Agenda

Emergence of Transformation-Tolerant Representations of Visual Objects in Rat Lateral Extrastriate Cortex

Speaker: Davide Zoccolan, SISSA

Abstract
Rodents are emerging as increasingly popular models of visual functions. Yet, evidence that rodent visual cortex is capable of advanced visual processing, such as object recognition, is limited. In my seminar, I will describe the results of a recent study in which we have investigate how neurons located along the progression of extrastriate areas that, in the rat brain, run laterally to primary visual cortex, encode object information. We found a progressive functional specialization of neural responses along these areas, with: i) a gradual increase of receptive field size and response latency; ii) a sharp reduction of the amount of low-level, energy-related visual information encoded by neuronal firing; and iii) a substantial increase in the ability of single neurons to support discrimination of visual objects under identity-preserving transformations (e.g., position and size changes). These findings strongly argue for the existence of a rat object-processing pathway, and point to the rodents as promising models to dissect the neuronal circuitry underlying transformation-tolerant recognition of visual objects.

Bio sketch
Davide Zoccolan obtained his Laurea (M.S. equiv) in Physics at the University of Torino (Italy) in 1997. He then joined the group of Prof. Vincent Torre at the International School for Advanced Studies (SISSA) of Trieste (Italy), where he studied sensory-motor integration, motor pattern generation, and decision-making in an invertebrate model system. After obtaining his PhD in Biophysics at SISSA in 2002, he was awarded a Long Term HFSP Postdoctoral Fellowship to work as a post-doctoral fellow in the research groups of Prof. James DiCarlo and Prof. Tomaso Poggio, at the McGovern Institute for Brain Research of the Massachusetts Institute of Technology (MIT), in Cambridge (USA). Here, he studied the neuronal mechanisms underlying visual object recognition, using a combination of computational modeling and single-unit neuronal recordings from primate inferotemporal cortex. Starting from 2006, in collaboration with Dr. David Cox, he developed an independent line of research within the DiCarlo’s lab, with the goal of establishing rodent models for the study of higher-level visual functions. In 2008, he pursued this research by joining the recently established lab of Dr. David Cox at the Rowland Institute at Harvard (Harvard University), in Cambridge (USA). In 2008, he has been awarded the Accademia Nazionale dei Lincei – Compagnia di San Paolo Grant to join SISSA Neurobiology and Cognitive Neuroscience Sectors and start, in 2009, a Visual Neuroscience Lab, where he studies the neuronal basis of visual object recognition using a combination of psychophysics and electrophysiology in rodents, and computational modeling. In 2013, he obtained a Consolidator ERC grant. He is currently Associate Professor in Psychobiology and Physiological Psychology.