Discussion
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EVENT, SHOCKS
Placebo research typically focuses on treatment interventions, which are described to individuals as beneficial for them and are also learned to be effective via conditioning. This study demonstrated for the first time that a placebo treatment could be replaced with an ER strategy that individuals actively implement, namely, distraction, so as to improve its effectiveness. The placebo-distraction was presented to participants as being effective in reducing fear and pain, and was surreptitiously paired with reduced painful stimulations, whereas the control-distraction was introduced as noneffective and was surreptitiously paired with increased painful stimulations. Consistent with our prediction, during a later test phase, where shocks were identical in intensity, the placebo-distraction was more effective than the control-distraction in reducing self-reported fear of pain. Moreover, when choosing between the two distractions, participants substantially preferred the placebo-distraction over the control-distraction for regulating their fear of pain.Relatively little attention has been dedicated to exploring the relations between placebos and cognitive ER strategies, with no study replacing the placebo treatment with a cognitive ER strategy. When categorizing the existing literature, we identified two types of relevant studies. The first includes studies that compared between placebos and cognitive ER strategies, in terms of their effectiveness and required cognitive resources. For instance, one studyFocusing on distraction, in another studyThe second type of studies exploring the intersection between placebos and ER strategies lies within the ER literature. Viewed from an ER perspective, one important factor required to successfully regulate emotions is ER self-efficacy, that is, beliefs about one’s ability to control emotionsThe second goal of this study was to explore whether the increased effectiveness of, and preference for, the placebo-distraction compared to the control-distraction, would generalize to a different domain of regulating fear of unpleasant pictures. We found partial support for a generalization effect. Specifically, the placebo-distraction was as effective as the control-distraction when regulating fear of unpleasant pictures, but was behaviorally preferred over the control-distraction in that context. Given that the effect sizes of behavioral ER choice measures are generally more robust than those of self-reported effectiveness measuresThe current findings have important implications. From a placebo research perspective, our results emphasize that the investigation of placebo effects does not have to be limited to treatment interventions, but can rather be expanded to include individuals’ internal attempts to influence their conditions. Clearly, this may be more challenging for researchers and for clinicians who treat patients. Compared to leading individuals to attribute an improvement in conditions to an intervention (e.g., a placebo analgesic cream that reduces pain), leading them to attribute an improvement in conditions to an internal action (e.g., distracting thoughts from the pain) can be tricky. This is mainly because when it comes to internal actions, individuals have a sense of how successful they are in implementing them. For instance, one can feel a failure to distract thoughts from pain during conditioning, which makes it hard to reliably attribute the reduction in pain to distraction attempts. This was a central reason for choosing to use distraction. Specifically, distraction is known to be a particularly effective ER strategy in the short-termA possible way to overcome this challenge could be using Open Label Placebos (OLPs), i.e., placebos that are provided without deception by explaining to participants about the placebo effect and its positive influence on outcomesFrom an ER research viewpoint, potent manipulations adopted from placebo research, such as conditioning, represent a novel approach for improving the effectiveness of ER strategies, as well as individuals’ drive to choose to implement these strategiesSeveral limitations of the present study should be noted. First, self-reported measures are naturally prone to reporting biases. To minimize demand characteristics, we used a cover story that the study was exploring the neural mechanisms underlying different ER strategies, while seemingly recording EEG. This way, participants were led to believe that their subjective experience was not our focus of interest. More importantly, in addition to self-reported fear of shocks and fear of unpleasant pictures, we adopted a behavioral measure from ER research that concerns preferences for the placebo-distraction in both domains. Nonetheless, future studies should utilize objective measures (e.g., neural) as well, to further minimize the influence of demand characteristics.Second, while the present findings are novel in the sense that they show for the first time how cognitive ER can benefit from placebo-induced expectancies, the question remains what made the placebo-distraction more effective, as well as preferred. One possible explanation is that participants put minimal or no effort into implementing the control-distraction, because it was presented as, and learned to be, ineffective. This seems unlikely for two main reasons. First, while this explanation is consistent with the fear of pain results, where the control-distraction did not differ from the no-regulation experience condition, it is inconsistent with the finding that the control-distraction effectively reduced fear of unpleasant pictures, relative to the no-regulation experience condition. Second, as mentioned above, participants’ adherence to both distraction types reached 100%.Nonetheless, it could be that participants were more motivated, and thus put considerably more effort into implementing the placebo-distraction. To test that, beyond measuring participants’ self-reported motivation and effort, future studies can utilize behavioral, physiological, and neural measures. For example, studies could use online neural indices of cognitive effort, such as the frontal-LPP, an event related potential component that was shown to indicate the degree of cognitive effort associated with ER implementationThird, given that the study was aimed to address the question of whether placebo-induced expectancies can boost distraction in the face of unpleasant emotions (namely, fear), we did not include neutral stimuli. Rather, the no-regulation experience condition, where participants experienced unpleasant emotions without regulating, served as a baseline. In future studies, an additional important baseline measuring responses to neutral stimuli, could be added to the standard, well-established no-regulation condition.Fourth, we found that participants chose the placebo-distraction more when it involved thinking about writing letters, relative to thinking about drawing shapes. It is important to note that this was the only case where the type of distraction used in the placebo condition interacted with the findings. Nonetheless, future studies could explore potential characteristics of ER strategies that make them more susceptible to placebo manipulations—similar to how classic placebo studies explore how specific characteristics of the placebo treatment (e.g., its color) enhance the placebo effect.Last, while we measured participants’ preferences for the placebo-distraction over the control-distraction, we did not measure the experiential consequences of s’ choices between the strategies, namely, their fear ratings after implementing their chosen distraction. It has been demonstrated that when given the opportunity to choose between two (inert) treatments, as opposed to no choice opportunity, participants show increased placebo effectsIn conclusion, the present study provides a unique empirical examination of whether placebo-induced expectancies can be harnessed to improve individuals’ internal attempts to cognitively regulate their emotions. This study employs, in addition to self-reported ER effectiveness, a robust behavioral measure that is relatively new to placebo research, namely, individuals’ preferences for the placebo ER strategy. Broadly, this work opens an avenue for bridging placebo research with ER research, and further expanding the scope of what can serve as a placebo treatment.