Receptive Fields in Human Visual Cortex Mapped with Surface Electrodes

Abstract

Most of our understanding of the functional organization of human visual cortex comes from lesion and functional imaging studies and by extrapolation from results obtained by neuroanatomical and neurophysiological studies in nonhuman primates. Although some single-unit and field potential recordings have been made in human visual cortex, none has provided quantitative characterization of spatial receptive fields (RFs) of individual sites. Here we use subdural electrodes implanted for clinical purposes to quantitatively measure response properties in different regions of human visual cortex. We find significant differences in RF size, response latency, and response magnitude for sites in early visual areas, versus sites in later stages of both the dorsal and ventral streams. In addition, we use this technique to estimate the cortical magnification factor in early human visual cortex. The spatial and temporal resolution of cortical surface recordings suggest that this technique is well suited to examine further issues in visual processing in humans.

Integration of EEG source imaging and fMRI during continuous viewing of natural movies

“…Thirdly, crosscorrelation analysis revealed that the mean response latency in Area 17 was slightly earlier than that observed in Area 18 and significantly earlier than responses in Area 19 (Pb.01). This trend is consistent with a recent study where visual stimuli were presented to subjects (selected for clinical purposes) with subdural electrodes implanted over different regions of the visual cortex [36], as well as with signal arrival times recorded across distinct visual regions in nonhuman primates [37]. Taken together, these EEG source imaging results indicate that the artifact-correction methodology correctly identified and removed unwanted nonneural components of the EEG signal while preserving those containing information which reflected the movie stimulus.…”

Population receptive field estimates in human visual cortex

“…9). Third, pRF size estimates across the visual cortex agree with estimates acquired using cortical surface electrodes in humans (Yoshor et al, 2007). stimuli were 3 s in duration and separated by 30-s intervals.…”

“…In addition, the fMRI-pRF sizes are comparable to human electrophysiological measurements estimated using surface electrode with a 2.2-mm-diameter recording area (Yoshor et al, 2007). Yoshor et al (2007) report pRF sizes in early visual cortex, roughly corresponding to V1/V2, as σ = 0.76°± 0.23°.…”

“…Yoshor et al (2007) report pRF sizes in early visual cortex, roughly corresponding to V1/V2, as σ = 0.76°± 0.23°. Sizes in later visual cortex roughly corresponding to V3/V3A/hV4, are estimated as σ = 1.49°± 0.81°.…”

Two Critical and Functionally Distinct Stages of Face and Body Perception

“…Experimental techniques with high temporal resolution, including scalp electroencephalography, magnetoencephalography (MEG), and intracranial recording in neuropsychological patients, report the earliest cortical response recorded to any visually presented stimulus occurs at latencies ranging from 50 to 100 ms after stimulus onset (Martínez et al, 1999;Furey et al, 2006;Yoshor et al, 2007). Other studies examining high-level visual object recognition report a selective response for specific object categories, including faces and bodies, beginning 100 -200 ms after stimulus onset (Bentin et al, 1996;Thorpe et al, 1996;Eimer, 1998;Allison et al, 1999;Liu et al, 2002Liu et al, , 2009Furey et al, 2006;Thierry et al, 2006;Engell and McCarthy, 2010).…”