Ci

Ma

b

a

ARRA

KAERCH

psBAC&pas2

Cts

0h

Learning and Motivation 44 (2013) 184– 195

Contents lists available at SciVerse ScienceDirect

Learning and Motivation

jo u r n al homep age : www.elsev ier .com/ locate / l&m

ued reacquisition trials during extinction weaken contextual renewaln human predictive learning

arieke Efftinga,∗, Bram Vervlietb, Tom Beckersa,b, Merel Kindta

University of Amsterdam, Amsterdam, The NetherlandsUniversity of Leuven, Belgium

r t i c l e i n f o

rticle history:eceived 18 December 2009eceived in revised form 3 December 2012vailable online 8 January 2013

eywords:ttenuation of renewalxtinctioneacquisitionontext specificityuman predictive learning

a b s t r a c t

Extinction is generally more context specific than acquisition, as illustrated by the renewaleffect. While most strategies to counteract renewal focus on decreasing the contextspecificity of extinction, the present work aimed at increasing the context specificity ofacquisition learning. Two experiments examined whether presenting cued reacquisitiontrials during extinction weaken renewal in human predictive learning. After acquisition inone context (AX) and extinction in another context (B), participants were given tests forrenewal in a subset of the acquisition context (A) and the original acquisition context (AX).In Experiment 1, presentation of reacquisition trials during extinction, featured by a con-textual cue from acquisition (X), weakened overall recovered responding in Context A butnot in Context AX. In Experiment 2, we replicated our findings, but this time reacquisitiontraining weakened renewed responding in Context A but not in Context AX. Most impor-tantly, reacquisition training with a novel contextual cue (Y) did not weaken renewal (in A),suggesting that backward blocking effects increased the contextual control over acquisitionperformance.

© 2012 Elsevier Inc. All rights reserved.

Acquisition and extinction of conditioned responding seem symmetrical learning phenomena, but they are based onartially different processes. A marked difference is the sensitivity to changes in the background context; whereas acqui-ition performance is ordinarily resistant to such changes (e.g., Nelson, 2002; Rosas, Vila, Lugo, & López, 2001; but see e.g.,onardi, Honey, & Hall, 1990), extinction performance is easily disrupted. For instance, when acquisition occurs in Context

and extinction in Context B, conditioned responding renews when the conditioned stimulus (CS) is tested in acquisitionontext A (Bouton & King, 1983; Vansteenwegen et al., 2005) or in a novel Context C (Bouton & Bolles, 1979; Neumann

Kitlertsirivatana, 2010). These so-called “renewal” effects have been demonstrated across species in a wide variety ofaradigms, including fear conditioning (e.g., Effting & Kindt, 2007; Soeter & Kindt, 2012; Thomas, Larsen, & Ayres, 2003),ppetitive conditioning (e.g., Bouton & Peck, 1989; Van Gucht, Vansteenwegen, Beckers, & Van den Bergh, 2008), conditioneduppression (e.g., Bouton & Bolles, 1979; Neumann, 2006), and human predictive learning (e.g., Rosas & Callejas-Aguilera,006).

One theoretical implication of renewal is that extinction does not erase the original excitatory association between the

S and the unconditioned stimulus (US). Rather, extinction is assumed to involve the formation of a CS-noUS associationhat exerts inhibitory control over the initial association (e.g., Bouton, 1993, 1994). In addition, renewal effects show thatwitching the context disrupts this new (inhibitory) learning, allowing the first learned association to produce behavioral

∗ Corresponding author at: Department of Clinical Psychology, University of Amsterdam, Weesperplein 4, 1018 XA Amsterdam, The Netherlands.E-mail address: M.Effting@uva.nl (M. Effting).

023-9690/$ – see front matter © 2012 Elsevier Inc. All rights reserved.ttp://dx.doi.org/10.1016/j.lmot.2012.12.002

M. Effting et al. / Learning and Motivation 44 (2013) 184– 195 185

effects again (i.e., conditioned responding). Hence, extinction represents new learning that is specific to the context inwhich it was acquired (e.g., Bouton, 2000, 2002, 2004). The practical implication of renewal has been acknowledged asrelapse following extinction-based treatments, such as exposure therapy (Bouton, 2000, 2002).

The contrast between the context dependency of extinction and the context independency of acquisition is striking, butnot absolute. There is growing evidence that acquisition learning (CS-US) can also become context specific, depending on theexperimental conditions. First, in rat appetitive conditioning, Nelson (2009) demonstrated that acquisition learning, typicallyunaffected by context shifts (e.g., Nelson & Bouton, 1997), is sensitive to context changes when it is relearned after extinction.Second, Rosas and colleagues (León, Abad, & Rosas, 2010; Rosas & Callejas-Aguilera, 2006; Rosas, García-Gutiérrez, & Callejas-Aguilera, 2006) showed in human contingency learning that increasing context salience decreases the transfer of acquisitionlearning across contexts. Third, initially context-free acquisition learning can become context dependent after extinction(Harris, Jones, Bailey, & Westbrook, 2000), indicating that the context independency of acquisition is sensitive to change. Inthis latter study, animals received conditioning to a CS in one context (A) followed by either extinction in another context (B)or no extinction. Subsequent testing of the CS in the conditioning context (A) or a novel context (C) showed smaller ABC thanABA renewal, suggesting that acquisition performance was contextually controlled. This context specificity of respondingwas, however, only observed for CSs that had been extinguished. There was no evidence of contextual control of acquisitionin the absence of extinction. These findings collectively suggest that extinction in Context B decreased the generalization ofacquisition learning from Context A to C. One possible mechanism is that by simultaneously switching the context and theCS-US contingency, Context A may in retrospect have been reconsidered as being important for predicting reinforcement,thereby inducing context specificity of acquisition learning (cf. Effting & Kindt, 2007; but see Harris et al., 2000). Given thehuman burden of relapse following treatment, an important issue is whether context specificity of acquisition learning canbe further increased to reduce renewal effects.

Animal studies on context conditioning may provide some hints for contextualizing acquisition learning. These studiessuggest that a context is not one discrete stimulus, but rather a variety of disparate contextual cues (Rudy, Huff, & Matus-Amat, 2004). Contextual cues may merge into a single context representation, but not necessarily do so (Rudy & O’Reilly,2001; Rudy et al., 2004). This is an interesting viewpoint because it opens the possibility that learning can become specific tocertain contextual cues, but not to others. This idea can be clarified by the observation of smaller ABC than ABA renewal. Asstated before, by conducting extinction in Context B acquisition learning may in retrospect become specific to the contextualcues of A, thereby reducing the likelihood that relevant contextual cues are shared by Context C. Thus, emphasizing the roleof acquisition context cues for reinforcement may induce context specificity of acquisition learning. This sparks the ideathat the effect of extinction in another Context B may be augmented by interspersing CS-US reacquisition trials featured byonly one contextual cue from A. The predicted effect would then be that the other contextual cues from A lose their abilityto elicit renewal. Interestingly, this prediction is in line with literature on retrospective revaluation in human contingencylearning, showing that the causal value of a stimulus can be changed indirectly by subsequent training with a previouslyassociated stimulus. In backward blocking, for instance, stimuli X and Y are first presented in compound and paired with theoutcome. Subsequently, stimulus X is further paired with the outcome, in the absence of stimulus Y. The typical result is adecrease in the rated value of Y as a predictor of the outcome (Dickinson & Burke, 1996; Melchers, Lachnit, & Shanks, 2004;Wasserman & Berglan, 1998). To date, however, this effect has not yet been investigated in contextual learning.

The present experiments were designed to test (1) whether renewal of predictive learning can be elicited by one con-textual cue from acquisition (Experiments 1 and 2), (2) whether this renewal can be reduced by interspersing reacquisitiontrials during extinction in the presence of the other contextual cue from acquisition (i.e., cued reacquisition) (Experiments1 and 2), and (3) whether the reduction of renewal by cued reacquisition is restricted to the use of a contextual cue fromacquisition (Experiment 2).

Experiment 1

Experiment 1 aimed to establish and reduce renewal in predictive learning. The design of the experiment is presented inTable 1. There were four phases: acquisition in Context AX, extinction in Context B, and two renewal tests. Renewal was firstassessed in a subset of contextual cues from acquisition (Context A) and, subsequently, in the original acquisition context(Context AX). During acquisition, one stimulus was paired with an outcome (S1+), while another stimulus was presentedwithout outcome (S2−). In the Extinction phase, both stimuli were no longer followed by the outcome. Participants in thecontrol group (EXT-only) received only extinction trials throughout extinction. By contrast, participants in the experimentalgroup (EXT-RX) received occasionally cued reacquisition trials among extinction trials. During a cued reacquisition trial,including one presentation of each S, S1 was again paired with the outcome in the presence of a specific cue (X) from theacquisition context. This context cue (X) was, however, absent on extinction trials. Predictive ratings of the outcome weremeasured during each stimulus.

We predicted that after simple extinction (EXT-only) participants would show renewed responding in Context A (i.e.,

without X). Given that Cue X reliably signaled S1-outcome occurrence after cued reacquisition (EXT-RX), renewal in ContextA (i.e., without X) was expected to be smaller for Group EXT-RX compared to Group EXT-only. The predictions for test inContext AX were less clear. We expected either no group differences in renewal or even larger renewal for Group EXT-RXthan for Group EXT-only, as Cue X became a reliable predictor for the S1-outcome association.

186 M. Effting et al. / Learning and Motivation 44 (2013) 184– 195

Table 1Experimental designs.

Exp Group Acquisition Extinction Renewal Test 1 Renewal Test 2

1 EXT-RX B: 12[S1−/S2−]/AX: 10[S1+/S2−] BX: 4[S1+/S2−] A: 3[S1−/S2−] AX: 1[S1−/S2−]EXT-only

B: 16[S1−/S2−]

2 EXT-RX

AX: 10[S1+/S2−]

B: 16[S1−/S2−]/BX: 4[S1+/S2−]/BY: 4[−]

A: 3[S1−/S2−] AX: 1[S1−/S2−]EXT-RY B: 16[S1−/S2−]/

BX: 4[−]/BY: 4[S1+/S2−]

EXT-only B: 16[S1−/S2−]/BX: 4[−]/BY: 4[−]

N(

M

P

pea

S

bApo9wm

C

oAacs

A

rw(

s

P

wfsauu

ote. Letters A, B, X, and Y refer to the context manipulations consisting of a colored computer screen (A or B) and a background sound or a visual stimulusX or Y). The numbers specify how many trials of each type were administered. S1 and S2 were the stimuli, + was the outcome.

ethod

articipantsForty-eight undergraduate psychology students (19 males, 29 females) participated in return for course credits or a small

ayment. Their age ranged from 18 to 33 years (M = 21.72, SD = 3.15) and none of them was color-blind. Due to technicalrror, data of 1 participant were not included, resulting in a final sample of 47 participants. Participants were randomlyssigned to either Group EXT-RX (n = 24; 10 males) or Group EXT-only (n = 23; 8 males).

timuliTwo gray geometric shapes were used as stimuli: a circle with a diameter of 56 mm and a triangle measuring 68 mm of

ase and 56 mm of height. Both shapes had a 1-mm black outline. Stimuli appeared against a white slide (14.8 cm × 11.1 cm).ssignment of the shapes as S1 and S2 was counterbalanced across participants. The outcome consisted of an emotionalicture from the International Affective Picture System (IAPS, Lang, Bradley, & Cuthbert, 2005), in which pictures are ratedn their valence (negative/positive) and arousal (low/high) using a 9-point Self-Assessment Manikin (SAM) (1 = negative,

= positive; 1 = low arousing, 9 = high arousing). Mean valence and arousal ratings for the picture (woman attacked by manith knife, # 6550) were 2.73 and 7.09, respectively. The picture measured 14.8 cm × 11.1 cm. Stimuli were projected in theiddle of a 19-in. computer screen.

ontext manipulationContexts were manipulated by changing the background color of the computer screen (context Cue A or B) and by turning

n or off a background sound (context Cue X). The colors of the computer screen (blue or red) that served as context Cues or B were counterbalanced across participants. The background sound consisted of a soundtrack that was produced by

midi-editing program (MOTU, Digital Performer 4.5). The track comprised a 4/4 drumbeat at 120 beats per minute inombination with a dominant cowbell-pattern played in 16ths. The sound was presented through two speakers (Q-TECHpeaker set 2.0) next to the computer monitor.

pparatusPredictive ratings of the outcome were assessed online during each stimulus presentation using a pointer on a continuous

ating scale. The pointer could be moved by dragging it with a mouse. Above the scale, the following question was shown: “Tohat extent do you expect the picture?” The scale consisted of 11 points labeled from ‘certainly not’ (0) through ‘uncertain’

5) to ‘certainly’ (10). The scale was displayed at the bottom of the computer screen.The experiment was run on a Pentium PC. A software program (Presentation version 10.3) controlled presentation of

timuli and recording of predictive ratings.

rocedureParticipants were tested individually in a small booth. After participants gave their informed consent, written instructions

ere given on the computer. It was explained that they would see different geometric shapes, which would sometimes beollowed by a picture (outcome). Participants were instructed to predict the occurrence of the outcome on the basis of the

hape. They were asked to indicate their outcome prediction during each shape by dragging a pointer on the rating scale with

mouse. Participants were required to confirm their prediction by clicking the mouse. One practice trial was then providedsing a shape different from the actual experiment (a square) and no outcome. After assurance that the instructions werenderstood, the experimenter left the room and the participant started the experiment.

M. Effting et al. / Learning and Motivation 44 (2013) 184– 195 187

The experiment consisted of an Acquisition phase, an Extinction phase and two Renewal test phases. In the Acquisitionphase, the relationship between S1 and the outcome was learned. Participants received 10 trials of both stimuli (S1 and S2).Each trial started with a stimulus presentation. After 2 s, the rating scale appeared. Both stimulus and scale remained on thescreen until a prediction of outcome occurrence was given. The outcome emerged 500 ms after S1 offset for the durationof 1.5 s. Thus, the interval between onset of S1 and the outcome was at least 2.5 s, with the actual time depending on themoment of responding. In case of an S2, the outcome was replaced by presentation of a 1.5-s white slide (14.8 cm × 11.1 cm).Intertrial intervals (ITIs) were divided into a fixed pre-trial interval of 2 s and a variable post-trial interval of 2.75, 3.25 or3.75 s with an average of 3.25 s. During trials and ITIs, the context was continuously presented. Order of trials and post-trialintervals were randomized, with the restriction that no more than two trials or post-trial intervals were of the same type.For both groups, acquisition occurred in Context AX, which consisted of colored screen A and background sound X.

In the Extinction phase, participants were exposed to 16 trials of each stimulus, divided into four blocks of four trials.For participants in the EXT-only group, both stimuli (S1 and S2) were always presented without the outcome, resultingin 16 extinction trials. Accordingly, participants learned that S1 was no longer followed by the outcome. Extinction trialswere delivered in Context B, which consisted of colored screen B in the absence of a background sound. For participants inthe EXT-RX group, the same nonreinforced stimulus presentation schedule as to the EXT-only group was applied. However,within each block, one extinction trial was replaced by a cued reacquisition trial, resulting in a total of 12 extinction trials and4 cued reacquisition trials. During a cued reacquisition trial, including one S1 and one S2 presentation, S1 was again pairedwith the outcome, but not S2. The order of S1 and S2 within a cued reacquisition trial was randomized. Cued reacquisitiontrials were presented within the combination of the extinction context (i.e., colored screen B) and a specific context cuefrom acquisition (i.e., sound X). Hence, the presence of X was predictive for occurrence of the outcome after the S1. As eachtrial was preceded by a pre-trial interval and followed by a post-trial interval, Context cue X was initiated 2 s before onsetof a reacquisition trial and remained on during the post-trial interval. The position of a cued reacquisition trial within eachblock was fixed. That is, trials were presented on the 3rd, 4th, 2nd, and 3rd positions in blocks 1–4, which corresponds withtrials e3, e8, e10, and e15. The parameters for stimulus, trial order, and ITIs were identical to those used in acquisition.

In the first Renewal test phase, recovery of predictive ratings was assessed in a subset of contextual cues from acquisition(Context A), that is, colored screen A without background sound X. Each stimulus was presented for three times, none of thembeing followed by the outcome. In the second Renewal test phase, recovered ratings were tested in the original acquisitioncontext (Context AX) by presenting S1 and S2 once. In both test phases, the same parameters for stimulus, trial order, and ITIsas during acquisition were applied. To control for outcome omission effects (cf. Effting & Kindt, 2007; Neumann, 2006), halfof the participants started extinction and both Renewal test phases with S1 followed by S2, whereas the other half startedwith S2 followed by S1. All phases were presented without interruption.

After the experiment, the picture outcome was rated on valence and arousal levels using a paper-and-pencil version ofthe SAM. The scales ranged from 1 (negative/low arousing) to 9 (positive/high arousing).

Results

Statistical analyses were performed using mixed analyses of variance (ANOVA) with stimulus and trial as within-subjectsfactors and group as a between-subjects factor. In all analyses, the factor stimulus included two levels (S1 and S2), just likethe factor group (EXT-RX and EXT-only), while levels of the factor trial varied depending on the exact analysis. Greenhouse-Geisser corrections were applied in case of violation of sphericity. Results most pertinent to our hypotheses were furtherexamined with post hoc simple interactions and pairwise comparisons adjusted for Type I error using Bonferroni corrections.An alpha level of .05 was used for all statistical analyses.

Outcome characteristicsThe mean valence rating for the picture outcome was 2.87 (SD = 1.26) and the mean arousal rating was 5.28 (SD = 2.26).

No differences were obtained between groups with respect to outcome ratings, Fvalence < 1, Farousal(1, 45) = 2.76, p = .10.

AcquisitionPredictive ratings to trials during all experimental phases are shown in Fig. 1. During acquisition, participants in both

groups developed a similar differentiation in ratings to S1 and S2. Confirming these impressions, a 2 × 10 × 2 (Stimulus × Trial:a1–a10 × Group) ANOVA yielded a significant effect for stimulus, F(1, 45) = 406.01, p < .01, and a Stimulus × Trial interaction,F(9, 405) = 53.99, ε = .63, p < .01, but no significant Stimulus × Trial × Group interaction, F < 1.09.

Generalization of acquisitionBoth groups showed a comparable decline in S1/S2 differentiation upon changing the context between acquisition (AX)

and extinction (B), with differential ratings still being present on the first extinction trial. These impressions were confirmed

by a 2 × 2 × 2 (Stimulus × Trial × Group) ANOVA comparing the last acquisition trial (a10) with the first extinction trial(e1). The analysis revealed significant effects of stimulus, F(1, 45) = 196.98, p < .001, and trial, F(1, 45) = 23.36, p < .001, anda Stimulus × Trial interaction, F(1, 45) = 35.79, p < .001. Pairwise comparisons indicated a significant decrease in S1 andincrease in S2 ratings upon changing the context, F(1, 45) = 8.59, p = .005, respectively, F(1, 45) = 48.31, p < .001, while S1 and

188 M. Effting et al. / Learning and Motivation 44 (2013) 184– 195

EXT-RXM

ean

US

expe

ctan

cy

S1

S2

Trial

Mea

n U

S ex

pect

ancy

S1

S2

0

2

4

6

8

10

a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 e1 e2 e3*

e4 e5 e6 e7 e8*

e9

e10*

e11

e12

e13

e14

e15*

e16 t1 t2 t3 t4

S1

S2

EXT-only

0

2

4

6

8

10

a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 e1 e2 e3*

e4 e5 e6 e7 e8*

e9

e10*

e11

e12

e13

e14

e15*

e16 t1 t2 t3 t4

S1

S2

Fst

Ss

E

ltPb

R

taecT1dss

R

rC

ig. 1. Mean (±SEM) outcome predictive ratings for S1 and S2 during 10 acquisition trials (a1–a10), 16 extinction trials (e1–e16), and four test trials (t1–t4)eparately for Group EXT-RX (upper panel) and Group EXT-only (lower panel) in Experiment 1. The extinction trials that were replaced by reacquisitionrials for Group EXT-R are indicated with an asterisk * (e3, e8, e10, and e15).

2 ratings significantly differed at the start of extinction, F(1, 45) = 43.85, p < .001. None of the effects involving group reachedignificance, Fs < 1.

xtinctionDifferential ratings to S1 and S2 progressively decreased across extinction trials in both groups. A 2 × 12 × 2 (Stimu-

us × Trial: e1–e2, e4–e7, e9, e11–e14, e16 × Group) ANOVA found main effects of stimulus, F(1, 45) = 31.11, p < .001, andrial, F(11, 495) = 151.56, ε = .38, p < .001, and a significant Stimulus × Trial interaction, F(11, 495) = 22.13, ε = .25, p < .001.airwise comparisons indicated no differential ratings on the last extinction trial, F < 1. The course of extinction did not differetween groups, as suggested by a nonsignificant Stimulus × Trial × Group interaction, F < 1.

eacquisitionParticipants in Group EXT-RX readily reacquired the discrimination by showing a gradual increase in ratings to S1 relative

o S2 across reacquisition trials. By contrast, ratings to S1 and S2 decreased for participants in Group EXT-only. Statisticalnalyses confirmed these observations. A 2 × 4 × 2 (Stimulus × Trial: e3, e8, e10, and e15 × Group) ANOVA yielded a mainffect of stimulus, F(1, 45) = 96.19, p < .001, and a main effect of group, F(1, 45) = 326.66, p < .001. There were also a signifi-ant Stimulus × Trial interaction, F(3, 135) = 14.74, ε = .67, p < .001, a Stimulus × Group interaction, F(1, 45) = 94.07, p < .001, arial × Group interaction, F(3, 135) = 14.00, ε = .55, p < .001, and most important, a Stimulus × Trial × Group interaction, F(3,35) = 15.65, ε = .67, p < .01. To decompose the three-way interaction, separate 2 × 2 (Stimulus × Trial) ANOVAs were con-ucted for each group. For Group EXT-RX, there was a significant Stimulus × Trial interaction, F(3, 69) = 16.81, ε = .68, p = .004,uggesting that S1 progressively regained predictive value for the outcome. For Group EXT-only, the analysis only yielded aignificant main effect of trial, F(3, 66) = 9.59, ε = .39, p = .003, indicating an overall decline in predictive ratings.

enewal in Context A (EXT-only)As demonstrating renewal in a subset of the acquisition context was one aim of the present study, we first analyzed

enewal after simple extinction (EXT-only) before comparing groups. A return to Context A (without X) after extinction inontext B produced a renewal effect. A 2 × 2 (Stimulus × Trial: e10 vs. t1) ANOVA revealed reliable effects for stimulus, F(1,

M. Effting et al. / Learning and Motivation 44 (2013) 184– 195 189

22) = 21.51, p < .001, trial, F(1, 22) = 137.52, p < .001, and the Stimulus × Trial interaction, F(1, 22) = 18.22, p < .001, the latterindicating a stronger increase in predictive ratings to S1 relative to S2 from extinction to test (i.e., differential renewal).

Renewal in Context A (EXT-only vs. EXT-RX)A return to one feature of the original acquisition context (A) following extinction in another context (B) yielded a

stronger increase in outcome predictions for S1 than for S2 (i.e., renewal). A reacquisition procedure weakened the increaseof ratings to both stimuli compared to a simple extinction procedure. These impressions were supported by a 2 × 2 × 2(Stimulus × Trial: e16 vs. t1 × Group) ANOVA, which revealed significant effects of stimulus, F(1, 45) = 29.94, p < .001, trial,F(1, 45) = 110.28, p < .001, and group, F(1, 45) = 6.98, p = .01. The significant Stimulus × Trial interaction, F(1, 45) = 34.43, p < .01,indicated the presence of a differential renewal effect. The three-way interaction (Stimulus × Trial × Group), the crucial testfor weakening renewal after reacquisition, was not significant, F(1, 45) = 2.00, p = .16. However, the Trial × Group interactionrevealed significance, F(1, 45) = 9.04, p < .004, showing that, overall, the increase in outcome predictions was smaller for thereacquisition group than the simple extinction group. Pairwise comparisons exploring the Trial × Group interaction yieldedno group differences on the last extinction trial (MEXT-Rx = 0.52; MEXT-only = 0.58), F < 1, while ratings were significantly lowerfor Group EXT-RX than for Group EXT-only on the first test trial in Context A (MEXT-Rx = 2.95; MEXT-only = 4.95), F(1, 45) = 12.10,p = .001. Thus, presenting cued reacquisition trials during extinction weakened the increase of outcome predictions ingeneral.

Renewal in Context AXTesting in the original acquisition context (AX) produced similar renewal effects in both groups. This was confirmed

by the statistical analyses comparing ratings on the last extinction trial in Context B (e16) with test in Context AX (t4). A2 × 2 × 2 (Stimulus × Trial × Group) ANOVA revealed no group main effect, F < 1.29, but there were main effects of stimulus,F(1, 45) = 57.33, p < .001, and trial, F(1, 45) = 156.43, p < .001. The interaction between stimulus and trial was significant, F(1,45) = 65.96, p < .01, reflecting renewed responding in Context AX. The extent of renewal did not differ between groups asindicated by a nonsignificant Stimulus × Trial × Group interaction, F < 1.

Renewal for S1 in Context A vs. Context AXActivation of acquisition performance (i.e., S1-outcome relationship) depended on test context (A vs. AX) following a reac-

quisition procedure (EXT-RX), but not following simple extinction (EXT-only). This was confirmed by a 2 × 2 (Trial × Group)ANOVA comparing S1 ratings in Context A (t1) with Context AX (t4). This analysis yielded a main effect of trial, F(1, 45) = 17.27,p < .01, indicating higher ratings in Context AX than in Context A, and a Trial × Group interaction, F(1, 45) = 11.17, p < .01. Theinteraction reflected that predictive ratings significantly increased from Context A to Context AX for Group EXT-RX, F(1,45) = 28.72, p < .01, whereas the difference was not significant for Group EXT-only, F < 1.

Discussion

Experiment 1 was conducted with two goals. First, it tested whether returning to only a subset of the acquisition context(A) after extinction in another context (B) would produce renewal in human predictive learning. Second, we tested whethersuch an effect would be weakened by cued reacquisition trials during extinction. Two groups received acquisition in ContextAX followed by either extinction in Context B (EXT-only) or extinction in Context B alternated with reacquisition in ContextB accompanied with acquisition Cue X (EXT-RX). Renewal was first assessed in Context A followed by a test in Context AX.

Group EXT-only successfully showed the contextual renewal effect: the acquired discrimination recovered again whenS1 and S2 were tested in one contextual feature from acquisition (A). Reacquisition training weakened overall respondingin this context (A) relative to simple extinction. The size of renewed responding in the original acquisition context (AX) didnot differ between groups.

One possible interpretation for the observed weakening of responding in Context A is in terms of retrospective revaluation.Reacquisition training may have induced a revaluation of the functional significance of contextual cues. That is, participantsmay retrospectively have inferred that context Cue A was a weak predictor for the outcome. As stated before, such aneffect would resemble backward blocking. That is, learning that Cue X signals S1 reinforcement might retrospectively blockthe ability of Cue A to elicit outcome predictions to S1. Such explanation, however, would predict a differential declineof responding after reacquisition (in Context A) with a larger decline for S1 than S2, which was not observed. Anotherpossibility is that reacquisition training enhanced inhibitory learning on extinction trials. Reacquisition trials in Context BXmay support some conditioning to Context B. In that case, subsequent nonreinforcement of S1 in Context B would result ina greater discrepancy (i.e., prediction error) and hence a greater associative loss to S1. Deepened extinction might producesmaller renewal effects (Thomas & Ayres, 2004), yielding weaker renewal in Context A for Group EXT-RX than Group EXT-only. However, a deepened extinction view would also predict an asymmetric context-switch effect on performance to

stimuli, with a weakening in predictive ratings for S1 but not for S2.

Experiment 2 was designed to test these alternative explanations. Furthermore, exposure to contexts and number ofextinction trials in Experiment 1 varied across groups. Experiment 2 was also designed to solve these possible confoundingissues.

1

E

aE

tld&rdcEwecE

opoyt

tae

M

P

pp

S

Iaascc

P

bA

tbrc(Ccascb

90 M. Effting et al. / Learning and Motivation 44 (2013) 184– 195

xperiment 2

Experiment 2 attempted to replicate the findings of Experiment 1, while controlling for differences in context exposurend extinction trials. Additionally, Experiment 2 was designed to disentangle possible explanations for the findings ofxperiment 1 by adding a second control group.

Associative accounts of backward blocking state that cues must have been associated for later retrospective revaluationo occur (Larkin, Aitken, & Dickinson, 1998; Melchers et al., 2004; Wasserman & Berglan, 1998). In human contingencyearning, following reinforcement training of two compounds (AB+, CD+), further reinforcement of one compound cue (A+)ecreases the causal judgments of the formerly associated cue (B), but not of a non-associated cue (e.g., D) (Dickinson

Burke, 1996; Wasserman & Berglan, 1998). Applied to the current study, reacquisition training featured by Cue X mayetrospectively decrease predictive ratings for Cue A, but only on the precondition that X and A were simultaneously presenturing acquisition. By implication, reacquisition with a novel context cue (Y) should not result in blocking of acquisitionontext Cue A, as these cues (A and Y) were never associated. For this reason, we included two reacquisition groups inxperiment 2 (see Table 1). Group EXT-RX received reacquisition trials in the presence of an acquisition context cue (X),hile for Group EXT-RY reacquisition occurred within a novel context cue (Y). The EXT-only control group merely received

xtinction trials. At test in Context A, reduced responding was predicted for Group EXT-RX relative to Group EXT-only. Ifaused by retrospective blocking, only Group EXT-RX should demonstrate reduced responding in Context A, but not GroupXT-RY (i.e., EXT-RX < EXT-RY = EXT-only).

On the other hand, if deepened extinction learning contributes to the observed effect in Experiment 1, a weakeningf responding would be expected irrespective of the cue for reacquisition being novel (Y) or not (X). Both reacquisitionrocedures would increase outcome expectations on extinction trials (because of the formation of B-outcome associationsn reacquisition trials), thereby increasing prediction error and deepening extinction learning. Enhanced extinction mayield weaker renewal effects, resulting in reduced renewed responding in Context A for both reacquisition groups relativeo the simple extinction group (i.e., EXT-RX = EXT-RY < EXT-only).

For equalizing context exposure during the Extinction phase, Groups EXT-RX and EXT-RY received additional exposureo Context BY alone, respectively, Context BX alone, while Group EXT-only was additionally exposed to both Contexts BXnd BY alone. For equalizing extinction trials across groups, both reacquisition groups received an additional block of fourxtinction trials just before renewal testing.

ethod

articipantsFifty-seven undergraduate students (15 males, 42 females) ranging in age from 17 to 28 years (M = 20.94, SD = 2.50)

articipated in return for course credits or a small payment. None of the participants were color-blind. Assignment ofarticipants to groups was random: EXT-RX (n = 18; 5 males), EXT-RY (n = 19; 5 males) and EXT-only (n = 20; 5 males).

timuli, context manipulation, and apparatusStimuli, contexts, and apparatus were identical to Experiment 1, except for the addition of Cue Y in manipulating contexts.

n Experiment 2, we manipulated contexts by changing the background color of the computer screen (context Cue A or B)nd presenting (or not) a background sound or a visual stimulus (context Cue X or Y). Characteristics for background colorsnd the background sound were similar to those used in Experiment 1. The visual stimulus consisted of fifteen yellowtars (*) with a diameter of 18 mm presented at the top, bottom, left and right side of the computer screen on top of theolored background, but never overlapping S1 or S2. Which of the stimuli (sound or visual symbol) served as X and Y wasounterbalanced.

rocedureExperiment 2 was conducted in a similar booth as Experiment 1, using in general the same procedure. As illustrated

y Table 1, participants in all groups received phases consisting of acquisition, extinction, and two renewal tests. In thecquisition phase, there were 10 trials with each stimulus in Context AX (e.g., colored screen A and sound X).

In the Extinction phase, both reacquisition groups received 20 trials with each stimulus, divided into five blocks of fourrials each. The first four blocks each included three extinction trials (e) and one reacquisition trial (r), while the fifthlock consisted of four extinction trials, resulting in a total of 16 extinction trials and 4 reacquisition trials. The position ofeacquisition trials within a block was similar to Experiment 1. Extinction trials were always delivered in Context B (i.e.,olored screen B). For Group EXT-RX, reacquisition trials were presented in Context BX including the extinction contexti.e., colored screen B) and an acquisition context cue (e.g., sound X). This group also received four trials of exposure toontext BY alone consisting of the extinction context and a novel context cue (e.g., colored screen B and visual symbol Y) toontrol for exposure to this context in Group EXT-RY. During BY alone trials, which lasted 17.5 s (the minimal duration for

reacquisition trial), no stimuli were presented. For Group EXT-RY, reacquisition trials occurred in Context BY (e.g., coloredcreen B and visual symbol Y). Participants in this group were also exposed to four 17.5-s trials of Context BX alone (e.g.,olored screen B and sound X). For both reacquisition groups, context alone trials (BX or BY) followed each of the first fourlocks of trials, that is, after e3, r2, e9, and e12. Group EXT-only received 16 extinction trials in Context B and four 17.5-s

M. Effting et al. / Learning and Motivation 44 (2013) 184– 195 191

trials of Contexts BX and BY alone to control for exposure to these contexts in Groups EXT-RX and EXT-RY. The schedulingof extinction and context trials (BX or BY) was similar to that in Group EXT-RX.

Similar to Experiment 1, renewal was first tested in Context A (i.e., colored screen A) followed by a test in the originalacquisition Context AX (e.g., colored screen A and sound X).

Results

The same statistical analyses were used as in Experiment 1 with only some modifications.1 In all analyses, the factor groupinvolved three levels (EXT-RX, EXT-RY, and EXT-only) except for the test of reacquisition, which included only two levels(EXT-RX vs. EXT-RY). To compare the three groups regarding the interactions most pertinent to our hypotheses, Helmert’scontrasts were conducted (Field, 2005, Appendix A.6; Effting & Kindt, 2007). In one contrast, the reacquisition group withan acquisition cue was compared with the simple extinction group and the reacquisition group with a novel cue combined(EXT-RX vs. EXT-only and EXT-RY). In a second contrast, the simple extinction group and the novel cue reacquisition groupwere directly compared (EXT-only vs. EXT-RY).

Outcome characteristicsRatings of one participant were missing. Mean valence and arousal ratings for the picture outcome of the remaining

participants were 7.32 (SD = 1.57) and 4.93 (SD = 1.84), respectively. There were no differences between groups in the waythey rated the outcome, Fs < 1.

AcquisitionFig. 2 depicts predictive ratings across all experimental phases. During acquisition, differential predictive ratings to

S1 and S2 developed gradually and similarly in all groups. Confirming these impressions, a 2 × 10 × 3 (Stimulus × Trial:a1–a10 × Group) ANOVA revealed a significant main effect of stimulus, F(1, 54) = 454.76, p < .001, and a Stimulus × Trialinteraction, F(9, 486) = 87.78, ε = .57, p < .001, but no significant Stimulus × Trial × Group interaction, F < 1.30.

Generalization of acquisitionA context switch between acquisition (AX) and extinction (B) caused a decline in S1/S2 differentiation. In line with

these impressions, a 2 × 2 × 3 (Stimulus × Trial: a10–e1 × Group) ANOVA yielded a main effect of stimulus, F(1, 54) = 282.22,p < .001, a main effect of trial, F(1, 54) = 28.24, p < .001, and a Stimulus × Trial interaction, F(1, 54) = 63.97, p < .001. Comparisonsshowed a significant decrease in S1 and an increase in S2 predictive ratings, F (1, 54) = 19.66, p < .001, respectively, F(1,54) = 69.39, p < .001, and a significant difference in S1 and S2 ratings at the start of extinction, F(1, 54) = 41.88, p < .001.A nonsignificant Stimulus × Trial × Group interaction, F < 1, indicated a comparable lack of transfer of acquisition learningacross contexts for all groups.

ExtinctionDifferential predictive ratings declined across extinction trials in all groups. A 2 × 16 × 3 (Stimulus × Trial:

e1–e16 × Group) ANOVA confirmed this impression, showing a main effect of stimulus, F(1, 54) = 34.15, p < .001, a main effectof trial, F(15, 810) = 109.06, ε = .34, p < .001, and a Stimulus × Trial interaction, F(15, 810) = 15.91, ε = .32, p < .001. Pairwisecomparisons indicated no differential ratings on the last extinction trial, F < 1.09. A nonsignificant Stimulus × Trial × Groupinteraction, F < 1, suggested a similar course of extinction in all groups.

ReacquisitionFig. 2 shows that both reacquisition groups (EXT-RX, EXT-RY) readily reacquired discriminative responding to S1 and

S2. On the first reacquisition trial, only the presentation of an acquisition cue (X), but not a novel cue (Y), elicited sig-nificant S1/S2 discrimination. These impressions were confirmed by a 2 × 4 × 2 (Stimulus × Trial: r1–r4 × Group) ANOVA,revealing main effects of stimulus, F(1, 35) = 180.22, p < .001, and trial F(3, 105) = 14.49, ε = .62, p < .001. The Stimulus × Trialinteraction reached significance as well, F(3, 105) = 57.18, ε = .58, p < .001, reflecting reacquisition of the previously learneddiscrimination.

A trend toward a significant Stimulus × Trial × Group interaction, F(3, 105) = 2.86, ε = .58, p = .07, including a significantlinear trend, F(1, 35) = 4.55, p = .04, suggested that the course of reacquisition varied between groups. Separate 2 × 2 (Stim-ulus × Group) ANOVAs conducted for each trial showed that discriminative ratings tended to differ between groups on the

first reacquisition trial, Fr1(1, 35) = 3.68, p = .06, but not on the other trials, all Fsr2–r4 < 1. Comparisons revealed that onlyGroup EXT-RX showed significant S1/S2 differentiation on the first reacquisition trial, F(1, 35) = 16.00, p < .001, but not GroupEXT-RY, F < 1.86.

1 Similar analyses including Modality of X (auditory vs. visual) as a between-subjects factor did not produce any significant effects for this factor and ledto results similar to those reported here. Therefore, the factor Modality of X was left out of the analyses.

192 M. Effting et al. / Learning and Motivation 44 (2013) 184– 195

Mea

n U

S ex

pect

ancy

S1

S2

EXT-RY

Mea

n U

S ex

pect

ancy

S1

S2

Trial

Mea

n U

S ex

pect

ancy

S1

S2

EXT-R X

0

2

4

6

8

10

a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 e1 e2 r1 e3 e4 e5 e6 r2 e7 r3 e8 e9 e10

e11 r4 e12

e13

e14

e15

e16 t1 t2 t3 t4

S1

S2

0

2

4

6

8

10

a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 e1 e2 r1 e3 e4 e5 e6 r2 e7 r3 e8 e9 e10

e11 r4 e12

e13

e14

e15

e16 t1 t2 t3 t4

S1

S2

EXT-only

0

2

4

6

8

10

a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 e1 e2 r1 e3 e4 e5 e6 r2 e7 r3 e8 e9 e10

e11 r4 e12

e13

e14

e15

e16 t1 t2 t3 t4

S1

S2

F(

R

cti

R

wwyAe

ig. 2. Mean (±SEM) outcome predictive ratings for S1 and S2 during 10 acquisition trials (a1–a10), 16 extinction trials (e1–e16), four reacquisition trialsr1–r4), and four test trials (t1–t4) separately for Group EXT-RX (upper panel), Group EXT-RY (middle), and Group EXT-only (lower panel) in Experiment 2.

enewal in Context A (EXT-only)Testing in Context A after extinction in Context B caused a renewal effect after simple extinction (EXT-only). This was

onfirmed by a 2 × 2 (Stimulus × Trial: e16 vs. t1) ANOVA, which yielded main effects of stimulus, F(1, 19) = 15.77, p = .001,rial, F(1, 19) = 85.16, p < .001, and a Stimulus × Trial interaction, F(1, 19) = 17.80, p < .001, the latter indicating a strongerncrease for S1 than S2 predictive ratings across contexts (i.e., differential renewal).

enewal in Context A (EXT-only, EXT-RX, and EXT-RY)A return to one feature of the original acquisition context (A) following extinction in another context (B) resulted in

eaker renewal after reacquisition with an acquisition cue (EXT-RX) than after simple extinction (EXT-only) or reacquisition

ith a novel cue (EXT-RY). These impressions were supported by a 2 × 2 × 3 (Stimulus × Trial: e16 vs. t1 × Group) ANOVA,

ielding main effects of stimulus, F(1, 54) = 47.51, p < .001, trial F(1, 54) = 187.37, p < .001, and group F(2, 54) = 12.87, p < .001.lso, the Stimulus × Trial interaction revealed significance, F(1, 54) = 44.16, p < .001, reflecting the presence of a renewalffect. The strength of renewal differed between groups as indicated by a significant Stimulus × Trial × Group interaction,

M. Effting et al. / Learning and Motivation 44 (2013) 184– 195 193

F(2, 54) = 4.23, p = .02. Helmert’s contrasts showed that renewal was smaller for the group receiving reacquisition with theoriginal cue (EXT-RX) compared to the simple extinction group and the novel cue reacquisition group combined (EXT-only,EXT-RY), t(54) = −2.83, p = .01, while the latter groups did not differ from each other, t < 1. Thus, only presenting reacquisitiontrials during extinction with a cue from acquisition effectively reduced renewal.

Renewal in Context AXTesting in the original acquisition context (AX) produced similar renewal effects in all groups. A 2 × 2 × 3 (Stimu-

lus × Trial × Group) ANOVA comparing the last extinction trial in Context B (e16) to test in Context AX (t4) revealed maineffects of stimulus, F(1, 54) = 85.69, p < .001, trial, F(1, 54) = 169.97, p < .001, and group, F(2, 54) = 6.21, p = .004, as well as aStimulus × Trial interaction, F(1, 54) = 81.31, p < .001, the latter reflecting renewal. Although the overall increase in predictiveratings varied across groups, as shown by a Trial × Group interaction, F(2, 54) = 7.29, p = .002, with a larger increase for GroupEXT-RX compared to Groups EXT-only and EXT-RY combined, t(54) = −3.82, p < .001, and no difference between the lattergroups, t < 1, the strength of renewal was comparable for all groups as indicated by a nonsignificant Stimulus × Trial × Groupinteraction, F < 1.

Renewal for S1 in Context A vs. Context AXTest context (A vs. AX) influenced performance to S1 following reacquisition with an acquisition cue (EXT-RX) but not

following simple extinction (EXT-only) or reacquisition with a novel cue (EXT-RY). A 2 × 3 (Trial: t1 vs. t4 × Group) ANOVAconfirmed these impressions. There was a main effect of trial, F(1, 54) = 5.68, p = .02, and a Trial × Group interaction, F(2,54) = 21.80, p < .001. Pairwise comparisons showed that predictive ratings increased from Context A to AX for Group EXT-RX,F(1, 54) = 44.40, p < .001, but did not significantly change across contexts for the other groups, Fs < 2.09.

Discussion

In Experiment 2, three groups underwent acquisition in Context AX followed by only extinction in Context B or extinctionin Context B alternated with reacquisition accompanied with either acquisition Cue X (BX) or novel Cue Y (BY). Renewal wasfirst assessed in Context A and subsequently in Context AX.

The results replicate and extend those of Experiment 1. A return to a subset of contextual cues from acquisition (A) afterextinction in another context (B) evoked again a clear renewal effect. A reacquisition procedure reduced recovered ratingsupon a switch from Context B to Context A. In contrast to Experiment 1, the reduction was differential: a greater decline inratings was observed for S1 than for S2, that is, a reduction in renewal. Most importantly, the reduction of renewal dependedon the cue used for reacquisition. Only reacquisition accompanied by a cue from acquisition (X), but not a novel cue (Y),was effective in reducing renewal in Context A. This pattern of results seems in line with associative models of backwardblocking. Such models heavily stress the necessity of two cues being previously trained in compound for backward blockingto occur. The pattern is the reverse of that anticipated by the idea of deepened extinction learning, according to which bothreacquisition procedures should have reduced renewal.

Returning to the original acquisition context (AX) evoked similar levels of renewal in all groups. Moreover, as in Exper-iment 1, the test context interacted with group for S1 responding. Group EXT-RX showed larger responding to S1 in theoriginal acquisition context (AX) than in a subset of it (A), whereas no such contextual control was found for the othergroups. These results are also in line with a backward blocking hypothesis, suggesting that the contextual control by contextCue A was only reduced when this cue was previously paired with the context cue provided during reacquisition.

General discussion

The present study was designed to test whether cued reacquisition trials during extinction would weaken renewal inhuman predictive learning. After acquisition in one context (AX) and extinction in another context (B), participants weretested for renewal in a subset of the acquisition context (A) and in the original acquisition context (AX). Reacquisition trialswere occasionally administered during extinction featured by either a context cue from acquisition (X) (Experiments 1 and2) or a novel context cue (Y) (Experiment 2).

Experiment 1 showed clear and comparable renewal effects in both test contexts (A, AX) after simple extinction, indicatingthat a return to only one context cue from acquisition (A) can cause a recovery of acquired responding. Reacquisition trainingweakened general recovered responding when tested in the absence of the reacquisition feature (in A), but not in its presence(in AX), relative to simple extinction. This implies that reacquisition training shifted control over responding to the cueprovided during reacquisition trials (X). Experiment 2 showed that reacquisition training attenuated renewal of respondinggiven that the reacquisition feature (X) was not present (in A, but not in AX). Most importantly, Experiment 2 found evidenceconsistent with the view that cued reacquisition blocks the ability of one context feature to elicit renewal. In line with abackward blocking account, reacquisition training weakened renewal (in A) only if it was accompanied by a context cue

from acquisition (X), but not by a novel context cue (Y). These results indicate that adding cued reacquisition trials to anextinction procedure can confine acquisition performance to a specific context cue.

The present results are the first demonstration of weakened renewal caused by reinforcing the target stimulus throughoutextinction. Previously, it has been shown that intermingling outcome alone trials among extinction trials can attenuate

1

rtktc

eAreosdnejc

Otrtwr

wcbtbci

rfBtcw

tmar

crfiefe

R

B

BBB

BBB

94 M. Effting et al. / Learning and Motivation 44 (2013) 184– 195

enewal (Rauhut, Thomas, & Ayres, 2001; Thomas, Longo, & Ayres, 2005; Vervliet, Vansteenwegen, & Hermans, 2010). Inhese studies, however, presentations of the target stimulus and the outcome occur in a noncontiguous relationship, alsonown as an explicitly unpaired procedure. By contrast, outcome delivery in the present study was always signaled by thearget stimulus (S1) and conditional on the presence of a contextual cue (X). The only study that prevented renewal by aued reinforcement procedure reinforced a stimulus other than the target stimulus during extinction (Rauhut et al., 2001).

In both experiments, presenting reacquisition trials featured by an acquisition context cue during extinction had similarffects. There was, however, one important difference. While such training weakened renewed responding (for S1) in Context

in Experiment 2, it only resulted in overall weakened responding (for S1 and S2) in Experiment 1. Before interpreting thisesult, one could ask why predictive ratings to the control stimulus (S2) increased when changing the context after normalxtinction. This increase cannot reflect recovery of previously acquired learning, as this stimulus was never paired with theutcome. The disruptive effect of context changes on control stimuli is, however, a common observation in human recoverytudies (e.g., Dirikx, Vansteenwegen, Eelen, & Hermans, 2009; Effting & Kindt, 2007; Neumann, 2006) and may reflectisruption of inhibition (Vervliet, Baeyens, Van den Bergh, & Hermans, 2013). In this view, the control stimulus was noteutral because it became inhibitory through association with the outcome during acquisition. It thus countered contextualxcitation and/or generalized excitation from S1. Context changes after acquisition and extinction may disrupt this inhibition,ust like they disrupt inhibition learning accrued to S1 during extinction. In the present experiments, disruptive effects ofontext changes were indeed found for the control stimulus following acquisition and extinction.

It remains unclear, however, why reacquisition led to only an overall reduction of recovered responding in Experiment 1.ne possibility is that the number of extinction trials varied across groups. Fewer extinction trials in the reacquisition group

han in the control group may produce less inhibitory learning (to S1), thereby increasing renewed responding to S1 in theeacquisition group. Possibly, a stronger renewal effect made it more difficult to detect a weakening effect of reacquisitionraining specifically to S1, resulting in the observation of only overall weakened responding (to both stimuli). Importantly,hen controlling for amount of extinction trials in Experiment 2, we did find a differential reduction of recovered responding,

eflecting a greater decrease in S1 than S2 ratings.Experiment 2 showed that weakened renewal was not a general effect of reacquisition but depended upon the context in

hich reacquisition training occurred. Only reacquisition in the presence of an acquisition context cue (X), but not a novelue (Y), weakened control of responding by the other acquisition context cue (A). This seems consistent with reports ofackward blocking in which further training of an associated cue (X) with the outcome produces a larger decremental effecto the target cue (A) than training a novel cue (Y) (e.g., Vadillo, Castro, Matute, & Wasserman, 2008). In explaining backwardlocking, associative models assume that cue X associatively activates both representations of the outcome and the absentue (A). The associative strength of the absent cue (A) will change in the opposite direction of cues that are present, resultingn an associative loss of A (e.g., Dickinson & Burke, 1996).

The observed effect in Experiment 2, however, may also be explained by a higher order reasoning account withouteference to associations. According to this account (e.g., De Houwer, Beckers, & Vandorpe, 2005), backward blocking resultsrom controlled inferences about the causal status of cues. In the present experiment, participants can only logically infer onX:S1+ trials, but not on BY:S1+ trials, that A was not likely to be linked to the outcome. Irrespective of the exact mechanism,he results of Experiment 2 suggest that retrieval of acquisition performance after reacquisition was under contextualontrol, just as contexts may control retrieval of extinction performance. Further research should test whether the renewaleakening effect of cued reacquisition also extends to other, novel contexts.

Finally, it is currently unclear to what extent presenting cued reacquisition trials in an alternated way (i.e., reacquisitionrials repeatedly alternated with extinction trials) may be responsible for the renewal weakening effect. Future research

ight investigate the effects of cued reacquisition presentations separately from extinction, for instance, concentrated in block prior to extinction training. If backward blocking accounts for weakening of renewal, such a procedure should alsoeduce the contextual control by Context A.

In conclusion, a traditional extinction procedure may be prone to relapse (renewal) because extinction learning is moreontext-specific than acquisition learning. Hence, contexts are important for retrieval of extinction learning but not foretrieval of acquisition learning. Whereas most strategies to counter renewal effects focus on decreasing the context speci-city of extinction learning, the present work aimed to increase the context specificity of acquisition learning. Extending thextinction procedure by showing that only some of the contextual cues from the acquisition learning episode are importantor reinforcement may weaken the ability of the other contextual cues to retrieve acquisition, thereby reducing renewalffects. This may suggest alternative ways for carrying out extinction-based therapies in clinical practice.

eferences

onardi, C., Honey, R. C., & Hall, G. (1990). Context specificity of conditioning in flavor-aversion learning: Extinction and blocking tests. Animal Learning &Behavior, 18, 229–237.

outon, M. E. (1993). Context, time, and memory retrieval in the interference paradigms of Pavlovian learning. Psychological Bulletin, 114, 80–99.outon, M. E. (1994). Context, ambiguity, and classical conditioning. Current Directions in Psychological Science, 3, 49–53.

outon, M. E. (2000). A learning theory perspective on lapse, relapse, and the maintenance of behavior change. Health Psychology, 19, 57–63.

http://dx.doi.org/10.1037/0278-6133.19.1(Suppl.).57outon, M. E. (2002). Context, ambiguity, and unlearning: Sources of relapse after behavioral extinction. Biological Psychiatry, 52, 976–986.outon, M. E. (2004). Context and behavioral processes in extinction. Learning & Memory, 11, 485–494. http://dx.doi.org/10.1101/lm.78804outon, M. E., & Bolles, R. C. (1979). Contextual control of the extinction of conditioned fear. Learning and Motivation, 10, 445–466.

M. Effting et al. / Learning and Motivation 44 (2013) 184– 195 195

Bouton, M. E., & King, D. A. (1983). Contextual control of the extinction of conditioned fear: Tests for the associative value of the context. Journal ofExperimental Psychology: Animal Behavior Processes, 9, 248–265.

Bouton, M. E., & Peck, C. A. (1989). Context effects on conditioning, extinction, and reinstatement in an appetitive conditioning preparation. Animal Learning& Behavior, 17, 188–198.

De Houwer, J., Beckers, T., & Vandorpe, S. (2005). Evidence for the role of higher order reasoning processes in cue competition and other learning phenomena.Learning & Behavior, 33, 239–249.

Dickinson, A., & Burke, J. (1996). Within-compound associations mediate the retrospective revaluation of causality judgements. Quarterly Journal ofExperimental Psychology, 49B, 60–80.

Dirikx, T., Vansteenwegen, D., Eelen, P., & Hermans, D. (2009). Non-differential return of fear in humans after a reinstatement procedure. Acta Psychologica,130, 175–182. http://dx.doi.org/10.1016/j.actpsy.2008.12.002

Effting, M., & Kindt, M. (2007). Contextual control of human fear associations in a renewal paradigm. Behaviour Research and Therapy, 45, 2002–2018.http://dx.doi.org/10.1016/j.brat.2007.02.011

Field, A. (2005). Discovering statistics using SPSS (2nd ed.). Thousand Oaks, CA: Sage Publications, Inc.Harris, J. A., Jones, M. L., Bailey, G. K., & Westbrook, R. F. (2000). Contextual control over conditioned responding in an extinction paradigm. Journal of

Experimental Psychology: Animal Behavior Processes, 26, 174–185. http://dx.doi.org/10.1037//0097-7403.26.2.174Lang, P. J., Bradley, M. M., & Cuthbert, B. N. (2005). International affective picture system (IAPS): Technical manual and affective ratings. Gainesville, FL: NIMH

Centre for the Study of Emotion and Attention, University of Florida.Larkin, M. J. W., Aitken, M. R. F., & Dickinson, A. (1998). Retrospective revaluation of causal judgments under positive and negative contingencies. Journal

of Experimental Psychology: Learning, Memory, and Cognition, 24, 1331–1352.León, S. P., Abad, M. J. F., & Rosas, J. M. (2010). Giving contexts informative value makes information context-specific. Experimental Psychology, 57, 46–53.

http://dx.doi.org/10.1027/1618-3169/a000006Melchers, K. G., Lachnit, H., & Shanks, D. R. (2004). Within-compound associations in retrospective revaluation and in direct learning: A challenge for

comparator theory. Quarterly Journal of Experimental Psychology, 57B, 25–53. http://dx.doi.org/10.1080/02724990344000042Nelson, J. B. (2002). Context specificity of excitation and inhibition in ambiguous stimuli. Learning and Motivation, 33, 284–310.

http://dx.doi.org/10.1006/lmot.2001.1112Nelson, J. B. (2009). Contextual control of first- and second-learned excitation and inhibition in equally ambiguous stimuli. Learning & Behavior, 37, 95–106.

http://dx.doi.org/10.3758/LB.37.1.95Nelson, J. B., & Bouton, M. E. (1997). The effects of a context switch following serial and simultaneous feature-negative discriminations. Learning and

Motivation, 28, 56–84.Neumann, D. L. (2006). The effects of physical context changes and multiple extinction contexts on two forms of renewal in a conditioned suppression task

with humans. Learning and Motivation, 37, 149–175. http://dx.doi.org/10.1016/j.lmot.2005.06.004Neumann, D. L., & Kitlertsirivatana, E. (2010). Exposure to a novel context after extinction causes a renewal of extinguished conditioned responses:

Implications for the treatment of fear. Behaviour Research and Therapy, 48, 565–570. http://dx.doi.org/10.1016/j.brat.2010.03.002Rauhut, A. S., Thomas, B. L., & Ayres, J. J. B. (2001). Treatments that weaken Pavlovian conditioned fear and thwart its renewal in rats: Implications for

treating human phobias. Journal of Experimental Psychology: Animal Behavior Processes, 27, 99–114. http://dx.doi.org/10.1037/0097-7403.27.2.99Rosas, J. M., & Callejas-Aguilera, J. E. (2006). Context switch effects on acquisition and extinction in human predictive learning. Journal of Experimental

Psychology: Learning, Memory, and Cognition, 32, 461–474. http://dx.doi.org/10.1037/0278-7393.32.3.461Rosas, J. M., García-Gutiérrez, A., & Callejas-Aguilera, J. E. (2006). Effects of context change upon retrieval of first and second-learned information in human

predictive learning. Psicológica, 27, 35–56.Rosas, J. M., Vila, N. J., Lugo, M., & López, L. (2001). Combined effect of context change and retention interval on interference in causality judgments. Journal

of Experimental Psychology: Animal Behavior Processes, 27, 153–164. http://dx.doi.org/10.1037/0097-7403.27.2.153Rudy, J. W., Huff, N. C., & Matus-Amat, P. (2004). Understanding contextual fear conditioning: Insights from a two-process model. Neuroscience and

Biobehavioral Reviews, 28, 675–685. http://dx.doi.org/10.1016/j.neubiorev.2004.09.004Rudy, J. W., & O’Reilly, R. C. (2001). Conjunctive representations, the hippocampus, and contextual fear conditioning. Cognitive, Affective, & Behavioral

Neuroscience, 1, 66–82.Soeter, M., & Kindt, M. (2012). Erasing fear for an imagined threat event. Psychoneuroendocrinology, 37, 1769–1779. http://dx.doi.org/10.1016/j.psyneuen.

2012.03.011Thomas, B. L., & Ayres, J. J. B. (2004). 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. Learning and Motivation, 35, 22–52.http://dx.doi.org/10.1016/S0023-9690(03)00040-7

Thomas, B. L., Larsen, N., & Ayres, J. J. B. (2003). Role of context similarity in ABA, ABC, and AAB renewal paradigms: Implications for theories of renewaland for treating human phobias. Learning and Motivation, 34, 410–436. http://dx.doi.org/10.1016/S0023-9690(03)00037-7

Thomas, B. L., Longo, C. L., & Ayres, J. J. B. (2005). Thwarting the renewal (relapse) of conditioned fear with the explicitly unpaired procedure: Possible inter-pretations and implications for treating human fears and phobias. Learning and Motivation, 36, 374–407. http://dx.doi.org/10.1016/j.lmot.2004.11.005

Vadillo, M. A., Castro, L., Matute, H., & Wasserman, E. A. (2008). Backward blocking: The role of within-compound associations and interference betweencues trained apart. Quarterly Journal of Experimental Psychology, 61, 185–193. http://dx.doi.org/10.1080/17470210701557464

Van Gucht, D., Vansteenwegen, D., Beckers, T., & Van den Bergh, O. (2008). Return of experimentally induced chocolate craving after extinc-tion in a different context: Divergence between craving for and expecting to eat chocolate. Behaviour Research and Therapy, 46, 375–391.http://dx.doi.org/10.1016/j.brat.2008.01.003

Vansteenwegen, D., Hermans, D., Vervliet, B., Francken, G., Beckers, T., Baeyens, F., et al. (2005). Return of fear in a human differential conditioning paradigmcaused by a return to the original acquisition context. Behaviour Research and Therapy, 43, 323–336. http://dx.doi.org/10.1016/j.brat.2004.01.001

Vervliet, B., Baeyens, F., Van den Bergh, O., & Hermans, D. (2013). Extinction, generalization, and return of fear: A critical review of renewal research in

humans. Biological Psychology, 92, 51–58. http://dx.doi.org/10.1016/j.biopsycho.2012.01.006

Vervliet, B., Vansteenwegen, D., & Hermans, D. (2010). Unpaired shocks during extinction weaken the contextual renewal of a conditioned discrimination.Learning and Motivation, 41, 22–31. http://dx.doi.org/10.1016/j.lmot.2009.08.001

Wasserman, E. A., & Berglan, L. R. (1998). Backward blocking and recovery from overshadowing in human causal judgement: The role of within-compoundassociations. Quarterly Journal of Experimental Psychology, 51B, 121–138.