Parametric responses to binocular depth in human visual cortex
Dipartimento
BIOLOGIA
Corso di studi
NEUROSCIENCE
Relatori
relatore Prof.ssa Morrone, Maria Concetta tutor Prof. Parker, Andrew J.
Parole chiave
binocular disparity
fMRI
human visual cortex
pedestal depth
population receptive field
psychophysics
random dot stereograms
stereopsis
Data inizio appello
10/12/2018
Consultabilità
Non consultabile
Data di rilascio
10/12/2088
Riassunto
The neural processing of binocular disparity is one of the main mechanisms allowing three-dimensional (3D) vision in humans, and it takes place in the cerebral cortex. By using functional Magnetic Resonance Imaging (fMRI), it is possible to model neuronal receptive fields averaged over a population of the order of hundreds of thousands of neurons (population receptive field, pRF). The aim of this project was therefore to characterize disparity pRFs organization and response properties, i.e. the variability in tuning curve profiles, regarding in particular the nature of the response (tuned/categorical) and tuning width, in most visual areas currently known (V1, V2, V3, V4, VOC, LO1-2, V3A-B, TO1-2, V7), and assess how they relate to depth perception. We found that disparity pRFs are organized in accordance with the Weber-Fechner law, for both correlated and anticorrelated disparity stimuli. In the first case, however, we estimated significantly smaller Weber fractions in almost all areas. We also report that pRF tuning width in areas VOC and V3AB is a strong predictor of perceptual stereoacuity threshold.
