Tuned to Tremor: Increased Sensitivity of Cortico-Basal Ganglia Neurons to Tremor Frequency in the MPTP Nonhuman Primate Model of Parkinson's Disease.

Rest tremor is one of the most prominent clinical features of Parkinson's disease (PD). Here, we hypothesized that cortico-basal ganglia neurons tend to fire in a pattern that matches PD tremor frequency, suggesting a resonance phenomenon. We recorded spiking activity in the primary motor cortex (M1) and globus pallidus external segment of 2 female nonhuman primates, before and after parkinsonian state induction with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. The arm of nonhuman primates was passively rotated at seven different frequencies surrounding and overlapping PD tremor frequency. We found entrainment of the spiking activity to arm rotation and a significant sharpening of the tuning curves in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine state, with a peak response at frequencies that matched the frequency of PD tremor. These results reveal increased sensitivity of the cortico-basal ganglia network to tremor frequency and could indicate that this network acts not only as a tremor switch but is involved in setting its frequency.SIGNIFICANCE STATEMENT Tremor is a prominent clinical feature of Parkinson's disease; however, its underlying pathophysiology is still poorly understood. Using electrophysiological recordings of single cortico-basal ganglia neurons before and after the induction of a parkinsonian state, and in response to passive arm rotation, this study reports increased sensitivity to tremor frequency in Parkinson's disease. We found sharpening of the population tuning to the midrange of the tested frequencies (1-13.3 Hz) in the healthy state that further increased in the parkinsonian state. These results hint at the increased frequency-tuned sensitivity of cortico-basal ganglia neurons and suggest that they tend to resonate with the tremor.

Hoarding behavior and its association with mental health and functioning in a large youth sample.

Hoarding behavior is prevalent in children and adolescents, yet clinicians do not routinely inquire about it and youth may not spontaneously report it due to stigma. It is unknown whether hoarding behavior, over and above obsessive-compulsive symptoms (OCS), is associated with major clinical factors in a general youth population. This observational study included N = 7054 youth who were not seeking help for mental health problems (ages 11-21, 54% female) and completed a structured interview that included evaluation of hoarding behavior and OCS, as a part of the Philadelphia Neurodevelopmental Cohort between November 2009 and December 2011. We employed regression models with hoarding behavior and OCS (any/none) as independent variables, and continuous (linear regression) or binary (logistic regression) mental health measures as dependent variables. All models covaried for age, sex, race, and socioeconomic status. A total of 374 participants endorsed HB (5.3%), most of which reported additional OCS (n = 317). When accounting for OCS presence, hoarding behavior was associated with greater dimensional psychopathology burden (i.e., higher P-factor) (ß = 0.19, p < .001), and with poorer functioning (i.e., lower score on the child global assessment scale) (ß = - 0.07, p < .001). The results were consistent when modeling psychopathology using binary variables. The results remained significant in sensitivity analyses accounting for count of endorsed OCS and excluding participants who met criteria for obsessive-compulsive disorder (n = 210). These results suggest that hoarding behavior among youth is associated with poorer mental health and functioning, independent of OCS. Brief hoarding-behavior assessments in clinical settings may prove useful given hoarding behavior's stigma and detrimental health associations.

When radical uncertainty is too much: Clinical aspects of Conviction Narrative Theory.

We propose extrapolating Conviction Narrative Theory (CNT) to clinical psychology and psychiatry. We demonstrate how CNT principles may benefit assessment, therapy, and possibly even modify public health views of neuropsychiatric disorders. Our commentary focuses on hoarding disorder as a model, elaborates on discrepancies in the scientific literature and suggests how the CNT may resolve them.

Comparable reliability and acceptability of telepsychiatry and face-to-face psychiatric assessments in the emergency room setting.

OBJECTIVE: This study aims to compare the reliability and acceptability of psychiatric interviews using telepsychiatry and face-to-face modalities in the emergency room setting. METHODS: In this prospective observational feasibility study, psychiatric patients (n = 38) who presented in emergency rooms between April and June 2020, went through face-to-face and videoconference telepsychiatry interviews in a non-randomised varying order. Interviewers and a senior psychiatry resident who observed both interviews determined diagnosis, recommended disposition and indication for involuntary admission. Patients and psychiatrists completed acceptability post-assessment surveys. RESULTS: Agreement between raters on recommended disposition and indication for involuntary admission as measured by Cohen's kappa was 'strong' to 'almost perfect' (0.84/0.81, 0.95/0.87 and 0.89/0.94 for face-to-face vs. telepsychiatry, observer vs. face-to-face and observer vs. telepsychiatry, respectively). Partial agreement between the raters on diagnosis was 'strong' (Cohen's kappa of 0.81, 0.85 and 0.85 for face-to-face vs. telepsychiatry, observer vs. face-to-face and observer vs. telepsychiatry, respectively).Psychiatrists' and patients' satisfaction rates, and psychiatrists' perceived certainty rates, were comparably high in both face-to-face and telepsychiatry groups. CONCLUSIONS: Telepsychiatry is a reliable and acceptable alternative to face-to-face psychiatric assessments in the emergency room setting. Implementing telepsychiatry may improve the quality and accessibility of mental health services.Key pointsTelepsychiatry and face-to-face psychiatric assessments in the emergency room setting have comparable reliability.Patients and providers report a comparable high level of satisfaction with telepsychiatry and face-to-face modalities in the emergency room setting.Providers report a comparable level of perceived certainty in their clinical decisions based on telepsychiatry and face-to-face psychiatric assessments in the emergency room setting.

Beyond uncertainty: A broader scope for "incentive hope" mechanisms and its implications.

We propose that food-related uncertainty is but one of multiple cues that predicts harsh conditions and may activate "incentive hope." An evolutionarily adaptive response to these would have been to shift to a behavioral-metabolic phenotype geared toward facing hardship. In modernity, this phenotype may lead to pathologies such as obesity and hoarding. Our perspective suggests a novel therapeutic approach.

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

BACKGROUND: 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. METHODS: We analyzed results from a stop-signal task to probe RI in 65 OCD patients (32 of whom were medicated) and 58 healthy controls (HCs). RESULTS: There was no statistically significant difference in stop-signal reaction time between the OCD group and the HC group, or between the medicated and unmedicated OCD patients. However, variability was significantly greater in the medicated OCD group compared to the unmedicated group. CONCLUSIONS: These results indicate that some samples of OCD patients do not have deficits in RI, making it unlikely that deficient RI underlies repetitive behaviors in all OCD patients. Future research is needed to fully elucidate the impact of medication use on stop-signal performance. Implications for future research on the cognitive processes underlying repetitive thoughts and behaviors are discussed.

Musical space synesthesia: automatic, explicit and conceptual connections between musical stimuli and space.

In musical-space synesthesia, musical pitches are perceived as having a spatially defined array. Previous studies showed that symbolic inducers (e.g., numbers, months) can modulate response according to the inducer's relative position on the synesthetic spatial form. In the current study we tested two musical-space synesthetes and a group of matched controls on three different tasks: musical-space mapping, spatial cue detection and a spatial Stroop-like task. In the free mapping task, both synesthetes exhibited a diagonal organization of musical pitch tones rising from bottom left to the top right. This organization was found to be consistent over time. In the subsequent tasks, synesthetes were asked to ignore an auditory or visually presented musical pitch (irrelevant information) and respond to a visual target (i.e., an asterisk) on the screen (relevant information). Compatibility between musical pitch and the target's spatial location was manipulated to be compatible or incompatible with the synesthetes' spatial representations. In the spatial cue detection task participants had to press the space key immediately upon detecting the target. In the Stroop-like task, they had to reach the target by using a mouse cursor. In both tasks, synesthetes' performance was modulated by the compatibility between irrelevant and relevant spatial information. Specifically, the target's spatial location conflicted with the spatial information triggered by the irrelevant musical stimulus. These results reveal that for musical-space synesthetes, musical information automatically orients attention according to their specific spatial musical-forms. The present study demonstrates the genuineness of musical-space synesthesia by revealing its two hallmarks-automaticity and consistency. In addition, our results challenge previous findings regarding an implicit vertical representation for pitch tones in non-synesthete musicians.

SIR+ models: accounting for interaction-dependent disease susceptibility in the planning of public health interventions.

Avoiding physical contact is regarded as one of the safest and most advisable strategies to follow to reduce pathogen spread. The flip side of this approach is that a lack of social interactions may negatively affect other dimensions of health, like induction of immunosuppressive anxiety and depression or preventing interactions of importance with a diversity of microbes, which may be necessary to train our immune system or to maintain its normal levels of activity. These may in turn negatively affect a population's susceptibility to infection and the incidence of severe disease. We suggest that future pandemic modelling may benefit from relying on 'SIR+ models': epidemiological models extended to account for the benefits of social interactions that affect immune resilience. We develop an SIR+ model and discuss which specific interventions may be more effective in balancing the trade-off between minimizing pathogen spread and maximizing other interaction-dependent health benefits. Our SIR+ model reflects the idea that health is not just the mere absence of disease, but rather a state of physical, mental and social well-being that can also be dependent on the same social connections that allow pathogen spread, and the modelling of public health interventions for future pandemics should account for this multidimensionality.

Validation of behavioral measures of social cognition in individuals diagnosed with schizophrenia.

Schizophrenia, a complex neuropsychiatric disorder, manifests severe impairments in social cognition, notably in Theory of Mind (ToM), empathy, and emotion recognition, which significantly influence social competence and overall functioning. These aspects are crucial for prognosis in individuals diagnosed with schizophrenia (SZ). This study validates a comics strip paradigm for ToM and empathy assessment, the Montreal Affective Voices (MAV) for measuring emotion recognition, and a Go-NoGo task for inhibition control estimation in individuals diagnosed with SZ, comparing their performance with healthy controls. SZ participants exhibited diminished abilities in the comics strip task, especially in ToM and empathy conditions, alongside challenges in identifying emotions from vocal cues in MAV. They responded slower and tended to be less accurate in the Go-NoGo task. The validated behavioral battery addresses the limitations of previous measures and emerges as a promising tool for future investigations into the neural systems underlying social cognition in schizophrenia. Such insights can lead to the development of long-needed treatment for negative symptoms and social dysfunctions in schizophrenia.

Randomized waitlist-controlled trial of buried in treasures facilitated support groups and in-home uncluttering (BIT+) for hoarding disorder.

OBJECTIVE: The Buried in Treasures (BIT) workshop is a promising treatment for hoarding disorder (HD), though many participants struggle with home uncluttering. This randomized waitlist-controlled trial investigated the efficacy of a version of BIT, augmented with in-home uncluttering practice (BIT+). METHOD: Adults (N = 41) with hoarding disorder were recruited from the community and randomly assigned to BIT+ or waitlist. BIT+ consisted of 16 sessions of the BIT workshop and 10 uncluttering home visits over 18 weeks. Outcome measures included the Saving Inventory-Revised (self-report) and the Clutter Image Rating Scale (self and independent evaluator rated). Between group repeated measures analyses using general linear modeling examined the effect of BIT+ vs waitlist control on hoarding symptoms after 18 weeks. Within group analyses examined pre-post effects for all BIT+ participants combined after 18 weeks. RESULTS: After 18 weeks, BIT+ participants benefited significantly more than waitlist controls on hoarding severity with large effect size (Cohen's d = 1.5, p < .001). BIT+ was also associated with improvement reductions in hoarding symptoms, clutter, and functional impairment. CONCLUSIONS: The BIT+ intervention offers promise as a treatment option for hoarding. Adding in-home uncluttering practice may incrementally improve discarding practices. Future controlled trials are warranted.

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.

Enabling Expedited Disposition of Emergencies Using Telepsychiatry in Israel: Protocol for a Hybrid Implementation Study.

BACKGROUND: Telepsychiatry is the use of virtual communication, such as a video link, to deliver mental health assessment, treatment, and follow-up. Previous studies have shown telepsychiatry to be feasible, accurate compared with in-person practice, and satisfying for psychiatrists and patients. Telepsychiatry has also been associated with reduced waiting times for evaluation and, in some studies, lower admission rates. However, most previous studies focused on using telepsychiatry in community settings and not on involuntary admission. OBJECTIVE: The aim of this study is to examine the effectiveness and implementation process of patient assessment for involuntary admissions in the psychiatric emergency department (ED) using a video link. METHODS: This type 1 hybrid implementation study will examine telepsychiatry effectiveness and the implementation process, by comparing telepsychiatry (n=240) with historical controls who had a face-to-face evaluation (n=240) during the previous, usual care period in 5 psychiatric EDs in Israel. A temporary waiver of the standing policy requiring in-person evaluations only, for the purpose of research, was obtained from the Israeli Ministry of Health. During the telepsychiatry phase, clinical staff and patients will join a video call from the ED, while the attending physician will log in elsewhere. The Promoting Action on Research Implementation in Health Services (PARIHS) framework will guide the evaluation of the telepsychiatry implementation process in the ED. PARIHS has the following 3 constructs: (1) evidence: staff's opinions regarding the innovation's viability and practicality, their satisfaction levels with its use, and patients' perceptions of the change; (2) context: level of approval of new strategies in the ED, decision-making processes, and the manner in which clinical teams converse and work together; (3) facilitation: adequacy of the facilitation efforts using champions reports. Primary clinical outcomes include ED length of stay and violent incidents obtained from medical records. RESULTS: This study received Helsinki approval from the Ethics Committee of Abarbanel Mental Health Center (174; March 13, 2023), Jerusalem Mental Health Center (22-21; November 6, 2022), Lev-Hasharon Mental Health Medical Center (LH12023; February 12, 2023), Tel-Aviv Medical Center (TLV-22-0656; January 3, 2023), and Sha'ar Menashe (1-4-23; April 18, 2023). Data collection began in July 2023 in 2 study sites and will begin soon at the others. CONCLUSIONS: Telepsychiatry could have significant benefits for patients in the psychiatric ED. Examining telepsychiatry effectiveness in the ED, in addition to identifying the facilitators and barriers of implementing it in different emergency settings, will facilitate better policy decisions regarding its implementation. TRIAL REGISTRATION: ClinicalTrials.gov NCT05771545; https://clinicaltrials.gov/study/NCT05771545. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49405.

Sleep architecture is associated with core symptom severity in autism spectrum disorder.

STUDY OBJECTIVES: While caregiver-reported sleep disturbances are common in children and adolescents with autism spectrum disorder (['), few studies have measured objective sleep in ASD compared to controls, and their findings are mixed. We investigated (1) differences in sleep architecture, specifically slow-wave sleep (SWS) and rapid eye movement (REM) sleep, between ASD and typically developing controls (TD); and (2) if any observed differences in sleep were associated with core ASD symptoms. METHODS: We used ambulatory polysomnography (PSG) in 53 participants with ASD (ages 4-18) and 66 age-matched TD in their home sleeping environment. The primary outcome measures were SWS and REM sleep. Core behavioral ASD symptoms were assessed using the Autism Diagnostic Interview-Revised (ADI-R). Spectral power bands during sleep, and additional behavioral measures, were examined in exploratory analyses. RESULTS: Compared to TD, participants with ASD exhibited a higher SWS ratio and lower REM sleep ratio. Within the ASD group, higher SWS was associated with more severe symptoms on the Restricted, Repetitive, and Stereotyped Behaviors subscale of the ADI-R. No association was observed between REM sleep ratio and any ASD symptom. CONCLUSIONS: Increased SWS and reduced REM sleep ratio differentiated ASD from TD. However, only increased SWS was associated with more severe core ASD symptoms. Increased SWS may reflect neuronal immaturity specific to ASD in this age group. These findings may inform the underlying mechanisms of clinical symptoms observed in children and adolescents with ASD.

A school-based health and mindfulness curriculum improves children's objectively measured sleep: a prospective observational cohort study.

STUDY OBJECTIVES: Poor sleep impedes children's cognitive, emotional, and psychosocial development. Pediatric sleep dysregulation is common, and children who live in communities of low socioeconomic status experience additional risk factors for short sleep duration and poor sleep quality. School-based training in mindfulness and yoga-informed practices can improve children's behavior and well-being, but effects on objectively measured sleep are unknown. METHODS: Effects of a school-based health and mindfulness curriculum, which taught practices such as paced breathing, on sleep and stress were examined in 115 children (49 girls, ages 8 to 11 at baseline). Fifty-eight children in a community of low socioeconomic status received the curriculum twice weekly for 2 years. Fifty-seven children in a socioeconomic status-matched community engaged in their usual physical education class instead. In-home ambulatory polysomnography and perceived social stress were measured in all children at 3 time points: at baseline (ie, prior to curriculum exposure) and at 2 yearly follow-ups. RESULTS: Children receiving the curriculum gained an average of 74 minutes of total sleep time, and 24 minutes of rapid eye movement sleep, per night over the 2-year study period. Children not receiving the curriculum experienced a decrease in total sleep time averaging 64 minutes per night, with no changes in rapid eye movement sleep. Sleep improved within the first 3 months of curriculum exposure, in a dose-dependent fashion. Higher curriculum engagement (eg, using the breathing exercises outside of class) was associated with larger gains in total and rapid eye movement sleep duration. Aggregate within-group changes in social stress were not significant. However, among children receiving the curriculum, those who experienced larger gains in total and rapid eye movement sleep duration also experienced larger increases in perceived social stress. CONCLUSIONS: A school-based health and mindfulness curriculum improved children's objectively measured sleep over 2 years. Social stress did not mediate these effects; instead, mindfulness training may have increased awareness of environmental stressors, while developing tools to reduce stress vulnerability. CITATION: Chick CF, Singh A, Anker LA, et al. A school-based health and mindfulness curriculum improves children's objectively measured sleep: a prospective observational cohort study. J Clin Sleep Med. 2022;18(9):2261-2271.

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.

Increased activation product of complement 4 protein in plasma of individuals with schizophrenia.

Structural variation in the complement 4 gene (C4) confers genetic risk for schizophrenia. The variation includes numbers of the increased C4A copy number, which predicts increased C4A mRNA expression. C4-anaphylatoxin (C4-ana) is a C4 protein fragment released upon C4 protein activation that has the potential to change the blood-brain barrier (BBB). We hypothesized that elevated plasma levels of C4-ana occur in individuals with schizophrenia (iSCZ). Blood was collected from 15 iSCZ with illness duration < 5 years and from 14 healthy controls (HC). Plasma C4-ana was measured by radioimmunoassay. Other complement activation products C3-ana, C5-ana, and terminal complement complex (TCC) were also measured. Digital-droplet PCR was used to determine C4 gene structural variation state. Recombinant C4-ana was added to primary brain endothelial cells (BEC) and permeability was measured in vitro. C4-ana concentration was elevated in plasma from iSCZ compared to HC (mean = 654 ± 16 ng/mL, 557 ± 94 respectively, p = 0.01). The patients also carried more copies of the C4AL gene and demonstrated a positive correlation between plasma C4-ana concentrations and C4A gene copy number. Furthermore, C4-ana increased the permeability of a monolayer of BEC in vitro. Our findings are consistent with a specific role for C4A protein in schizophrenia and raise the possibility that its activation product, C4-ana, increases BBB permeability. Exploratory analyses suggest the novel hypothesis that the relationship between C4-ana levels and C4A gene copy number could also be altered in iSCZ, suggesting an interaction with unknown genetic and/or environmental risk factors.

Examining subjective sleep quality in adults with hoarding disorder.

Hoarding disorder (HD), characterized by difficulty parting with possessions and functionally impairing clutter, affects 2-6% of the population. Originally considered part of Obsessive-Compulsive Disorder (OCD), HD became a distinct diagnostic entity in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. While sleep impacts OCD, little is known about sleep in HD. As HD patients often report poor sleep in clinical settings, understanding global subjective sleep quality and disturbances may lead to novel therapeutic targets. To address this gap, the authors used a sample of convenience: an existing data set designed to screen research study eligibility and explore the psychopathology and phenomenology of OCD and HD. The data set included information collected from individuals with HD (n = 38), OCD (n = 26), and healthy participants (n = 22) about insomnia, sleep quality, and mood using interviews and structured instruments including the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Depression Anxiety Stress Scales (DASS). In this data set, HD and OCD groups reported significantly greater insomnia symptoms and poorer sleep quality compared with healthy controls while controlling for depression, age, and gender. A sizable minority of HD and OCD individuals met criteria for comorbid sleep disorders. OCD and HD groups differed in delayed sleep phase prevalence. To our knowledge, this is the first study examining subjective sleep quality and insomnia in HD as compared to healthy individuals and those with OCD, while controlling for relevant clinical characteristics. Given that there are evidence-based treatments for insomnia and other sleep disorders, our study raises the possibility that treatment interventions targeting sleep may improve HD outcomes.

Why check? A meta-analysis of checking in obsessive-compulsive disorder: Threat vs. distrust of senses.

Compulsive checking is the most common ritual among individuals with obsessive-compulsive disorder (OCD). Yet, other than uncertainty, the variables prompting checking are not fully understood. Laboratory studies suggest that task conditions - whether threatening (anxiety-relevant) or neutral, and task type - whether requiring perceptual or reasoning decision-making - may be influential. The purpose of our meta-analysis was to compare OCD participants and healthy controls on experimental tasks involving uncertainty in which a behavioral measure of checking was obtained. Four databases were searched. Twenty-two studies met the inclusion criteria, including 43 conditions comparing 663 OCD participants to 614 healthy controls. Due to the dependent structure of the data a robust variance estimation analysis approach was used. Overall effects were similar for neutral and threatening conditions. However, OCD participants responded with greater checking compared to controls on perceptual tasks, but not on reasoning tasks. Results support previous reports suggesting that OCD checking can be observed in neutral conditions, possibly posing as a risk factor for a checking vicious cycle. In addition, our results support OCD models which focus on checking as stemming from interference with automatic processes and distrust of sensory modalities.

High-Resolution Spectral Sleep Analysis Reveals a Novel Association Between Slow Oscillations and Memory Retention in Elderly Adults.

Objective: In recognition of the mixed associations between traditionally scored slow wave sleep and memory, we sought to explore the relationships between slow wave sleep, electroencephalographic (EEG) power spectra during sleep and overnight verbal memory retention in older adults. Design, Setting, Participants, and Measurements: Participants were 101 adults without dementia (52% female, mean age 70.3 years). Delayed verbal memory was first tested in the evening prior to overnight polysomnography (PSG). The following morning, subjects were asked to recall as many items as possible from the same List (overnight memory retention; OMR). Partial correlation analyses examined the associations of delayed verbal memory and OMR with slow wave sleep (SWS) and two physiologic EEG slow wave activity (SWA) power spectral bands (0.5-1 Hz slow oscillations vs. 1-4 Hz delta activity). Results: In subjects displaying SWS, SWS was associated with enhanced delayed verbal memory, but not with OMR. Interestingly, among participants that did not show SWS, OMR was significantly associated with a higher slow oscillation relative power, during NREM sleep in the first ultradian cycle, with medium effect size. Conclusions: These findings suggest a complex relationship between SWS and memory and illustrate that even in the absence of scorable SWS, older adults demonstrate substantial slow wave activity. Further, these slow oscillations (0.5-1 Hz), in the first ultradian cycle, are positively associated with OMR, but only in those without SWS. Our findings raise the possibility that precise features of slow wave activity play key roles in maintaining memory function in healthy aging. Further, our results underscore that conventional methods of sleep evaluation may not be sufficiently sensitive to detect associations between SWA and memory in older adults.