Electroencephalographic Study of the Mechanisms of Inhibition of Emotional Memories in Young Healthy Subjects

Forgetfulness has long been considered a pathology of memory. However, the brain's voluntary suppression of certain unpleasant memories is essential for building a healthy memory. This suppression capacity can be measured using the "Think/No-Think" (TNT) paradigm.However, while the areas involved in these processes of suppression are now well described, the nature and temporal dynamics of the processes of inhibition and orientation of attention is still poorly defined. The aim of this study is to describe the nature of the attentional and inhibitory mechanisms involved in the suppression of emotionally negative memories, and their temporal articulation using electroencephalography (EEG). To this end, we will use a model of memory deletion derived from a perceptual attentional task and simulating the deletion phase in order to control the nature and timing of the processes involved. This approach will allow us to observe the presence of correspondences between the responses measured during the attentional test simulating the suppression and the actual phase of suppression, for which we cannot control the nature of the operations undertaken by the subject. In addition, we will assess the emotional response through physiological measures of autonomic nervous system activity (heart rate and electrodermal response) immediately after the TNT phase or one day later, which will allow us to evaluate the influence of memory suppression mechanisms on their emotional content.

From a practical point of view, this study is organized into 3 groups of participants (healthy young adults). Each group will perform a perceptual attentional test and a TNT task, which will be preceded and followed by a measure of emotional response. Group 1 will allow us to test our main hypothesis from a behavioral point of view, as well as to calibrate the attentional task and its consistency with the TNT task. Group 2 will carry out the same tests but during an EEG examination to decode the temporal dynamics of attention states during the process of memory suppression. Group 3 will perform these same tests with a 24-hour interval between the TNT phase and the emotional assessment to estimate the effect of a retention period on forgetfulness functions.

The description of these mechanisms and their physiological correlates will allow us to better understand how this ability to voluntarily control the flow of thoughts associated with negative memories is implemented, and thus to better understand the alterations in this capacity that can be observed during certain mental pathologies such as anxiety or depression.