Neuroimaging
We have used neuroimaging to answer specific questions that could not be satisfactorily addressed using psychophysics alone. With fMRI, we have mapped the cortical distribution of absolute and relative disparity signals across visual cortex (Neri et al 2004), and have demonstrated that they are to some extent separately encoded within dorsal and ventral streams (Neri 2005; see Fig. 1).
With EEG, we have estimated the timescale of natural scene segmentation (Neri 2017). A specific occipital EEG marker with coarse retinotopic properties, the N2pc wave, was found to reflect the perceptual significance of object boundaries and not their definition within the physical image (Fig. 2). The perceptual specificity of the modulation occurs very early (within 100 ms after stimulus onset), challenging compartmentalized accounts of bottom-up/top-down processing in natural scene understanding (forthcoming).
Relevant publications:
• Neri P Object segmentation controls image reconstruction from natural scenes 2017 PLoS Biology 15 (8) e1002611
• Neri P A stereoscopic look at visual cortex 2005 Journal of Neurophysiology 93 1823-1826
• Neri P, Bridge H, Heeger DJ Stereoscopic processing of absolute and relative disparity in human visual cortex 2004 Journal of Neurophysiology 92 1880-1891