of seizures. During these recordings, the epilepsy patients memorized the lists of words, while electrodes placed on the hippocampus and amygdala recorded the brain’s electrical activity. “These patients were important for researchers to be able to observe and record intracerebral activities”, he explains.
New types of treatment
Overall, the Columbia University team demonstrated that high-frequency brain waves in the amygdala, a center for emotional processes, and the hippocampus, a center for memory processes, are essential for improving memory for emotional stimuli. Disruptions in this neural mechanism, caused by electrical brain stimulation or depression, impair memory specifically for emotional stimuli.
Not by chance, the amygdala is a set of neurons that make up part of the brain and is a region responsible for creating the “emotional coloring” to cognitive processing. The mechanism for creating and storing memories takes place in the interaction between the amygdala and the hippocampus. Knowing this, the scientists were able to hypothesize why patients with depression and post-traumatic disorders have more difficulty processing new information.
For the neuroscientist, the understanding of this neuronal mechanism can be used in favor of new treatments. “It can be used, for example, to strengthen some memories in cases of Alzheimer’s patients or patients with dementia.”
And the opposite also becomes valid: by inhibiting these high-frequency activities, it may be that the effects of a traumatic memory are softened. In the case of a patient who suffered an “extremely negative” trauma, which generated generalized anxiety, “perhaps, if we reduce the effect of these highly emotional memories, we can also reduce some of these symptoms in cases of post-traumatic stress disorder” , ends.