Win-shift and win-stay learning in the short-beaked echidna (<Emphasis Type="Italic">Tachyglossus aculeatus</Emphasis>)

Numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. In three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). This is a species and a foraging situation that have not been examined in this way before. Echidnas were better able to learn to avoid a previously rewarding location (to "win-shift") than to learn to return to a previously rewarding location (to "win-stay"), at short retention intervals, but were unable to learn either of these strategies at retention intervals of 90 min. The short retention interval results support the ecological hypothesis, but the long retention interval results do not. Electronic Publication     

A tuned-trace theory of interval-timing dynamics

Animals on interval schedules of reinforcement can rapidly adjust a temporal dependent variable, such as wait time, to changes in the prevailing interreinforcement interval. We describe data on the effects of impulse, step, sine-cyclic, and variable-interval schedules and show that they can be explained by a tuned-trace timing model with a one-back threshold-setting rule. The model can also explain steady-state timing properties such as proportional and Weber law timing and the effects of reinforcement magnitude. The model assumes that food reinforcers and other time markers have a decaying effect (trace) with properties that can be derived from the rate-sensitive property of habituation (the multiple-time-scale model). In timing experiments, response threshold is determined by the trace value at the time of the most recent reinforcement. The model provides a partial account for the learning of multiple intervals, but does not account for scalloping and other postpause features of responding on interval schedules and has some problems with square-wave schedules.     

Parts and wholes in person recognition: developmental trends

This study's aim is the investigation of short-term visual person recognition in 8- and 10-year-olds and adults, within the part-whole paradigm introduced by. Natural unfamiliar whole persons were contrasted with natural unfamiliar faces to test for differences between person processing and face processing. Two experiments showed advantages of whole face recognition over isolated face feature recognition. Also, these was a complete over part probe advantage (CPA, ) for person recognition in all age groups. Thus, recognition became more accurate between 8 years and adulthood, but no developmental shift in visual information processing was observable with face and whole person recognition. I conclude that person recognition does not rely on processes completely different from those of face recognition and that this holds for 8- and 10-year-olds as well as for adults.     

Neural substrates of the ‘low‐level’ system for speech articulation: Evidence from primary opercular syndrome

We describe a patient with progressive disorder of speech, without language impairment (opercular syndrome). Morphometric analysis confirmed asymmetric volume reduction of the precentral areas (>left). Diffusion imaging showed significant white matter changes in the left frontal lobe, with specific involvement of the left corticobulbar tract and connections between supplementary/pre‐supplementary motor areas and the frontal operculum (frontal aslant tract). We suggest that the organization of expressive language includes a ‘low level’ motor system principally distributed in the left hemisphere that shows specific susceptibility to neurodegeneration, distinct from neural systems subtending praxic, and cognitive aspects of language.     

中国大学生的记忆的自我参照效应

记忆的自我参照效应是指记忆材料与自我相联系时的记忆效果优于其它编码条件的现象,这种优势主要体现在以回忆经验为特征的R反应(“记得”)上。西方一些研究表明,自我参照的记忆成绩优于参照母亲的记忆。本研究以中国大学生为被试,得到参照父亲和母亲的记忆与自我参照有同样好的成绩,显著优于参照名人的记忆,并且父母之间无差异。这支持了独立型／依赖型自我概念模型中的东方文化下的自我概念包括父母的观点。     

人类工作记忆的某些神经影像研究

采用神经影像技术研究人类工作记忆的脑机理是目前一个十分活跃的研究领域。研究表明存在负责不同信息加工的工作记忆系统 ,如词语工作记忆、空间工作记忆等 ,其中词语工作记忆主要由大脑左半球参与 ,空间工作记忆主要由大脑右半球参与。前额叶在工作记忆中的作用相当复杂 ,包括对记忆信息的注意和抑制、管理、整合等功能。合理巧妙的实验设计、多种研究手段的综合应用必将使人类工作记忆的脑机理得到充分阐明。     

来源记忆中背景的情绪效价与唤醒对提取过程的影响

以往研究表明情绪背景对来源记忆存在影响,但背景的情绪效价和唤醒如何影响熟悉性及回想尚存争议。本研究以ERPs技术作为测量手段,采用来源记忆多键范式,操纵背景的情绪效价及唤醒强度,以探讨编码阶段背景情绪影响来源记忆提取的认知神经机制。学习阶段,呈现中性汉字及情绪图片（正性高唤醒、正性低唤醒、负性高唤醒、负性低唤醒）;测验阶段,仅呈现汉字,被试进行五键判断。行为结果发现：来源正确的比率比来源错误的比率更高,反应时更短;同时提取正性背景的辨别力更强,反应时更短;提取高唤醒背景反应时更短。脑电结果发现了分别代表熟悉性及回想的FN400及LPC新旧效应,且在500～700 ms,提取正性背景及高唤醒背景诱发显著更正的ERPs,但效价与唤醒没有交互作用。总体来说,来源记忆中背景效价及唤醒度对回想过程存在独立影响,体现为正性背景及高唤醒背景对来源提取的促进作用。     

信息保持、短时存贮与执行控制的脑模型

工作记忆的脑机制是认知神经科学研究的重要问题。研究者在分析大量脑成像研究数据的基础上,创建了许多解释工作记忆神经基础的模型。Smith和Jonides发展了工作记忆成分结构模型和贮存与执行加工分离模型。Postle和D’Esposito建构了工作记忆相对表征混合模型,D’Esposito, Postle和Rypma阐述了工作记忆加工阶段动态模型。Fletcher和Henson提出工作记忆额叶分区整合理论。该文通过对上述模型或理论的评价,总结了工作记忆脑成像研究中存在的问题,展望了该研究领域的发展趋势。     

执行功能研究方法评述

虽然对执行功能的研究长期以来都是从神经心理学角度出发的,但现在发展心理学领域中也出现了大量的研究,其研究方法也层出不穷。该文从发展心理学角度分析了研究儿童冷执行功能和热执行功能的常用方法,包括搜寻任务、规则运用任务、优势规则抑制任务、矛盾冲突任务、问题解决任务、图片工作记忆任务、心理理论任务、延迟满足任务、儿童博弈任务和反向择物。通过对这些方法的分析,作者发现,执行功能的概念已逐步扩展到包容整个认知过程,而已有的关于执行功能的观点都只强调了其中某一个或几个方面,还没有一种观点能够将上述方法所研究的执行功能概括完整。执行功能的本质还远远不能清晰地展示在我们面前。