Reconsolidation and memory infidelity in Lymnaea

Lymnaea stagnalis were operantly conditioned to not perform aerial respiratory behaviour in a specific context (i.e. context-1). The memory for this learned response was reactivated 3 days later in context-1. During the 1 h reconsolidation period following memory reactivation, randomly picked snails were either maintained in context-1 or exposed to a new context (i.e. context-2). One hour later in the post-reconsolidation period, snails in context-1 were placed for 1 h in context-2 and vice-versa. In neither the hypoxic reconsolidation nor the post reconsolidation periods did snails receive a reinforcing stimulus when they opened their pneumostome. All snails were blindly tested for memory 24 h later period in context-2. Only those snails that had been exposed to context-2 during the reconsolidation period exhibited 'memory' for context-2. That is, memory infidelity was observed. Snails exposed to context-2 in only the post-reconsolidation period did not show memory for context-2. The immediate cooling of snails after their exposure to the new context in the reconsolidation period blocked the formation the implanted memory. Snails trained in context-1 and exposed to context-2 in the consolidation period only, also did not have memory for context-2. However, the memory for context-1 could still be recalled following successful implantation of the 'new' memory. All data presented here are consistent with the notion that during the reconsolidation process memory can be updated.     

Stimulus competition in pre/post and online ratings in an evaluative learning design

Evaluative learning is said to differ from Pavlovian associative learning in that it reflects stimulus contiguity, not contingency. Thus, evaluative learning should not be subject to stimulus competition, a proposal tested in the current experiments. Participants were presented in elemental and compound training phases with pictures of shapes as CSs. Each shape/pair of shapes was followed by a picture of a happy or an angry face as the US. In Experiments 1 and 2, evaluative ratings were collected before and after the experiment, and, in Experiment 3, participants provided evaluations online. Stimulus competition was evident in all experiments confirming that evaluative learning is sensitive to stimulus contingencies.     

The influence of extinction and counterconditioning instructions on evaluative conditioning effects

In three experiments, we tested the influence of instructions about an allegedly upcoming extinction or counterconditioning phase on evaluative conditioning (EC) effects. After an acquisition phase in which neutral stimuli were related to positive or negative stimuli via instructions (Experiments 1 and 2a) or actual pairings (Experiment 2b), three different groups of participants were either informed that in the next phase the neutral stimuli would be presented without positive or negative stimuli (extinction instruction), that the neutral stimuli in the next phase would be paired with stimuli of the opposite valence than before (counterconditioning instruction), or received no further instructions. Afterwards, liking of the originally neutral stimuli was measured either with an evaluative rating (Experiment 1) or with an Implicit Association Test (IAT; Experiments 2a and 2b). EC was reduced in the counterconditioning condition of Experiment 1 and in the joint analysis of Experiments 2a and 2b. The extinction instruction led to a reduction of EC only in Experiment 1. Finally, whether the acquisition phase consisted of instructions about CS–US pairings (Experiment 2a) or the actual experience of CS–US pairings (Experiment 2b) did not significantly impact the observed changes in liking. Overall, our results suggest that similar mechanisms might mediate instruction- and experienced-based EC. Our results are in line with propositional models of EC but can be explained also by association formation models and dual process models of EC, provided that certain auxiliary assumptions are made.     

条件联结觉察在评价性条件反射中的作用

评价性条件反射(Evaluative Conditioning, EC)指通过将一个中性刺激和一个情绪性刺激重复配对, 使中性刺激获得情绪性刺激的情感性评价。条件联结觉察(Contingency Awareness)指被试觉察到中性刺激和情绪性刺激的配对规律。当前, 条件联结觉察在EC中的作用尚存争议。一些研究证明, 条件联结觉察独立于EC, 甚至阻碍了EC; 另一些研究则表明, 条件联结觉察促进EC的发生; 还有些研究发现条件联结觉察在EC中的作用受其他变量的调节。因此, 在将来的研究中, 需发展出更准确的觉察测量、检验其他变量的调节作用、加强多感觉通道的EC研究、探索EC的加工机制。     

Verbal behavior

The recent history and current status of the area of verbal behavior are considered in terms of three major thematic lines: the operant conditioning of adult verbal behavior, learning to be an effective speaker and listener, and developments directly related to Skinner's Verbal Behavior. Other topics not directly related to the main themes are also considered: the work of Kurt Salzinger, ape-language research, and human operant research related to rule-governed behavior.     

THE AVERSIVE CONTROL OF EXCESSIVE ALCOHOL CONSUMPTION BY CHRONIC ALCOHOLICS IN THE LABORATORY SETTING1

The efficacy of several methods of aversive control of excessive alcoholic drinking was investigated in a semi-naturalistic setting that permitted objective measurement of the drinking behavior of chronic alcoholics. Studies 1A and 1B compared an escape-conditioning procedure with a control procedure in which aversive electrical shocks were administered before drinking. Neither procedure effectively decreased subjects' pretreatment, baseline alcoholic drinking behavior. In Study 2, aversive response-contingent shocks effectively suppressed alcoholic drinking, but drinking subsequently returned to its former levels after withdrawal of punishment. Self-administered shock appeared to be as effective as experimenter-administered punishment for controlling drinking, even when the punishment contingency was faded out over time. Study 3 replicated the suppressant effect of punishment, and demonstrated that contingent shock was significantly more effective than yoked, noncontingent shock. A direct comparison of self- versus experimenter-administered punishment suggested a possible slight advantage for the latter.     

ATTENTION TRAINING: THE USE OF OVERCORRECTION AVOIDANCE TO INCREASE THE EYE CONTACT OF AUTISTIC AND RETARDED CHILDREN

A crucial first step in teaching and training the retarded and autistic is to develop and maintain eye contact with the therapist. Functional movement training (an overcorrection procedure) plus edibles and praise were compared with edibles and praise alone as a method of developing eye contact in three such children. In both conditions, the child was given food and praise when eye contact occurred within 5 sec of the therapist's verbal prompt: “Look at me.” Functional movement training avoidance plus edibles and praise produced about 90% attention for the three children, while edibles and praise alone were less effective (eye contact never exceeded 55%). Functional movement training avoidance combined with edibles and praise appears to be an effective method of teaching eye contact and possibly other forms of instruction-following to behaviorally disordered children who are not always responsive to positive consequences.     

Transgenic inhibition of neuronal calcineurin activity in the forebrain facilitates fear conditioning, but inhibits the extinction of contextual fear memories

It is unclear whether protein phosphatases, which counteract the actions of protein kinases, play a beneficial role in the formation and extinction of previously acquired fear memories. In this study, we investigated the role of the calcium/calmodulin dependent phosphatase 2B, also known as calcineurin (CaN) in the formation of contextual fear memory and extinction of previously acquired contextual fear. We used a temporally regulated transgenic approach, that allowed us to selectively inhibit neuronal CaN activity in the forebrain either during conditioning or only during extinction training leaving the conditioning undisturbed. Reducing CaN activity through the expression of a CaN inhibitor facilitated contextual fear conditioning, while it impaired the extinction of previously formed contextual fear memory. These findings give the first genetic evidence that neuronal CaN plays an opposite role in the formation of contextual fear memories and the extinction of previously formed contextual fear memories.