The ability to resist distracting stimuli whilst voluntarily focusing on a task is fundamental to our everyday cognitive functioning. Here, we investigated how this ability develops, and thereafter declines, across the lifespan using a single task/experiment. Young children (5–7 years), older children (10–11 years), young adults (20–27 years), and older adults (62–86 years) were presented with complex visual scenes. Endogenous (voluntary) attention was engaged by having the participants search for a visual target presented on either the left or right side (...) of the display. The onset of the visual scenes was preceded – at stimulus onset asynchronies (SOAs) of 50, 200, or 500 ms – by a task-irrelevant sound (an exogenous crossmodal spatial distractor) delivered either on the same or opposite side as the visual target, or simultaneously on both sides (cued, uncued, or neutral trials, respectively). Age-related differences were revealed, especially in the extreme age-groups, which showed a greater impact of crossmodal spatial distractors. Young children were highly susceptible to exogenous spatial distraction at the shortest SOA (50 ms), whereas older adults were distracted at all SOAs, showing significant exogenous capture effects during the visual search task. By contrast, older children and young adults' search performance was not significantly affected by crossmodal spatial distraction. Overall, these findings present a detailed picture of the developmental trajectory of endogenous resistance to crossmodal spatial distraction from childhood to old age and demonstrate a different efficiency in coping with distraction across the four age-groups studied. (shrink)

The extent to which visual information on the contralateral, unattended side influences the performance of patients with hemispatial neglect was studied in a visuomotor reaching task. We replicated the well-established finding that, relative to target-alone trials, normal subjects are slower to reach to targets in the presence of visual distractors which appear either ipsilateral or contralateral to the target, with greater interference in the former condition. Six patients with hemispatial neglect showed even greater interference than did the normal subjects when (...) the distractor appeared ipsilaterally but showed no significant interference from contralateral distractors. This pattern of performance was qualitatively similar for patients with lesions restricted to posterior regions and for patients with more extensive lesions involving both posterior and anterior brain regions. These findings suggest that, in the visuomotor domain, information on the contralateral side is processed minimally, if at all, in patients with hemispatial neglect. (shrink)