Abstract
Aging is known to increase capture effect by salient distractors. Meanwhile, aging also declines the ability of perceptual grouping. Since well-grouped items can also capture attention, older adults may release from distraction if the distractor is well-grouped. This study evaluated this possibility by the collinear masking effect. The collinear masking effect refers to the condition that a collinear distractor can mask a local target in visual search. Thirty-two young adults and 26 normal older adults participated in this experiment. Results showed a larger collinear masking effect for older than young adults. BOLD signal revealed that young adults activated the left superior parietal area to suppress the collinear distractor, while older adults did not. Further, older adults additionally recruited frontal-parietal networks which implied that their attention was captured by the collinear distractor. The collinear masking effect also correlate to bilateral motor cortex and putamen activations in older adults, suggesting a heavy motor demands on older adults. Our data thus showed that older adults are more distracted by well-grouped distractors, which is due to more capture, less suppression, and more complex motor execution. Thus aging does not release older adults from distraction by well-grouped items.
Acknowledgement: MOST106-2420-H-039-002-MY3