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1.
Am J Respir Crit Care Med ; 205(11): 1281-1289, 2022 06 01.
Article in English | MEDLINE | ID: mdl-35333140

ABSTRACT

Rationale: Patients discharged from the hospital for chronic obstructive pulmonary disease (COPD) exacerbation have impaired quality of life and frequent readmission and death. Clinical trials to reduce readmission demonstrate inconsistent results, including some demonstrating potential harms. Objectives: We tested whether a pragmatic proactive interdisciplinary and virtual review of patients discharged after hospitalization for COPD exacerbation would improve quality of life, using the Clinical COPD Questionnaire, and reduce all-cause 180-day readmission and/or mortality. Methods: We performed a stepped-wedge clinical trial. We enrolled primary care providers and their patients after hospital discharge for COPD at two Department of Veterans Affairs medical centers and 10 outpatient clinics. A multidisciplinary team reviewed health records and developed treatment recommendations delivered to primary care providers via E-consult. We facilitated uptake by entering recommendations as unsigned orders that could be accepted, modified, or canceled. Providers and patients made all final treatment decisions. Measurements and Main Results: We enrolled 365 primary care providers. Over a 30-month period, 352 patients met eligibility criteria, with 191 (54.3%) patients participating in the control and 161 (45.7%) in the intervention. The intervention led to clinically significant better Clinical COPD Questionnaire scores (-0.47; 95% confidence interval [CI], -0.85 to -0.09; 52.6% missing) but did not reduce 180-day readmission and/or mortality (adjusted odds ratio, 0.83; 95% CI, 0.49 to 1.38), in part because of wide CIs. Among the 161 patients in the intervention group, we entered 519 recommendations as unsigned orders, of which 401 (77.3%) were endorsed. Conclusions: A pragmatic health system-level intervention that delivered proactive specialty supported care improved quality of life but did not reduce 180-day readmission or death. Clinical trial registered with www.clinicaltrials.gov (NCT02021955).


Subject(s)
Patient Discharge , Pulmonary Disease, Chronic Obstructive , Hospitals , Humans , Patient Readmission , Quality of Life
2.
Sleep Breath ; 27(1): 303-308, 2023 03.
Article in English | MEDLINE | ID: mdl-35347655

ABSTRACT

PURPOSE: In-person visits with a trained therapist have been standard care for patients initiating continuous positive airway pressure (CPAP). These visits provide an opportunity for hands-on training and an in-person assessment of mask fit. However, to improve access, many health systems are shifting to remote CPAP initiation with equipment mailed to patients. While there are potential benefits of a mailed approach, relative patient outcomes are unclear. Specifically, many have concerns that a lack of in-person training may contribute to reduced CPAP adherence. To inform this knowledge gap, we aimed to compare treatment usage after in-person or mailed CPAP initiation. METHODS: Our medical center shifted from in-person to mailed CPAP dispensation in March 2020 during the COVID-19 pandemic. We assembled a cohort of patients with newly diagnosed obstructive sleep apnea (OSA) who initiated CPAP in the months before (n = 433) and after (n = 186) this shift. We compared 90-day adherence between groups. RESULTS: Mean nightly PAP usage was modest in both groups (in-person 145.2, mailed 140.6 min/night). We did not detect between-group differences in either unadjusted or adjusted analyses (adjusted difference - 0.2 min/night, 95% - 27.0 to + 26.5). CONCLUSIONS: Mail-based systems of CPAP initiation may be able to improve access without reducing CPAP usage. Future work should consider the impact of mailed CPAP on patient-reported outcomes and the impact of different remote setup strategies.


Subject(s)
COVID-19 , Continuous Positive Airway Pressure , Humans , Pandemics , Postal Service , COVID-19/therapy , Cognition
3.
Psychol Med ; 52(13): 2692-2701, 2022 10.
Article in English | MEDLINE | ID: mdl-33622437

ABSTRACT

BACKGROUND: Antisaccade tasks can be used to index cognitive control processes, e.g. attention, behavioral inhibition, working memory, and goal maintenance in people with brain disorders. Though diagnoses of schizophrenia (SZ), schizoaffective (SAD), and bipolar I with psychosis (BDP) are typically considered to be distinct entities, previous work shows patterns of cognitive deficits differing in degree, rather than in kind, across these syndromes. METHODS: Large samples of individuals with psychotic disorders were recruited through the Bipolar-Schizophrenia Network on Intermediate Phenotypes 2 (B-SNIP2) study. Anti- and pro-saccade task performances were evaluated in 189 people with SZ, 185 people with SAD, 96 people with BDP, and 279 healthy comparison participants. Logistic functions were fitted to each group's antisaccade speed-performance tradeoff patterns. RESULTS: Psychosis groups had higher antisaccade error rates than the healthy group, with SZ and SAD participants committing 2 times as many errors, and BDP participants committing 1.5 times as many errors. Latencies on correctly performed antisaccade trials in SZ and SAD were longer than in healthy participants, although error trial latencies were preserved. Parameters of speed-performance tradeoff functions indicated that compared to the healthy group, SZ and SAD groups had optimal performance characterized by more errors, as well as less benefit from prolonged response latencies. Prosaccade metrics did not differ between groups. CONCLUSIONS: With basic prosaccade mechanisms intact, the higher speed-performance tradeoff cost for antisaccade performance in psychosis cases indicates a deficit that is specific to the higher-order cognitive aspects of saccade generation.


Subject(s)
Bipolar Disorder , Psychotic Disorders , Schizophrenia , Humans , Schizophrenia/diagnosis , Bipolar Disorder/psychology , Psychotic Disorders/psychology , Reaction Time/physiology , Phenotype
4.
JAMA ; 328(22): 2230-2241, 2022 12 13.
Article in English | MEDLINE | ID: mdl-36511927

ABSTRACT

Importance: The effectiveness of remotely delivered, self-directed, weight loss programs in routine clinical practice is largely unknown. Objective: To test whether a self-directed, remotely administered behavioral lifestyle intervention improves weight and self-reported general health status compared with usual care. Design, Setting, and Participants: In this randomized clinical trial, 511 adults with a body mass index (BMI) of 30 or more and less than 45 (based on electronic health record [EHR] weight and height), were enrolled from 30 Veterans Health Administration (VHA) sites between February 15, 2018, and December 18, 2018 (final follow-up February 18, 2021). Interventions: Participants were randomly assigned to the intervention group (n = 254) or the control group (n = 257). Both received usual care. Participants randomized to the intervention received Diabetes Prevention Program-based self-directed videos, handouts, and coaching messages via an online platform or US mail for 12 months. Main Outcomes and Measures: Coprimary outcomes were weight measured in primary care and recorded in the EHR and self-reported general health status using the Medical Outcomes Study 12-Item Short Form Health Survey (SF-12) physical component score (PCS; higher scores are better [range, 0-100]) at the 12-month follow-up. The between-group minimal clinically important differences are 3 kg for weight and 5 points for the SF-12 PCS. Linear mixed models used weights and SF-12 PCS measured at either time point, with participants analyzed according to randomization assignment. Statistical significance for each coprimary outcome was based on a 2-sided α level of .025. Results: Among 511 participants randomized (mean age, 57.4 [SD, 13.9] years; 231 female [45%]), 429 (84.0%) had EHR-based weights and 410 (80.2%) had SF-12 PCS data at 12 months. The unadjusted mean weight at 12 months declined from 102.7 kg to 99.8 kg in the intervention group compared with 101.9 kg to 101.0 kg in the control group (adjusted between-group mean difference, -1.93 [97.5% CI, -3.24 to -0.61]; P = .001). At 12 months, the unadjusted mean SF-12 PCS scores declined from 44.8 to 44.3 among intervention participants compared with 44.5 to 43.2 among control participants (adjusted between-group mean difference, intervention minus control, 0.69 [97.5% CI, -1.11 to 2.49]; P = .39). Cardiovascular events represented the highest percentage of serious adverse events, accounting for 25% of events in the intervention group and 35% in the control group. Conclusions and Relevance: Among adults with obesity, a remotely delivered self-directed, behavioral lifestyle intervention, compared with usual care, resulted in statistically significantly greater weight loss at 12 months, although the difference was not clinically important. There was no significant difference in self-reported general physical health status at 12 months. Trial Registration: ClinicalTrials.gov Identifier: NCT03260140.


Subject(s)
Behavior Therapy , Obesity , Weight Reduction Programs , Adult , Female , Humans , Middle Aged , Behavior Therapy/methods , Health Status , Obesity/diagnosis , Obesity/therapy , Weight Loss , Weight Reduction Programs/methods , Body Weight , Telemedicine/methods , Self Care , Healthy Lifestyle , Male , Aged
5.
Bipolar Disord ; 23(8): 801-809, 2021 12.
Article in English | MEDLINE | ID: mdl-33550654

ABSTRACT

OBJECTIVES: Affective and psychotic features overlap considerably in bipolar I disorder, complicating efforts to determine its etiology and develop targeted treatments. In order to clarify whether mechanisms are similar or divergent for bipolar disorder with psychosis (BDP) and bipolar disorder with no psychosis (BDNP), neurobiological profiles for both the groups must first be established. This study examines white matter structure in the BDP and BDNP groups, in an effort to identify portions of white matter that may differ between the bipolar and healthy groups or between the bipolar subgroups themselves. METHODS: Diffusion-weighted imaging data were acquired from participants with BDP (n = 45), BDNP (n = 40), and healthy comparisons (HC) (n = 66). Fractional anisotropy (FA), radial diffusivity (RD), and spin distribution function (SDF) values indexing white matter diffusivity or spin density were calculated and compared between the groups. RESULTS: In comparisons between both the bipolar groups and HC, FA (FDR < 0.00001) and RD (FDR = 0.0037) differed minimally, in localized portions of the left cingulum and corpus callosum, while reductions in SDF (FDR = 0.0002) were more widespread. The bipolar subgroups did not differ from each other on FA, RD, or SDF metrics. CONCLUSIONS: Together, these results demonstrate a novel profile of white matter differences in bipolar disorder and suggest that this white matter pathology is associated with the affective disturbance common to those with bipolar disorder rather than the psychotic features unique to some. The white matter alterations identified in this study may provide substrates for future studies examining specific mechanisms that target affective domains of illness.


Subject(s)
Bipolar Disorder , Psychotic Disorders , White Matter , Anisotropy , Bipolar Disorder/complications , Bipolar Disorder/diagnostic imaging , Bipolar Disorder/pathology , Diffusion Magnetic Resonance Imaging/methods , Humans , Psychotic Disorders/complications , Psychotic Disorders/diagnostic imaging , Psychotic Disorders/pathology , White Matter/diagnostic imaging , White Matter/pathology
6.
Bipolar Disord ; 22(6): 602-611, 2020 09.
Article in English | MEDLINE | ID: mdl-31721386

ABSTRACT

OBJECTIVES: Smooth pursuit eye movement deficits are an established psychosis biomarker across schizophrenia, schizoaffective and psychotic bipolar disorder (BPwP). Whether smooth pursuit deficits are also seen in bipolar disorder without psychosis (BPwoP) is unclear. Here we present data from the Psychosis and Affective Research Domains and Intermediate Phenotypes (PARDIP) study comparing bipolar patients with and without psychotic features. METHODS: Probands with BPwP (N = 49) and BPwoP (N = 36), and healthy controls (HC, N = 71) performed eye tracking tasks designed to evaluate specific sensorimotor components relevant for pursuit initiation and pursuit maintenance. RESULTS: While BPwoP did not differ from either BPwP or HC on initial eye acceleration, they performed significantly better than BPwP on early (P < .01) and predictive (P = .02) pursuit maintenance measures, both without differing from HC. BPwP were impaired compared to HC on initial eye acceleration, and on early and predictive pursuit maintenance (all P < .01). In contrast to the three pursuit measures, BPwP and BPwoP were both impaired on general neurocognitive assessments in relation to HC (both P < .001), without a significant difference between the two bipolar patient groups. CONCLUSIONS: Our findings support the model that impairments of sensorimotor and cognitive processing as required for early and later predictive smooth pursuit maintenance are relatively specific to those bipolar patients with a history of psychosis. This suggests that the neural circuitry for developing feed-forward predictive models for accurate pursuit maintenance is associated with the occurrence of psychotic features in bipolar patients. In contrast, generalized neuropsychological impairments did not differentiate the two bipolar patient groups.


Subject(s)
Bipolar Disorder/physiopathology , Bipolar Disorder/psychology , Psychotic Disorders/physiopathology , Pursuit, Smooth/physiology , Adult , Biomarkers , Bipolar Disorder/diagnosis , Female , Humans , Male , Middle Aged , Phenotype , Schizophrenia
7.
Hum Brain Mapp ; 40(1): 65-79, 2019 01.
Article in English | MEDLINE | ID: mdl-30184306

ABSTRACT

Combining statistical parametric maps (SPM) from individual subjects is the goal in some types of group-level analyses of functional magnetic resonance imaging data. Brain maps are usually combined using a simple average across subjects, making them susceptible to subjects with outlying values. Furthermore, t tests are prone to false positives and false negatives when outlying values are observed. We propose a regularized unsupervised aggregation method for SPMs to find an optimal weight for aggregation, which aids in detecting and mitigating the effect of outlying subjects. We also present a bootstrap-based weighted t test using the optimal weights to construct an activation map robust to outlying subjects. We validate the performance of the proposed aggregation method and test using simulated and real data examples. Results show that the regularized aggregation approach can effectively detect outlying subjects, lower their weights, and produce robust SPMs.


Subject(s)
Brain Mapping/methods , Brain/diagnostic imaging , Brain/physiology , Data Interpretation, Statistical , Image Processing, Computer-Assisted/methods , Unsupervised Machine Learning , Brain Mapping/standards , Humans , Image Processing, Computer-Assisted/standards , Magnetic Resonance Imaging
8.
Hum Brain Mapp ; 40(1): 163-174, 2019 01.
Article in English | MEDLINE | ID: mdl-30260540

ABSTRACT

Despite a growing number of reports about alterations in intrinsic/resting brain activity observed in patients with psychotic disorders, their relevance to well-established cognitive control deficits in this patient group is not well understood. Totally 88 clinically stabilized patients with a psychotic disorder and 50 healthy controls participated in a resting-state magnetic resonance imaging study (rs-MRI) and performed an antisaccade task in the laboratory to assess voluntary inhibitory control ability. Deficits on this task are a well-established biomarker across psychotic disorders as we found in the present patient sample. First, regional cerebral function was evaluated by measuring the amplitude of low frequency fluctuations (ALFF) in rs-MRI BOLD signals. We found reduced ALFF in patients in regions known to be relevant to antisaccade task performance including bilateral frontal eye fields (FEF), supplementary eye fields (SEF) and thalamus. Second, areas with ALFF alterations were used as seed areas in whole-brain functional connectivity (FC) analysis. Altered FC was observed in a fronto-thalamo-parietal network that was associated with inhibition error rate in patients but not in controls. In contrast, faster time to generate a correct antisaccade was associated with FC in FEF and SEF in controls but this effect was not seen in patients. These findings establish a behavioral relevance of resting-state fMRI findings in psychotic disorders, and extend previous reports of alterations in fronto-thalamo-parietal network activation during antisaccade performance seen in task-based fMRI studies.


Subject(s)
Connectome , Executive Function/physiology , Frontal Lobe/physiopathology , Inhibition, Psychological , Nerve Net/physiopathology , Parietal Lobe/physiopathology , Psychotic Disorders/physiopathology , Schizophrenia/physiopathology , Thalamus/physiopathology , Adult , Female , Frontal Lobe/diagnostic imaging , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Nerve Net/diagnostic imaging , Parietal Lobe/diagnostic imaging , Psychotic Disorders/diagnostic imaging , Saccades/physiology , Schizophrenia/diagnostic imaging , Thalamus/diagnostic imaging
9.
Neuroimage ; 183: 635-649, 2018 12.
Article in English | MEDLINE | ID: mdl-30048750

ABSTRACT

A common assumption in the study of brain functional connectivity is that the brain network is stationary. However it is increasingly recognized that the brain organization is prone to variations across the scanning session, fueling the need for dynamic connectivity approaches. One of the main challenges in developing such approaches is that the frequency and change points for the brain organization are unknown, with these changes potentially occurring frequently during the scanning session. In order to provide greater power to detect rapid connectivity changes, we propose a fully automated two-stage approach which pools information across multiple subjects to estimate change points in functional connectivity, and subsequently estimates the brain networks within each state phase lying between consecutive change points. The number and positioning of the change points are unknown and learned from the data in the first stage, by modeling a time-dependent connectivity metric under a fused lasso approach. In the second stage, the brain functional network for each state phase is inferred via sparse inverse covariance matrices. We compare the performance of the method with existing dynamic connectivity approaches via extensive simulation studies, and apply the proposed approach to a saccade block task fMRI data.


Subject(s)
Brain Mapping/methods , Brain/physiology , Magnetic Resonance Imaging/methods , Models, Neurological , Nerve Net/physiology , Humans , Image Processing, Computer-Assisted/methods
10.
J Cogn Neurosci ; 29(2): 368-381, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27676615

ABSTRACT

Cognitive control is engaged to facilitate stimulus-response mappings for novel, complex tasks and supervise performance in unfamiliar, challenging contexts-processes supported by pFC, ACC, and posterior parietal cortex. With repeated task practice, however, the appropriate task set can be selected in a more automatic fashion with less need for top-down cognitive control and weaker activation in these brain regions. One model system for investigating cognitive control is the ocular motor circuitry underlying saccade production, with basic prosaccade trials (look toward a stimulus) and complex antisaccade trials (look to the mirror image location) representing low and high levels of cognitive control, respectively. Previous studies have shown behavioral improvements on saccade tasks after practice with contradictory results regarding the direction of functional MRI BOLD signal change. The current study presented healthy young adults with prosaccade and antisaccade trials in five mixed blocks with varying probability of each trial type (0%, 25%, 50%, 75%, or 100% anti vs. pro) at baseline and posttest MRI sessions. Between the scans, participants practiced either the specific probability blocks used during testing or only a general 100% antisaccade block. Results indicated an overall reduction in BOLD activation within pFC, ACC, and posterior parietal cortex and across saccade circuitry for antisaccade trials. The specific practice group showed additional regions including ACC, insula, and thalamus with an activation decrease after practice, whereas the general practice group showed a little change from baseline in those clusters. These findings demonstrate that cognitive control regions recruited to support novel task behaviors were engaged less after practice, especially with exposure to mixed task contexts rather than a novel task in isolation.


Subject(s)
Brain/physiology , Cognition/physiology , Executive Function/physiology , Practice, Psychological , Probability Learning , Saccades/physiology , Brain/diagnostic imaging , Brain Mapping , Cerebrovascular Circulation , Eye Movement Measurements , Female , Humans , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Oxygen/blood , Reaction Time , Recognition, Psychology/physiology , Young Adult
11.
Brain Cogn ; 115: 12-20, 2017 07.
Article in English | MEDLINE | ID: mdl-28371646

ABSTRACT

The context or trial history of a task influences response efficiency in mixed paradigms based on cognitive control demands for task set selection. In the current study, the impact of context on prosaccade and antisaccade trials in single and mixed tasks was investigated with BOLD fMRI. Prosaccades require a look towards a newly appearing target, while antisaccades require cognitive control for prepotent response inhibition and generation of a saccade to the opposite location. Results indicated slower prosaccade reaction times and more antisaccade errors for switched than repeated or single trials, and slower antisaccade reaction times for single than mixed trials. BOLD activation was greater for the mixed than the single context in frontal eye fields and precuneus, while switch trials had greater activation than repeat trials in posterior parietal and middle occipital cortex. Greater antisaccade activation was observed overall in saccade circuitry, although effects were evident primarily for the mixed task when considered separately. Finally, an interaction was observed in superior frontal cortex, precuneus, anterior cingulate, and thalamus with strong responses for antisaccade switch trials in the latter two regions. Altogether this response pattern demonstrated the sensitivity of cognitive control to changing task conditions, especially due to task switching costs. Such context-specific differences highlight the importance of trial history when assessing cognitive control.


Subject(s)
Brain/physiology , Cognition/physiology , Saccades/physiology , Adolescent , Brain/diagnostic imaging , Female , Humans , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Reaction Time/physiology , Young Adult
12.
J Neurophysiol ; 115(2): 763-72, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-26609113

ABSTRACT

Cognitive control supports flexible behavior adapted to meet current goals and can be modeled through investigation of saccade tasks with varying cognitive demands. Basic prosaccades (rapid glances toward a newly appearing stimulus) are supported by neural circuitry, including occipital and posterior parietal cortex, frontal and supplementary eye fields, and basal ganglia. These trials can be contrasted with complex antisaccades (glances toward the mirror image location of a stimulus), which are characterized by greater functional magnetic resonance imaging (MRI) blood oxygenation level-dependent (BOLD) signal in the aforementioned regions and recruitment of additional regions such as dorsolateral prefrontal cortex. The current study manipulated the cognitive demands of these saccade tasks by presenting three rapid event-related runs of mixed saccades with a varying probability of antisaccade vs. prosaccade trials (25, 50, or 75%). Behavioral results showed an effect of trial-type probability on reaction time, with slower responses in runs with a high antisaccade probability. Imaging results exhibited an effect of probability in bilateral pre- and postcentral gyrus, bilateral superior temporal gyrus, and medial frontal gyrus. Additionally, the interaction between saccade trial type and probability revealed a strong probability effect for prosaccade trials, showing a linear increase in activation parallel to antisaccade probability in bilateral temporal/occipital, posterior parietal, medial frontal, and lateral prefrontal cortex. In contrast, antisaccade trials showed elevated activation across all runs. Overall, this study demonstrated that improbable performance of a typically simple prosaccade task led to augmented BOLD signal to support changing cognitive control demands, resulting in activation levels similar to the more complex antisaccade task.


Subject(s)
Brain Mapping , Cognition , Saccades , Adolescent , Cerebral Cortex/physiology , Humans , Probability , Reaction Time , Young Adult
13.
Stat Med ; 35(15): 2635-51, 2016 07 10.
Article in English | MEDLINE | ID: mdl-26875570

ABSTRACT

We propose an innovative and practically relevant clustering method to find common task-related brain regions among different subjects who respond to the same set of stimuli. Using functional magnetic resonance imaging (fMRI) time series data, we first cluster the voxels within each subject on a voxel by voxel basis. To extract signals out of noisy data, we estimate a new periodogram at each voxel using multi-tapering and low-rank spline smoothing and then use the periodogram as the main feature for clustering. We apply a divisive hierarchical clustering algorithm to the estimated periodograms within a single subject and identify the task-related region as the cluster of voxels that have periodograms with a peak frequency matching that of the stimulus sequence. Finally, we apply a machine learning technique called clustering ensemble to find common task-related regions across different subjects. The efficacy of the proposed approach is illustrated via a simulation study and a real fMRI data set. Copyright © 2016 John Wiley & Sons, Ltd.


Subject(s)
Brain Mapping , Cluster Analysis , Magnetic Resonance Imaging , Algorithms , Brain , Humans
14.
Exp Brain Res ; 233(3): 959-69, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25537465

ABSTRACT

Eye movement circuitry involved in saccade production offers a model for studying cognitive control: visually guided prosaccades are stimulus-directed responses, while goal-driven antisaccades rely upon more complex control processes to inhibit the prepotent tendency to look toward a cue, transform its spatial location, and generate a volitional saccade in the opposite direction. By manipulating the relative probability of these saccade types, we measured participants' behavioral responses to different levels of implicit trial-type probability and task-switching demands in conditions with relatively long inter-trial fixation and trial-type cue lengths. Results indicated that when prosaccades were less probable in a run, more prosaccade errors were generated; however, for antisaccades, trial-type probability had no effect on the percent of correct responses. For reaction times, specifically in runs with a larger probability of antisaccade trials, latencies increased for both anti- and pro-saccades. Furthermore, task switching resulted in a lower percentage of correct responses on switched trials, but a prior antisaccade trial led to slower reaction times for both trial types (i.e., a task switch cost for prosaccades and switch benefit for antisaccades). These findings indicate that cognitive control demands and residual inhibition from antisaccades alter performance relative to trial-type probability and task switching within a run, with the prosaccade task showing greater susceptibility to the influence of a large probability of cognitively complex antisaccades.


Subject(s)
Executive Function/physiology , Inhibition, Psychological , Reaction Time/physiology , Saccades/physiology , Adolescent , Female , Humans , Male , Photic Stimulation , Probability , Young Adult
15.
Neuroimage ; 84: 97-112, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-23981437

ABSTRACT

The analysis of functional neuroimaging data often involves the simultaneous testing for activation at thousands of voxels, leading to a massive multiple testing problem. This is true whether the data analyzed are time courses observed at each voxel or a collection of summary statistics such as statistical parametric maps (SPMs). It is known that classical multiplicity corrections become strongly conservative in the presence of a massive number of tests. Some more popular approaches for thresholding imaging data, such as the Benjamini-Hochberg step-up procedure for false discovery rate control, tend to lose precision or power when the assumption of independence of the data does not hold. Bayesian approaches to large scale simultaneous inference also often rely on the assumption of independence. We introduce a spatial dependence structure into a Bayesian testing model for the analysis of SPMs. By using SPMs rather than the voxel time courses, much of the computational burden of Bayesian analysis is mitigated. Increased power is demonstrated by using the dependence model to draw inference on a real dataset collected in a fMRI study of cognitive control. The model also is shown to lead to improved identification of neural activation patterns known to be associated with eye movement tasks.


Subject(s)
Brain Mapping/methods , Evoked Potentials, Motor/physiology , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Pattern Recognition, Automated/methods , Saccades/physiology , Volition/physiology , Adult , Algorithms , Artificial Intelligence , Bayes Theorem , Computer Simulation , Data Interpretation, Statistical , Female , Humans , Image Enhancement/methods , Male , Models, Neurological , Models, Statistical , Reproducibility of Results , Sensitivity and Specificity
16.
Dev Neurosci ; 36(1): 1-9, 2014.
Article in English | MEDLINE | ID: mdl-24457421

ABSTRACT

Aerobic fitness is associated with white matter integrity (WMI) in adults as measured by diffusion tensor imaging (DTI). This study examined the effect of an 8-month exercise intervention on WMI in children. Participants were 18 sedentary, overweight (BMI≥85th percentile) 8- to 11-year-old children (94% Black), randomly assigned to either an aerobic exercise (n=10) or sedentary attention control group (n=8). Each group was offered an instructor-led after-school program every school day for approximately 8 months. Before and after the program, all subjects participated in DTI scans. Tractography was conducted to isolate the superior longitudinal fasciculus and investigate whether the exercise intervention affected WMI in this region. There was no group by time interaction for WMI in the superior longitudinal fasciculus. There was a group by time by attendance interaction, however, such that higher attendance at the exercise intervention, but not the control intervention, was associated with increased WMI. Heart rate and the total dose of exercise correlated with WMI changes in the exercise group. In the overall sample, increased WMI was associated with improved scores on a measure of attention and improved teacher ratings of executive function. This study indicates that participating in an exercise intervention improves WMI in children as compared to a sedentary after-school program.


Subject(s)
Exercise , Frontal Lobe/pathology , Nerve Fibers, Myelinated/pathology , Overweight/therapy , Parietal Lobe/pathology , Child , Cognition/physiology , Female , Humans , Male , Neuropsychological Tests , Overweight/pathology , Overweight/psychology , Physical Fitness , Treatment Outcome
17.
medRxiv ; 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38883764

ABSTRACT

Background: Past studies associating personality with psychosis have been limited by small nonclinical samples and a focus on general symptom burden. This study uses a large clinical sample to examine personality's relationship with psychosis-specific features and compare personality dimensions across clinically and neurobiologically defined categories of psychoses. Methods: A total of 1352 participants with schizophrenia, schizoaffective disorder, and bipolar with psychosis, as well as 623 healthy controls (HC), drawn from the Bipolar-Schizophrenia Network for Intermediate Phenotypes (BSNIP-2) study, were included. Three biomarker-derived biotypes were used to separately categorize the probands. Mean personality factors (openness, conscientiousness, extraversion, agreeableness, and neuroticism) were compared between HC and proband subgroups using independent sample t-tests. A robust linear regression was utilized to determine personality differences across biotypes and diagnostic subgroups. Associations between personality factors and cognition were determined through Pearson's correlation. A canonical correlation was run between the personality factors and general functioning, positive symptoms, and negative symptoms to delineate the relationship between personality and clinical outcomes of psychosis. Results: There were significant personality differences between the proband and HC groups across all five personality factors. Overall, the probands had higher neuroticism and lower extraversion, agreeableness, conscientiousness, and openness. Openness showed the greatest difference across the diagnostic subgroups and biotypes, and greatest correlation with cognition. Openness, agreeableness, and extraversion had the strongest associations with symptom severity. Conclusions: Individuals with psychosis have different personality profiles compared to HC. In particular, openness may be relevant in distinguishing psychosis-specific phenotypes and experiences, and associated with biological underpinnings of psychosis, including cognition. Further studies should identify potential causal factors and mediators of this relationship.

18.
Res Sq ; 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-38260530

ABSTRACT

Idiopathic psychosis shows considerable biological heterogeneity across cases. B-SNIP used psychosis-relevant biomarkers to identity psychosis Biotypes, which will aid etiological and targeted treatment investigations. Psychosis probands from the B-SNIP consortium (n = 1907), their first-degree biological relatives (n = 705), and healthy participants (n = 895) completed a biomarker battery composed of cognition, saccades, and auditory EEG measurements. ERP quantifications were substantially modified from previous iterations of this approach. Multivariate integration reduced multiple biomarker outcomes to 11 "bio-factors". Twenty-four different approaches indicated bio-factor data among probands were best distributed as three subgroups. Numerical taxonomy with k-means constructed psychosis Biotypes, and rand indices evaluated consistency of Biotype assignments. Psychosis subgroups, their non-psychotic first-degree relatives, and healthy individuals were compared across bio-factors. The three psychosis Biotypes differed significantly on all 11 bio-factors, especially prominent for general cognition, antisaccades, ERP magnitude, and intrinsic neural activity. Rand indices showed excellent consistency of clustering membership when samples included at least 1100 subjects. Canonical discriminant analysis described composite bio-factors that simplified group comparisons and captured neural dysregulation, neural vigor, and stimulus salience variates. Neural dysregulation captured Biotype-2, low neural vigor captured Biotype-1, and deviations of stimulus salience captured Biotype-3. First-degree relatives showed similar patterns as their Biotyped proband relatives on general cognition, antisaccades, ERP magnitudes, and intrinsic brain activity. Results extend previous efforts by the B-SNIP consortium to characterize biologically distinct psychosis Biotypes. They also show that at least 1100 observations are necessary to achieve consistent outcomes. First-degree relative data implicate specific bio-factor deviations to the subtype of their proband and may inform studies of genetic risk.

19.
Sci Rep ; 14(1): 13859, 2024 06 15.
Article in English | MEDLINE | ID: mdl-38879556

ABSTRACT

Smooth pursuit eye movements are considered a well-established and quantifiable biomarker of sensorimotor function in psychosis research. Identifying psychotic syndromes on an individual level based on neurobiological markers is limited by heterogeneity and requires comprehensive external validation to avoid overestimation of prediction models. Here, we studied quantifiable sensorimotor measures derived from smooth pursuit eye movements in a large sample of psychosis probands (N = 674) and healthy controls (N = 305) using multivariate pattern analysis. Balanced accuracies of 64% for the prediction of psychosis status are in line with recent results from other large heterogenous psychiatric samples. They are confirmed by external validation in independent large samples including probands with (1) psychosis (N = 727) versus healthy controls (N = 292), (2) psychotic (N = 49) and non-psychotic bipolar disorder (N = 36), and (3) non-psychotic affective disorders (N = 119) and psychosis (N = 51) yielding accuracies of 65%, 66% and 58%, respectively, albeit slightly different psychosis syndromes. Our findings make a significant contribution to the identification of biologically defined profiles of heterogeneous psychosis syndromes on an individual level underlining the impact of sensorimotor dysfunction in psychosis.


Subject(s)
Biomarkers , Psychotic Disorders , Pursuit, Smooth , Humans , Male , Female , Pursuit, Smooth/physiology , Psychotic Disorders/diagnosis , Psychotic Disorders/physiopathology , Adult , Young Adult , Bipolar Disorder/diagnosis , Bipolar Disorder/physiopathology , Middle Aged , Case-Control Studies , Adolescent
20.
J Neurosci ; 32(20): 7034-41, 2012 May 16.
Article in English | MEDLINE | ID: mdl-22593071

ABSTRACT

Cognitive control is required for correct performance on antisaccade tasks, including the ability to inhibit an externally driven ocular motor response (a saccade to a peripheral stimulus) in favor of an internally driven ocular motor goal (a saccade directed away from a peripheral stimulus). Healthy humans occasionally produce errors during antisaccade tasks, but the mechanisms associated with such failures of cognitive control are uncertain. Most research on cognitive control failures focuses on poststimulus processing, although a growing body of literature highlights a role of intrinsic brain activity in perceptual and cognitive performance. The current investigation used dense array electroencephalography and distributed source analyses to examine brain oscillations across a wide frequency bandwidth in the period before antisaccade cue onset. Results highlight four important aspects of ongoing and preparatory brain activations that differentiate error from correct antisaccade trials: (1) ongoing oscillatory beta (20-30 Hz) power in anterior cingulate before trial initiation (lower for error trials); (2) instantaneous phase of ongoing alpha/theta (7 Hz) in frontal and occipital cortices immediately before trial initiation (opposite between trial types); (3) gamma power (35-60 Hz) in posterior parietal cortex 100 ms before cue onset (greater for error trials); and (4) phase locking of alpha (5-12 Hz) in parietal and occipital cortices immediately before cue onset (lower for error trials). These findings extend recently reported effects of pre-trial alpha phase on perception to cognitive control processes and help identify the cortical generators of such phase effects.


Subject(s)
Alpha Rhythm/physiology , Brain Mapping/psychology , Brain Waves/physiology , Cerebral Cortex/physiology , Cognition/physiology , Adult , Brain Mapping/methods , Female , Humans , Photic Stimulation/methods , Psychomotor Performance/physiology , Saccades/physiology
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