Hubel and Wiesel’s research surrounding area V1 of the primary visual cortex provided one of the first descriptions of the receptive fields in mammals. By flashing 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). The use of manually mapping the receptive fields with simple dots, lines and edges meant that they not only discovered orientation tuning in single neurons, but also described the columnar organisation of ocular dominance and orientation preferences in the cerebral cortex (Ringach, 2004). Although Hubel and Wiesel’s findings were an extreme advance in our understanding of the visual cortex (Wurtz, 2009), it became apparent that there were cells in the visual system that responded to stimuli far more complicated than orientated lines meaning that the cells in area V1 were much more modifiable than Hubel and Wiesel had suggested. In this essay, Hubel and Wiesel’s classic receptive field shall be discussed along with reasons as to why it can no longer offer us a satisfactory explanation into visual perception. First to be discussed are the specific types of cells which were defined in Hubel and Wiesel’s classic experiment into the striate cortex.
Hubel and Wiesel defined the classic receptive field as a restricted region of the visual cortex. If a specific stimulus fell into this area, this may drive the cell to evoke action potential responses (Zipser, Lamme & Schiller, 1996). By shining orientated slits of light into the cat’s eye, they were able to discover that each cell had its own specific stimulus requirements (Barlow, 1982). Different cells differed from each other in many ways; some preferred a spe...
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Wurtz, R. H. (2009). Recounting the impact of Hubel and Wiesel. The Journal of Physiology, 587, 2817-2823
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Figure 1.2 shows a simple schematic detailing the combination or retinal information and eye velocity estimates to generate a perceived motion direction. This diagram is analogous to figure 1.1, showing the integration of signals from a lower ‘detector’ level, at the eye movement and retinal velocity estimate level, and later at an integrator stage, after which the motions have been transformed into the perceived direction. This diagram also illustrates the focus of chapters 2, 3 and 4. Chapter 2 investigates the motion aftereffect (see adaptation section) which follows simultaneous retinal motion and repetitive smooth pur...
The ‘where visual pathway’ is concerned with constructing three dimensional representations of the environment and helps our brain to navigate where things are, independently of what they are, in space in relation to itself (Mishkin & Ungerleider & Macko, 1983).... ... middle of paper ... ... The 'Standard' of the 'Standard'.
by the internal computers of the instrument, to create an image of internal body tissues. These images were then displayed on the screen for the user,
The changes occurred in the outer layer of the brain. Precisely, the cortex changed. The deeper structure of the brain was influence by the change specially the thalamus. This organ of the brain filters the visual information. The thalamus sends the visual information to the virtual cortex. The coordination between the two organs of the brain helped the performance of the reading by the Indian
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The formal characteristics of the work are crucial in their produced effect upon the audience. It is a four panel screen landscape, whose size of 7354 cubic meters is made referent in the title. Despite its monumental size, the work does not function as an oppressive weapon but rather a positive force, one that is able to free us from our inhibitions. Rist frequently experiments with the various ways in which video can be projected onto surfaces. Though she does not push the technical boundaries of the video medium medium, she nonetheless pushes the limits within video projection. Requiring seven different projectors to be linked seamlessly, her work is a technical achievement for this feat alone. A large circular couch occupies the center of the exhibition space. Its shape is meant to be reminiscent of the human iris, but also bring to mind the iris of the camera as well.
Visual Discrimination is “using the sense of sight to notice and compare the features of different items to distinguish one item from another” (NCLD Editorial Team, 2014) http://www.ncld.o...
Each one of us lives in our own unique world of perception. As individuals, we may experience life in an entirely different way through our senses and life experiences. Therefore, perception can be tricky since it is very personal to each one of us. According to the Merriam-Webster online dictionary, perception has three meanings; (1) “the way you think about or understand someone or something,” (2) “the ability to understand or notice something easily,” and, (3) “the way that you notice or understand something using one of your senses” (2014, para. 1). C.S. Lewis said, “What you see and what you hear depends a great deal on where you are standing. It also depends on what sort of person you are” (n.d., para. 11). In other words,
S.A. Clark, T. A. (1988). Receptive fields in the body-surface map in adult cortex defined by temporally correlated inputs. Nature, 332.
Perception is a mysterious thing; it faces a lot of misconception, for it can merely be described as a lens, as it decides how someone views the events happening around them. Perception is the definition of how someone decides to use their senses to observe and make conceptions about events or conditions they see or that are around them. Perception also represents how people choose to observe regardless if it’s in a negative or positive way. In other words, perception can be described as people's cognitive function of how they interpret abstract situations or conjunctures around them. All in all, perception can do three things for someone: perception can change the way someone thinks in terms of their emotions and motivations, perception acts
There are many different Visual Perception principles in perception. The main principles are Gestalt. Gestalt is a German word meaning 'form' or 'shape'. Gestalt psychologists formulated a series of principles that describe how t...
Blakslee, S. (1993, August 31). The New York Times. Retrieved May 2, 2014, from www.nytimes.com: http://www.nytimes.com/1993/08/31/science/seeing-and-imagining-clues-to-the-workings-of-the-mind-s-eye.html