The orienting system describes a system whereby reflexive and more controlled eye movements are initiated as part of the attentional response. The orienting systeminvolves the superior colliculus, magno cells in the pulvinar (thalamus) and the secondary and tertiary areas of the extrastriate cortex e.g. V5. The orienting system follows the second 'geniculate' pathway. This pathway projects first to the superior colliculus and then to the pulvinar of the thalamus before projecting mainly to the posteria parietal area, but there are also projections that fan out to points along the V1 and V4 pathway. La Berge provides a model that describes the complex interaction between the superior colliculus and other brain areas. Broadly, a functional pattern can be discern which describes a number of layers within the superior colliculus . The superficial or upper layers are involved in passing sensory information at high speeds to be analysed for location of the a target, which is passed on to the cortex. This movement-sensitive system is important. References David Andrews, "From theory to practice. "
The brain pathway that orients visual attention to a stimulus is referred to as the orienting system. There are two main types of visual orientations, covert (exogenous) which occurs when a salient environmental change causes a shift in attention and overt (endogenous) which occurs when the individual makes a conscious decision to orient attention to a stimuli During a covert orientation of attention, the individual does not physically move, and during a overt orientation of attention the individual's eyes and head physically move in the direction of the stimulus . Information acquired through covert and overt visual orientations travels through the norepinephrine system, indirectly effecting the ventral visual pathway. The four specific brain regions involved in this process are the frontal eye field, the temporoparietal junction, the pulvinar, and the superior colliculus . The frontal eye field is involved in goal-driven eye movements and can inhibit stimulus driven eye movements. The temporoparietal junction appears to be involved location-cueing tasks, and individuals with lesions in this area have difficulty with attentional reorienting. The pulvinar is located posterior to the thalamus and it's role in the orientating system is still being researched; however it is thought to be involved in covert orienting. Finally, the superior colliculus provides information about the location of the stimuli to which attention is directed. References
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orienting system describes a system whereby reflexive and more controlled eye movements are initiated as part of the attentional response. The orienting systeminvolves the superior colliculus, magno cells in the pulvinar (thalamus) and
brain pathway that orients visual attention to a stimulus is referred to as
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secondary and tertiary areas of the extrastriate cortex e.g. V5. The orienting system follows the second 'geniculate' pathway. This pathway projects first to the superior colliculus and then to the pulvinar of the thalamus before projecting mainly to the posteria parietal area, but there are also projections that fan out to points along the V1 and V4 pathway.
orienting system. There are two main types of visual orientations, covert (exogenous) which occurs when a salient environmental change causes a shift in attention and overt (endogenous) which occurs when the individual makes a conscious decision to orient attention to a stimuli During a covert orientation of attention, the individual does not physically move, and during a overt orientation of attention the individual's eyes and head physically move in the direction of the stimulus .
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La Berge provides a model that describes the complex interaction between the superior colliculus and other brain areas. Broadly, a functional pattern can be discern which describes a number of layers within the
Information acquired through covert and overt visual orientations travels through the norepinephrine system, indirectly effecting the ventral visual pathway. The four specific brain regions involved in this process are the frontal eye field, the temporoparietal junction, the pulvinar, and the
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superficial or upper layers are involved in passing sensory information at high speeds to be analysed for location of the a target, which is passed on to the cortex. This movement-sensitive system is important.
frontal eye field is involved in goal-driven eye movements and can inhibit stimulus driven eye movements. The temporoparietal junction appears to be involved location-cueing tasks, and individuals with lesions in this area have difficulty with attentional reorienting. The pulvinar is located posterior to the thalamus and it's role in the orientating system is still being researched; however it is thought to be involved in covert orienting. Finally, the superior colliculus provides information about the location of the stimuli to which attention is directed.
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References David Andrews, "From theory to practice. "
References