Dissociating the effects of automatic activation and explicit expectancy on reaction times in a simple associative learning task.

After repeated associations between two events, E1 and E2, responses to E2 can be facilitated either because participants consciously expect E2 to occur after E1 or because E1 automatically activates the response to E2, or because of both. In this article, the authors report on 4 experiments designed to pit the influence of these 2 factors against each other. The authors found that the fastest responses to a target in a reaction time paradigm occurred when automatic activation was highest and conscious expectancy lowest. These results, when considered together with previous findings indicating that, under most conditions, the relation between expectancy and reaction times is in the opposite direction, are indicative of a reversed association-an interaction pattern that J. C. Dunn and K. Kirsner (1988) demonstrated to be the only one that unambiguously points to the involvement of independent processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A direct laboratory comparison of Pavlovian conditioning and traditional associative learning.

24 adult human Ss were presented with a learning task which combined salivary conditioning with traditional associative learning: paired-associate learning of a 50 word Russian-English vocabulary and serial motor learning of a sequence of 100 adjacent bolts. Conditioning proceeded best when Ss did not know they were being conditioned, while associative learning was reasonably effective when Ss knew what they were associating. The view is expressed that the present data support strongly the hypothesis that Pavlov's laws of conditioning are primarily laws of unconscious biological learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Practice effects in reaction-time tasks in brain-injured patients.

"A study of performance trends in simple and choice reaction time tasks in nonpsychotic, brain-injured patients and a matched group of control patients indicated that, within the limits investigated (30 trials in each task), there were no significant practice effects with respect to mean reaction time for either group in either task. The performances of those brain-injured patients whose initial reaction times were within normal limits also failed to reflect significant practice effects… . The brain-injured patients showed a significant increase in intra-individual variability in simple reaction time with continued practice. However, this difference in trends was not found in the choice reaction task." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing elemental and configural associative theories in human causal learning: A case for attention.

In two causal learning experiments with human participants, the authors compared various associative theories that assumed either elemental (unique cue, modified unique cue, replaced elements model, and Harris' model) or configural processing of stimuli (Pearce's theory and a modification of it). The authors used modified patterning problems initially suggested by Redhead and Pearce (1995). Predictions for all theories were generated by computer simulations. Both configural theories and the unique cue approach failed to account for the observations. The replaced elements model was able to account for part of the data, but only if the replacement parameters could vary across discrimination problems. The Harris model and the modified unique cue approach, assuming that the salience of stimuli decreases with an increasing number of stimuli in a compound, successfully accounted for all of our data. This success implies that attentional factors should be explicitly taken into account in associative learning theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of similarity in human associative learning.

In 2 experiments, humans received sequences of patterns that were similar (AX→BX, AY→BY, AZ→BZ) or dissimilar (CX→DY, CY→DZ, CZ→DX). The patterns were portrayed as bugs that could be eliminated with 2 insecticide sprays (red or blue). Either spray eliminated bugs with Features A and C, and participants learned by trial and error to use one spray (e.g., red) to eliminate bugs with Feature B and the other spray (e.g., blue) to eliminate those with Feature D. In Experiment 1, participants' spray choice for bugs with Feature A came to match that used to eliminate bugs with Feature B, but there was no such associative transfer between Features C and D. That is, similarity promoted associative transfer of responding between paired patterns when the features used to manipulate similarity (i.e., X, Y, and Z) were irrelevant. In Experiment 2, in which X, Y, and Z were relevant to the solution of configural discrimination, similarity hindered such associative transfer. These results complement those found in pigeons (R. A. Rescorla & D. J. Gillan, 1980) and indicate that similarity should not be accorded independent status as a principle of associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance expectancy as a determinant of actual performance: A partial replication.

Astudy by Aronson and Carlsmith (1962) indicated that Ss preferred to fail in order to confirm a failure expectancy than to be successful and disconfirm the expectancy. The present study was a partial replication of the Aronson and Carlsmith study. E demands were minimized, and it was expected that the results should have paralleled those of Aronson and Carlsmith if E demands in the latter study had not confounded the dependent variable. 40 1st-year, female nursing students were used. The results indicated that Aronson and Carlsmith's findings might be accounted for by E demands. Ss of the present study behaved as though they preferred to succeed rather than to confirm a failure expectancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

UCS intensity and performance in eyelid conditioning.

Studies of the effects of UCS intensity on performance in human eyelid conditioning are reviewed, particularly with respect to a recent claim that this variable determines the proportion of Ss who condition and not the performance level of individual Ss. The evidence reviewed clearly indicates that UCS intensity does affect the level of performance in Ss who condition. The function involved appears to be negatively accelerated and to approach an asymptote within a relatively small range of intensity values. These effects of UCS intensity are interpreted as reflecting both motivational and associative factors. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do reaction times in the perruchet effect reflect variations in the strength of an associative link?

In 3 experiments, we examined Perruchet, Cleeremans, and Destrebecqz’s (2006) double dissociation of cued reaction time (RT) and target expectancy. In this design, participants receive a tone on every trial and are required to respond as quickly as possible to a square presented on 50% of those trials (a partial reinforcement schedule). Participants are faster to respond to the square following many recent tone–square pairings and slower to respond following many tone-alone presentations. Of importance, expectancy of the square is highest when performance on the RT task is poorest—following many tone-alone trials. This finding suggests that RT performance is determined by the strength of a tone–square link and that this link is the product of a non-expectancy-based learning mechanism. The present experiments, however, provide evidence that the speeded RTs are not the consequence of the strengthening and weakening of a tone–square link. Thus, the RT Perruchet effect does not provide evidence for a non-expectancy-based link-formation mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploration of cerebellar-dependent associative learning in schizophrenia: Effects of varying and shifting interstimulus interval on eyeblink conditioning.

Eyeblink conditioning abnormalities have been reported in schizophrenia, but the extent to which these anomalies are evident across a range of delay intervals (i.e., interstimulus intervals; ISIs) is unknown. In addition, the effects of ISI shifts on learning are unknown, though such manipulations can be informative about the plasticity of cerebellar timing functions. Therefore, the primary purpose of the present study was to investigate the interactions between ISI manipulations and learning in schizophrenia. A standard delay eyeblink conditioning procedure with four different interstimulus intervals (ISIs; 250, 350, 550, 850 ms) was employed. Each eyeblink conditioning experiment was immediately followed by another with a different ISI, thus permitting the characterization of conditioned response (CR) learning at one ISI and the extent to which CRs could be generated at a different latency following an ISI shift. Collapsing across all conditions, the schizophrenia group (n = 55) had significantly fewer conditioned responses and longer onset latencies than age-matched controls (n = 55). Surprisingly, shifting to a new ISI had negligible effects on conditioned response rates in both groups. These findings contribute to evidence of robust eyeblink conditioning abnormalities in schizophrenia and suggest impaired cerebellar function, but underscore the need for more research to clarify the source of these abnormalities and their relationship to clinical manifestations of schizophrenia. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A mutation in the AMPA-type glutamate receptor, glr-1, blocks olfactory associative and nonassociative learning in Caenorhabditis elegans.

The α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-type ionotropic glutamate receptor mediates fast excitatory neurotransmission in the vertebrate brain and is important for synaptic plasticity and the initial induction of long-term potentiation (LTP). This study found that the putative Caenorhabditis elegans AMPA receptor gene, glr-1, plays a significant role in experience-dependent behavior in C. elegans. glr-1 mutants are deficient in an olfactory associative learning task, in which diacetyl (DA) is paired with acetic acid solution. glr-1 mutant nematodes are also impaired in nonassociative learning (habituation) with the same DA stimulus. The C. elegans learning mutants, lrn-1 and lrn-2, are impaired in chemosensory associative learning yet have no deficits in habituation. The results suggest that although associative and nonassociative learning can be genetically dissociated ( lrn-1 and lrn-2), they also share some common molecular processes, including glr-1 -mediated neurotransmission. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal contexts: Filling the gap between episodic memory and associative learning.

People can create temporal contexts, or episodes, and stimuli that belong to the same context can later be used to retrieve the memory of other events that occurred at the same time. This can occur in the absence of direct contingency and contiguity between the events, which poses a challenge to associative theories of learning and memory. Because this is a learning and memory problem, we propose an integrated approach. Theories of temporal contexts developed in the memory tradition provide interesting predictions that we test using the methods of associative learning to assess their generality and applicability to different settings and dependent variables. In 4 experiments, the integration of these 2 areas allows us to show that (a) participants spontaneously create temporal contexts in the absence of explicit instructions; (b) cues can be used to retrieve an old temporal context and the information associated with other cues that were trained in that context; and (c) the memory of a retrieved temporal context can be updated with information from the current situation that does not fit well with the retrieved memory, thereby helping participants to best adapt their behavior to the future changes of the environment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Evaluative conditioning in humans: A meta-analysis.

This article presents a meta-analysis of research on evaluative conditioning (EC), defined as a change in the liking of a stimulus (conditioned stimulus; CS) that results from pairing that stimulus with other positive or negative stimuli (unconditioned stimulus; US). Across a total of 214 studies included in the main sample, the mean EC effect was d = .52, with a 95% confidence interval of .466–.582. As estimated from a random-effects model, about 70% of the variance in effect sizes were attributable to true systematic variation rather than sampling error. Moderator analyses were conducted to partially explain this variation, both as a function of concrete aspects of the procedural implementation and as a function of the abstract aspects of the relation between CS and US. Among a range of other findings, EC effects were stronger for high than for low contingency awareness, for supraliminal than for subliminal US presentation, for postacquisition than for postextinction effects, and for self-report than for implicit measures. These findings are discussed with regard to the procedural boundary conditions of EC and theoretical accounts about the mental processes underlying EC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of drug expectancy in the control of human drug seeking.

Human drug seeking may be goal directed in the sense that it is mediated by a mental representation of the drug or habitual in the sense that it is elicited by drug-paired cues directly. To test these 2 accounts, the authors assessed whether a drug-paired stimulus (S+) would transfer control to an independently trained drug-seeking response. Smokers were trained on an instrumental discrimination that established a tobacco S+ in Experiment 1 and a tobacco and a money S+ in Experiment 2 that elicited an expectancy of their respective outcomes. Participants then learned 2 new instrumental responses, 1 for each outcome, in the absence of these stimuli. Finally, in the transfer test, each S+ was found to augment performance of the new instrumental response that was trained with the same outcome. This outcome-specific transfer effect indicates that drug-paired stimuli controlled human drug seeking via a representation or expectation of the drug rather than through a direct stimulus-response association. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronic immobilization stress alters aspects of emotionality and associative learning in the rat.

Chronic stress significantly alters limbic neuroarchitecture and function, and potentiates emotionality in rats. Chronic restraint stress (CRS) increases aggression among familiar rats, potentiates anxiety, and enhances fear conditioning. Chronic immobilization stress (CIS) induces anxiety behavior and dendritic hypertrophy in the basolateral amygdala, which persist beyond a recovery period. However, little else is known about the emotional impact of CIS as a model of chronic stress or depression. Therefore, the authors present two experiments examining emotional and learned responses to CIS. In Experiment I, the authors examine individual differences in behaviors during and after CIS, specifically: struggling, aggression, learned helplessness, inhibitory avoidance, and escape behavior. In Experiment II, the authors confirm the effects of CIS on aggression and struggling during immobilization, and correlate individual responses with aspects of conditioned fear. Here the authors report significant effects of CIS on aggression, inhibitory avoidance, escape, as well as learned aspects of fear (i.e., fear conditioning) and inescapable stress (i.e., struggling and helplessness). These results emphasize the emotional and learned responses to CIS evident during and after the stress treatment, as well as the importance of individual differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of the diffusion model to two-choice tasks for adults 75-90 years old.

The effects of aging on simple 2-choice decision making was investigated with the diffusion model (R. Ratcliff, 1978). Data for 75- to 90-year-olds were collected and compared with previous data from 60- to 75-year-olds and college students for 5 tasks: a signal detection-like task, letter and brightness discrimination with masking, recognition memory, and lexical decision. The model fit the data well and therefore allows components of processing to be examined as a function of age. Compared with decision-making processes in college students, decision criteria and nondecision components of processing increased with participants' age. However, the quality of the evidence on which decisions were based decreased with age only for letter and brightness discrimination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incubation of creative performance and specific associative priming.

In the context of an associative theory of creativity, the effect of specific associative priming upon incubation of creative performance was studied. 2 experiments were conducted. In Experiment I, using 30 Ss, it was demonstrated that performance on a remote-associate task was enhanced by specific priming. In a 2nd study, using the same method and materials, high scores (HC) and low scorers (LC) on the Remote Associate Test (a measure of creative potential) were compared in a 2 X 2 X 3 factorial design also included 2 levels of priming (some and none) and 3 time relationships (immediate, pre-24 hr. and post-24 hr.) HC Ss performed significantly better than LC Ss, and the effect of specific priming was significantly greater than no priming. The time relationship had no effect. These data lend support to an associative interpretation of the phenomenon of incubation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acquired equivalence and distinctiveness in human discrimination learning: Evidence for associative mediation.

In the first stage of Experiments 1-3, subjects learned to associate different geometrical figures with colors or with verbal labels. Performance in Stage 2, in which the figures signaled which of 2 motor responses should be performed, was superior in subjects required to make the same response to figures that had shared the same Stage 1 associate. A third stage of testing showed that the events used as associates in Stage 1 were capable of evoking the motor response trained in Stage 2, an outcome predicted by an associative interpretation of such transfer effects. Experiment 4 provided evidence that the relevant associations can be effective in controlling motor responding even when subjects report an antagonistic relationship between the events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simultaneous backward conditioned inhibition and mediated conditioning.

Demonstrations of retrospective revaluation suggest that remembered stimuli undergo a reduction in association with the unconditioned stimulus (US) present during learning. Conversely, demonstrations of mediated conditioning in flavor-conditioning experiments with rats suggest that remembered stimuli undergo an increase in association with the US present during learning. In a food allergy prediction task with 23 undergraduates, we demonstrated simultaneous backward conditioned inhibition and mediated conditioning effects. These results are compatible with the hypothesis that the direction of change (decrease or increase) in associative strength depends on whether the remembered stimulus was of a different category (conditioned stimulus/antecedent) or the same category (US/outcome) as the presented US. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Dissociations between reaction times and temporal order judgments: A diffusion model approach.

A diffusion model for simple reaction time (RT) and temporal order judgment (TOJ) tasks was developed to account for a commonly observed dissociation between these 2 tasks: Most stimulus manipulations (e.g., intensity) have larger effects in RT tasks than in TOJ tasks. The model assumes that a detection criterion determines the level of sensory evidence needed to conclude that a stimulus has been presented. Analysis of the performance that would be achieved with different possible criterion settings revealed that performance was optimal with a lower criterion setting for the TOJ task than for the RT task. In addition, the model predicts that effects of stimulus manipulations should increase with the size of the detection criterion. Thus, the model suggests that commonly observed dissociations between RT and TOJ tasks may simply be due to performance optimization in the face of conflicting task demands. (PsycINFO Database Record (c) 2010 APA, all rights reserved)