This version had both σd and σf parameters, but no k parameter. Model fits were compared using two different measures that see more account for differences in number of model parameters: cross-validated r2 and AIC. See Supplemental Experimental Procedures. Eye position was monitored during the experiments, and analysis of the data did not reveal any potential artifacts. See Supplemental Experimental Procedures. This work was supported by a Career Award in the Biomedical

Sciences from the Burroughs Wellcome Fund and a National Research Service Award (NRSA) from the National Eye Institute (F32-EY016260) to J.L.G., and National Institutes of Health Grants R01-MH069880 (to D.J.H.), R01-EY016200 (to M.C.), and R01-EY019693 (to D.J.H. and M.C.). F.P. was supported by Gardner Research Unit, RIKEN Brain Science Institute, The Italian Academy for Advanced Studies in America, and training grants from the National Institute of Mental Health (T32-MH05174) and National Eye Institute (T32-EY1393309). We thank the Center for Brain Imaging at New York University for technical assistance, Aniruddha Fulvestrant cost Das, Adam Kohn, and J. Anthony Movshon for helpful comments on previous versions of the manuscript, and Vince Ferrera and Brian A. Wandell for generous support and advice. “
“Broad-band neuroelectric field potentials

recorded from within the brain have been used to investigate brain functioning in nonhuman animals began shortly after the discovery of the electroencephalogram or EEG (Bullock, 1945, Galambos, 1941 and Marshall et al., 1937). While the technique was overshadowed by action potential recording for a number of years, its importance has reemerged over the past decade because of the observations that the field

potential is linked to the neural underpinnings of hemodynamic signals (Logothetis et al., 2001), as well as magnetoencephalographic (MEG) and scalp EEG signals (Heitz et al., 2010, Mitzdorf, 1985, Schroeder et al., 1991 and Steinschneider mafosfamide et al., 1992). Additionally, it is now widely recognized (e.g., Schroeder et al., 1998) that because field potentials are generated by transmembrane current flow in ensembles of neurons (Eccles, 1951 and Lorente de No, 1947), they can index processes and events that are causal to action potentials. Finally, field potentials form part of the signal spectrum that can drive neuroprosthetic devices (Hatsopoulos and Donoghue, 2009), even when accessed indirectly with noninvasive recording from the scalp (Wolpaw, 2007). Recent reports have suggested that field potentials recorded within the brain are in general, extremely local phenomena, reflecting neuronal processes occurring within approximately 200–400 μm of the recording electrode in the cortex (Katzner et al., 2009 and Xing et al., 2009). This basic proposition is imbued in the common use of the term local field potential (LFP), which has become widespread in the literature, particularly over the last 10 years.