Robert Savoy

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Generalization can be defined quantitatively and can be used to assess the performance of principal component analysis (PCA). The generalizability of PCA depends on the number of principal components retained in the analysis. We provide analytic and test set estimates of generalization. We show how the generalization error can be used to select the number(More)
We apply nine analytic methods employed currently in imaging neuroscience to simulated and actual BOLD fMRI signals and compare their performances under each signal type. Starting with baseline time series generated by a resting subject during a null hypothesis study, we compare method performance with embedded focal activity in these series of three(More)
The objective of this study was to investigate phonological processing in the brain by using sub-syllabic speech units with rapidly changing frequency spectra. We used isolated stop consonants extracted from natural speech consonant-vowel (CV) syllables, which were digitized and presented through headphones in a functional magnetic resonance imaging (fMRI)(More)
This study examined the cortical representation of vibrotactile detection in humans using event-related fMRI paired with psychophysics. Suprathreshold vibrotactile stimulation activated several areas, including primary (SI) and second somatosensory cortices (SII/PV). For threshold-level stimuli, poststimulus activity in contralateral and ipsilateral SII/PV(More)
Sputtering of highly oriented pyrolytic graphite (HOPG) by 248-nanometer laser radiation was studied. Neutral carbon atoms and small clusters were ejected with significantly higher translational energies than were expected from a simple model of thermal vaporization in the absence of a potential barrier. The HOPG also developed a remarkable surface(More)
C. Goutte1, L.K. Hansen1, R. Savoy2, S.C. Strother3 1Dept. of Mathematical Modelling, D.T.U., Lyngby, Denmark, 2Massachusets General Hospital, Boston, USA, 3PET Imaging Service, Minneapolis VA Medical Center, USA Delay analysis The high temporal resolution of fMRI allows to supplement the spatial analysis of the hemodynamic response to focal neuronal(More)
BOLD Effect (Blood Oxygen Level Dependent Effect) The change in T ∗ 2 that is caused by changes in the amount of oxygenated hemoglobin in the venous circulation of the brain. Because oxygenated hemoglobin has a much smaller magnetic susceptibility than deoxygenated hemoglobin, and because neural activity causes a change in the amount of oxygenated(More)
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