title: Invariant object recognition with trace learning and multiple stimuli present during training.
abstract: Over successive stages, the ventral visual system develops neurons that respond with view, size and position invariance to objects including faces. A major challenge is to explain how invariant representations of individual objects could develop given visual input from environments containing multiple objects. Here we show that the neurons in a 1-layer competitive network learn to represent combinations of three objects simultaneously present during training if the number of objects in the training set is low (e.g. 4), to represent combinations of two objects as the number of objects is increased to for e.g. 10, and to represent individual objects as the number of objects in the training set is increased further to for e.g. 20. We next show that translation invariant representations can be formed even when multiple stimuli are always present during training, by including a temporal trace in the learning rule. Finally, we show that these concepts can be extended to a multi-layer hierarchical network model (VisNet) of the ventral visual system. This approach provides a way to understand how a visual system can, by self-organizing competitive learning, form separate invariant representations of each object even when each object is presented in a scene with multiple other objects present, as in natural visual scenes.
authors.affiliation: Department of Experimental Psychology, Oxford University, Centre for Computational Neuroscience, South Parks Road, Oxford OX1 3UD, England.
authors.forename: S M
authors.initials: SM
authors.lastname: Stringer
authors.forename: E T
authors.initials: ET
authors.lastname: Rolls
authors.forename: J M
authors.initials: JM
authors.lastname: Tromans
mesh_terms: D000818:Animals; D003198:Computer Simulation; D005793:Generalization, Psychological; D006801:Humans; D007858:Learning / Q000502:physiology*; D008959:Models, Neurological; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D014793:Visual Cortex / Q000166:cytology*; D014795:Visual Pathways / Q000502:physiology