【作者】 袁艳芳；

【导师】 张功亮；

【作者基本信息】 苏州大学 ， 应用心理学（专业学位）， 2019， 硕士

【摘要】 知觉学习(Perceptual learning,PL)是指由于训练或经验而引起的长期稳定的知觉变化,它反映了大脑的可塑性(Karni&Sagi,1991;Fahle,1994;Ahissar&Hochstein,1997)。视知觉学习研究中一个重要议题是任务难度对视知觉学习的影响。本研究采用事件相关电位技术(Event-related potentials,ERPs)记录,在刺激匹配情况下,不同难度任务的朝向知觉学习大脑神经变化。19名被试分别经过1天短期和5天长期的朝向辨别训练并测得训练后ERP数据。ERP结果显示,首先,后部N1(130～170ms)和前部P2(140～180ms)在4个任务难度中表现相同:短期学习和长期学习中困难任务的后部N1(130～170ms)显著增大,容易任务有微弱的变化;前部P2(140～180ms)都显著减小。此外,后部P2(200～240ms)和前部N2(250～350ms)在4个难度条件下有不同的知觉学习表现:后部枕叶P2(200～240ms)在55°简单任务中没有学习效应,而47.3°困难任务在短期学习阶段P2显著减小,48.4°,46.1°困难任务在短期学习和长期学习阶段后部P2显著增大;短期学习中N2(250～350ms)在四种任务中都显著增大,长期训练只有最容易55°任务显著增大,其他三个困难任务在长期学习中只保持了短期学习的变化,未继续增大;中央P3(450～550ms)只表现出难度水平的差异。另一方面,我们按照ERPs测试期的行为正确率把被试的ERPs前测和长期学习后测数据进行心理量以及物理量的匹配,结果显示:后部N1和前部N2显著增大,前部P2显著减小,但后部P2却无显著变化。匹配刺激后两种条件下的结果提示了后部P2对任务难度的敏感性。本研究为匹配刺激情况下,在短期与长期学习过程中不同难度任务的知觉学习变化提供了直接的电生理证据。更多还原

【Abstract】 Perceptual learning(PL)refers to the relatively permanent modification of perception and behavior following a sensory experience and reflect the plasticity of brain neuro(Karni and Sagi,1991;Fahle,1994;Ahissar and Hochstein,1997).Effect of task difficulty on visual perceptual learning is hot debated.Our study matches the stimulus of different task difficulty levels and record the change in learning by using event-related potentials(ERPs).19 participants were required to finish a task of orientation discrimination for 1 days and 5 days respectively.Our results show that posterior N1(130-170ms)of 4 difficulty levels are increased significantly,especially in the 3 hard tasks,although P1 did not changed statistically.The frontier P2 shows a tendency of decrease in all tasks but P2 in the posterior area has no changes in easy task and in the 3 hard tasks shows diverse changes in both short-term and long-term learning.In the easy task,the frontier N2 increases in both short-term and long-term training;in the hard tasks,it merely increases in the short-term learning significantly.In addition,P3 are not identical in different tasks but not modulated by perceptual learning.Besides these findings,we find the posterior P2 is sensitive to task difficulty greatly.Our research provides direct electrophysiological evidence for task difficulty modulation of perceptual learning-related neuroplasticity.更多还原