Reversed PREE under multiple schedules: Exploration of a modulation hypothesis

When reinforcer rates are manipulated in within-subjects designs, persistence in subsequent extinction trials is sometimes greater to the response alternative associated with the higher reinforcer rate (“reversed” partial reinforcement extinction effect, RPREE). The RPREE is often held to be a contradiction to the conventional PREE. To explore the interaction between these effects, student subjects were exposed to a multiple high-density and low-density reinforcement schedule, then to extinction conditions. Subjects in two control conditions received the high- and low-density schedules only. For all groups, general extinction persistence was elevated, and a within-subjects RPREE occurred under the multiple schedule. The RPREE was caused by the low-density component increasing persistence to the high-density component; the high-density component did not decrease persistence to the low-density component. These results support the view that the RPREE may be a within-subjects effect of the conventional PREE.     

Use of the ABA fear renewal paradigm to assess the effects of extinction with co-present fear inhibitors or excitors: Implications for theories of extinction and for treating human fears and phobias

In four experiments using albino rats in an ABA fear renewal paradigm, we studied conditioned fear in the A test context following extinction in Context B. Conditioned suppression of operant responding was the index of fear. In Experiments 1-3, we found that extinguishing a feared cue in compound with a putative conditioned inhibitor of fear led to more fear in the test context than did a conventional extinction procedure. In Experiments 4a and 4b, we found that extinguishing three feared cues in compound required one third the time and generally led to less fear to the cues in the test context than did the extinction of each cue separately. Thus, fear in the test context seems to vary inversely with the values of co-present cues during extinction in Context B. Results imply that cue value is actually reduced by extinction procedures rather than merely being opposed by a growing inhibitory process. Implications for theories of renewal and for clinical practice are discussed.     

学习困难与一般初中生过度自信特点的比较

采用比较研究的实验范式,从偏离校准、优于常人、控制错觉和过分乐观三个效应上比较学习困难初中生和一般初中生的过度自信特点。结果显示:(1)在"偏离校准"效应上,学习困难初中生在困难任务中和学习一般初中生同样存在过度自信的认知偏差,但在简单任务中则存在不自信。(2)在"优于常人"效应上,学习困难初中生和学习一般初中生都存在过度自信的认知偏差。简单任务中,他们认为自己"优于常人",而困难任务中,他们认为自己"差于常人"。(3)在"控制错觉和过分乐观"效应上,学习困难初中生和学习一般初中生都存在过度自信的认知偏差。男生比女生的过度自信程度更大。     

Extinction, spontaneous recovery and renewal of flavor preferences based on taste-taste learning

This paper presents evidence of extinction, spontaneous recovery and renewal in a conditioned preferences paradigm based on taste-taste associations. More specifically, in three experiments rats exposed to a simultaneous compound of citric acid-saccharin solution showed a preference for the citric solution when the preference was measured with a two-bottle test (citric vs. water). Experiment 1 revealed that conditioned preferences were extinguished by repeated presentations of the citric acid solution without the saccharin. In Experiment 2, an additional test trial was introduced 21 days after the extinction treatment. Delayed testing resulted in the recovery of the extinguished preference for the citric, reflecting a spontaneous recovery effect. Experiment 3 revealed a preference renewal effect that was obtained when the extinction was conducted in a context different from that of the remaining experimental stages. The implications of these results are analyzed with attention paid to the mechanisms underlying learning of flavor preferences.     

Mechanisms of resurgence II: Response-contingent reinforcers can reinstate a second extinguished behavior

Three experiments with rat subjects examined resurgence of an extinguished instrumental response using the procedure introduced by Epstein (1983) with pigeons. There were three phases: (1) initial acquisition of pressing on a lever (L1) for pellet reward, (2) extinction of L1, and (3) a test session in which a second lever (L2) was inserted, briefly reinforced, and then extinguished. Experiment 1 confirmed that if pressing L2 delivered 20 pellets followed by extinction, rats would resume L1 responding in the final test. Experiment 2 compared the effects of response-contingent and non-contingent rewards delivered upon insertion of L2. Although insertion of L2 alone did not increase L1 responding, response-contingent and non-contingent rewards led to comparable increases in L1 responding. Experiment 3 found that the delivery of non-contingent pellets during extinction of L1, which would be expected to reduce the ability of pellets to set the occasion for the L1 response, also reduced the effects of both response-contingent and non-contingent rewards during the final test. The results indicate that in this method, the resurgence treatment leads to an increase in L1 pressing due to simple presentation of the pellet; delivering the reinforcer after extinction of L1 reinstates L1 responding by setting the occasion for the L1 response.     

Detection of visual-tactile contingency in the first year after birth

It is well documented that in the first year after birth, infants are able to identify self-performed actions. This ability has been regarded as the basis of conscious self-perception. However, it is not yet known whether infants are also sensitive to aspects of the self when they cannot control the sensory feedback by means of self-performed actions. Therefore, we investigated the contribution of visual–tactile contingency to self-perception in infants. In Experiment 1, 7- and 10-month-olds were presented with two video displays of lifelike baby doll legs. The infant’s left leg was stroked contingently with only one of the video displays. The results showed that 7- and 10-month-olds looked significantly longer at the contingent display than at the non-contingent display. Experiment 2 was conducted to investigate the role of morphological characteristics in contingency detection. Ten-month-olds were presented with video displays of two neutral objects (i.e., oblong wooden blocks of approximately the same size as the doll legs) being stroked in the same way as in Experiment 1. No preference was found for either the contingent or the non-contingent display but our results confirm a significant decrease in looking time to the contingent display compared to Experiment 1. These results indicate that detection of visual–tactile contingency as one important aspect of self-perception is present very early in ontogeny. Furthermore, this ability appears to be limited to the perception of objects that strongly resemble the infant’s body, suggesting an early sensitivity to the morphology of one’s own body.     

Role of stiffness in weight perception

Abstract:  Here, we focused on a load-on task to clarify the judgment mechanism for weight perception. We measured hand trajectory and surface electromyography to estimate time-varying stiffness and torque patterns in joints. Our results showed that the goal of learning motor skills under load-on tasks is to maintain the hand position, and that humans produce force with cocontraction and increasing stiffness levels according to the weight of an object. Finally, we examined whether stiffness is an effective parameter as an efferent signal for weight perception and found that stiffness plays an important role in weight perception.     

认知方式、视错觉及其关系的跨文化研究

运用测验法研究了藏、回、汉族小学三年级、五年级、初二、高二共1032名儿童认知方式的特点,考察了不同认知方式与视错觉之间的关系。结果表明:1)认知方式的民族、居住环境和年龄差异显著,藏族儿童、居住在草原上的儿童、低年级儿童倾向于场依存性,汉族和回族儿童、生活在城市和山村的儿童、高年级儿童倾向于场独立性;2)视错觉的文化差异显著,居住环境和年龄是影响视错觉的重要变量;3)认知方式对视错觉有影响,场独立性者错觉量小,场依存性者错觉量大。     

The effects of physical context changes and multiple extinction contexts on two forms of renewal in a conditioned suppression task with humans

Three experiments examined the effects of physical context changes and multiple extinction contexts on the renewal of conditioned suppression in humans. A conditioned suppression task used an undesirable event as the unconditional stimulus (US). One conditional stimulus (CS+) predicted the occurrence of the US and another (CS−) predicted US absence. In Experiment 1 (N = 32), conditioned suppression was acquired to the CS+ in one context and extinguished in a different context. An increase in suppression was found for the CS+ and not for the CS− when subsequent test trials were conducted in the acquisition context (ABA renewal). Experiment 2 (N = 32) tested for ABC Renewal and showed increased suppression to both the CS+ and CS− when test was conducted in a novel context. Experiment 3 (N = 80) showed that these two effects were abolished when extinction was conducted in multiple contexts. The experiments extend the ABA renewal of conditioned suppression found with non-human animal subjects and the reduction of renewal by extinction in multiple contexts. Context changes may also facilitate cue competition effects after training with elementary stimuli, as shown by the effects of US omission in the ABA and ABC renewal groups.     

Inducing and reducing false memories: a Swedish version of the Deese-Roediger-McDermott paradigm

Participants tend to falsely remember a nonpresented critical word after having studied a list of the word's primary associates. We present here a Swedish version of the Deese-Roediger-McDermott paradigm, which provides a tractable method of experimentally inducing and investigating such illusory memories. In Experiment 1 it was demonstrated that the constructed stimulus material induced highly reliable false-recall and false-recognition effects, and, moreover, that veridical and false memories were associated with a similar phenomenological experience of remembering. The results from Experiment 2 indicated that the susceptibility to false recognition can be substantially reduced when participants are explicitly required to monitor the sources of their memories. These findings are consistent with predictions derived from the source-monitoring framework.