Age-related decline in global form suppression

作者：Wiegand Iris^*; Finke Kathrin; Toellner Thomas; Starman Kornelija; Mueller Hermann J; Conci Markus

来源：Biological Psychology, 2015, 112: 116-124.

DOI：10.1016/j.biopsycho.2015.10.006

• Cognitive Aging
• Global-local Processing
• Kanizsa figures
• Inhibition deficit
• Event-related potentials
• Posterior contralateral negativity (PCN)
• N2-posterior contralateral (N2pc)

Visual selection of illusory 'Kanizsa' figures, an assembly of local elements that induce the percept of a whole object, is facilitated relative to configurations composed of the same local elements that do not induce a global form-an instance of 'global precedence' in visual processing. Selective attention, i.e., the ability to focus on relevant and ignore irrelevant information, declines with increasing age; however, how this deficit affects selection of global vs. local configurations remains unknown. On this background, the present study examined for age-related differences in a global-local task requiring selection of either a 'global' Kanizsa- or a local' non-Kanizsa configuration (in the presence of the respectively other configuration) by analyzing event-related lateralizations (ERLs). Behaviorally, older participants showed a more pronounced global-precedence effect. Electrophysiologically, this effect was accompanied by an early (150-225 ms) 'positivity posterior contralateral' (PPC), which was elicited for older, but not younger, participants, when the target was a non-Kanizsa configuration and the Kanizsa figure a distractor (rather than vice versa). In addition, timing differences in the subsequent (250-500 ms) posterior contralateral negativity (PCN) indicated that attentional resources were allocated faster to Kanizsa, as compared to non-Kanizsa, targets in both age groups, while the allocation of spatial attention seemed to be generally delayed in older relative to younger age. Our results suggest that the enhanced global-local asymmetry in the older age group originated from less effective suppression of global distracter forms on early processing stages indicative of older observers having difficulties with disengaging from a global default selection mode and switching to the required local state of attentional resolution.

• 出版日期2015-12