Emotional events are often better remembered than neutral events. Research suggests this is due, at least in part, to the amygdala and its interactions with other brain regions in the medial temporal lobe (MTL). Although there is broad support for the role of the amygdala and MTL in memory, little is known about how the amygdala differentially modulates recall vs. recognition memory. Prior work shows that direct electrical stimulation of the human amygdala enhances recognition memory and increases neuronal oscillations between the amygdala and downstream MTL regions. However, the effects of amygdala stimulation on recall memory and subsequent amygdala-MTL interactions is unknown. We are interested in examining the neural correlates of recall memory in the context of amygdala-mediated memory enhancement. This research aims to use previously collected data from experiments using depth electrodes to directly stimulate the amygdala in human patients to investigate whether brief electrical stimulation enhances recall memory and influences amygdala-MTL interactions (see Figure 1 in Supplement for task design). More specifically, this study explores the interactions between the amygdala and hippocampus and how these interactions may facilitate recall memory. To extract behavioral data, each individual patient's free recall list of remembered images was examined, and it was determined whether the image they recalled was one they actually saw during the encoding phase and whether the image was associated with amygdala stimulation. Data analysis determined the ratio of images recalled that were associated with amygdala stimulation during encoding (see Figure 2 in Supplement), whether a clustering effect occurred, and the percentile of the stimulated images in the recall list. Finally, an analysis script incorporated permutation testing in Python on the original dataset to test the null hypothesis. For the uncompleted aspects of this project, the neural correlates of amygdala-mediated recall memory enhancement within the amygdala and hippocampus will be analyzed by examining the neural data for each patient's recall-memory trials and calculating the difference between the oscillatory activity for remembered images in the BLA stimulation condition vs. the non-stimulation condition. Additionally, the subsequent memory effects will be investigated to determine the neural states during encoding that predict successful recall during retrieval. Finally, the neural correlates of correctly recalled vs. incorrectly recalled items will be studied by examining the neuronal oscillations between the BLA and hippocampus during recall of an image that the patient saw during encoding vs. false recall of an image that the patient never saw during encoding. Together, the results of this project will clarify the involvement of the amygdala and amygdala-hippocampal interactions in recall memory, opening a path to future therapies for episodic memory loss.
University / Institution: University of Utah
Format: In Person
SESSION A (9:00-10:30AM)
Area of Research: Social Sciences
Faculty Mentor: Cory Inman