Age-specific binding effects

3x2x2 design factor 1: condition (feature-alone color, feature-alone shape, binding) factor 2: block (two experimental runs/condition/participants) factor 3: group (old vs young participants) In this study, we compared the electrophysiological activity associated with the binding process in young (N=22, mean age=28.5) and old (N=22; mean age=67.4) participants in a change detection task. Analysis of event-related brain potentials (ERP) focused on the differences between feature-alone (color or shape) and feature-conjunction (color-shape) conditions in stimulus encoding. Independently of aging, discrimination ability was significantly attenuated in the binding condition. The effect, however, was more pronounced in old participants. ERP components related to the visual feature detection and processing (posterior N1 and frontal P2) were not modulated in the binding condition. Only in old participants, a late positive ERP component (LPC) was increased signaling the allocation of additional resources.

本实验采用3×2×2实验设计，其中因素1为任务条件（单独特征颜色、单独特征形状、特征绑定），因素2为实验区块（每名被试、每个实验条件均完成两轮实验任务），因素3为被试组别（青年组与老年组）。本研究在变化检测任务中，对比了青年（N=22，平均年龄28.5岁）与老年（N=22，平均年龄67.4岁）被试的特征绑定过程相关脑电活动。事件相关电位（event-related brain potentials, ERP）分析聚焦于刺激编码阶段中，单独特征（颜色或形状）与特征结合（颜色-形状）条件间的差异。无论是否伴随衰老，绑定条件下的辨别能力均显著减弱；但该效应在老年被试中更为突出。与视觉特征检测及加工相关的ERP成分（后部N1与前部P2）在绑定条件下未出现显著调制。仅在老年被试中，晚期正成分（late positive component, LPC）的波幅显著升高，提示其调用了更多的认知资源。