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Offset-Control Attenuates Context Conditioning Induced by US-unpredictability in a Human Conditioned Suppression Paradigm


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We investigated whether offset-control of the unconditioned stimulus (US) reduces context conditioning induced by US-unpredictability within a human conditioned suppression preparation. We also examined lack of control vs. loss of control. Three groups (No Controllability, NC; Controllability, C; Loss of Controllability, LC) received unsignaled USs during two learning phases (ACQ1-2). The NC group, never had offset-control, whereas the C group, always had offset-control. The LC group, had offset-control during ACQ1, but not during ACQ2. Results indicated that US-unpredictability led to contextual conditioned suppression during ACQ1, only when participants did not have offset-control; when they did, no context conditioning was established. From ACQ1 to ACQ2, contextual conditioned suppression increased in the LC, group, but it was not more pronounced than in the NC group. These data suggest that offset-control attenuates context conditioning induced by US-unpredictability and – at least in this paradigm – loss of control is not worse than lack of control
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39Psychologica Belgica
2013, 53/1, 39-56
* Ann Meulders, Research Group on Health Psychology, Department of Psychology, Univer-
sity of Leuven; Jelle Mampaey, Institute for Behavioural Sciences, University of Hasselt;
Yannick Boddez, Debora Vansteenwegen, and Frank Baeyens, Centre for the Psychology
of Learning and Experimental Psychopathology, Department of Psychology, University of
Leuven; Fernando Blanco, Laboratorio de Psicología del Aprendizaje, Universidad de
Deusto, Bilbao, Spain.
This research is supported by a University of Leuven grant no. GOA/2001/01.
Correspondence concerning this article should be addressed to Ann Meulders, Research
Group on Health Psychology, Department of Psychology, University of Leuven, Tiense-
straat 102, box 3726, 3000 Leuven. E-mail:
Ann Meulders(1), Jelle Mampaey(2), Yannick Boddez(1), Fernando Blanco(3),
Debora Vansteenwegen(1), & Frank Baeyens(1)*
(1) University of Leuven, (2) University of Hasselt, & (3) Universidad de
Deusto, Spain
We investigated whether offset-control of the unconditioned stimulus (US)
reduces context conditioning induced by US-unpredictability within a human
conditioned suppression preparation. We also examined lack of control vs. loss
of control. Three groups (No Controllability, NC; Controllability, C; Loss of
Controllability, LC) received unsignaled USs during two learning phases
(ACQ1-2). The NC group, never had offset-control, whereas the C group,
always had offset-control. The LC group, had offset-control during ACQ1, but
not during ACQ2. Results indicated that US-unpredictability led to contextual
conditioned suppression during ACQ1, only when participants did not have
offset-control; when they did, no context conditioning was established. From
ACQ1 to ACQ2, contextual conditioned suppression increased in the LC
group, but it was not more pronounced than in the NC group. These data sug-
gest that offset-control attenuates context conditioning induced by US-unpre-
dictability and – at least in this paradigm – loss of control is not worse than lack
of control.
In general, the ability to predict important life events allows an organism to
prepare adequately for upcoming events and sometimes even control (e.g.,
escape/avoid or approach) them (Dickinson, 1980; Hollis, 1997). When
important life events are unpredictable, however, an organism cannot initiate
proper preparatory responses. A large number of animal studies demonstrates
that exposure to unpredictable stressors evokes more negative emotional con-
sequences, such as generalised anxiety and enhanced autonomic responding,
than exposure to identical predictable stressors (Abbott, Schoen, & Badia, Page 39 Tuesday, March 12, 2013 3:42 PM
1984; Mineka, Cook, & Miller, 1984; Rosellini, Warren, & DeCola, 1987).
Furthermore, impaired performance after exposure to unpredictable stressors
and preference for predictability have been often reported both in animals
(Fanselow, 1980) and in humans (Craske, Glover, & DeCola, 1995; Lejuez,
Eifert, Zvolensky, & Richards, 2000).
Contemporary models of classical conditioning provide a rich theoretical
framework to understand the emotional and behavioural/motivational disrup-
tion induced by unpredictable stressors. In particular, these effects can be
attributed to context conditioning (Fanselow, 1980; Odling-Smee, 1975). In
a typical cued fear conditioning experiment, an unconditioned stimulus (US)
and a conditioned stimulus (CS) are repeatedly presented together. After a
few paired CS-US presentations, the initially neutral CS will start to elicit
conditioned fear responding in anticipation of the US. Associative learning
models assume that the formation of an excitatory CS-US association under-
lies such cued fear responses (Rescorla & Wagner, 1972). Likewise, a context
in which unpredictable shocks are administered acquires associative strength
and therefore evokes more contextual fear and thus chronic (i.e., long-lasting)
conditioned fear than a context in which predictable shocks are presented
(Balsam & Tomie, 1985; Meulders, Vervliet, Fonteyne, Baeyens, Hermans,
& Vansteenwegen, 2012; Vansteenwegen, Iberico, Vervliet, Marescau, &
Hermans, 2008).
Experimental research devoted to context conditioning in humans is
rather scant and is largely restricted to fear conditioning experiments. Impor-
tant pioneer work by Grillon stimulated the research interest in this topic
(Grillon, 2002). In a between-subjects paradigm (Grillon & Davis, 1997), one
group of participants received paired presentations of a light-CS and a shock-
US (predictable group), whereas another group received explicitly unpaired
CS-US presentations (unpredictable group). Basically, results corroborated
the animal conditioning findings, that is, the unpredictable experimental con-
text elicited more contextual fear responding compared to the predictable
context in an immediate test as well as in a test after a retention interval
(Grillon & Davis, 1997). Vansteenwegen and co-workers (Iberico, Vansteen-
wegen, Vervliet, Dirikx, Marescau, & Hermans, 2008; Vansteenwegen et al.,
2008) subsequently replicated and extended these findings in an elegant
within-subjects design. Recently, Meulders, Vervliet, Vansteenwegen, Her-
mans, and Baeyens (2011) replicated the basic findings of Grillon and Vans-
teenwegen in a human conditioned suppression paradigm and they added an
important feature to the procedure, more precisely, a US-only group. A US-
only manipulation typically comprises the presentation of temporally unpre-
dictable, unsignaled USs in absence of any predictors for their occurrence or
absence. In other words, USs are presented temporally unpredictable and
without any cue signalling their occurrence just like in an explicitly unpaired Page 40 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 41
manipulation, but also safety signals indicating the non-occurrence of the US
are omitted. In human fear conditioning research, unpredictable aversive
experiences are commonly modelled by delivering shocks and CSs in an
explicitly unpaired manner (Fonteyne, Vervliet, Hermans, Baeyens, & Vans-
teenwegen, 2010; Grillon, 2002; see Meulders et al., 2012, for an exception).
In animal research, however, US-only presentations are typically used to pro-
duce US-unpredictability (e.g., Fanselow, 1980). According to the safety sig-
nal hypothesis (Seligman & Binik, 1977), the identification of safety signals
(present in the unpaired procedure, but not in the US-only procedure) might
be able to reduce context conditioning because they offer a short period of
relief. In line with this hypothesis, Meulders et al. (2011) showed that the US-
only manipulation yielded higher levels of context conditioning as compared
with the unpaired manipulation – at least in a between-subjects design.
Given the empirical evidence that has accumulated to support the notion
that US-unpredictability induces context conditioning and a myriad of nega-
tive emotional consequences, one might wonder how these emotional distur-
bances might be alleviated. One possible way to counter the debilitating
effects of US-unpredictability might be, to offer the opportunity to terminate
the negative effects of the US (i.e., offset-control). Previous research indeed
showed that offset-control over a series of unsignaled 20% CO2 inhalations
reduced self-reported anxiety and intense panic experiences in individuals
with high levels of suffocation fear (Zvolensky, Lejuez, & Eifert, 1998).
Therefore, in the present paper, we focus on the intriguing question of what
happens when USs are presented unpredictable (US-only procedure) but their
negative consequences can be controlled (offset-control). More specifically,
we address the question whether unpredictable USs still produce context con-
ditioning if their adverse consequences can be terminated.
Research also indicates that a lack of control over aversive stimuli often
results in negative emotional responding evidenced by elevated psychologi-
cal arousal and catastrophic cognitions (Sanderson, Rapee, & Barlow, 1989).
Catastrophic cognitions refer to chronic anticipation and expectations of cat-
astrophic outcomes, that is, continuously having the idea that something bad
is going to happen, impeding the ability to relax and feel safe. Loss of control
over aversive events is even more detrimental (in terms of elevated autonomic
responding, emotional disturbance and impaired performance) than lack of
control (Crombez, Eccleston, De Vlieger, Van Damme, & De Clercq, 2008;
Zvolensky, Eifert, Lejuez, & McNeil, 1999). Because the few studies on this
topic applied biologically potent USs (e.g., painful shock and 20% CO2 inha-
lation) our second aim was to explore whether loss of control would also have
a larger impact on performance than mere lack of control when biologically
non-significant, instructional USs are used. Page 41 Tuesday, March 12, 2013 3:42 PM
We predicted that: a) US-unpredictability induces context conditioning in
the group without offset-control, but not in the groups having offset-control,
and that b) loss of offset-control in the group that previously had control leads
to more context conditioning compared with the group that never had any
control at all. Furthermore, the response patterns for the group that always
had control or never had control are not expected to change during the exper-
Thirty undergraduate psychology students (14 males and 16 females, mean
age in years = 19, ranging from 18-23) participated in this study in return for
course credit. None of them had previous experience with the Martians prep-
aration, and they were all uninformed with respect to the purpose of the exper-
iment. All participants were randomly assigned to one of the three experimen-
tal groups: No Controllability (NC) group, Loss of Controllability (LC) group
or Controllability (C) group.
Apparatus, software, and stimuli
The experimental procedure (referred to as the Martians task) was imple-
mented within a flexible Windows 95 environment by Baeyens and Clarysse
(1998) using Microsoft Visual C++ 5.0. The experiment was run on a Pen-
tium III 730 MHz, 128 Mb RAM multimedia PC (Dell Optiplex GX110); par-
ticipants responded on the spacebar and the escape button of the computer
The US consisted of the simultaneous presentation of a 0.5-s white flash-
ing screen (5 flashes at a rate of 10 flashes/s; flash-time = 50 ms, inter-flash-
time = 50 ms) accompanied by a metallic sound (WindowsTM 95 “In the com-
puter program error.wav”). Auditory stimuli were played back in continuous
looping and presented in stereo at 85 dB through a TyphoonTM Bass Vibra-
tion Headset. Following the procedure of Meulders et al. (2011), context was
manipulated by changing the background colour of the computer screen. Dur-
ing the pretraining, the baseline measurement, the instructional US phase, and
the control instruction phase the background colour remained black, but dur-
ing the context conditioning phase it was coloured pink. Page 42 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 43
In the present study, we employed the US-only procedure described by
Meulders et al. (2011) to establish US-unpredictability in all experimental
groups. In order to manipulate offset-control, a control button[1] was intro-
duced as a means to terminate the negative consequences of the US. Condi-
tioned suppression was assessed as an index of context conditioning. Three
between-subjects groups were included: the No Controllability (NC), the
Controllability (C), and the Loss of Controllability (LC) groups. The experi-
ment consisted of five phases: the pretraining, the baseline assessment, the
instructional US phase, offset-control instruction phase and the context con-
ditioning phase. Note that the pretraining phase, the instructional US phase,
and offset-control instruction phase served to practice the operant task (i.e.,
bar-pressing) and to instruct participants about the effects of the US and the
control button, whereas the context conditioning phase was the actual learn-
ing phase with intermittent test trials after each block. During the first part of
the context conditioning phase (ACQ1), unpredictable and uncontrollable
USs were delivered in the NC group, whereas in the C and the LC groups USs
were unpredictable but their consequences could be terminated. During the
second part of the context conditioning phase (ACQ2), loss of control was
operationalized by making the use of the control button ineffective in the LC
group, whereas the C and the NC groups continued the training that they
received during the first part of this phase.
The purpose of the pretraining phase was to teach participants to continuously
press the spacebar of their computer keyboard. Participants were told that
“Martians were trying to invade Earth” and that their landing could be pre-
vented by pressing the spacebar (“shooting a laser gun at each of the Martians
that would try to land”). Instructions told that in case of a hit an explosion
rather than a Martian would be depicted on the screen. We further emphasised
the importance of emitting a regular bar-pressing pattern because a new Mar-
tian would appear about every 0.25 s and they just had one single missile per
Martians appeared one by one in rows on the screen, from left to right and
from top to bottom, at intervals of 0.25 s, with a space of 0.8 cm in between
each Martian (or explosion). If the participant pressed the spacebar before a
new Martian was displayed, an explosion appeared at that position. The main
1. Note that the control button was available in all groups during the entire experiment, but
that pressing this button was effective only when participants were provided with offset-
control. Page 43 Tuesday, March 12, 2013 3:42 PM
goal was to have as few Martians and as many explosions as possible on the
screen. Only one bar-press per Martian was allowed. If more than one bar-
press was recorded (that is, if either the participant’s bar-pressing rate
exceeded 4/s, or she/he held the space bar down), a Martian was displayed.
The screen was filled when 70 Martians or explosions (10 in each of 7 rows;
inter-row distance was 2 cm) had been presented. At the time the screen was
filled, it scrolled up, one line at a time, to make room for new Martians. The
pretraining phase lasted for 50 s. At the end of this phase, participants
received feedback about the total hit rate and the number of killed and missed
Baseline assessment
This phase was identical to the pretraining phase except that it lasted only for
25 s. At the end of this phase, during a 3-s period bar-pressing behaviour was
recorded to serve as a baseline test, during which participants did not notice
any changes i.e., Martians just kept landing at the same rate and the back-
ground colour of the computer screen (i.e., context) remained the same.
Instructional US phase
In this phase, the instructional US was introduced. Instructions explained that
the Martians developed a powerful anti-laser shield (US = white flashing
screen accompanied by a metallic sound). If participants continued “to fire
their laser gun” (press the spacebar) when this anti-laser shield is activated,
their “gun shots” would bounce back and “an inescapable invasion of Mar-
tians would be triggered”. An invasion lasted for 20 s and consisted of a white
flashing screen accompanied by a complex sound pattern (WindowsTM 95
“Robotz~2.wav”). Martians now invaded the screen and bar-pressing was
ineffective during the invasion (no explosions appeared consequently after
bar-pressing). Participants were told that they can avoid invasions, if they
cease firing their “laser gun” during the activation of the anti-laser shield or
in other words, if they suppress their bar-pressing behaviour during US pres-
entation. Basically, if no key press was registered during the US, the Martians
kept appearing on the computer screen and nothing else happened, but if a
response was recorded, the US was followed by an “invasion of Martians”.
During the instructional US phase, four USs were presented and the
experimenter explicitly illustrated the impact of bar-pressing during the US.
On the first trial, the experimenter refrained from pressing the spacebar
before the presentation of the US; at the second trial, he kept pressing the
spacebar during the US in order to trigger an invasion; the third trial, the
experimenter again ceased bar-pressing during the US and demonstrated that
there was no danger of starting to press the spacebar again immediately after Page 44 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 45
the US had disappeared from the computer screen; and at the fourth trial, the
experimenter demonstrated that it was essential to stop “firing” before the US
was actually presented, by showing the impossibility of avoiding the invasion
when stopping firing once the US appeared.
Offset-control instruction phase
In this phase, a “new weapon” to terminate invasions was introduced. The
newly developed weapon could be activated by pressing the “control button”
(escape button on the keyboard) in case an invasion is triggered. Furthermore,
instructions told that this modern weapon is a prototype and that it is not reli-
ably tested yet. It is possible that during the experiment the weapon a) works
effectively all the time, b) is never operational, or c) sometimes works and
sometimes fails to work effectively. When participants finished reading the
instructions, the experimenter showed them the use of this control button.
Context conditioning phase
This phase was divided in two learning stages (ACQ1 and ACQ2), each com-
prising four 4-trial blocks (B1-B2 for ACQ1 and B3-4 for ACQ2). All partic-
ipants received four US-only trials per block in which the USs were sched-
uled temporally unpredictable (mean ITI = 10 s, range = 7.5 s-12.5 s). As a
consequence, participants could not avoid invasions. After each block a con-
text assessment trial (3 s) was run.
The three experimental groups were distinguished based on the crucial
controllability manipulation: in the No Controllability (NC) group, pressing
the control button never terminated the invasion of Martians once it had been
triggered, whereas in the Controllability (C) group, participants could always
successfully terminate the invasion by using the control button. For the Loss
of Controllability (LC) group, pressing the control button reliably ended the
invasion during the first part of the context conditioning phase (ACQ1), but
during the second part (ACQ2) participants could no longer terminate the
invasion by pressing the control button.
Response definition: conditioned suppression of bar-pressing behaviour
As mentioned before, after each acquisition block (Block 1-8), a context
assessment trial was run. During a context assessment trial the total number
of bar-presses was recorded for each participant during a 3-s period. Obvi-
ously, no USs were presented during the context assessment. Because a Mar-
tian was about to land every 0.25 s, the optimal response rate is 12 bar-
presses/3 s, resulting in the elimination of all Martians and thus providing an
indication of optimal operant responding. Following Meulders et al. (2011) Page 45 Tuesday, March 12, 2013 3:42 PM
suppression of bar-pressing during these context assessment trials, indicated
by lower bar-pressing levels than during the baseline assessment, will be used
as an index of context conditioning[2]. Due to US-unpredictability in the
present set-up, the US can be expected to occur at any moment. This chronic
anticipation of US is thought to result in a more general contextual suppres-
sion compared with the suppression of bar-pressing behaviour in response to
the CS in the classical Martian task. Based on the fact that the unsignaled USs
are actually contingent upon the presence of the experimental background
context, this context should gain some associative strength and start to elicit
expectancy of the US, resulting in a true conditioned response (i.e., suppres-
sion of bar-pressing compared with the baseline). Note – for the statistical
analyses, means were calculated over two blocks (i.e., eight trials).
Descriptive statistics
Use of the control button
We expected that participants would use the control button more frequently
when it effectively terminated the negative consequences of the US i.e., the
invasion of Martians. Although the control button was only effective in the
groups with offset-control, the majority of participants in each group pressed
this button on every trial in which an invasion was triggered; 100%, 80% and
70% of the participants, in the C, LC and the NC groups, respectively. More
specifically, only three participants in the NC group did not use the control
button on every trial with a triggered invasion, respectively on 43%, 15%, and
11% of these trials. Further, two participants in the LC group did not use the
control button on every trial with a triggered invasion (always during the
training without offset-control, i.e., ACQ2), on 38% and 19% of the trials,
2. The standard Martian preparation was mostly used to assess conditioned responding to dis-
crete CSs (Baeyens, Vansteenwegen, Beckers, Hermans, Kerkhof, & De Ceulaer, 2005).
Consequently, suppression ratios were calculated to analyse bar-pressing data, using the
following formula: A/(A+B), with A being the number of bar-presses during the CS and B
being the number of bar-presses in absence of the CS. Because the main interest of the
present study was not cued (CS) conditioning but contextual conditioned responding, we
followed the suggestion of Meulders et al. (2011). As no clear-cut equivalent for B is at
hand (the context is omnipresent), they analysed the absolute bar-pressing behaviour and
used a pre-treatment baseline measurement as a comparison. Page 46 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 47
Triggered invasions
Invasions were triggered on at least half of the US-only trials in all experi-
mental groups during the entire experiment, suggesting that participants
could not predict the US and avoid the invasions merely on the basis of tem-
poral conditioning. Invasions were triggered on 91%, 88%, and 61% of the
trials, respectively in the C, LC and NC group. It seems reasonable that par-
ticipants without offset-control after a while would elicit less invasions com-
pared to participants with offset-control. Because more context conditioning
is established in the groups without control, indexed by more suppression of
bar-pressing behaviour, evidently more invasions will be avoided compared
with the groups with control. Moreover, we acknowledge that invasions were
typically longer in the groups without offset-control since they were not able
to terminate them once they were triggered like in the groups with control.
Conditioned suppression of bar-pressing behaviour
We analysed the mean number of bar-presses during the context assessment
trials (3 s) averaged over two conditioning blocks. As a result, the two learn-
ing phases (ACQ1 and ACQ2) were each divided in two blocks of eight trials,
respectively referred to as B1/B2 and B3/B4.
Baseline differences
A simple one-way ANOVA was carried out to assure that no baseline differ-
ences were present between the respective conditions before the experimental
treatment was applied. The analysis showed that baseline responding did not
differ between groups, F(2, 27) = 1.31, MSE = 2.63, p = .29.
Test of context conditioning: ACQ1
As can be seen in Figure 1, by the end of the first learning phase (B2), bar-
pressing behaviour was more suppressed during the context in the NC group
than in the C group and the LC group. A 3 x 3 [Block (Baseline, B1, and B2)
x Group (NC, LC, and C)] repeated measures ANOVA was performed on the
absolute bar-pressing data. This analysis showed a significant main effect of
Group, F(2, 27) = 9.20, MSE = 6.09, p < .001, and a significant main effect
of Block, F(2, 54) = 6.44, MSE = 3.82, p < .01. The Block x Group interac-
tion, however, was not significant, F(4, 54) = 1.86, MSE = 3.82, p = .13.
Planned comparisons confirmed that bar-pressing behaviour in the NC
group became more suppressed from baseline to B2 as compared to the LC
group and the C group, F(1, 27) = 4.22, MSE = 5.54, p < .05. At B2, the bar-
pressing behaviour between the LC group and the C group did not differ, F < Page 47 Tuesday, March 12, 2013 3:42 PM
1, whereas more contextual conditioned suppression of bar-pressing behav-
iour was present in the NC group compared with the C group, F(1, 27) = 8.01,
MSE = 7.21, p < .01, as well as compared with the LC group, F(1, 27) = 10.54,
MSE = 7.21, p < .01. Next, within-group contrasts calculated from baseline to
B2 also were in line with our predictions. In the C group and the LC group,
no differences in bar-pressing behaviour occurred from baseline to B2, both
F < 1, whereas bar-pressing during the context in the NC group became more
suppressed from baseline to B2, F(1, 27) = 9.83, MSE = 5.54, p < .01.
Taken together, these data suggest that the experience with unpredictable
USs enhances context conditioning as indicated by contextual conditioned
suppression of bar-pressing, only when participants are not able to terminate
the negative consequences of the US (NC group). In contrast, when partici-
pants are able to control these adverse consequences (C and LC group), no
context conditioning is established. In brief, offset-control seems to attenuate
context conditioning as induced by onset-unpredictability of the US.
Figure 1
Mean number of bar-presses (and SE’s) during baseline assessment and both parts of
the context conditioning phase (ACQ1-2) for the three experimental groups: the
Control (C) group, the No Control (NC) group, and the Loss of Control (LC) group.
Note that “B1”, “B2”, “B3”, and “B4” respectively refer to the mean triggered
invasions for Block 1-2, Block 3-4, Block 5-6, and Block 7-8
B1 B2 B3 B4
Mean number of bar-presses during the contexxt (3 s)
CLC NC Page 48 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 49
Test of context conditioning: ACQ2
As can be seen in Figure 1, bar-pressing levels in the C and in the NC groups
remained stable, that is, more contextual conditioned suppression was
observed in the NC group than in the C group. Moreover, bar-pressing during
the context became more suppressed in the LC group when comparing the
Baseline-B2 difference and the Baseline-B4 difference, but this conditioned
suppression was still relatively smaller than in the NC group (Baseline-B4
difference). To evaluate the effect of loss of control on context conditioning,
we carried out a 3 x 3 [Block (B2, B3, and B4) x Group (NC, LC, and C)]
repeated measures ANOVA on the bar-pressing data. This analysis yielded a
significant main effect of Group, F(2, 27) = 6.11, MSE = 17.06, p < .01,
whereas the main effect of Block and the Block x Group interaction did not
turn out significant, respectively, F < 1, and, F(4, 54) = 1.91, MSE = 2.56,
p= .12.
Although, the data-pattern in Figure 1 seems to suggest that bar-pressing
behaviour in the respective experimental groups evolved differently from
ACQ1 to ACQ2, this difference was not statistically significant for C group
and the LC group, F(1, 27) = 2.58, MSE = 4.08, p = .11, nor for the C group
and the NC group, Fs < 1. Bar-pressing behaviour did tend to become more
suppressed in the LC group as compared to the NC group from B2 to B4,
F(1, 27) = 3.53, MSE = 4.08, p < .07. Pairwise contrasts calculated at B4
showed that no differences were present between the LC group and the C
group, F(1, 27) = 1.32, MSE = 9.08, p = .26, and the LC group and the NC
group, F(1, 27) = 1.24, MSE = 9.08, p = .28. As expected the difference
between the C group and the NC group was still present at the end of ACQ2
(B4), F(1, 27) = 5.12, MSE = 9.08, p < .05. Finally, within-group contrasts
from the end of ACQ1 (B2) to the end of ACQ2 (B4) were calculated to eval-
uate how contextual conditioned suppression of bar-pressing behaviour
evolved within each group. As expected, for the C group and the NC group,
no differences occurred from B2 to B4, both F < 1. For the LC group, bar-
pressing behaviour during the context tended to become more suppressed
from B2 to B4, F(1, 27) = 3.34, MSE = 4.08, p = .07, and compared with base-
line, significantly more contextual conditioned suppression was observed at
B4, F(1, 27) = 5.53, MSE = 4.18, p < .05. These results provide only minimal
evidence for the hypothesis that in the case of US-unpredictability, loss of off-
set-control is manifested in context conditioning. No evidence was found to
support the notion that loss of control is worse than lack of control in terms
of performance. Page 49 Tuesday, March 12, 2013 3:42 PM
Unsignaled presentations of unconditioned stimuli are known to produce con-
text conditioning in animals (e.g., Bouton, 1984; Fanselow, 1980) as well as
in humans (Fonteyne, Vervliet, Hermans, Baeyens, & Vansteenwegen, 2009;
Grillon, 2002; Meulders et al., 2012; Meulders et al., 2011; Vansteenwegen
et al., 2008). The present paper addresses the empirical question of whether
context conditioning induced by US-unpredictability can be attenuated by
providing the opportunity to terminate the negative consequences of the US,
that is, by offset-control. Furthermore, we also wanted to explore whether los-
ing control is more debilitating than lacking control per se.
In a human conditioned suppression preparation (e.g., Arcediano, Ortega,
& Matute, 1996; Meulders et al., 2011), three experimental groups received
unsignaled, temporally unpredictable USs. During the context conditioning
phase, we manipulated the opportunity to control the offset of the US-conse-
quences in these three conditions. During the entire context conditioning
phase, participants in the No Controllability (NC) group never had offset-con-
trol, whereas participants in the Controllability group always had offset-con-
trol. The Loss of Controllability (LC) group, had offset-control during the
first part of the context conditioning phase (ACQ1), but lost it in the second
part (ACQ2). Suppression of bar-pressing behaviour compared with the base-
line bar-pressing level was assessed to index context conditioning.
First and most importantly, results indicated that offset-control (the ability
to terminate the negative consequences of the US) reduces context condition-
ing as induced by US-unpredictability. More specifically during ACQ1, con-
textual conditioned suppression of bar-pressing was more substantial in the
group without offset-control (NC group) than in both groups having offset-
control (LC and C groups). These data can be interpreted as follows: in gen-
eral, two different behavioural responses optimise performance on the exper-
imental task in the present set-up: a) suppression of bar-pressing behaviour in
order to avoid invasions (avoidance behaviour), and b) pressing the control
button in order to terminate invasions once triggered (escape behaviour). In
this experiment, escape behaviour is driven by the operant response-outcome
contingency whereas avoidance behaviour is driven by the Pavlovian context-
US pairings[3]. A functional analysis of these behaviours demonstrates that
3. This is mainly a procedure-specific argument and is not intended to explain complex and
persistent avoidance behaviour in e.g., anxiety disorders. In the Martians task, due to the
pairings of the context and the US (temporal US-unpredictability) contextual suppression
will develop. Because a negative outcome is avoided due to this behaviour (i.e., a possible
invasion) this can be labelled as avoidance behaviour. On the other hand, the contingency
between the operant (pushing the control button) and the ending of an ongoing negative
outcome (i.e., ending an invasion) can be labelled as escape behaviour. Page 50 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 51
for participants in the offset-control groups, the avoidance behaviour has a
higher cost than the escape behaviour, since the latter is always effective, but
the former is not. In fact, if they use the control button when an invasion is
already triggered, it will reliably terminate the invasion. If participants in the
offset-control groups, however, suppress their bar-pressing behaviour and no
US is presented, Martians will be able to land and therefore this has a relative
higher cost in terms of poorer task performance in the specified game context.
In contrast, for participants in the group without offset-control, the escape
behaviour is not costly but also not effective. Therefore, in order to perform
well, they have to engage in the more costly avoidance behaviour.
Second, loss of control did not seem to have a more detrimental impact
on performance than just lacking control. In particular, although loss of con-
trol resulted in more contextual conditioned suppression of bar-pressing
from ACQ1 to ACQ2, participants in the Loss of Controllability (LC) group
did not have higher levels of contextual conditioned suppression than the
group that never had offset-control (NC group) during ACQ2. These data
suggest that at least in this paradigm, using a non-biologically significant,
instructional US, loss of control is not worse than mere lack of control. These
results seem to diverge from those reported with biologically significant USs
such as pain (electrocutaneous shock) or panic (20% CO2 inhalation)
(Crombez et al., 2008; Zvolensky et al., 1999). Nonetheless, we do acknowl-
edge that the lack of a statistical significant difference between the lack of
control and loss of control groups should be interpreted with caution and
claims about the genuine absence of differences at this moment is prelimi-
nary. Future research should investigate whether prolonged training within
the present set-up might still generate the predicted differences between
these conditions.
Third, an observation that needs further attention is the fact that even
when participants had no offset-control at all, they used the control button fre-
quently and quite persistently. That is, also the Loss of Controllability (LC)
group kept pressing the control button as much as the group that never had
controllability (NC), although, participants in the former group factually
experienced the disconfirmation of offset-control (i.e., the fact that the control
button was no longer effective). These results can be tentatively interpreted
as an “illusion of control” effect (Langer, 1975; Matute, 1995; Matute,
Vadillo, Vegas, & Blanco, 2007). The persistent use of the control button in
the groups without offset-control might suggest that participants overestimate
the potential effectiveness of their own behaviour to terminate the invasions
and thus demonstrate wrongful perceived control beliefs (possibly due to
delayed operant trace conditioning). Alternatively, it might be that partici-
pants acted following the adage “better safe than sorry”. As no additional
punishment followed if the control button was pressed when it was ineffec- Page 51 Tuesday, March 12, 2013 3:42 PM
tive, the cost of the escape behaviour (i.e., pressing the control button) always
remained relatively low. It is also possible that participants without offset-
control kept trying to use the control button because they did not fully trust its
(non-)functioning i.e., a lack of inhibitory learning of the response-no out-
come contingency. Future research may address the possible mechanisms
underlying this peculiar observation.
Fourth, the implications of these findings for the clinical practice should
be considered as well. To date, several procedures to reduce contextual anxi-
ety (i.e., context conditioning) have been advanced, such as repeated non-
reinforced context exposure (Fonteyne et al., 2010) and signalling procedures
(i.e., offering predictive cues in an unpredictable context) (Fonteyne et al.,
2009). The latter procedure dovetails with the psychotherapeutic treatment
protocols for panic disorder (PD), that is, perceived unpredictable panic
attacks are put under control of internal (bodily) cues that occur before a typ-
ical full-blown panic attack (Craske & Barlow, 2008; Craske et al., 1995).
Next to enhancing predictability of aversive events, eliminating the negative
consequences of aversive events (offset-control) might be a pathway to
reduce contextual anxiety and emotional distress. For example, asthma
attacks are also often perceived as unpredictable due to inaccurate perception
of asthma triggers (Janssens, Verleden, De Peuter, Van Diest, & Van den
Bergh, 2009), leading to high comorbidity with PD (Lehrer, Karavidas, Lu,
Feldman, Kranitz, Abraham et al., 2008) and poor asthma control (Put, Van
den Bergh, Lemaigre, Demedts, & Verleden, 2003). Hence, from this point of
view, providing offset-control over the negative effects of an asthma attack,
for example by the use of an asthma inhaler, might reduce chronic anxiety and
thus might reduce chronic apprehension and worrying about future unpredict-
able asthma attacks. Future research might further disentangle the benefits of
offset-control vs. prediction in the treatment of clinical anxiety.
Finally, a limitation that is intrinsically entangled with the offset-control
manipulation in the present set-up is that although the number of presenta-
tions of the primary (unpredictable) US (i.e., activation of the anti-laser
screen) was kept constant across the experimental groups, the number and
length of the invasions (i.e., the consequences of the US) was not optimally
controlled for. Illusion of control (e.g., Matute, 1994; Matute, 1995) as well
as learned helplessness paradigms (e.g., Maier & Seligman, 1976; Seligman
& Beagley, 1975) typically use yoked designs to overcome this problem.
Therefore, further research should consider using such yoked designs. Not-
withstanding this limitation, the results clearly demonstrate that the control-
lability procedure attenuates context conditioning (effect). For example, from
a clinical perspective, it would be interesting to have a way to reduce context
conditioning i.e., to prevent spreading of chronic fear in an asthma patient by
providing offset-control over unpredictable asthma attacks (e.g., through Page 52 Tuesday, March 12, 2013 3:42 PM
A. MEULDERS et al. 53
medication), and that irrespective of the possible mechanisms underlying this
effect. Another limitation might involve the context manipulation in the
present set-up. Context typically refers to long-lasting cues as compared to
discrete cues (CSs) with a clear on- and offset. Formulating a strict definition
of context, however, is difficult and continuously under debate (e.g., Balsam
& Tomie, 1985). A definition of context might be based on its perceptual
characteristics (e.g., complexity, foreground/background), spatial character-
istics (e.g., three-dimensionality), temporal characteristics (e.g., longer dura-
tion, see Grillon, 2002), and/or by its functional characteristics (e.g., modula-
tory properties, see Bouton, 2002). We believe that the contexts used in this
experimental set-up (i.e., the background colour of the computer screen) com-
prise some of these features, such as background-foreground differentiation
and the longer lasting duration of the context presentation than the presenta-
tion of the cues (i.e., US). However, the contexts used in our study contain no
strict modulatory functions and are not three-dimensional. Therefore, the con-
texts used in this study might lack some ecological validity. However, chang-
ing the background colour of the computer screen has been used before to
manipulate contexts in the Martians task (e.g., renewal studies, Havermans,
Keuker, Lataster, & Jansen, 2005). The background colour of the computer
screen seems a highly task relevant contextual feature since it is embedded in
the broader game context of the Martians task.
To recapitulate, the present study provided evidence for the notion that
offset-control reduces context conditioning as induced by exposure to unpre-
dictable USs. Contrary to previous research with biologically potent USs, loss
of control did not turn out to have worse effects on performance than mere
lack of control.
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Received February 27, 2012
Revision received June 1, 2012
Accepted June 8, 2012 Page 56 Tuesday, March 12, 2013 3:42 PM
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Full-text available
Recent research has shown superstitious behaviour and illusion of control in human subjects exposed to the negative reinforcement conditions that are traditionally assumed to lead to the opposite outcome (i.e. learned helplessness). The experiments reported in this paper test the generality of these effects in two different tasks and under different conditions of percentage (75% vs. 25%) and distribution (random vs. last-trials) of negative reinforcement (escape from uncontrollable noise). All three experiments obtained superstitious behaviour and illusion of control and question the generality of learned helplessness as a consequence of exposing humans to uncontrollable outcomes.
Predictability of aversive events impacts the development and maintenance of anxiety, particularly panic disorder. Although animal studies typically have found a preference for signaled (predictable) over unsignaled (unpredictable) aversive events, results of research with human participants have been less clear. Using panic-relevant paradigm, the authors examined predictability preference with humans as a function of anxiety sensitivity and gender during repeated administrations of 20% carbon-dioxideenriched air. Participants preferred predictable administrations, with high-anxiety individuals showing greater preference than low-anxiety individuals and women showing greater preference than men. In addition to providing information to better understand human predictability preference for panic-related events, results also may aid in determining the applicability of predictability to the cognitive-behavioral treatment of panic disorder. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Panic disorder is characterized by unexpected panic attacks, anxiety about experiencing future attacks, and avoidance or dread of situations where attacks might occur. Panic attacks are defined as discrete periods of fear that develop abruptly and are accompanied by physical symptoms, cognitive symptoms, or both. Panic attack symptoms include sweating, shortness of breath, heart palpitations, trembling or shaking, chest pain or discomfort, feeling of choking, nausea, fear of dying or going crazy, derealization or depersonalization, chills or hot flushes, numbness, and feeling dizzy, unsteady, or faint. The first criterion of panic disorder is the presence of recurrent, unexpected panic attacks. It is required that “unexpected” panic attacks occur, meaning that from the patient's perspective, such attacks seem to occur “out of the blue” or without any obvious causes. This is an important feature when conducting a differential diagnosis, as panic attacks that occur due to other anxiety disorders are situationally bound or situationally predisposed (e.g., panic attacks cued by social situations in social phobia). Although panic disorder patients may experience such situationally bound or situationally predisposed panic, in order to meet diagnostic criteria for panic disorder, they must experience recurrent, “unexpected” panic attacks. Also, the panic attacks must not be caused by the direct physiological effects of a substance or general medical condition. Experiencing unexpected panic attacks is necessary, but not sufficient, for a diagnosis of panic disorder.
Recently, the study of biological function has been reaccepted as a legitimate focus of research in the field of animal learning. This "new" functionalism suffuses 2 distinct perspectives with which researchers approach the study of Pavlovian conditioning. Those who adopt the ecological perspective explore the role of conditioning within functional, naturally occurring categories of behavior, for example, intraspecific defense, reproduction, or food recognition. From this perspective, the central question is, In what ways does conditioning contribute to animals' ability to survive and reproduce? For those researchers who explore the cause rather than the function of conditioning, the central question is, How, and under what circumstances, does conditioning occur? Although, historically, those who studied causal mechanisms eschewed functional considerations, close examination of the new cognitive perspective reveals decidedly functional themes. A brief review of research originating in each of these 2 perspectives demonstrates the ways in which they increasingly are finding common ground in a "new" study of function.
Control over the offset of repeated administrations of 20% carbon-dioxide-enriched air was assessed in nonclinical participants (n = 30) reporting elevated levels of anxiety sensitivity-a population at an increased risk for experiencing panic attacks and possibly developing panic disorder. In Phase I, participants were randomly assigned to 1 of 2 conditions: one that permitted offset control over gas inhalation and one that did not. These conditions were reversed in Phase II. Across phases, a lack of offset control resulted in greater self-reported anxiety compared with having control, although no significant differences were observed for heart rate. Whereas all participants demonstrated a Stroop interference effect for general (e.g., coffin) compared with specific (e.g., dizzy) physical threat word types prior to the first experimental phase, this effect persisted only for participants who had offset control in Phase I. We discuss these results in relation to the differential effects of offset control, with implications for better understanding anxious responding during elevated bodily arousal.
Animal research has shown that extinguished conditioned performance is modulated by the environmental context in which extinction treatment has occurred. When the conditioned stimulus is presented outside the extinction context, conditioned responding is renewed. In two experiments, whether a renewal effect can also be found in humans was investigated. In Experiment 1, a renewal effect was observed, although the effect was small and far from complete. In Experiment 2, a more substantial renewal effect was observed. The extent to which this effect occurred depended on the degree to which context was manipulated. In a third experiment, the exact nature of the observed renewal effect was examined. Results indicated that, as opposed to animals, the extinction context does not modulate extinguished conditioned responding in humans.
The independence of action of controllability and predictability has recently been questioned by research demonstrating that the effects of control over shock termination can be mimicked by feedback stimuli when a contextual fear measure is used. This suggests that the varied effects of controllability, particularly controllability of shock termination, may result not from controllability per se but from predictability of shock absence. The present experiments address this issue by examining whether controllability and predictability similarly affect contextual fear under several parametric conditions. In Experiment 1, control over shock termination was found to reduce contextual fear at an earlier point in training than prediction of shock absence. Experiment 2 demonstrated an effect of controllability under conditions in which the feedback effect is precluded. Experiment 3 examined the possibility that the group differences observed in the above experiments could be due to a potential difference in the conditionability of the response-produced stimulation and the external feedback stimulus. The outcome of this study makes it unlikely that this is the case, since no evidence of overshadowing of the feedback stimulus was observed on a test of its associative strength. These experiments suggest that the effects of controllability may not be reducible to those of predictability. Furthermore, they have important implications for theoretical proposals concerning the effect of feedback on contextual fear.