Shifting attention to different levels within global-local stimuli: A study of normal participants and a patient with temporal-parietal lobe damage

Abstract

Shifts of attention to different levels of global-local stimuli were examined in normal participants and a patient with right temporal-parietal lobe damage. Global-local stimuli were presented in sequential couplets and the target could either be at the same global-local level or the target could change levels within each couplet. Normal participants were faster to respond to the second stimulus when the target remained at the same level compared to when it changed levels. This level-shifting effect appeared to be independent of any perceptual- or identity/response-based priming, and did not appear to be due to the size of the stimuli per se. In contrast, the patient did not display any level-shifting effects when the target appeared at the global level, whereas he did display this effect when the target appeared at the local level. These results suggest that the right temporal-parietal lobe may be involved in activating attentional weights to the different levels of global-local stimuli. These results also indicate that intra-stimulus attentional shifts are mediated by different neurocognitive mechanisms than are spatial attentional shifts.