Christopher Murphy Lewis

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The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal(More)
Functional MRI (fMRI) studies have shown that low-frequency (<0.1 Hz) spontaneous fluctuations of the blood oxygenation level dependent (BOLD) signal during restful wakefulness are coherent within distributed large-scale cortical and subcortical networks (resting state networks, RSNs). The neuronal mechanisms underlying RSNs remain poorly understood. Here,(More)
Correlations in spontaneous brain activity provide powerful access to large-scale organizational principles of the CNS. However, making inferences about cognitive processes requires a detailed understanding of the link between these couplings and the structural integrity of the CNS. We studied the impact of multiple sclerosis, which leads to the severe(More)
People differ in their ability to perform novel perceptual tasks, both during initial exposure and in the rate of improvement with practice. It is also known that regions of the brain recruited by particular tasks change their activity during learning. Here we investigate neural signals predictive of individual variability in performance. We used(More)
This paper examines the role of the federal government in the market for terrorism reinsurance. We investigate the stock price response of affected industries to a sequence of 13 events culminating in the enactment of the Terrorism Risk Insurance Act (TRIA) of 2002. In the industries most likely to be affected by TRIA—banking, construction, insurance, real(More)
This experiment assessed the effects of a red versus a green versus a white office environment on worker productivity and mood. An equal number of males and females completed a mood questionnaire before and after proofreading in one of the three offices. It was predicted that the subjects in the red office would report more tension and possibly make more(More)
The Wharton Financial Institutions Center provides a multidisciplinary research approach to the problems and opportunities facing the financial services industry in its search for competitive excellence. The Center's research focuses on the issues related to managing risk at the firm level as well as ways to improve productivity and performance. The Center(More)
Intrinsic covariation of brain activity has been studied across many levels of brain organization. Between visual areas, neuronal activity covaries primarily among portions with similar retinotopic selectivity. We hypothesized that spontaneous interareal coactivation is subserved by neuronal synchronization. We performed simultaneous high-density(More)
The right postero-lateral cerebellum participates with the left frontal lobe in the selection and production of words. Using fMRI, we examined whether cerebellar activity switches hemispheres in parallel with recruitment of putative compensatory right homologous frontal regions in post-stroke aphasia. Re-examining the data of Blasi et al. [Blasi, V., Young,(More)