How do the brain and eyes jointly process information?

IntroductionThe intricacies of the gentlemans gentleman eye modify us to interpret light and distinguish colour to produce vision. It is, however, the complexity of the treat in the ocular path authority from eye to nous along which this tuition is interpreted and manifested that allows us to create a pattern of the surrounding world, otherwise kn consume as optical perception (Gibson, 1950). Whilst vision begins with the eye and ends with the brain, the way these organs work together and the coition influence each has on our perception is fundamental to producing what we see.Light is first refracted onto the cornea of the eye before button to the pupil and lens. An image is then projected onto the retina, resulting in the production of ganglion cells specialize to describe depth, colour, normal, motion, and light intensity (Nelson, 2007). Nerve spikes from the ganglion cells containing this info transmit to the brains optic nerve, by which optic reading is passed for interpretation in the visual cortex.The right and left visual cortices comprise part of the occipital lobe of the brain, both receiving information from the opposite hemispheres visual field. The estimated ane hundred forty million neurons in the primary visual cortex (V1) (Lueba & Kraftsik, 1994) fire when visual stimuli appear within their receptive field, and these fields ar tuned to receive stimuli of particular proposition eastern hemisphereations and colours (Kandal et al., 2000). The receptive fields of neurons in more complex visual swear outing beas ar able to detect more intricate stimuli such(prenominal) as reflexions (Kanwisher, McDermott & Chun, 1997) or direction (Allman et al. 1984). The five identified visual beas (V1-V5) are interconnected with varying strengths, allowing information to be projected forward from one to another and feedback to be given. As the visual information passes through this hierarchy, it is proposed that is bear on by two pathways o f neural representation. These pathways, named the dorsal and ventral streams, are hypothesised to batch with spatial attention and the recognition and perception of visual stimuli respectively, and involve the personnel casualty of visual information and representation further into the brain integrating it with awareness, attention, and warehousing functions (Ungerleider & Mishkin, 1982).The process of visual perception, as the eyes stunning comment is interpreted throughout the brain enables us to observe and construct our own visual world.Gibson (1966) proposed a direct theory of perception, affording the richness of the sensory input with the construction of the perceived visual outcome. He claimed that a variety of environmental cues, or affordances, aid the interpretation of the visual scene. These include brightness, texture gradient, relative size, and superimposition (where one object blocks another). Gibson believed that when combined with invariants (constancies wi thin the environment ie. parallel lines appearing to converge toward a horizon) and optic flow (the pattern of light try within a visual scene) this was enough to enable the perceiver to orient themselves and the surrounding environment.There are, however, complexities to Gibsons bottom-up theory of visual processing. It may be overly simplistic to underestimate the role of a top-down influence from the brain. Gibsons theory does not account for times when the visual system is fooled, or becomes subject to an illusion.Rubins Vase (Rubin, 1915) is a classic shell of how the human visual system is subject to ambiguity, where one iodine visual stimulus empennage be perceived as two unequivocal images. If the visual system directly processes light into an image, it would follow that a single visual input would lead to a universal and singular output. However, the creative activity of ambiguity in the perception of a visual stimulus suggests in that respect may be times when the brain cannot decide as to what representation to assign to the visual input.Further questions are raised when looking at the influence of scope, and how this can lead us to misinterpret visual stimuli. The Ebbinghaus Illusion, demonstrates perceptual distortion, highlighting the role of contextual cues, where a circle surrounded by large circles is judged as smaller than the same circle surrounded by small circles (Obonai, 1954). This is significative of a higher-level process in which the brain applies context relevant logic to the interpretation of a visual stimuli.Additionally, sustain provides loaded influence over the processing of visual information. Impossible illusions such as Eschers Waterfall, and the Hollow Face Illusion (Gregory, 1997) exploit fantasys of experiential perceptual learning, such as knowledge that adjacent edges must join, and human faces are always convex. These illusions demonstrate how the brain aims to perceive coherence in 3D objects to make sen se out of its visual environment, creating a captivating paradox between what we know and what we are actually seeing. opthalmic perception can be ambiguous, distorted, paradoxical, and even fictitious (Gregory, 1980). It appears to be influenced by context, visualise, and expectation, a concept asserted by Richard Gregory (1970) who theorised perception as a top-down process. Deduced from observations of when the human visual system makes errors, Gregory proposed that the brain constructs a visual hypothesis from information processed by the eye based on former experience and knowledge.If the top-down, constructivist theory h grays true, at that place are implications for the constancy of percepts between individuals. We all take idiosynchratic knowledge and experience. Do differences in internal representation lead individuals to perceive visual stimuli differently from each otherAdditionally, what is to be said for the perception of those that make up no knowledge or experie nceDoherty et al. (2010) observed an absence of suceptibility to the Ebbinghaus illusion in a number of children under seven years of age, perhaps suggestive that experience and knowledge does have an influence on visual information processing. Without the knowledge base, the children were not affected by the contextual cues.MacLeod (2007) proposes that top-down theories are based on times when visual conditions are poor, and bottom-up theories are founded in ideal viewing conditions neither of which is an all encompassing report of perception. Recent research highlights the interaction of both constructivist and direct processes (MacLeod, 2007), with the proposal that when bottom-up, sensory information is abundant there is less input from contextual hypotheses, and when there is an absence of stimulus information, the brain draws on its prior knowledge and experience to comprehend the input (Ramachandran, 1994).It becomes apparent that the study of human perception and how it is influenced by not only the anatomical structure of the visual pathway, but in any case psychological components such as experience and knowledge will enable us to further understand how the eyes and the brain interact to process visual information.ReferencesAllman, J., Miezin, F., McGuinness, E. (1985) Direction- and velocity-specific responses from beyond the classical receptive field in the sum temporal visual area (MT) Perception, 14(2), pp. 105 126.Doherty, M., Campbell, N., Hiromi, T., and Phillips, W. 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