An occasional presence of bivalent stimuli in a block of univalent trials can elicit a slowing of the response on all subsequent univalent trials.This type of modulation of cognitive control is termed the bivalency ef...An occasional presence of bivalent stimuli in a block of univalent trials can elicit a slowing of the response on all subsequent univalent trials.This type of modulation of cognitive control is termed the bivalency effect.To explore whether this modulation is task specific,this study used a triplet task switching paradigm,with three following tasks that were presented concussively:a shape color judgment(red vs.blue),a number parity judgment(odd vs.even),and a letter case judgment(lowercase vs.upper-case).The event-related potential(ERP)results showed that(1)the bivalency effect was reflected by the decreased amplitude of N2 and P3a over the frontal region for both the color and letter tasks;(2)the bivalency effect occurred earlier for the color task compared with that for the letter task;(3)for the number parity task,the bivalency effect was observed in the increased N1 and the decreased P2p over the parietal region.These findings indicate that the modulation of cognitive control is task-specific after the presentation of bivalent stimuli in task switching.展开更多
人类认知系统在动态环境中展现出卓越的适应性,其核心机制之一是任务切换中对无关信息的有效抑制。本研究聚焦逆向抑制的触发机制,通过改进线索呈现范式(恒定无意义线索)和任务结构(完全排除重复试次),在单义刺激与反应条件下考察任务...人类认知系统在动态环境中展现出卓越的适应性,其核心机制之一是任务切换中对无关信息的有效抑制。本研究聚焦逆向抑制的触发机制,通过改进线索呈现范式(恒定无意义线索)和任务结构(完全排除重复试次),在单义刺激与反应条件下考察任务线索对逆向抑制的驱动作用。实验发现:(1)任务线索组存在显著N-2重复代价(ABA vs CBA序列差异39 ms,p<0.05),而映射指令组无此效应;(2)项目不重复试次中逆向抑制效应更强(ηp^(2)=0.214 vs 0.390),表明抑制机制存在任务与项目双重层级;(3)线索-目标间隔时间主效应显著(500 ms vs 1000 ms差异40 ms,p<0.001),提示线索加工深度影响抑制强度。结论表明:任务线索可独立触发逆向抑制,其作用层级体现为任务层面的全局性抑制与项目层面的特异性抑制协同共存,其中项目不重复条件下的抑制效应显著增强;抑制强度受线索加工时间的动态调节,更长的准备时间通过优化任务定势重构显著提升抑制效能。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.32360201,31860278 and 31760285).
文摘An occasional presence of bivalent stimuli in a block of univalent trials can elicit a slowing of the response on all subsequent univalent trials.This type of modulation of cognitive control is termed the bivalency effect.To explore whether this modulation is task specific,this study used a triplet task switching paradigm,with three following tasks that were presented concussively:a shape color judgment(red vs.blue),a number parity judgment(odd vs.even),and a letter case judgment(lowercase vs.upper-case).The event-related potential(ERP)results showed that(1)the bivalency effect was reflected by the decreased amplitude of N2 and P3a over the frontal region for both the color and letter tasks;(2)the bivalency effect occurred earlier for the color task compared with that for the letter task;(3)for the number parity task,the bivalency effect was observed in the increased N1 and the decreased P2p over the parietal region.These findings indicate that the modulation of cognitive control is task-specific after the presentation of bivalent stimuli in task switching.
文摘人类认知系统在动态环境中展现出卓越的适应性,其核心机制之一是任务切换中对无关信息的有效抑制。本研究聚焦逆向抑制的触发机制,通过改进线索呈现范式(恒定无意义线索)和任务结构(完全排除重复试次),在单义刺激与反应条件下考察任务线索对逆向抑制的驱动作用。实验发现:(1)任务线索组存在显著N-2重复代价(ABA vs CBA序列差异39 ms,p<0.05),而映射指令组无此效应;(2)项目不重复试次中逆向抑制效应更强(ηp^(2)=0.214 vs 0.390),表明抑制机制存在任务与项目双重层级;(3)线索-目标间隔时间主效应显著(500 ms vs 1000 ms差异40 ms,p<0.001),提示线索加工深度影响抑制强度。结论表明:任务线索可独立触发逆向抑制,其作用层级体现为任务层面的全局性抑制与项目层面的特异性抑制协同共存,其中项目不重复条件下的抑制效应显著增强;抑制强度受线索加工时间的动态调节,更长的准备时间通过优化任务定势重构显著提升抑制效能。
