A hierarchical model of the early visual system is presented. This model consists of three retinotopically connected layers. Each layer is composed of a one dimensional array of processing units or neurons. The principle feature of this model is that neighbouring neurons exert mutually inhibitory interactions only. This architecture can generate one dimensional center-surround (CS) and orientation selective (OS) receptive field profiles consistent with those observed in the early parts of the visual system. Previous studies have considered steady state receptive field profiles (RFP) only. In this article, linear spatiotemporal receptive fields are derived and simulated. Our studies show that the time taken for these receptive fields to evolve from the initial state to the steady state is short. Furthermore, as background mean luminance increases, the time taken to reach steady state decrease. In the steady state, these receptive fields yield the CS and OS profiles akin to measured RFP of ganglion and cortical cells.
['Nicolangelo Iannella', 'Abdesselam Bouzerdoum']
Time evolution of receptive fields