Abstract  Three experiments tested whether events taking place before a rat has access to a target taste, sucrose, can proactively interfere with the acquisition of a sucrose aversion when sucrose is followed by a lithium chloride injection. Using a serial overshadowing procedure with various delays before lithium injection, proactive interference by a taste (Experiments 1 and 3) and by a novel context (Experiment 2) was found following two conditioning sessions, but not after a single conditioning session. Conversely, overshadowing by a taste given after the target was detectable after a single conditioning trial (Experiment 3) and, thus, indicated that retroactive interference involves a process different from that producing proactive interference. A simulation confirmed that the results are consistent with a modified Rescorla and Wagner (1972) interpretation of Revusky’s (1971) concurrent interference theory of delay learning.

• Content Type Journal Article
• Pages 1-12
• DOI 10.3758/s13420-011-0064-0
• Authors
  • Dorothy W. S. Kwok, University of Sydney, Sydney, Australia
  • Evan J. Livesey, University of Sydney, Sydney, Australia
  • Robert A. Boakes, School of Psychology (A18), University of Sydney, Sydney, NSW 2006, Australia

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  The aim of this study was to delineate the minimal conditions for extinction of Pavlovian modulation in humans. Previous experiments at our lab showed that, after X ➔ A+/A– acquisition training, X– trials did not extinguish differential X ➔ A+/A– responding, while X ➔ A– trials did. Additionally, X ➔ A– extinction training seemed only to extinguish differential X ➔ A+/A– responding, while leaving differential responding on a concurrently trained Y ➔ B+/B– discrimination intact. It thus seemed that the X ➔ A+/A– discrimination can only be extinguished by X ➔ A– extinction trials. (Rescorla, Journal of Experimental Psychology: Animal Behavior Processes 12, 16–24, 1986), on the other hand, found that the minimal conditions for extinction were broader in pigeons: Namely, he found that an acquired X ➔ A+/A– discrimination could be extinguished by presenting the original feature X in combination with a different target (B) that was minimally trained as an exciter. We thus wanted to examine whether this was also the case in humans. We found that nonreinforced X ➔ B– presentations did not abolish discriminative X ➔ A/A responding when target B was a nonreinforced stimulus. Nonreinforced X ➔ B– trials did extinguish the X ➔ A+/A– discrimination when target B had previously been trained as a target for modulation (X ➔ B+/B– or Y ➔ B+/B– training) or as a reinforced exciter (B+). Our results thusf parallel and extend those in nonhuman animals (Rescorla, Journal of Experimental Psychology: Animal Behavior Processes 12, 16–24, 1986).

• Content Type Journal Article
• Pages 1-12
• DOI 10.3758/s13420-011-0060-4
• Authors
  • Priya R. van Vooren, Department of Psychology, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium
  • Mathijs Franssen, Department of Psychology, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium
  • Tom Beckers, Department of Psychology, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium
  • Dirk Hermans, Department of Psychology, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium
  • Frank Baeyens, Department of Psychology, University of Leuven, Tiensestraat 102, B-3000 Leuven, Belgium

• Journal Learning & Behavior
• Online ISSN 1543-4508
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Erratum to: Changes in attention to an irrelevant cue that accompanies a negative patterning discrimination

• Content Type Journal Article
• Category Erratum
• Pages 115-115
• DOI 10.3758/s13420-011-0061-3
• Authors
  • Jemma C. Dopson, School of Psychology, Cardiff University, Cardiff, CF10 3AT Wales
  • Guillem R. Esber, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
  • John M. Pearce, School of Psychology, Cardiff University, Cardiff, CF10 3AT Wales

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494
• Journal Volume Volume 40
• Journal Issue Volume 40, Number 1

Abstract  In the present experiments, we investigated the effects of mindfulness on behavioral extinction and resurgence. Participants received instrumental training; either they received FI training (Experiment 1), or they were trained to emit high rates and low rates of response via exposure to a multiple VR yoked-VI schedule prior to exposure to a multiple FI FI schedule in order to alter their rates of responding learned during Experiment 2. Participants were then exposed to either a focused- (mindfulness) or an unfocused-attention induction task. All participants were finally exposed to an extinction schedule in order to determine whether a mindfulness induction task presented immediately prior to extinction training affected extinction (Experiment 1) and behavioral resurgence (Experiment 2). During the extinction phase, the rates of responding were higher in the control group than in the mindfulness group, indicating that the mindfulness group was more sensitive to the contingencies and, thus, their prior performance extinguished more readily (Experiment 1). Moreover, rates of response in the extinction components less precisely reflected previous training in the mindfulness group, suggesting less resurgence of past behaviors after the mindfulness induction (Experiment 2).

• Content Type Journal Article
• Pages 1-11
• DOI 10.3758/s13420-011-0062-2
• Authors
  • Louise McHugh, Department of Psychology, Swansea University, Singleton Park, Swansea, SA2 8PP UK
  • Jonathan Procter, Department of Psychology, Swansea University, Singleton Park, Swansea, SA2 8PP UK
  • Michaela Herzog, Department of Psychology, Swansea University, Singleton Park, Swansea, SA2 8PP UK
  • Anne-Kathrin Schock, Department of Psychology, Swansea University, Singleton Park, Swansea, SA2 8PP UK
  • Phil Reed, Department of Psychology, Swansea University, Singleton Park, Swansea, SA2 8PP UK

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  The goal of the present study was to evaluate the role of verbal stimuli in the production of response variability in humans. College students were distributed into three groups and asked to type three-digit sequences. Participants in the systematic group were instructed to produce sequences according to a rule of their choice; those in the random group were instructed to produce sequences according to chance; and those in the control group were not instructed about how to produce sequences. The experiment employed an ABA design. During the A phases, low-frequent sequences were reinforced (variability contingency), whereas during the B phase, reinforcement was withdrawn (extinction). The results indicated the following: (1) The instructions were efficient at producing systematic and random-like patterns for the systematic and random groups, respectively; in the absence of instructions, a mix of both patterns was observed. (2) Behavior was sensitive to extinction independently of the instructions provided. (3) Systematic patterns favored a more equiprobable distribution of sequences across trials. (4) Reaction times were longer for responding in a systematic than in a random-like fashion. The present findings suggest that individual differences in meeting variability contingencies may be due, at least partially, to instructional control.

• Content Type Journal Article
• Pages 1-13
• DOI 10.3758/s13420-011-0058-y
• Authors
  • Alessandra S. Souza, Department of Psychology, Cognitive Psychology Unit, University of Zurich, Binzmühlestrasse 14/22, CH-8050 Zürich, Switzerland
  • Thaissa Neves R. Pontes, Universidade de Brasília, Brasília, Brazil
  • Josele Abreu-Rodrigues, Universidade de Brasília, Brasília, Brazil

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  Discriminating same from different multiitem arrays can be represented as a discrimination between arrays involving low variability and arrays involving high variability. In the present investigation, we first trained pigeons with the extreme values along the variability continuum (arrays containing 16 identical items vs. 16 nonidentical items), and we later tested the birds with arrays involving intermediate levels of variability; we created these testing arrays either by manipulating the combination of same and different items (mixture testing) or by changing the number of items in the same and different arrays (number testing). According to an entropy account (Young & Wasserman, Journal of Experimental Psychology: Animal Behavior Processes 23:157–170, 1997), the particular means of changing variability should have no effect on same–different discrimination performance: Equivalent variability should yield equivalent performance. In this critical test of an entropy account, we found that entropy could explain a large portion of our data, but not the entire collection of results.

• Content Type Journal Article
• Pages 1-11
• DOI 10.3758/s13420-011-0063-1
• Authors
  • Leyre Castro, Department of Psychology, The University of Iowa, E11 Seashore Hall, Iowa City, IA 52242, USA
  • Edward A. Wasserman, Department of Psychology, The University of Iowa, E11 Seashore Hall, Iowa City, IA 52242, USA
  • Michael E. Young, Department of Psychology, Southern Illinois University, Carbondale, USA

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  The effects of reinforcement on delayed matching to sample (DMTS) have been studied in two within-subjects procedures. In one, reinforcer magnitudes or probabilities vary from trial to trial and are signaled within trials (designated signaled DMTS trials). In the other, reinforcer probabilities are consistent for a series of trials produced by responding on variable-interval (VI) schedules within multiple-schedule components (designated multiple VI DMTS). In both procedures, forgetting functions in rich trials or components are higher than and roughly parallel to those in lean trials or components. However, during disruption, accuracy has been found to decrease more in rich than in lean signaled DMTS trials and, conversely, to decrease more in lean than in rich multiple VI DMTS components. In the present study, we compared these procedures in two groups of pigeons. In baseline, forgetting functions in rich trials or components were higher than and roughly parallel to those in lean trials or components, and were similar between the procedures. During disruption by prefeeding or extinction, accuracy decreased more in rich signaled DMTS trials, whereas accuracy decreased more in lean multiple VI DMTS components. These results replicate earlier studies and are predicted by a model of DMTS from Nevin, Davison, Odum, and Shahan (2007).

• Content Type Journal Article
• Pages 1-13
• DOI 10.3758/s13420-011-0059-x
• Authors
  • John A. Nevin, The University of New Hampshire, 20 Harborview Lane, Vineyard Haven, MA 02568, USA
  • Timothy A. Shahan, Department of Psychology, Utah State University, Logan, UT 84322, USA
  • Amy L. Odum, Department of Psychology, Utah State University, Logan, UT 84322, USA
  • Ryan Ward, Columbia University Medical Center, New York State Psychiatric Institute, 1051 Riverside Drive, Unit #50, New York, NY 10032, USA

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  In three experiments, we used the allergist task to examine the role of error correction mechanisms in the acquisition and extinction of causal judgments in people. Consistent with existing human and animal studies, acquisition of causal judgments was influenced by the discrepancy between the allergenic outcome and that predicted by all of the cues present on a trial (the “common error” term). However, in the present experiments, we failed to detect any evidence for the use of a common error term in extinction learning: Judgments of the allergenic properties of a cue were unaffected by the predictive value of the other cues present on a trial. This asymmetry in the use of a common error term in acquisition and extinction learning is inconsistent with previous animal studies and also with most models of associative learning. However, approaches that allow learning to be specific to a particular arrangement of elemental cues (context specific and state based) offer some explanation of the observed asymmetry.

• Content Type Journal Article
• Pages 1-15
• DOI 10.3758/s13420-011-0056-0
• Authors
  • Oren Griffiths, School of Psychology, University of New South Wales, Sydney, 2052 Australia
  • R. Frederick Westbrook, School of Psychology, University of New South Wales, Sydney, 2052 Australia

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract   Experiment 1 compared the acquisition of a feature-positive and a feature-negative discrimination in humans. In the former, an outcome was signaled by two stimuli together, but not by one of these stimuli alone. In the latter, the outcome was signaled by one stimulus alone, but not by two stimuli together. Using a within-group design, the experiment revealed that the feature-positive discrimination was acquired more readily than the feature-negative discrimination. Experiment 2 tested an explanation for these results, based on the Rescorla–Wagner theory, by examining how novel discriminations, based on a combination of a feature-positive and a feature-negative discrimination, were solved. The results did not accord with predictions from the theory. Alternative explanations for the results are considered.

• Content Type Journal Article
• Pages 1-9
• DOI 10.3758/s13420-011-0057-z
• Authors
  • Anja Lotz, Fachbereich Psychologie, Philipps-Universität Marburg, Gutenbergstrasse 18, 35032 Marburg, Germany
  • Metin Uengoer, Fachbereich Psychologie, Philipps-Universität Marburg, Gutenbergstrasse 18, 35032 Marburg, Germany
  • Stephan Koenig, Fachbereich Psychologie, Philipps-Universität Marburg, Gutenbergstrasse 18, 35032 Marburg, Germany
  • John M Pearce, School of Psychology, Cardiff University, CF10 3AT Cardiff, UK
  • Harald Lachnit, Fachbereich Psychologie, Philipps-Universität Marburg, Gutenbergstrasse 18, 35032 Marburg, Germany

• Journal Learning & Behavior
• Online ISSN 1543-4508
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Abstract  The present experiments investigated the sunk cost error, an apparently irrational tendency to persist with an initial investment, in rats. This issue is of interest because some have argued that nonhuman animals do not commit this error. Two or three fixed-ratio (FR) response requirements were arranged on one lever, and an escape option was arranged on a second lever. The FRs were of different sizes, and escaping was the behavior of interest. Several variables that might influence the decision to persist versus escape were manipulated: the number of trials with different FR schedules in an experimental session (Exps. 1 and 2), effort to escape (Exp. 2), and the size of the larger FR (Exp. 3). The sunk cost error would result in never escaping, and the optimal strategy would be to escape from the larger FR. The main variable that determined persisting versus escaping was the size of the large FR. Rats that escaped from the large FR—apparently optimal behavior—did so at a suboptimal point, and hence committed the sunk cost error.

• Content Type Journal Article
• Pages 1-12
• DOI 10.3758/s13420-011-0055-1
• Authors
  • Paula Magalhães, Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054 New Zealand
  • K. Geoffrey White, Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054 New Zealand
  • Tessa Stewart, Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054 New Zealand
  • Emma Beeby, Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054 New Zealand
  • William van der Vliet, Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054 New Zealand

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  The present series of five flavor aversion experiments with rat subjects examined compound conditioning at varying CS–US intervals. Using a taste–taste design, Experiments 1A and 1B demonstrated overshadowing at a 0-min CS–US interval and potentiation at a 120-min CS–US interval, and these effects occurred with both tastes of the compound. Experiment 2 showed that the aversion to a single element is reduced when the CS–US interval is increased to 120 min, but the aversion for a compound taste is not. Experiments 3A and 3B explored odor + taste compound conditioning; the results demonstrated odor potentiation across the trace interval and a transition from taste overshadowing to taste potentiation. Collectively, the data show that the change from overshadowing to potentiation was not due to changes in the aversions produced by compound conditioning but, instead, was due to a more rapid loss of conditionability across a trace interval prior to the US in single-element conditioning. These experiments suggest that following compound conditioning, the aversion to each element represents generalization decrement from the configured compound, but the designation of overshadowing or potentiation actually depends on the status of conditioning in the single-element control.

• Content Type Journal Article
• Pages 1-15
• DOI 10.3758/s13420-011-0054-2
• Authors
  • W. Robert Batsell, Department of Psychology, Kalamazoo College, Kalamazoo, MI 49006, USA
  • Elizabeth Wakefield, Department of Psychology, Kalamazoo College, Kalamazoo, MI 49006, USA
  • Leigh Ann Ulrey, Department of Psychology, Kalamazoo College, Kalamazoo, MI 49006, USA
  • Katie Reimink, Department of Psychology, Kalamazoo College, Kalamazoo, MI 49006, USA
  • Steven L. Rowe, Department of Psychology, Kalamazoo College, Kalamazoo, MI 49006, USA
  • Scott Dexheimer, Department of Psychology, Kalamazoo College, Kalamazoo, MI 49006, USA

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  The nonverbal discrimination of relative and absolute number of sequential visual stimuli was investigated with humans in bisection, reproduction, and report tasks. Participants viewed a sequence of 40 red and black objects on each trial, randomly intermixed, and had to identify the number of red objects, which varied from 1 to 20. To prevent the use of a verbal-counting strategy, participants were required to name the objects as they appeared. The characteristics of human performance resembled those of pigeons in analogous procedures (Tan & Grace Learning and Behavior 38:408-417, 2010; Tan, Grace, Holland, & McLean Journal of Experimental Psychology 33:409-427, 2007): Average response number increased systematically with sample number, and bisection points were located at the arithmetic, not the geometric, mean. Additionally, in both the reproduction and report tasks, coefficients of variation decreased for values less than 6 but increased or remained constant for larger values, suggesting that different representations were used for small and large numbers.

• Content Type Journal Article
• Pages 1-10
• DOI 10.3758/s13420-011-0053-3
• Authors
  • Lavinia Tan, Reed College, Department of Psychology, Portland, OR 97202, USA
  • Randolph C. Grace, University of Canterbury, Department of Psychology,, Christchurch, New Zealand

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494

Abstract  Behavioral momentum theory provides a framework for understanding how conditions of reinforcement influence instrumental response strength under conditions of disruption (i.e., resistance to change). The present experiment examined resistance to change of divided-attention performance when different overall probabilities of reinforcement were arranged across two components of a multiple schedule. Pigeons responded in a delayed-matching-to-sample procedure with compound samples (color + line orientation) and element comparisons (two colors or two line orientations). Reinforcement ratios of 1:9, 1:1, and 9:1 for accurate matches on the two types of comparison trials were examined across conditions using reinforcement probabilities (color/lines) of .9/.1, .5/.5, and .1/.9 in the rich component and .18/.02, .1/.1, and .02/.18 in the lean component. Relative accuracy with color and line comparisons was an orderly function of relative reinforcement, but this relation did not depend on the overall rate of reinforcement between components. The resistance to change of divided-attention performance was greater for both trial types in the rich component with presession feeding and extinction, but not with decreases in sample duration. These findings suggest promise for the applicability of quantitative models of operant behavior to divided-attention performance, but they highlight the need to further explore conditions impacting the resistance to change of attending.

• Content Type Journal Article
• Pages 1-12
• DOI 10.3758/s13420-011-0052-4
• Authors
  • Christopher A. Podlesnik, Department of Psychology, University of Auckland, Private Bag 92019, Victoria Street West, Auckland, 1142 New Zealand
  • Eric Thrailkill, Psychology Department, Utah State University, Logan, UT, USA
  • Timothy A. Shahan, Psychology Department, Utah State University, Logan, UT, USA

• Journal Learning & Behavior
• Online ISSN 1543-4508
• Print ISSN 1543-4494