INSPIRE Proposal: Spatiotemporal structure of the rs-fMRI signal reflects contributions from different types of brain activity

Emory University, Atlanta GA

Investigators

Abstract

This INSPIRE award is partially funded by the Perception, Action, and Cognition Program in the Division of Behavioral and Cognitive Sciences in the Directorate for Social, Behavioral, and Economic Sciences, the Physics of Living Systems Program in the Division of Physics in the Directorate for Mathematical and Physical Sciences, and the Neural Systems Cluster in the Division of Integrative Organismal Systems in the Directorate for Biology, and the Office of Integrative Activities. A key roadblock to understanding how the human brain works is that it is currently impossible to examine activity throughout the whole brain non-invasively with both a spatial resolution that is adequate to resolve functional areas and a temporal resolution on the time scale of cognitive processes. One possible improvement is to use resting state functional magnetic resonance imaging (rs-fMRI), which can image the whole brain non-invasively with potentially acceptable resolution. The drawback is that rs-fMRI measures the relative oxygenation level of the blood and contains contributions from non-localized fluctuations in blood flow and volume in addition to localized contributions linked to neural activity. The possibility exists that particular spatial and temporal patterns in the rs-fMRI signal may represent separable contributions from different types of brain activity. For example, the rs-fMRI signal may carry not only information about the magnitude and duration of neural activity but also information about the underlying patterns or "carrier waves" for neural information processing. If successful, this project would allow the mapping of different types of brain activity throughout the whole brain, a feat that cannot be achieved by any current imaging modality. To this end, the investigators conduct simultaneous functional magnetic resonance imaging and direct neural recording to determine the relation between fluctuations in the rs-fMRI signal and electrophysiological brain activity and to examine the effect of spontaneous fluctuations in the rs-fMRI signal on perception and cognition. Goals are to 1) identify rs-fMRI analogues of high frequency and very low frequency electrical activity using multimodal experiments and spatiotemporal analysis; 2) determine how spontaneous fluctuations in activity affect the processing of sensory stimuli in rats and humans; and 3) explore whether the rs-fMRI analogues of high and very low frequency activity specifically predict human performance on cognitively demanding tasks. Collectively, the studies will lead to a better understanding of how spatiotemporal patterns of brain activity measured non-invasively combine during neurocognitive processing, knowledge that is likely to provide new insights about mental processing differences across individuals, within individuals across time, and across groups with different brain organization (e.g., damage or disease). A strong broader impact of this award is that it will allow the researcher to ramp up her efforts to provide a clearinghouse for information and resources for mothers in STEM fields, helping them stay in the academic pipeline. The PI recently initiated a web resource and forum, "Moms in STEM," and has organized a community of female scientists committed to contributing articles and information to the website.