Modulation of spontaneous fMRI activity in human visual cortex by behavioral state. Export

@article{citeulike:4745169, abstract = {The phenomenon of spontaneous fMRI activity is increasingly being exploited to investigate the connectivity of functional networks in human brain with high spatial-resolution. Although mounting evidence points towards a neuronal contribution to this activity, its functional role and dependence on behavioral state remain unclear. In this work, we used BOLD fMRI at 7 T to study the modulation of spontaneous activity in occipital areas by various behavioral conditions, including resting with eyes closed, eyes open with visual fixation, and eyes open with fixation and focal visual stimulation. Spontaneous activity was separated from evoked activity and from signal fluctuations related to cardiac and respiratory cycles. We found that spontaneous activity in visual areas was substantially reduced (amplitude (44\%) and coherence (25\%)) with the fixation conditions relative to the eyes-closed condition. No significant further modulation was observed when the visual stimulus was added. The observed dependence on behavioral condition suggests that part of spontaneous fMRI signal fluctuations represents neuronal activity. Possible mechanisms for the modulation of spontaneous activity by behavioral state are discussed. The observed linear superposition of spontaneous fMRI activity with focal evoked activity related to visual processing has important implications for fMRI studies, which ideally should take into account the effect of spontaneous activity to properly define brain activations during task conditions.}, author = {Bianciardi, M. and Fukunaga, M. and van Gelderen, P. and Horovitz, S. G. and de Zwart, J. A. and Duyn, J. H.}, citeulike-article-id = {4745169}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.neuroimage.2008.10.034}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19028588}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19028588}, doi = {10.1016/j.neuroimage.2008.10.034}, issn = {1095-9572}, journal = {NeuroImage}, keywords = {bold, fmri, resting-state, visual\_system}, month = {March}, number = {1}, pages = {160--168}, posted-at = {2009-06-09 10:31:57}, priority = {2}, title = {Modulation of spontaneous fMRI activity in human visual cortex by behavioral state.}, url = {http://dx.doi.org/10.1016/j.neuroimage.2008.10.034}, volume = {45}, year = {2009} }

TY - JOUR ID - citeulike:4745169 L3 - citeulike-article-id:4745169 N2 - The phenomenon of spontaneous fMRI activity is increasingly being exploited to investigate the connectivity of functional networks in human brain with high spatial-resolution. Although mounting evidence points towards a neuronal contribution to this activity, its functional role and dependence on behavioral state remain unclear. In this work, we used BOLD fMRI at 7 T to study the modulation of spontaneous activity in occipital areas by various behavioral conditions, including resting with eyes closed, eyes open with visual fixation, and eyes open with fixation and focal visual stimulation. Spontaneous activity was separated from evoked activity and from signal fluctuations related to cardiac and respiratory cycles. We found that spontaneous activity in visual areas was substantially reduced (amplitude (44%) and coherence (25%)) with the fixation conditions relative to the eyes-closed condition. No significant further modulation was observed when the visual stimulus was added. The observed dependence on behavioral condition suggests that part of spontaneous fMRI signal fluctuations represents neuronal activity. Possible mechanisms for the modulation of spontaneous activity by behavioral state are discussed. The observed linear superposition of spontaneous fMRI activity with focal evoked activity related to visual processing has important implications for fMRI studies, which ideally should take into account the effect of spontaneous activity to properly define brain activations during task conditions. IS - 1 JF - NeuroImage SN - 1095-9572 EP - 168 TI - Modulation of spontaneous fMRI activity in human visual cortex by behavioral state. VL - 45 SP - 160 KW - bold KW - fmri KW - resting-state KW - visual_system AU - Bianciardi, M AU - Fukunaga, M AU - van Gelderen, P AU - Horovitz, SG AU - de Zwart, JA AU - Duyn, JH PY - 2009/03/01/ UR - http://dx.doi.org/10.1016/j.neuroimage.2008.10.034 ER -