View clinical trials related to Consolidation.
Filter by:Memory benefits from sleep and these benefits are putatively achieved through reactivation of the neural memory trace during sleep. Studies examining the effects of reactivation commonly focus on single, isolated items - but real-life memories never exist in a vacuum. Individual memories are bound to the context (e.g., the location, time and state of mind in which they are encoded) and this context is later reinstated to recall the details related to the memory. The question of how context participated in the process of sleep reactivation has never been directly examined. This experiment will monitor brain activity during memory encoding, sleep and finally retrieval to investigate the role context plays in sleep-related memory consolidation. Monitoring will be done using functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) recordings. Participants will go through a series of training trials, in which they will have to learn to associate several small images of items or animals with a larger image of scenes - and also learn the spatial location of these smaller images on the screen. The order of the presented images and the scenes in which they are embedded will remain constant throughout training, creating a solid, consistent temporal context in which item memories will be embedded. After training, participants will receive a 90 minute nap opportunity, during which the sounds associated with specific images will be unobtrusively presented. I expect memory for the spatial location of the cued images to improve. Importantly, I hypothesize that this effect will carry over to other items associated with the same scene (i.e., embedded in the same context) and that the temporal order in which the images were learned will govern this effect. I will use the EEG and fMRI data to estimate, on the basis of neuronal pattern activity, the level of contextual reinstatement and will build on these data, in combination with the behavioral results, to model the level of contextual involvement during sleep. These results could pave the way towards a unified theory of sleep's role in memory consolidation, which would encompass computational models of context and memory as well.
The context in which memories are encoded is a major factor influencing how memories are organized. Individual memories are bound to the context (e.g., the location, time and state of mind in which they are encoded) and this context is later reinstated to recall the details related to the memory. Although the role of context has been explored with regard to memory encoding and retrieval, its role during sleep-related memory consolidation has not been explored. Memories are thought to be reactivated during sleep, subsequently benefitting from the process. This study will use encephalography (EEG) in humans to consider several competing hypotheses regarding context's role in sleep reactivation, thereby enhancing the current understanding of how reactivation of memory over sleep relates to models of context and memory. Participants will learn to associate pictures of scenes to different sounds and to smaller images of items and animals, and then learn the spatial locations of these smaller images on a grid. Crucially, for half of these scenes, the sounds themselves will then also be linked directly to some of images during training. The associated sounds will then be unobtrusively presented during sleep, in a manner that has been shown to improve associated memories. The subsequent memory benefits will reveal whether (1) all images associated with the cued scene will benefit from cuing, demonstrating a context-reactivation effect; (2) only the images directly associated with presented sound will benefit from the cuing, demonstrating a item-reactivation effect; or (3) some composite of these two models. Regardless of which hypothesis is correct, the results will expand our current understanding regarding the role context plays in sleep consolidation.
The purpose of this study is to test the efficacy of an evidence-based tailored physical activity program adapted for adults with acute leukemia. Implementation-related process evaluation of the physical activity program will also be assessed.
These studies test the hypothesis that sensory areas of the brain participate in the consolidation of speech motor memory by using transcranial magnetic stimulation to suppress activity in somatosensory and auditory cortex following adaptation in order to block retention of learning.