right eye receives the inputs, e.g., an apple shown to the left eye among many other apples of the same appearance shown to the right eye. Nevertheless, such inputs, e.g., the left-eye apple, can also strongly capture attention overly and covertly (even overriding attentional guidance by endogenous goals), implicating V1 for exogenous attentional shifts according to V1 Saliency Hypothesis. Even though separate regions are thought to be in existence for these two attentional processes, the question still remains on whether these regions interact with one another, indicating more research on this point is still needed. Neural overlap for voluntary and reflexive attention There appears to be agreement that multiple areas of the brain are involved in shifts of attention, however research is not quite as conclusive regarding the amount of overlap evident with voluntary versus reflexive attention. Rosen et al. study found a fair amount of overlap between endogenous and exogenous shifts of attention. Both conditions showed activation in the dorsal and parietal premotor areas. However, the voluntary condition also showed activation in the right dorsolateral prefrontal cortex, which did not appear in the reflexive condition. As this area has been shown to be associated with working memory, it may indicate that working memory is engaged voluntarily. The subcortical global pallidus region was also activated only in the voluntary condition. Additionally, the activation shown in the temporoparietal junction [TPJ] was slightly different in both conditions, with the endogenous condition showing more spreading to the lateral, anterior and superior regions. Although these differences did exist, overall there was a lot of overlap demonstrated for voluntary and reflexive shifts of attention. Specifically both showed activations in the dorsal premotor region, the frontal eye field area, and the superior parietal cortex (SPC), although, the SPC exhibited greater activation in the endogenous condition. Attention can be guided by top-down processing or via bottom up processing. Posner's model of attention includes a posterior attentional system involved in the disengagement of stimuli via the parietal cortex, the shifting of attention via the superior colliculus and the engagement of a new target via the pulvinar. The anterior attentional system is involved in detecting salient stimuli and preparing motor responses. See also Attention deficit hyperactivity disorder References Further reading Attention