The objectives of this SC3 grant are to determine the neural mechanisms that support memory awareness (i.e., knowing when you remember and when you do not) and metacognitive control of memory (e.g., being able to use appropriate strategies to improve memory), and whether they can be enhanced via non-invasive brain stimulation. This research lays the groundwork for the development of brain stimulation- based interventions that would improve impairments in memory awareness and memory functions for individuals with neurological and psychiatric disorders. Specifically, the experiments in this proposal examine accurate memory awareness by using `metamemory' tasks, in which participants report their confidence about their future memory performance. Confidence about future memory performance is compared with actual memory performance, which provides an objective measure of memory awareness. I have previously shown that high definition transcranial direct current stimulation (HD-tDCS), a type of brain stimulation, over the dorsolateral prefrontal cortex (DLPFC) leads to improved memory awareness, and that this result replicates. The proposed experiments are logical extensions of this exciting finding. First, Exps. 1-2 apply different kinds of brain stimulation that differ in strength, spatial focality, and potential side effects, in order to test what form of brain stimulation is optimal for pursuing as a potential intervention. Next, Exps. 3-4 test whether there are also brain stimulation-induced improvements in memory awareness using different kinds of memory tasks. This will inform which kinds of tasks are most likely to show brain stimulation-based improvements in memory awareness. Finally, Exps. 5-6, test whether brain stimulation-based improvements in memory awareness lead to improvements in memory performance via metacognitive control mechanisms. In other words, if memory awareness is improved, does this knowledge about one's memory also lead to better strategic decision making to improve memory. From a basic research perspective, the proposed experiments will lead to gains in scientific knowledge about the neural underpinnings of accurate memory awareness and inform broader theories of prefrontal function. From a health perspective, the proposed experiments have the potential to provide a foundation for brain stimulation- based interventions for impairments in memory awareness. Brooklyn College of the City University of New York provides an excellent environment for involving individuals from under-represented groups at all levels, from faculty and graduate students to undergraduate and even high school students. With continued SCORE support, Dr. Chua will be well positioned to have a strong, independent research career, enabling her to involve more students from under-represented minorities in high quality neuroscience research.
This project tests hypotheses about the brain mechanisms underlying awareness of one's memory and under what circumstances non-invasive brain stimulation improves memory awareness and memory. From a public health perspective, memory awareness is a critical issue because individuals with impaired memory awareness may be reluctant to seek help or compensate for their cognitive deficits. Testing how memory awareness can be enhanced with brain stimulation, and how this improves later memory performance, may be useful for developing interventions for specific deficits related to memory and awareness, and prefrontal dysfunction.