Aversive functions of response effort: Fact or artifact?

Historically, effort has been viewed as aversive. Most supporting evidence comes from studies demonstrating increased force/effort requirements reduce operant responding. Changes in force/effort requirements, however, are often accompanied by changes in response definition when mechanical devices are used to define the response. As a consequence, responses measured at one point in a study may go unmeasured at other points. In an alternative approach, we used a continuous measurement strategy that provided a means to fix the threshold force defining the response class and simultaneously allowed independent manipulation of the force criteria required to produce reinforcement. Rats pressed a force transducer according to a fixed‐ratio 5 schedule of food delivery. The criterion force was systematically increased and decreased; the threshold for response detection was constant. When response rates included only criterion responses, overall rate decreased when force requirements increased. By contrast, when all responses, both those meeting force criteria and those that did not (above the threshold but below the criteria for reinforcement) were included in the rate calculation, increases in force increased response rate. Increases in force criteria also increased the maximum force (g) and time‐integral of force (g‐s) of operant behavior. Control conditions showed increases in responding could be explained by the emergence of subcriterion responses, irrespective of force. We conclude that prior results showing effort decreases response rates are due to an artifact arising from inadvertent changes in response definitions. Increases in effort may better be understood as changes in the response:reinforcer payoff owing to the emergence of a subcriterion response class.     

词语型类别属性归纳中分类与属性推理过程的时间特征

先前的研究中没有清晰分离类别属性归纳任务中分类过程与属性推理过程的ERP特征。本研究采用了事件相关电位技术(ERPs), 通过在词语型类别属性归纳任务的结论呈现阶段分开呈现结论类别和结论属性, 探讨了类别属性归纳中分类过程和属性推理过程的ERP特征。实验结果显示：在结论类别呈现阶段, 结论无关类别比结论关联类别诱发了更大的N400, 表明N400与类别属性归纳中的语义分类过程密切相关。在结论属性呈现阶段, 无论是在类别关联还是在类别无关条件下, 不一致属性比一致属性均诱发了更大的前部N2成分, 反映了属性知觉上的失匹配或规则的违背。随后, 在300~400 ms的时间窗口发现, 一致属性比不一致属性在前部脑区诱发了更大的类似于P3a的正偏转, 反映了对一致属性的更多关注。同时, 实验还发现, 当结论类别与前提类别关联时, 在300~400 ms的时间窗口, 一致属性比不一致属性在后部脑区也诱发了更大的类似于P3b的正偏转, 反映了推理预期的满意程度; 随后, 在400~600 ms的时间窗口, 不一致属性比一致属性在后部脑区诱发了更大的正偏转, 这与推理规则的违反相关。     

Drug Tolerance, Drug Addiction, and Drug Anticipation

ABSTRACT— Environmental cues associated with drugs often elicit withdrawal symptoms and relapse to drug use. Such cues also modulate drug tolerance. The contribution of drug-associated stimuli to withdrawal and tolerance is emphasized in a Pavlovian-conditioning analysis of drug administration. Conditional responses occur in the presence of cues that have been associated with the drug in the past, such as the setting in which the drug was taken. These conditional responses mediate the expression of tolerance and withdrawal symptoms. Recently, it has become apparent that internal predrug cues, as well as environmental cues, elicit pharmacological conditional responses that contribute to tolerance and withdrawal. Such internal cues include cognitive or proprioceptive cues incidental to self-administration, drug-onset cues that are experienced shortly after administration, and emotional cues. According to the conditioning analysis, addiction treatment should incorporate learning principles to extinguish the association between stimuli (environmental and internal) present at the time of drug administration and the effects of the addictive drug.     

Examining the sex- and circadian dependency of a learning phenotype in mice with glycine transporter 1 deletion in two Pavlovian conditioning paradigms

Behavioural characterisation of transgenic mice has been instrumental in search of therapeutic targets for the modulation of cognitive function. However, little effort has been devoted to phenotypic characterisation across environmental conditions and genomic differences such as sex and strain, which is essential to translational research. The present study is an effort in this direction. It scrutinised the stability and robustness of the phenotype of enhanced Pavlovian conditioning reported in mice with forebrain neuronal deletion of glycine transporter 1 by evaluating the possible presence of sex and circadian dependency, and its consistency across aversive and appetitive conditioning paradigms. The Pavlovian phenotype was essentially unaffected by the time of testing between the two circadian phases, but it was modified by sex in both conditioning paradigms. We observed that the effect size of the phenotype was strongest in female mice tested during the dark phase in the aversive paradigm. Critically, the presence of the phenotype in female mutants was accompanied by an increase in resistance to extinction. Similarly, enhanced conditioned responding once again emerged solely in female mutants in the appetitive conditioning experiment, which was again associated with an increased resistance to extinction across days, but male mutants exhibited an opposite trend towards facilitation of extinction. The present study has thus added hitherto unknown qualifications and specifications of a previously reported memory enhancing phenotype in this mouse line by identifying the determinants of the magnitude and direction of the expressed phenotype. This in-depth comparative approach is of value to the interpretation of behavioural findings in general.     

高渗氯化钠羟乙基淀粉40注射液对肝肿瘤并高血压患者硬膜外复合全身麻醉诱导期的脑保护作用

观察预注高渗氯化钠羟乙基淀粉40注射液对肝肿瘤合并高血压患者硬膜外复合全身麻醉诱导期的脑保护作用。选择50例患有高血压ASA分级Ⅱ级～Ⅲ级肝肿瘤手术患者,随机分为高渗氯化钠羟乙基淀粉40注射液(H)组和复方氯化钠(复方乳酸林格液R)组,每组25例。于输注前(T0)、输注完毕即刻(T1)、气管插管后即刻(T2)、气管插管后5min(T3)、气管插管后15min(T4)、气管插管后30min(T5)抽取静脉血离心后检测血清中S100B、IL-6、TNF-a的浓度。与T0点相比,H组,T5点S100B轻度降低但无统计学差异(P0.05),IL-6、TNF-a无明显变化(P0.05);R组在T5点S100B明显上升(P0.01);IL-6、TNF-a明显上升(P0.05或P0.01)。与R组相比,H组患者在T3-5时点S100B、IL-6和TNF-a均低(P0.05或P0.01)。结论为预注高渗氯化钠羟乙基淀粉40注射液在肝肿瘤合并高血压患者硬膜外复合全身麻醉诱导期具有脑保护作用。     

口腔疣状癌分型研究的思考

通过口腔疣状癌特殊类型发现与分型标准建立的探讨,阐明了口腔疣状癌分型的重要性以及对治疗的重要指导意义。并通过总结说明,任何一门学科的发展既依赖于科学技术的进步,也要求科学工作者有怀疑的精神,同时应具有一定的哲学思想,将哲学思想的各种理论贯穿研究其中。     

不熟悉材料伴随熟悉类别标签时儿童的归纳推理

对呈现在儿童面前的不熟悉的材料用儿童熟悉的、各不相同的类别标签命名之后,使儿童面临知觉相似和类别冲突的情形下,研究了儿童的归纳推理及其发展。研究结果显示,在此情形下,5岁儿童的归纳推理主要是基于知觉相似的,7岁儿童基于知觉相似和基于类别的归纳推理之间差异不显著,11岁儿童则主要基于类别进行归纳推理。     

Reflex theory in a linguistic context: Sergej M. Dobrogaev on the social nature of speech production

The development of reflex theory in its Pavlovian interpretation had significant resonance in a wide range of academic research areas. Its impact on the so-called humanities was, perhaps, no less than the effect it had in medical science. The idea of the conditioned reflex suggesting a physiological explanation of behaviour patterns received a particularly warm welcome in philosophy and psychology as it provided a scientifically-based tool for a conceptual u-turn towards objectivism. This article looks into the ways these ideas contributed to the formation of the Soviet language theory, namely, to the sociological interpretation of language development and speech production presented in the pioneering works of Sergej M. Dobrogaev (1873–1952).

Second-order conditioning of human causal learning

This article provides the first demonstration of a reliable second-order conditioning (SOC) effect in human causal learning tasks. It demonstrates the human ability to infer relationships between a cause and an effect that were never paired together during training. Experiments 1a and 1b showed a clear and reliable SOC effect, while Experiments 2a and 2b demonstrated that first-order extinction did not affect SOC. These results were similar to those found in animal and human conditioning and suggested that a similar associative mechanism could explain these effects. However, they can also be used to look into the underlying causal mental model people build and store while they are learning this task. From a cognitive view, overall results suggest that an independent rather than a chain causal mental model is stored after second-order learning in human causal tasks.     

Fear conditioning in posttraumatic stress disorder: evidence for delayed extinction of autonomic, experiential, and behavioural responses

Aversive conditioning has been proposed as an important factor involved in the etiology of posttraumatic stress disorder (PTSD). However, it is not yet fully understood exactly which learning mechanisms are characteristic for PTSD. PTSD patients (n=36), and healthy individuals with and without trauma exposure (TE group, n=21; nTE group, n=34), underwent a differential fear conditioning experiment consisting of habituation, acquisition, and extinction phases. An electrical stimulus served as the unconditioned stimulus (US), and two neutral pictures as conditioned stimuli (CS+, paired; CS-, unpaired). Conditioned responses were quantified by skin conductance responses (SCRs), subjective ratings of CS valence and US-expectancy, and a behavioural test. In contrast to the nTE group, PTSD patients showed delayed extinction of SCRs to the CS+. Online ratings of valence and US-expectancy as well as the behavioural test confirmed this pattern. These findings point to a deficit in extinction learning and highlight the role of affective valence appraisals and cognitive biases in PTSD. In addition, there was some evidence that a subgroup of PTSD patients had difficulties in learning the CS-US contingency, thereby providing preliminary evidence of reduced discrimination learning.