1. fMRI: Biological Basis and Experiment Design Lecture 4 History Basic mechanism Outstanding questions

2. movie of steric conformations, from wikipedia.com

4. Basic BOLD Signal inversely proportional to deoxyhemoglobin concentration CBF = cerebral blood flow –increased CBF increases signal strength CBV = cerebral blood volume –increased venous blood volume decreases signal strength CMRO 2 = cerebral metabolic rate of oxygen –increased CMRO 2 decreases signal strength “... blood oxygenation level-dependent (BOLD) contrast: a change in the signal strength of brain water protons produced by the paramagnetic effects of venous blood deoxyhemoglobin.” –Ogawa et al. 1993

5. Harrison, Harel et al., Cerebral Cortex 12:225 (2002)

6. Discussion papers “Spikes versus BOLD: what does neuroimaging tell us about neuronal activity?” –David Heeger, Alex Huk, Wilson Beisler & Duane Albrecht –Nature Neuroscience 3(7):631. “Neurophysiological investigation of the basis of the fMRI signal” –Nikos Logothetis, Jon Pauls, Mark Augath, Torsten Trinath & Axel Oeltermann –Nature 412:150. “Separate spatial scales determine neural activity- dependent changes in tissue oxygen within central visual pathways,” –Jeffrey Thompson, Matthew Peterson, Ralph Freeman –Journal of Neuroscience 25(39)9046