Accounting for the computational basis of consciousness: a connectionist approach

This paper argues for an explanation of the mechanistic (computational) basis of consciousness that is based on the distinction between localist (symbolic) representation and distributed representation, the ideas of which have been put forth in the connectionist literature. A model is developed to substantiate and test this approach. The paper also explores the issue of the functional roles of consciousness, in relation to the proposed mechanistic explanation of consciousness. The model, embodying the representational difference, is able to account for the functional role of consciousness, in the form of the synergy between the conscious and the unconscious. The fit between the model and various cognitive phenomena and data (documented in the psychological literatures) is discussed to accentuate the plausibility of the model and its explanation of consciousness. Comparisons with existing models of consciousness are made in the end.     

封闭性知觉在大范围优先性中的特殊性

本文研究当封闭性作为被试分辨的图形性质时,空间位置不确定性和视野位置对大范围优先性有何影响。实验发现：（１）无论复合刺激呈现在视野的中央或外周．分辨复合刺激的整体性质的反应时（ＲＴ）比分辨局部性质的ＲＴ短,整体性质对分辨局部性质的反应有较强的干扰作用。相反,局部性质对分辨整体性质的反应的影响较小;（２）刺激位置的不确定对大范围优先性没有显著影响;（３）与周边刺激相比,分辨视野中央的复合刺激的ＲＴ较短,但整体性质的ＲＴ优势和对局部性质的干扰作用,不受刺激在视野中的位置的影响。这些实验结果揭示了封闭性知觉在大范围优先性中的特殊性。     

加压素对记忆巩固过程作用的研究 Ⅰ.精氨酸加压素(AVP)对大鼠记忆巩固过程的易化作用及脑内游离氨基酸含量的变化

本文研究了精氨酸加压素易化记忆巩固过程的作用,测定了这一作用过程中脑内15种游离氨基酸含量的变化。 1.第三天建立实验前1小时皮下注射AVP(2μg/只)显著地延缓了大鼠主动逃避条件反应的消退过程。 2.给予AVP的动物在建立期皮层视区和海马两脑区的GABA(γ-氨基丁酸)含量及海马的异亮氨酸含量下降。在保持期两脑区的苏氨酸含量下降,赖氨酸含量上升,海马的谷氨酸含量下降,但两脑区的GABA含量都没有显著变化。 3.电击应激反应的实验结果表明,给予AVP的动物海马的GABA含量及皮层视区苯丙氨酸含量下降。单独注射AVP后1小时,两脑区的天冬氨酸含量下降。AVP注射后48小时,脑内各种氨基酸含量都没有明显变化。     

氦-氖激光对大鼠躲避条件反应的影响与纹状体神经介质的变化

用54只大鼠为材料,观察了以光导纤维导入脑内的氦-氖激光对其躲避条件反射(CAR)形成的影响和六种神经介质含量的变化。结果表明,四组动物中,只有氦-氖激光照射尾核的一组动物的学习行为指标(CAR阳性率、CAR反应次数)显著优于手术对照组,同时脑纹状体内去甲肾上腺素(NE)和多巴胺(DA)显著增高,而5-羟色胺(5-HT)降低,这是该组动物的特异性脑化学改变。     

50—90岁成人的短时记忆研究

本工作研究了102例50—90岁成人的短时记忆,其中85例进行了较详细的体格检查。以22例20—25岁青年的记忆检查作为对照,结果看到: 1.在图片自由回忆、逻辑故事识记、数字广度识记三个项目上,记忆都有随年龄增长而逐步减退的明显趋势; 2.识记逻辑故事时,对中心意义的记忆减退较分节记忆减退缓慢,顺背数字的记忆广度随年龄增长而减小较其他项目都要缓慢,表明老年记忆减退有其特点; 3.神经系统和心血管系统的病理性或老年性变化与记忆减退有关。     

记忆与学习的脑化学研究 Ⅱ.海马内注射胰蛋白酶与胰凝乳蛋白酶对大白鼠暗箱迴避模式记忆的影响

本实验选择了胰凝乳蛋白酶与胰蛋白酶,它们同属水解酶,能够内切蛋白质与肽类底物的某些键位。26只刚成年的雄性大鼠分作三组:生理盐水/不巩固组(NS/NC)、胰蛋白酶/不巩固组(T/NC)与胰凝乳蛋白酶/不巩固组(CT/NC)。 实验结果表明,双侧海马内注射(AP_2L_2H_4与AP_4L_3H_5)胰凝乳蛋白酶与胰蛋白酶后,对暗箱廻避(DBA)模式记忆有不同的影响。胰蛋白酶注射后,该记忆保持明显降低,而胰凝乳蛋白酶注射后仍可巩固。所用的实验剂量大致为半致死剂量的三分之一。     

青年人和老年人的元记忆与记忆能力关系的比较研究

采用自编“元记忆简短问卷”和“成人元记忆问卷”,对９０例被试（分为青年、老年和老老年组）进行元记忆及其与记忆关系的比较研究。结果表明：（１）预测记词对数和记图数随增龄而减少,年龄差异明显。评估准确性未显示年龄差异。训练后,预测成绩明显提高,但评估准确性未见提高。测后自评与预测情况相似,但其准确性高于预测,元记忆可能通过记忆过程而有提高;（２）自信程度和使用方法数均随增龄而减少,可能这是影响记忆成绩的重要因素;（３）联想学习和图象自由回忆成绩均与“元记忆简短问卷”和“成人元记忆问卷”的各项自评有不同程度的相关,表明元记忆与记忆关系密切。     

汉字独体字识别中的框架结构效应

本研究用两个实验证明了汉字独体字识别中存在框架结构效应。所谓框架结构就是构成一个字基本框架的笔画。实验一发现框架结构具有明显的启动效应。实验二发现独体字的识别从笔画开始,提取框架结构是独体字识别过程中的必经阶段,两个实验均未发现字频效应。     

Optimal Hierarchical Learning Path Design With Reinforcement Learning

E-learning systems are capable of providing more adaptive and efficient learning experiences for learners than traditional classroom settings. A key component of such systems is the learning policy. The learning policy is an algorithm that designs the learning paths or rather it selects learning materials for learners based on information such as the learners’ current progresses and skills, learning material contents. In this article, the authors address the problem of finding the optimal learning policy. To this end, a model for learners’ hierarchical skills in the E-learning system is first developed. Based on the hierarchical skill model and the classical cognitive diagnosis model, a framework to model various mastery levels related to hierarchical skills is further developed. The optimal learning path in consideration of the hierarchical structure of skills is found by applying a model-free reinforcement learning method, which does not require any assumption about learners’ learning transition processes. The effectiveness of the proposed framework is demonstrated via simulation studies.     

Disentangling the Relations Between Different Components of Family Socioeconomic Status and Chinese Preschoolers’ School Readiness

Family socioeconomic status (SES) has been frequently linked to children’s early development. Treating SES as an aggregated variable has many issues, as different components of SES may relate to child outcomes through divergent mechanisms. The purpose of the study was to examine whether parents’ engagement in home learning activities and children’s participation in extracurricular activities (EAs) would function as pathways through which individual SES components related to children’s school readiness. A total of 588 families with preschool‐aged children were recruited from Guangdong province in China. Children’s receptive vocabulary, Chinese reading, and early math skills were individually assessed at three time points, and children’s social skills were rated by parents. Parents reported their engagement in home learning activities with children and their children’s participation in EAs. The results showed that all three components of family SES were related to multiple aspects of children’s school readiness, but through different pathways. Parental income was related to children’s school readiness through EA participation only; parental education and occupational status were associated with school readiness via both parental engagement and child EA participation. The findings suggest that considering SES components separately will produce a more nuanced understanding of the divergent pathways through which family SES may relate to children’s school readiness. Chinese government may provide parent education programs focused on cognitive stimulation for low‐SES families to promote children’s school readiness. Furthermore, the government needs to ensure children’s equal access to EAs to prevent increasing the developmental gap among children from discrepant socioeconomic backgrounds.