Omer Linkovski

Did I turn off the stove? Good inhibitory control can protect from influences of repeated checking.

BACKGROUND AND OBJECTIVES Obsessive-compulsive disorder (OCD) is an anxiety disorder characterized by compulsions aimed at reducing anxiety associated with intrusive cognitions. However, compulsive behaviors such as repeated checking were found to increase rather than decrease uncertainty related to obsessive thoughts (e.g., whether the gas stove was turned off). Some recent studies illustrate that OCD patients and their family members have inhibitory deficits, often demonstrated by the stop-signal task. The current study aims to investigate relations between inhibitory control and effects of repeated checking. METHODS Fifty-five healthy participants carried out a stop-signal task followed by a repeated-checking task. Additionally, participants were asked to complete self-report questionnaires measuring OCD, anxiety and depression symptoms. RESULTS Confirming our hypothesis, participants with poor inhibitory capabilities demonstrated greater uncertainty and memory distrust as a consequence of repeated checking than participants with good inhibitory control. LIMITATIONS Our findings concern an initial investigation on a sample of healthy participants and should be replicated and extended to clinical populations. CONCLUSIONS These results suggest that deficits in inhibitory control may underlie cognitive vulnerability in OCD. An updated model integrating neuropsychological findings with current OCD models is suggested.

The Role of Response Inhibition in Medicated and Unmedicated Obsessive‐Compulsive Disorder Patients: Evidence from the Stop‐Signal Task

Numerous studies have investigated response inhibition (RI) in obsessive‐compulsive disorder (OCD), with many reporting that OCD patients demonstrate deficits in RI as compared to controls. However, reported effect sizes tend to be modest and results have been inconsistent, with some studies finding intact RI in OCD. To date, no study has examined the effect of medications on RI in OCD patients.

Stop checking: Repeated checking and its effects on response inhibition and doubt.

BACKGROUND Repeated checking is a common ritual in obsessive-compulsive disorder (OCD). van den Hout and Kindt (2003b) devised a task demonstrating paradoxical reductions in memory confidence following repeated checking. This effect was later found to be contingent upon response inhibition. The current study aims to (1) test an alternative interpretation, whereby repeated-checking effects are caused by viewing multiple exemplars, and (2) test whether repeated checking affects response inhibition. METHOD 132 students participated in two experiments (66 in Experiment 1 and 66 in Experiment 2). Participants were randomly allocated to a repeated-checking task or a simple-action task that featured similar multiple exemplars without the need for checking. Both tasks were followed by a stop-signal task, measuring response inhibition. Experiment 1 featured a stop-signal task with neutral go-signals while Experiment 2 incorporated familiar and unfamiliar stimuli from the previous task as go-signals. RESULTS In both experiments, the repeated-checking group exhibited reduced memory confidence compared to the simple-action group. Groups did not differ in their response inhibition for neutral stimuli (Experiment 1), while familiar go-signals had a detrimental effect on response inhibition (Experiment 2). LIMITATIONS Our results examine the association between checking and response inhibition in healthy participants without attention deficit hyperactivity disorder and dyslexia. Replication with clinical samples awaits future studies. CONCLUSIONS Repeated checking impairs memory confidence. Increased familiarity of stimuli shortens the time it takes to respond to them while it impairs inhibition response to them. These effects possibly provide initial evidence for the hypothesized role of response inhibition in the maintenance of OCD.

Inhibiting uncertainty: Priming inhibition promotes reduction of uncertainty.

Uncertainty affects performance in many cognitive tasks, including the visual-search task, and individual differences in the experience of uncertainty may contribute to several psychological disorders. Despite the importance of uncertainty, to date, no study has explained the basic mechanisms underlying individual differences in the experience of uncertainty. However, it has been suggested that inhibition, a cognitive mechanism aimed at suppressing unwanted thoughts or actions, may affect the development of uncertainty. In the current study, we investigated the relationship between inhibition and behavioral responses to uncertainty in the visual-search task. To accomplish this goal, forty six university students completed a novel combined visual-search and stop-signal task, in which we manipulated the degree to which the inhibitory control system was activated by varying the proportions of stop signals in separate blocks. We utilized target-absent trials in the visual-search task as a behavioral probe of responses to uncertainty. We found that activating higher levels of inhibitory control resulted in faster responses to target-absent visual-search trials, while not affecting target-present trials. These findings suggest that activation of inhibitory control may causally affect behavioral responses to uncertainty. Thus, individual differences in inhibitory control may influence the ability to rely on internal-ambiguous cues which are common in visual-search and other cognitive tasks. Clinical implications for obsessive-compulsive disorder (OCD) and other disorders involving deficient inhibitory control and difficulty with uncertainty are discussed.

Is it for real? Evaluating authenticity of musical pitch-space synesthesia.

In spatial-sequence synesthesia, ordinal sequences are visualized in explicit spatial locations. We examined a recently documented subtype in which musical notes are represented in spatial configurations, to verify consistency and automaticity of musical pitch-space (M-S) synesthesia. An M-S synesthete performed a mapping pre-task (Exp. 1) used to indicate the locations of 7 auditory or visually presented notes, in 2 sessions a month apart. Results revealed strong correlations between sessions, suggesting the synesthete’s musical forms were consistent over time. Experiment 2 assessed automaticity of M-S synesthesia. The same synesthete and matched controls preformed a spatial Stroop-like task. Participants were presented with an auditory or visual musical note and then had to reach for an asterisk (target) with a mouse cursor. The target appeared in a compatible or incompatible location (according to the synesthete’s spatial representation). A compatibility effect was found for the synesthete but not for controls. The synesthete was significantly faster when the target appeared in compatible locations than in incompatible ones. Our findings show that for synesthetes, auditory and visually presented notes automatically trigger attention to specific spatial locations according to their specific M-S associations.

Augmenting Buried in Treasures with in-home uncluttering practice: Pilot study in hoarding disorder

Hoarding disorder is characterized by difficulty parting with possessions and by clutter that impairs the functionality of living spaces. Cognitive behavioral therapy conducted by a therapist (individual or in a group) for hoarding symptoms has shown promise. For those who cannot afford or access the services of a therapist, one alternative is an evidence-based, highly structured, short-term, skills-based group using CBT principles but led by non-professional facilitators (the Buried in Treasures [BIT] Workshop). BIT has achieved improvement rates similar to those of psychologist-led CBT. Regardless of modality, however, clinically relevant symptoms remain after treatment, and new approaches to augment existing treatments are needed. Based on two recent studies - one reporting that personalized care and accountability made treatments more acceptable to individuals with hoarding disorder and another reporting that greater number of home sessions were associated with better clinical outcomes, we tested the feasibility and effectiveness of adding personalized, in-home uncluttering sessions to the final weeks of BIT. Participants (n = 5) had 15 sessions of BIT and up to 20 hours of in-home uncluttering. Reductions in hoarding symptoms, clutter, and impairment of daily activities were observed. Treatment response rate was comparable to rates in other BIT studies, with continued improvement in clutter level after in-home uncluttering sessions. This small study suggests that adding in-home uncluttering sessions to BIT is feasible and effective.

Mirror Neurons and Mirror-Touch Synesthesia

Since mirror neurons were introduced to the neuroscientific community more than 20 years ago, they have become an elegant and intuitive account for different cognitive mechanisms (e.g., empathy, goal understanding) and conditions (e.g., autism spectrum disorders). Recently, mirror neurons were suggested to be the mechanism underlying a specific type of synesthesia. Mirror-touch synesthesia is a phenomenon in which individuals experience somatosensory sensations when seeing someone else being touched. Appealing as it is, careful delineation is required when applying this mechanism. Using the mirror-touch synesthesia case, we put forward theoretical and methodological issues that should be addressed before relying on the mirror-neurons account.

Training and transfer in aging – is pathway overlap really necessary?

ABSTRACT Voelker et al. (this issue) discuss how training improves task speed. They suggest two constraints when exploring how training changes cognition through transfer: (1) a link between improved connectivity and response speed and (2) the transfer task should use pathways altered by training. Looking at the literature on aging, we believe the latter constraint should be reconsidered. We discuss evidence from developmental aging, questioning whether the transfer task necessarily requires using training task pathways. Additionally, we expand the discussion of state training to research on aging—specifically, the link between resting state network activity, mindfulness training, and executive functioning.