Richard Buxton, PhD

My primary research program focuses on applying quantitative MRI techniques to address basic questions in neurophysiology, particularly the physiological basis of functional MRI (fMRI). Functional MRI methods are widely used to map patterns of neural activity in the human brain, based on the fact that blood flow increases much more than oxygen metabolism during neural activation. The resulting change in blood oxygenation produces a change in the MR signal (called the Blood Oxygen Level Dependent (BOLD) effect). This surprising physiological phenomenon is still poorly understood, despite the fact that this effect lies at the heart of all fMRI studies. The primary experimental tool we use is the calibrated-BOLD method, which allows us to measure oxygen metabolism changes from combined blood flow and BOLD measurements. We combine the experimental data with extensive mathematical modeling efforts, including models of the imaging process and the underlying physiology. We are currently using these methods to investigate the links between neural activity, blood flow and energy metabolism.

Buxton RB, Griffeth VE, Simon AB, Moradi F. Variability of the coupling of blood flow and oxyen metabolism respponses in the brain: a problem for interpreting BOLD studies but potentially a new window on the underlying neural activity. Front Neurosci 8:139, 2014.

Liang CL, Ances BM, Perthen JE, Moradi F, Liau J, Buracas GT, Hopkins SR, Buxton RB. Luminance contrast of a visual stimulus modulates the BOLD response more than the cerebral blood flow response in the human brain. Neuroimage 2013 64:104-11.

Blockley NP, Griffeth VEM, Gemuska MA, Bulte DP, Buxton RB. An analysis of the use of hyperoxia for measuring venous cerebral blood volume: comparison of the existing method with a new analysis approach. Neuroimage 72:33-44, 2013.

Griffeth VEM, Blockley NP, Simon AB, Buxton RB. A new functional MRI approach for investigating modulations of brain oxygen metabolism. PLoS One 8:e68122, 2013.

Moradi F, Buxton RB. Adaptation of cerebral oxygen metabolism and blood flow and modulation of neurovascular coupling with prolonged stimulation in human visual cortex. Neuroimage 2013 82:182-9, 2013.

Devor A, Bandettini PA, Boas DA, Bower JM, Buxton RB, et al. Connecting the dots in the B.R.A.I.N. Neuron 80:270-4, 2013.

Buxton RB. The physics of functional magnetic resonance imaging. Rep Prog Phys 76:096601, 2013.

Blockley NP, Griffeth VE, Buxton RB. A general analysis of calibrated BOLD methodology for measuring CMRO2 responses: Comparison of a new approach with existing methods. Neuroimage 60:279-289, 2012.

Moradi F, Buracas GT, Buxton RB. Attention strongly increases oxygen metabolic response to stimulus in primary visual cortex. Neuroimage 59:601-7, 2012.

Buxton RB. Dynamic models of BOLD contrast. Neuroimage 62:953-61, 2012.

Griffeth VE, Buxton RB. A theoretical framework for estimating cerebral oxygen metabolism changes using the calibrated BOLD approach: modeling the effects of blood volume distribution, hematocrit, oxygen extraction fraction, and tissue signal properties on the BOLD signal. Neuroimage 58:198-212, 2011.

Buxton RB. Interpreting oxygenation-based neuroimaging signals: the importance and the challenge of understanding brain oxygen metabolism. Front Neuroenergetics 2:8, 2010.

Buxton, RB. Introduction to Functional Magnetic Resonance Imaging: Principles and Techniques, Cambridge University Press, 2002. Second revised edition published in October 2009.