视知觉学习的认知与神经机制研究

知觉学习是指由于训练或经验而引起的长期稳定的知觉变化,是一种内隐性的学习。近20年来,视知觉学习的大量研究结果提示大脑皮层的各个区域,甚至包括初级感觉皮层,在成熟之后仍然具有一定的可塑性。该文根据近年来的研究进展,对视知觉学习在大脑的什么地方,什么时候,以何种方式发生等热点问题进行了探讨。研究提示,视知觉学习涉及了包括初级视皮层在内的多个大脑皮层,并且存在一种自上而下的调控机制;视知觉学习可以在不同的时间尺度上发生,快速学习之后将伴随着慢速学习;通过视知觉学习,人们对于复杂物体的表征将从高级皮层区域移向低级皮层区域,任务执行也将趋于自动化     

EQUIVALENCE CLASS FORMATION: A METHOD FOR TEACHING STATISTICAL INTERACTIONS

Many students struggle with statistical concepts such as interaction. In an experimental group, participants took a paper‐and‐pencil test and then were given training to establish equivalent classes containing four different statistical interactions. All participants formed the equivalence classes and showed maintenance when probes contained novel negative exemplars. Thereafter, participants took a second paper‐and‐pencil test. Participants in the control group received two versions of the paper‐and‐pencil test without equivalence‐based instruction. All participants in the experimental group showed increased paper‐and‐pencil test scores after forming the interaction‐indicative equivalence classes. Class‐indicative responding also generalized to novel exemplars and the novel question format used in the paper‐and‐pencil test. Test scores did not change with repetition for control group participants. Implications for behavioral diagnostics and teaching technology are discussed.     

WITHIN‐SUBJECT REVERSIBILITY OF DISCRIMINATIVE FUNCTION IN THE COMPOSITE‐STIMULUS CONTROL OF BEHAVIOR

According to the composite-stimulus control model (Weiss, 1969, 1972b), an individual discriminative stimulus (S^D) is composed of that S^D''s on-state plus the off-states of all other relevant S^Ds. The present experiment investigated the reversibility of composite-stimulus control. Separate groups of rats were trained to lever-press for food whenever a tone or a light S^D was present. For one group, the nonreinforced S^Δ condition was tone-and-light absence ($\bar{T}$+$\bar{L}$). Tone-plus-light (T+L) was S^Δ in the other group. On a “stimulus compounding” test that recombined composite elements, maximum responding occurred to that composite consisting only of elements occasioning response increase. That was T+L for the group trained with $\bar{T}$+$\bar{L}$ as S^Δ and $\bar{T}$+$\bar{L}$ for the group trained with T+L as S^Δ. The S^Δ composite was next reversed over groups in Phase 2. In Phase 2 tests, maximum responding that was comparable in magnitude to that of Phase 1 was again controlled by the composite consisting only of elements most recently occasioning response increase—whether T+L or $\bar{T}$+$\bar{L}$. The inhibitory conditioning history of both composite-elements currently occasioning responding did not weaken the summative effect. These results confirm and extend Weiss''s composite-stimulus control model, and demonstrate that such control is fully reversible. We discuss how translating conditions of the stimulus-compounding paradigm to a composite continuum creates a functional and logical connection to intradimensional control measured through stimulus generalization, reducing the number of different behavioral phenomena requiring unique explanations.     

Response persistence: the effects of stimulus control on negatively reinforced problem behavior in a concurrent operant

In the context of instructional demands, compliance and problem behavior can be considered concurrent operants. Of applied interest is increasing one response (i.e., compliance) while decreasing the other (i.e., problem behavior). Strategic arrangement of reinforcement can alter response allocation accordingly. Such schedules can also influence response persistence and generalization. A case study is used to illustrate the effects of stimulus-reinforcer relations in a concurrent-operants arrangement involving an adult with developmental disabilities and problem behavior. Results are discussed in the context of basic operant research findings in the areas of stimulus control and behavioral persistence.     

情绪对时间知觉的影响

研究了情绪唤醒度和愉悦度对时间知觉的影响及其机制.以53名大学生为被试,采用中国情绪图片系统为情绪诱发材料,使用时间两分法和泛化法考察唤醒和注意机制对时间知觉的影响.结果表明:在短时距下,(1)唤醒度和愉悦度对时间知觉的影响可能是独立的,两个实验中交互作用都不显著;(2)情绪主要通过唤醒机制影响时间知觉,被试在高唤醒情绪下知觉到的时间显著长于在低唤醒情绪下知觉到的时间.     

识别电位认知功能探析

识别电位(Recognition Potential, RP)是被试看到可识别视觉刺激时, 在200~250ms内达到峰值的脑电反应。识别电位的研究正处于理论探讨阶段, 有两种主要观点用于解释RP。一种观点强调RP反映了视知觉分析成分; 另一种观点强调RP反映了语义或概念加工成分。两种观点至今未达成一致。最近, 针对两种观点质疑, 研究者们提出了类别特征加工的观点, 这一新观点在理论上符合大脑经济性的原则, 具有一定的优越性, 但尚需要更多的实证研究的支持。未来的RP研究应从实验材料的多样化、多研究方法结合、类别特征加工能力的习得机制等方面展开。     

再谈在中国应提倡使用避孕套预防艾滋病

人们性观念的转变和性行为准则的放松导致了性传播疾病(STDs)逐年增多.据统计,中国已进入艾滋病(AIDS)的广泛流行期.再次提出应当提倡使用避孕套,充分发挥避孕套的双重保护作用以限制AIDS在国内的蔓延;通过大量的资料,再次阐述了推广使用避孕套的必要性和重要性,并就在国内推广过程中可能会出现的相关问题作了进一步说明.     

Further evaluation of emerging speech in children with developmental disabilities: training verbal behavior

The conceptual basis for many effective language-training programs are based on Skinner's (1957) analysis of verbal behavior. Skinner described several elementary verbal operants including mands, tacts, intraverbals, and echoics. According to Skinner, responses that are the same topography may actually be functionally independent. Previous research has supported Skinner's assertion of functional independence (e.g., Hall & Sundberg, 1987; Lamarre & Holland, 1985), and some research has suggested that specific programming must be incorporated to achieve generalization across verbal operants (e.g., Sigafoos, Reichle, & Doss, 1990). The present study provides further analysis of the independence of verbal operants when teaching language to children with autism and other developmental disabilities. In the current study, 3 participants' vocal responses were first assessed as mands or tacts. Generalization for each verbal operant across alternate conditions was then assessed and subsequent training provided as needed. Results indicated that generalization across verbal operants occurred across some, but not all, vocal responses. These results are discussed relative to the functional independence of verbal operants as described by Skinner.     

A preliminary evaluation of the emergence of novel mand forms

Strategies that produce generalized responding are valuable, especially with regard to language acquisition, because relatively little training may result in large behavior changes. Conditions that result in generalized manding were analyzed in the current study. We demonstrated in reversal designs that undesirable or single-word responses were the predominant mand forms of 3 preschool children. Multiple baseline designs with 2 participants and a reversal design with 1 participant were then used to demonstrate the extent to which differential reinforcement of single-word mands (e.g., "cars") or framed mands (e.g., "I want the cars, please") would result in the emergence of other single-word and framed mands for different items (e.g., mands for music, puppets, or puzzles). Results showed that prompting and differential reinforcement of one or two mand frames resulted in the emergence of other framed mands for all participants.