Object-centred neglect: simulation with head-centred coding based on Gaussian gaze-dependent units.
Right brain damaged patients affected by contralesional object-centred neglect are able to process all objects around them but systematically omit the left part of these objects. We show that pure object-centred neglect can be simulated by a basis function neural network in which the activity of units allowing head-centred coding of space is based on the activity of gaze-dependent units with no lateral gradient of preferred eye positions along the horizontal space. This type of network simulates complete dissociation between object-centred and egocentric neglect, as observed in patients' copies of multi-item drawings. Based on these results and available neurophysiological, clinical and brain imaging data, it is proposed that disruption of a cerebral network including dorsal occipital and parietal areas and the supplementary eye fields could be the main cause of object-centred neglect.
Silvetti
Massimo
M
Fondazione Santa Lucia IRCCS, Roma, Italy. massimo.silvetti@uniroma1.it
Pessa
Eliano
E
Doricchi
Fabrizio
F
D000465:Algorithms; D002540:Cerebral Cortex / Q000503:physiopathology; D003198:Computer Simulation; D005403:Fixation, Ocular / Q000502:physiology*; D005556:Form Perception; D006801:Humans; D008959:Models, Neurological; D016571:Neural Networks, Computer; D016011:Normal Distribution; D010468:Perceptual Disorders / Q000503:physiopathology*; D014795:Visual Pathways / Q000503:physiopathology