视觉工作记忆巩固机制

PSYCH OpenIR > 认知与发展心理学研究室

	视觉工作记忆巩固机制
其他题名	Mechanism of Visual Working Memory Consolidation
	孙慧明
	2010-05
摘要	视觉工作记忆巩固过程是指容易受到干扰的感觉表征被转化为较为稳固的视觉工作记忆进而不受后继刺激干扰的过程。Vogel等(2006)用掩蔽变化检测范式研究视觉工作记忆巩固的时间进程，认为记忆成绩逐渐升高最终达到稳定的过程反映的就是视觉工作记忆巩固的过程。本文研究刺激主观复杂度和掩蔽刺激特性对视觉工作记忆巩固的影响，以揭示视觉工作记忆巩固的机制。刺激的主观复杂度取决于刺激的客观复杂度和被试的知识经验。研究一通过5个实验考察了刺激的主观复杂度对视觉工作记忆巩固的影响。实验1的结果表明，被试的经验知识影响视觉工作记忆的成绩，但并不影响视觉工作记忆的巩固。实验2排除语音编码，并操纵SOA，得到与实验1一致的结果。实验3以中国和德国大学生作为被试，操纵被试的经验知识和刺激的客观复杂度，结果表明工作记忆成绩受客观复杂度和被试的经验知识的影响，但巩固却不受其影响。实验4的结果排除了因感觉编码加工时间过短造成上述结果的可能性。实验5发现被试对汉字颜色的巩固速率和对汉字本身的巩固速率相同。研究一的结果一致表明，视觉工作记忆的巩固可能与刺激的主观复杂度无关。研究二通过2个实验探讨掩蔽刺激的特性对巩固过程的干扰作用，结果表明，掩蔽刺激和记忆项目的相似性程度高低并不影响巩固过程(实验6)，掩蔽刺激的位置因素会影n向到巩固现象的发生(实验7)，只有当掩蔽刺激项目的位置和记忆项目的位置重叠时，掩蔽刺激才会干扰到巩固过程。基于上述研究结果，本文提出，视觉工作记忆巩固过程可能反映的并不是记忆项目的表征本身不断固化的过程；巩固现象之所以会发生，可能是由于当记忆项目消失之后，关闭进入WM中的通道需要时间。
其他摘要	In this study, we used the masked change detection paradigm of Vogel, Woodman and Luck (2006) to investigate whether subjective complexity of the to-be remembered stimuli does influence VWM consolidation. Consolidation is a process that should transform a transient perceptual representation into durable representation in VWM that survives interference by new sensory input (Jolicoeur & Dell'Acqua, 1998; Vogel, Woodman, & Luck, 2006). Subjective complexity refers to a joint effect of the physical characteristics of the stimulus and the perceiver’s expertise with the material. For that purpose in the first part of this study, we briefly presented physically simple and complex material (Chinese characters, pseudo characters, and novel symbols with few or many strokes) to novices or experts (Germans and Chinese participants) and we masked the stimuli after a variable delay. Within different types of materials (Experiment 1, 2, 3 and 5) and within different samples of participants (Experiment 4) we obtained very consistent results. First, subjective complexity influenced the maximally reached working memory performance which is often called its capacity. Second, masks clearly impaired consolidation but they did so independent of subjective complexity which was the case even when we compared colour and Chinese characters (Experiment 5) and when we ruled out the possibilities of verbal coding and too short SOA (Experiment 2). Third, memory performance increased with increasing SOA and reached the asymptote around 450 ms. In the second part of this study, we aim to investigate whether the quality of the mask modifies consolidation. In Experiment 6, still we found that the similarity between mask stimuli and to-be-remembered items does not influence consolidation. Consolidation is only influenced when the position of remembered items and masks are non-overlapping (Experiment 7), masks took effect in a location-based manner. They were only effective if they were presented at the locations of to memorized targets. On the basis of the results, we try to reveal the mechanism of consolidation process. Two explanation may exist. One possible explanation is an enhancement of the quality of representation. Vogel et al. (2006) spoke of vulcanization. The representations are getting more durable over time and this takes up to 400 ms. However, also the opposite process is conceivable. The representation is not enhanced over time but impaired by the mask and this effect is getting smaller with longer SOAs. This also could explain why memory performance increases with SOA; it is because interference decreases with delay. Both mechanisms would lead to the same consequence, a degraded representation of the memory entry with short SOAs. From the view of perceptual processes we consider interference effects as more likely than vulcanization.
学科领域	基础心理学
关键词	视觉工作记忆巩固主观复杂度客观复杂度经验知识
学位类型	博士
语种	中文
学位专业	心理学
学位授予单位	中国科学院研究生院
学位授予地点	北京
文献类型	学位论文
条目标识符	http://ir.psych.ac.cn/handle/311026/20350
专题	认知与发展心理学研究室
作者单位	中国科学院心理研究所
推荐引用方式 GB/T 7714	孙慧明. 视觉工作记忆巩固机制[D]. 北京. 中国科学院研究生院,2010.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
视觉工作记忆巩固机制.pdf（1186KB）	学位论文		限制开放	CC BY-NC-SA	请求全文