【作者】 夏天生； 李慧； 王凌；

【Author】 Tiansheng Xia;Hui Li;Ling Wang;School of Psychology & Center for Studies of Psychological Application,South China Normal University;

【机构】 华南师范大学心理学院&心理应用研究中心；

【摘要】 比例一致效应指的是冲突效应量的大小会受到实验中一致试次所占比例的调节,这一效应常常被用来探讨认知控制的动态变化。传统的解释是注意调节假说,认为被试根据一致试次的比例来策略性地调节注意在刺激的任务相关和任务无关维度的分配,从而调节了认知加工中冲突的大小。但是这一观点最近受到了可能性学习这一假说的挑战。可能性学习假说认为被试会无意识地学习无关刺激维度与反应之间的可能性,并以此来预期特定的反应。同时,可能性假说也暗示了一个理论问题,即在习得新的刺激-反应联结后,认知控制系统如何运行。本研究采用功能核磁共振成像技术去探讨这一问题。我们采用一个比较新颖的范式,通过任务规则的变化可以获得正的或反转的Simon效应。实验采用3×2×2混合设计(54名被试),自变量分别为一致性比率、反应规则、刺激-反应位置一致性,其中一致性比率为被试间变量,其余两个为被试内变量,因变量为反应时、正确率和BOLD信号。虽然两种理论对正的Simon效应具有同样的预期,但反转的Simon效应提供了支持可能性学习假说的证据。具体说来,与基线组相比,反转Simon效应的效应量在高一致组中减小,而在多数不一致组中增加,表明被试习得了空间一致或不一致的刺激-反应联结。功能成像的结果显示在额顶区域出现相似的比例一致效应,主要包括双侧上顶叶(superior parietal lobe,SPL)、双侧背外侧前运动皮层(dorsal premotor cortex,d PMC)、前辅助运动区/前中扣带回(presupplementary motor area/anterior midcingulate cortex,Pre-SMA/a MCC)和左侧背外侧前额叶(dorsolateral prefrontal cortex,DLPFC)。在这些区域,当新习得的刺激-反应联结与任务相关的刺激-反应联结不一致时,大脑激活和功能性连通性都显著增加,并且这种效应不依赖于任务规则。这些结果表明,前中扣带回和背外侧前额叶主要监测新习得的刺激-反应联结诱发的冲突,并以此调节上顶叶和背外侧前运动皮层的加工。习得的刺激-反应联结可能表征在上顶叶。更多还原

【Abstract】 The dynamics of cognitive control have been investigated by the proportion congruency effect.However,the traditional interpretation of attention modulation for the effect is challenged by the account of contingency learning recently.The latter also implies a theoretical question:how the cognitive control system operates after learning new stimulus-response(S-R) associations.We employed a novel paradigm,in which the Simon effect was positive or reversed depending on task rules.The proportion congruency was manipulated with a between-subject design(n = 54).Although the modulation of the positive Simon effect itself could not differentiate between the two hypotheses as having the sameprediction,the alternation of the reversed Simon effect provided evidence supporting the contingency learning account.Specifically,the amount of the reversed effect decreased in the mostly congruent group but increased in the mostly incongruent group compared to the baseline group,suggesting that participants learned spatially compatible or incompatible S-R associations.Functional neuroimaging showed similar proportion congruency effect in frontoparietal regions,including bilateral superior parietal lobule(SPL) and dorsal premotor cortex(d PMC),pre-supplementary motor area/anterior midcingulate cortex(Pre-SMA/a MCC),and left dorsolateral prefrontal cortex(DLPFC).In these regions there were increases in both activity and functional connectivity when responses defined by the newly learned and task-relevant S-R associations were different regardless of task rules.These results suggest that a MCC and DLPFC shifted to responding mainly to conflict induced by the newly learned S-R associations,and thereby biased processing in SPL and d PMC.The SPL might represent the learned S-R associations.更多还原