Inhibiting uncertainty: Priming inhibition promotes reduction of uncertainty

The aversiveness of intrusiveness: Evidence from involuntary musical imagery

OBJECTIVE

Intrusive thoughts are characterized by a sense of intrusiveness of foreign entry into cognition. While not always consisting of negative content, intrusive thoughts are almost solely investigated in that context. Involuntary Musical Imagery (INMI) offers a promising alternative, as it is a type of involuntary cognition that can be used to evaluate intrusiveness without negative content.

METHODS

In Study 1, 200 participants completed self-report questionnaires to assess several aspects of intrusiveness: meta-awareness, control, repetitiveness, frequency, and subjective experience of INMI. In Study 2, 203 participants completed self-report questionnaires to explore the clinical characteristics (depression, stress, anxiety, and rumination) which might mediate the connection between INMI frequency and INMI negative experience.

RESULTS

Study 1 revealed, through exploratory factor analysis, that intrusiveness shares variance with the negative experience of INMI but not with INMI frequency. In Study 2, ruminative thinking was found to mediate the relationship between frequent INMI and the negative experience of INMI.

CONCLUSION

These results suggest that INMI might be used to investigate intrusiveness in the lab without the potential confound of negative emotions. In addition, the results suggest that neither the content nor the frequency of intrusive thoughts can solely explain why these thoughts are aversive to some but not others. Ruminative style might be the missing link to explain how and why these intrusive thoughts become aversive and obsessive. In other words, we suggest that the cause for intrusiveness lies not in the thought or repetitiveness, but in the thinker.

The Effect of Symptom-Provocation on Inhibitory Control in Obsessive-Compulsive Disorder Patients Is Contingent upon Chronotype and Time of Day

Studies have shown that alertness can affect inhibitory control, the mechanism responsible for stopping behaviors, thoughts, or emotions. Inhibitory control is particularly important for helping individuals with Obsessive-Compulsive Disorder (OCD) resisting their symptoms. Chronotype is the mechanism governing an individual's fluctuation of alertness throughout the day. Previous studies have shown that individuals with a 'morning' chronotype have worse OCD symptoms in the evening and vice versa. We administered a novel 'symptom-provocation stop signal task' (SP-SST), in which individually tailored OCD triggers were presented and inhibitory control was measured. Twenty-five treatment-seeking OCD patients completed the SP-SST three times per day for seven consecutive days. Stop signal reaction time (SSRT), which measures inhibitory control, was calculated separately for symptom-provocation trials and for neutral trials. Results yielded that: (a) stopping was significantly harder in the symptom-provocation compared to neutral trials, and (b) the chronotype by time-of-day interaction predicts inhibition for both symptom-provocation and neutral trials, indicating better inhibition in the optimal time of day. Furthermore, we concluded that individually tailored OCD triggers have a detrimental effect on inhibitory control. Most importantly, higher alertness levels, which can be predicted by the interaction of chronotype and time of day, affect inhibitory control, both in general and for OCD triggers specifically.

Impaired Non-Selective Response Inhibition in Obsessive-Compulsive Disorder

Two prominent features of obsessive-compulsive disorder (OCD) are the inability to inhibit intrusive thoughts and behaviors and pathological doubt or intolerance of uncertainty. Previous study showed that uncertain context modeled by equiprobable presentation of excitatory (Go) and inhibitory (NoGo) stimuli requires non-selective response inhibition in healthy subjects. In other words, it requires transient global inhibition triggered not only by excitatory stimuli but also by inhibitory stimuli. Meanwhile, it is unknown whether OCD patients show abnormal brain activity of the non-selective response inhibition system. In order to test this assumption, we performed an fMRI study with an equiprobable Go/NoGo task involving fourteen patients with OCD and compared them with 34 healthy controls. Patients with OCD showed pathological slowness in the Go/NoGo task. The non-selective response inhibition system in OCD included all brain areas seen in healthy controls and, in addition, involved the right anterior cingulate cortex (ACC) and the anterior insula/frontal operculum (AIFO). Moreover, a between-group comparison revealed hypoactivation of brain regions within cingulo-opercular and cortico-striato-thalamo-cortical (CSTC) circuits in OCD. Among hypoactivated areas, the right ACC and the right dorsolateral prefrontal cortex (DLPFC) were associated with non-selective inhibition. Furthermore, regression analysis showed that OCD slowness was associated with decreased activation in cingulate regions and two brain areas related to non-selective inhibition: the right DLPFC and the right inferior parietal lobule (IPL). These results suggest that non-selective response inhibition is impaired in OCD, which could be a potential explanation for a relationship between inhibitory deficits and the other remarkable characteristic of OCD known as intolerance of uncertainty.

An Integrative Model for Understanding Obsessive-Compulsive Disorder: Merging Cognitive Behavioral Theory with Insights from Clinical Neuroscience

Several models have been proposed for the emergence and maintenance of obsessive-compulsive disorder (OCD). Although these models have provided important insights and inspired treatment development, no single model has yet sufficiently accounted for the complexed phenotype of the disorder. In the current paper, we propose a novel model that integrates elements from cognitive behavioral models of OCD with neurocognitive approaches to the disorder. This Reciprocal Interaction Model (RIM) for OCD is based on two assumptions: (a) similar observed symptoms can stem from different etiological processes; and (b) neuropsychological deficits (such as reduced response inhibition and overreliance on the habit formation system) and cognitive behavioral processes (such as temporary reduction in anxiety after engaging in compulsive behaviors) mutually affect each other such that abnormalities in one system influence the second system and vice-versa-creating a vicious cycle of pathological processes. Indeed, the bidirectional inhibitory connection between anxiety/obsessions and executive control is at the heart of the model. We begin by briefly reviewing the current models for OCD. We then move on to describe the RIM, the supporting evidence for the model, the model's predictions, and potential clinical implications.

ADHD and Interfering Thoughts in High and Low Conflict Conditions

BACKGROUND

Individuals with an ADHD diagnosis have increased levels of interfering thoughts, especially in the form of mind wandering. This was mostly investigated in sustained attention tasks; hence it is unclear whether the findings are only due to their difficulties in those types of tasks. Moreover, it is unclear how the amount of control invested in the task will affect those differences between control and ADHD groups.

METHOD

ADHD and matched control groups performed the Stroop task under high and low conflict conditions while measuring their interfering thoughts level.

RESULTS

Individuals with ADHD have more interfering thoughts compared to a control group even when they are able to change their control level according to the task conflict.

CONCLUSION

Interfering thoughts are an independent predictor of ADHD impairments, observed regardless of the degree of control invested in the task.

Momentary Induction of Inhibitory Control and Its Effects on Uncertainty

Deficient inhibitory control and difficulty resolving uncertainty are central in psychopathology. How these factors interact remains unclear. Initial evidence suggests that inducing inhibitory control improves resolution of uncertainty. This may occur only when participants overcome action tendencies, which are dominant tendencies to perform certain behaviors. Our study explored the links between inhibitory control and behavioral responses to uncertainty while manipulating action-tendencies’ strength. In three experiments, 132 undergraduates completed a task that combined induction of momentary changes in inhibitory control level (Stroop task), with responses to uncertainty (visual-search task). We manipulated action-tendencies’ strength by varying uncertainty proportions across experiments. Results indicated that momentary induction of inhibitory control improved resolution of high-uncertainty during mostly low-uncertainty trials but hampered resolution of low-uncertainty during mostly high-uncertainty trials. Identical inhibitory control induction did not affect resolution of uncertainty when uncertainty conditions were equalized. Participants’ subjective uncertainty measures were similar across experiments. Our results suggest that momentary inhibitory control induction modifies behavioral responses to uncertainty and selectively affects trials that require overcoming dominant action tendencies. These findings indicate a potentially unique and multifaceted relationship between inhibitory control and behavioral responses to uncertainty. Clinical implications for models of Obsessive-Compulsive Disorder and experimental implications to post-conflict processes are discussed.

But first, coffee: The roles of arousal and inhibition in the resistance of compulsive cleansing in individuals with high contamination fears

Inhibition plays a crucial role in reducing intrusive thoughts and compulsive behaviors, such as handwashing, in response to the feeling of disgust. The current study examines whether manipulating arousal can facilitate inhibition and the resistance of compulsive cleansing. Forty-seven participants with high contamination fears were recruited for this study. Participants were divided into a caffeine group or a no-caffeine group. Participants touched a potentially contaminated and disgusting stimulus ("dirty" diapers) and were asked to wait as long as they could before washing their hands. Only the caffeine group exhibited greater pre-post stop-signal reaction time improvement in the stop-signal task, indicating improved inhibition. Participants in the caffeine group exhibited significantly lower subjective distress and urges-to-wash their hands both after touching the stimulus and while waiting to engage in the cleansing behavior. Similarly, the caffeine group resisted the urge to compulsively cleanse for about twice as long as those in the no-caffeine group. Time spent washing, subjective distress levels, and urge-to-wash levels after participants washed their hands were similar between groups. The current findings support the notion that increased arousal improves inhibition, which may play a role in improving our ability to resist intrusive disgust and compulsive cleansing behaviors.

Pediatric OCD in the era of RDoC

The NIMH Research Domain Criteria (RDoC) initiative was established with the goal of developing an alternative research classification to further research efforts in mental health. While RDoC acknowledges that constructs should be considered within a developmental framework, developmental considerations have not yet been well integrated within the existing RDoC matrix. In this paper, we consider RDoC in relation to pediatric OCD, a paradigmatic example of a neuropsychiatric disorder that often has onset in childhood but is also present across the lifespan. We discuss three RDoC subdomains with relevance to OCD as exemplars, providing for each construct a brief review of normative developmental changes, the state of construct-relevant research in pediatric OCD, and challenges and limitations related to developmental considerations within each subdomain. Finally, we conclude with a brief discussion of how RDoC may continue to evolve with regard to developmental considerations in order to further research in pediatric OCD.