Response production during extinction training is not sufficient for extinction of evaluative conditioning.

Two high-powered experiments examined the role of evaluative response production in the extinction of evaluative conditioning (EC) by positioning EC in the procedural and conceptual framework of classical conditioning (CC). According to Rescorla's response inhibition hypothesis, more frequent responding during extinction training results in larger extinction during testing. Experiment 1 used three extinction conditions following response acquisition in an EC procedure: evaluative responses were measured only after extinction; after acquisition and after extinction; or were continuously measured after acquisition, during extinction and after extinction. Based on Rescorla's response inhibition hypothesis, we predicted that extinction of EC would be the highest in the third condition. Experiment 2 was aimed at further facilitating extinction of EC by encouraging participants to experience that their evaluation may change over the course of the experiment. To this end, half of the participants completed pre- and post-acquisition ratings prior to practicing continuous response expression in the extinction phase. Contrary to our predictions, no extinction of EC was observed in either of these experiments. We conclude that Rescorla's inhibition response hypothesis may not apply to EC and discuss the theoretical implications of this finding.

Recovery of attention with renewal.

One experiment determined the relationship between renewed associative strength and attention. Following cue1-outcome pairings in Context A, cue1 was extinguished in Context B while cue2 was conditioned. On test cue2 was chosen as a predictor of the outcome in Context B. Both cues were chosen equally often as predictors in Context A. Consistent with attributing attention to effective associative strength (as noted in a previous study), participants could locate only cue2 in Context B while both were located in Context A, regardless of having been chosen as a predictor. Attention varied as a function of both cues' associative strengths across contexts.

A focused attention intervention for coping with ostracism.

Ostracism-being excluded and ignored-thwarts satisfaction of four fundamental needs: belonging, self-esteem, control, and meaningful existence. The current study investigated whether training participants to focus their attention on the here-and-now (i.e., focused attention) reduces distress from an ostracism experience. Participants were first trained in either focused or unfocused attention, and then played Cyberball, an online ball-tossing game for which half the participants were included or ostracized. Participants reported their levels of need satisfaction during the game, and after a short delay. Whereas both training groups experienced the same degree of need-threat in the immediate measure, participants who were trained in focused attention showed more recovery for the delayed measure. We reason that focused attention would not reduce the distress during the ostracism experience, but it aided in recovery by preventing participants from reliving the ostracism experience after it concludes.

Associative structure of integrated temporal relationships.

According to the temporal-coding hypothesis (TCH; Savastano & Miller, Behavioural Processes 44:147-162, 1998), acquired associations include temporal information concerning the interval between the associated elements. Moreover, the TCH posits that subjects can integrate two independently acquired associations that share a common element (e.g., S2-S1 and S1-US), which results in the creation of a third association with its own temporal relationship (S2-US). Some evidence has suggested that such temporal integration occurs at the time of testing (Molet, Miguez, Cham, & Miller, Journal of Experimental Psychology: Animal Behavior Processes 38:369-380, 2012). Here we report two fear-conditioning experiments with rats conducted to identify the associative structure of the integrated temporal relationship. The goal was to distinguish between two possible associative structures that could exist following an initial test on which temporal integration occurs: (1) Conditioned responding to S2 on subsequent tests could be the result of recurring successive activation of two independently learned temporal maps that remain independently stored in memory (i.e., S2-S1 plus S1-US). (2) Temporal integration at the moment of initial testing could result in the formation of a direct S2-US (or S2-response) temporal map. Integration was found to occur at test and to produce a new association that was independent of associations with the common element (S1). However, the associative status of S1 appeared to modulate whether or not the new association with S2 was US-specific (S2-US) or directly activated a fear response (S2-response).

Acquired equivalence of cues by presentation in a common context in rats.

It is well established that humans and other animals may treat two perceptually different cues alike, if the cues have been individually paired with a common antecedent or a common consequence. Recently, Molet et al. (Psychon Bull Rev 18:618-623, 2011) reported evidence for a new form of acquired equivalence in human conditional discrimination, namely context-mediated equivalence. In the present research, using a flavor conditioning procedure, we asked whether rats would show similar context-mediated equivalence to demonstrate that this new form of acquired equivalence is a general phenomenon. Rats experienced two flavor cues A and B each presented either in the same context, X, or each in its own distinctive context, X or Y. Subsequently, the rats experienced B with sucrose in a third context, Z, and then the generalization of conditioning to A was assessed. When tested in Context Z, consumption of A was more marked when A and B had both been presented in the same context than when they had been presented in two different contexts. Thus, importantly, in the absence of the training context, cues that shared a common context at different times came to be treated as equivalent. This represents the first evidence of context-mediated equivalence in a nonhuman species.

Decision making by humans in a behavioral task: do humans, like pigeons, show suboptimal choice?

Consistent with human gambling behavior but contrary to optimal foraging theory, pigeons show a strong preference for an alternative with low probability and high payoff (a gambling-like alternative) over an alternative with a greater net payoff (Zentall & Stagner, Proceedings of the Royal Society B, 278, 1203-1208, 2011). In the present research, we asked whether humans would show suboptimal choice on a task involving choices with probabilities similar to those for pigeons. In Experiment 1, when we selected participants on the basis of their self-reported gambling activities, we found a significantly greater choice of the alternative involving low probability and high payoff (gambling-like alternative) than for a group that reported an absence of gambling activity. In Experiment 2, we found that when the inhibiting abilities of typical humans were impaired by a self-regulatory depletion manipulation, they were more likely to choose the gambling-like alternative. Taken together, the results suggest that this task is suitable for the comparative study of suboptimal decision-making behavior and the mechanisms that underlie it.

Simultaneous discrimination reversal learning in pigeons and humans: anticipatory and perseverative errors.

Pigeons were trained on a two-choice simultaneous discrimination (red vs. green) that reversed midway through each session. After considerable training, they consistently made both anticipatory errors prior to the reversal and perseverative errors after the reversal, suggesting that time (or number of trials) into the session served as a cue for reversal. In Experiment 2, to discourage the use of time as a cue, we varied the location of the reversal point within the session such that it occurred semirandomly after Trial 10, 25, 40, 55, or 70. Pigeons still tended both to anticipate and to perseverate. In Experiment 3, we required 20 pecks to a stimulus on each trial to facilitate memory for the preceding response and sensitivity to local reinforcement contingencies, but the results were similar to those of Experiment 2. We then tested humans on a similar task with a constant (Experiment 4) or variable (Experiment 5) reversal location. When the reversal occurred consistently at the midpoint of the session, humans, like pigeons, showed a tendency to anticipate the reversal; however, they did not show perseverative errors. When the reversal location varied between sessions, unlike pigeons, humans adopted a win-stay/lose-shift strategy, making only a single error on the first trial of the reversal.

Mere Exposure Effect Is Sometimes Insensitive to Mood Inductions.

The mere exposure effect (MEE) is defined as repeated exposures to a stimulus enhancing affective evaluations of that stimulus (Zajonc, 1968). The three prominent explanations of the MEE are Zajonc's "neophobia" account, the uncertainty reduction account, and the perceptual fluency approach. Zajonc's "neophobia" account posits that people have an inherent low level of fear of novel objects and exposure to the objects partially extinguishes this novelty-based fear. The uncertainty reduction account asserts that people find uncertainty aversive and habituation reduces uncertainty. The fluency account postulates that people "like" representations of things with which they are fluent. In four experiments, we induced positive and negative moods before or after target exposures. In addition to assessing the MEE in each condition, we assessed the mood induction. The central hypothesis assessed in this series was that there would be an interaction between mood and the MEE. Although the three accounts of the MEE generated divergent predictions, none of the accounts were well supported by the data. Tests for mood induction demonstrated the efficacy of the induction procedures and the MEE was consistently observed, but Bayesian analysis indicated that at least in the present preparation mood had no effect on the MEE.

Relative judgments affect assessments of stimulus duration.

Humans were trained on two independent temporal discriminations, with correct choice dependent on the initial stimulus duration. In Experiment 1, the durations were 1.0 and 4.0 sec, with one set of choice stimuli, and 2.0 and 8.0 sec, with a different set of choice stimuli. The 2.0- and 4.0-sec values were selected to be the geometric mean of the two values in the other discrimination. In Experiment 2, the durations were 2.0 and 5.0 sec for one discrimination and 3.5 and 6.5 sec for the other. The 3.5- and 5.0-sec values were selected to be the arithmetic mean of the two values in the other discrimination. In both experiments, participants showed evidence for relational coding of the duration pairs. That is, the test durations were selected to be at the presumed bisection point (i.e., they should have produced indifferent choice), but instead the shorter test duration from the longer duration pair produced a "short" bias (in both experiments), whereas the longer duration from the shorter duration pair produced a "long" bias (in the second experiment). Results were similar to those from Zentall, Weaver, and Clement (2004) with pigeons.

Latent timing in human conditioned avoidance.

Four experiments explored signal timing in human conditioned avoidance. Participants received discrimination training with different duration signals that announced the outcome (S+) or not (S-). Temporal discrimination and superposition of performance to S+ signals of different length (3, 6, or 9 s) was found both in within-subjects (Experiment 1a) and between-subjects (Experiment 1b) designs. S- signals also produced a temporal discrimination and superposition effect during a single test trial conducted after the meaning of the signals was reversed through instructions. Experiments 2a and 2b replicated these results in a situation in which (a) the durations of the S+ and S- signals were different (4.5 or 9 s) to prevent any temporal generalization between them (Experiment 2a), and (b) only S- signals were presented during training, precluding developing of inhibition to S- (Experiment 2b). These results show that participants time both S+ and S- signals in human conditioned avoidance, and they further suggest that the timing of a cue is independent of reinforcement.

The impact of arbitrarily applicable relational responding on evaluative learning about hypothetical money and shock outcomes.

Evaluative learning comprises changes in preferences after co-occurrences between conditioned stimuli (CSs) and an unconditioned stimulus (US) of affective value. Co-occurrences may involve relational responding. Two experiments examined the impact of arbitrary relational responding on evaluative preferences for hypothetical money and shock outcomes. In Experiment 1, participants were trained to make arbitrary relational responses by placing CSs of the same size but different colours into boxes and were then instructed that these CSs represented different intensities of hypothetical USs (money or shock). Liking ratings of the CSs were altered in accordance with the underlying bigger/smaller than relations. A reversal of preference was also observed: the CS associated with the smallest hypothetical shock was rated more positively than the CS associated with the smallest amount of hypothetical money. In Experiment 2, procedures from Relational Frame Theory (RFT) established a relational network of more than/less than relations consisting of five CSs (A-B-C-D-E). Overall, evaluative preferences were altered, but not reversed, depending on (a) how stimuli had been related to one another during the learning phase and (b) whether those stimuli referred to money or shocks. The contribution of RFT to evaluative learning research is discussed.

Acquisition, extinction and temporal discrimination in human conditioned avoidance.

Two experiments were conducted with the aim of designing a videogame for the study of human conditioned avoidance. Participants had to destroy enemy spaceships with the goal of increasing the score in a counter. Coloured signals might announce the launching of a bomb that could hit participant's spaceship producing a 30 points decrease in participant's score. Three groups of participants were trained in discriminating between a warning signal (W) and a safety signal (S) in Experiment 1. Instrumental group could avoid the loss of points by hiding the spaceship before the offset of W. Participants in the Yoked group received the same treatment received by their instrumental partners, regardless of their behaviour. In the Pavlovian group, W was always followed by the loss of points, regardless of participant's behaviour. Discrimination between W and S was better in the Instrumental groups than in the Yoked and Pavlovian control groups. Experiment 2 found extinction of avoidance when the warning signal was not followed by the bomb. Temporal discrimination was found within the participants that received the instrumental contingency in both experiments, with higher avoidance response towards the end of the warning signal. Temporal discrimination disappeared after extinction in Experiment 2.

Attenuating social affective learning effects with Memory Suppression manipulations.

People can form opinions of other individuals based on information about their good or bad behavior. The present study investigated whether this affective learning might depend on memory links formed between initially neutral people and valenced information. First, participants viewed neutral faces paired with sentences describing prosocial or antisocial behaviors. Second, memory suppression manipulations with the potential to aid in the forgetting of valenced information were administered. Using the Think/No think paradigm, the effectiveness of four different suppression instructions was compared: Unguided Suppression, Guided Suppression, Distraction, and Thought Substitution. Overall, all the tasks appreciably reduced affective learning based on prosocial information, but only the Guided Suppression and Thought Substitution tasks reduced affective learning based on antisocial information. These results suggest that weakening the putative memory link between initially neutral people and valenced information can decrease the effect of learned associations on the evaluation of other people. We interpreted this as indicative that social affective learning may rely on declarative memories.

Timing: an attribute of associative learning.

The evidence reviewed in this paper suggests that when two events occur in spatiotemporal proximity to one another, an association between the two events is formed which encodes the timing of the events in relation to one another (including duration, order, and interval). The primary evidence supporting the view that temporal relationships are encoded is that subsequent presentation of one event ordinarily elicits behavior indicative of an expectation of the other event at a specific time. Thus, temporal relationships appear to be one of several attributes encoded at acquisition.

There is no sweet escape from social pain: glucose does not attenuate the effects of ostracism.

Ostracism causes social pain and is known to activate regions of the brain that are involved in the representation of physical pain. Previous research has observed that acetominophen (a common pain reliever) can reduce the pain of exclusion. The taste and consumption of glucose can also relieve physical pain, and the purpose of the current study was to examine whether it might also reduce the negative emotional effects of ostracism. In an appropriately powered experiment, participants were given 25g of glucose or a sucralose placebo before being ostracized while playing Cyberball. Strong effects of ostracism were observed, however, there was no effect of glucose on immediate or delayed self-reported needs or mood. These results are discussed in reference to the possibility that social pain is unlike physical pain since the latter is affected by glucose, which is believed to lessen pain by increasing endogenous opioid activity.

Integration of multiple memories in sensory preconditioning.

The present study demonstrates that humans' response to a single stimulus (S1) is determined by what follows S1's associates. The experiment used a sensory preconditioning (SPC) design where S1 was associated with both S2 and S3 on separate trials before establishing relationships between these latter stimuli with an outcome or its absence in a second phase. When S2 and S3 were associated with the same consequence, either an outcome or its absence, strong consequence-based responding to S1 was observed in a reaction time test. Participants responded quickly to indicate that the outcome was, or was not, predicted by S1. When S2 predicted the outcome and S3 did not, SPC was weaker although participants were not slower to respond to S1. Implications on the understanding of the mechanisms that allow for the response to S1 to emerge are discussed.

Conditioned place preference and aversion for music in a virtual reality environment.

The use of a virtual reality environment (VRE) enables behavioral scientists to create different spatial contexts in which human participants behave freely, while still confined to the laboratory. In this article, VRE was used to study conditioned place preference (CPP) and aversion (CPA). In Experiment 1, half of the participants were asked to visit a house for 2 min with consonant music and then they were asked to visit an alternate house with static noise for 2 min, whereas the remaining participants did the visits in reverse order. In Experiment 2, we used the same design as Experiment 1, except for replacing consonant music with dissonant music. After conditioning in both experiments, the participants were given a choice between spending time in the two houses. In Experiment 1, participants spent more time in the house associated with the consonant music, thus showing a CPP toward that house. In Experiment 2, participants spent less time in the house associated with the dissonant music, thus showing a CPA for that house. These results support VRE as a tool to extend research on CPP/CPA in humans.

The impact of facial emotional expressions and sex on interpersonal distancing as evaluated in a computerized stop-distance task.

This study utilizes a novel computerized stop-distance task to examine social space preferences of young adult female and male participants (18-23 years old) who envisioned being approached by others of both sexes who were displaying different facial emotional expressions. The results showed that those displaying anger were kept furthest away, followed by those displaying fear, then sadness, and then neutral expressions, leaving those displaying happiness closest to the participant. It was observed that female participants maintained greater distance from approachers than male participants, and that female approachers were allowed to come nearer than male approachers. These sex differences were observed for most of the emotional facial expressions.

Spatial integration of boundaries in a 3D virtual environment.

Prior research, using two- and three-dimensional environments, has found that when both human and nonhuman animals independently acquire two associations between landmarks with a common landmark (e.g., LM1-LM2 and LM2-LM3), each with its own spatial relationship, they behave as if the two unique LMs have a known spatial relationship despite their never having been paired. Seemingly, they have integrated the two associations to create a third association with its own spatial relationship (LM1-LM3). Using sensory preconditioning (Experiment 1) and second-order conditioning (Experiment 2) procedures, we found that human participants integrated information about the boundaries of pathways to locate a goal within a three-dimensional virtual environment in the absence of any relevant landmarks. Spatial integration depended on the participant experiencing a common boundary feature with which to link the pathways. These results suggest that the principles of associative learning also apply to the boundaries of an environment.

Guilt by association and honor by association: the role of acquired equivalence.

Guilt by association and honor by association are two types of judgments that suggest that a negative or positive quality of a person or object can transfer to another person or object, merely by co-occurrence. Most examples have been demonstrated under conditions of direct associations. Here, we provide experimental evidence of guilt by association and honor by association via indirect associations. We show that participants may treat two individuals alike if they have been separately paired with a common event using an acquired-equivalence paradigm. Our findings suggest that association fallacies can be examined using a paradigm originally developed for research with nonhuman animals and based on a representation mediation account.