The Subcortical and Cortical Visual Pathways Analysis

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In order to be selective in attending to a complex environment infants need to be capable of engaging and disengaging in attention. When newborns are awake and alert their attention is not random it is organised and selective (Ruff & Rothbart, 2001). Attention engagement is an effortful engagement with stimuli; it is also referred to as sustained attention (Stechlar & Latz, 1966). The ability to detect changes in stimuli over sustained periods requires effort (Ruff & Rothbart, 2001). Attention disengagement refers to when attention to a stimulus is terminated (Colombo, 2001). Attention disengagement is necessary in order to shift attention to other aspects of the environment. Disengagement is often studied with a spatial cuing paradigm (Butcher, Kalverboer, & Geuze, 2000). In this essay the subcortical and cortical visual pathways will be discussed. The subcortical system is devoted mainly to processing information received from the central area of the retina (Bronson, 1974). The cortical system is concerned with the analysis and encoding of complex visual patterns (Bronson, 1974). This essay will discuss research that has shown the subcortical visual system components to be more developed at birth than those in the cortical system. This essay introduces the basic processes of attention, the methods that are used to assess them, and the brain structures involved. This essay will further discuss the importance of developmental changes in attentional processes.

Research studies have shown infants can engage in obligatory attention. Stechlar and Latz (1966) observed three infants for three weeks almost every day following birth. The infants were presented with three types of visual stimuli such as; black and white drawings of fac...

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...om subcortical to cortical processing has been evaluated throughout this essay. Studies have shown that infants are able to engage but the infants gaze is captured by salient contours and only limited aspects of a stimulus are attended to and encoded. Research has highlighted that stimulus orienting is exogenously controlled in new-borns. Other research studies have argued the visual system changes rapidly after birth and there is not an absence of cortical functioning in the newborn and proposed a complex model to explain the layers of the visual cortex (Johnson, 1990). Furthermore, the research has concluded that the ability to disengage from attention occurs during 6-14 weeks and that disengaging attention is a discontinuous process. Research on the disengaging and engaging attention has shown human perception reflects continued neural plasticity (Bronson, 1974).

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