Hubel and Wiesel's research around area V1 of the primary visual cortex provided one of the first descriptions of receptive fields in mammals. By projecting various lines along the receptive field, Hubel and Wiesel were able to classify cortical neurons into two distinct groups: simple and complex (Hubel & Wiesel, 1963). Using manual mapping of receptive fields with simple dots, lines, and edges allowed them not only to uncover orientation tuning in individual neurons, but also to describe the columnar organization of ocular dominance and orientation preferences in the cerebral cortex (Ringach, 2004). Although Hubel and Wiesel's findings represented an extreme advance in our understanding of the visual cortex (Wurtz, 2009), it became clear that some cells in the visual system responded to stimuli much more complex than oriented lines, meaning that the cells in area V1 were much more changeable than Hubel and Wiesel had suggested. In this essay, the classic receptive field of Hubel and Wiesel will be discussed as well as the reasons why it can no longer offer us a satisfactory explanation of visual perception. It is first appropriate to discuss the specific cell types that were defined in Hubel and Wiesel's classic striate cortex experiment. Hubel and Wiesel defined the classical receptive field as a restricted region of the visual cortex. If a specific stimulus falls in this area, it can lead the cell to evoke action potential responses (Zipser, Lamme & Schiller, 1996). By shining aimed slits of light into the cat's eye, they were able to discover that each cell had its own specific stimulus needs (Barlow, 1982). Different cells differed from each other in several ways; some preferred a spe...... middle of paper ......och, C. (2013). Brain Cells for Grandma. Accessed February 20, 2014 from https://www2.le.ac.uk/centres/csn/Publications/scientificamerican0213-30.pdf Ringach, DL (2004). Mapping receptive fields in the primary visual cortex. Journal of Physiology, 558, 717-728. Rossi, A.F., Desimone, R. and Ungerleider, LG (2001). Contextual modulation in macaque primary visual cortex. The Journal of Neuroscience, 21, 1698-1709. Tanaka, K., Saito, H.A., Fukada, Y., & Moriya, M. (1991). Coding of individual object images in the inferotemporal cortex of the macaque monkey. Journal of Neurophysiology, 66, 170-190. Wurtz, R.H. (2009). Recount the impact of Hubel and Wiesel. The Journal of Physiology, 587, 2817-2823Zipser, K., Lamme, VAF and Schiller, PH (1996). Contextual modulation in primary visual cortex. The Journal of Neuroscience, 16, 7376-7389.