Cognitive control in obsessive-compulsive disorder (OCD): Proactive control adjustments or consistent performance?

Cognitive control is often parsed into proactive and reactive control components. In proactive control, task- and goal-relevant information is utilized in a top-down manner to improve performance, while reactive control is a late-response corrective mechanism that occurs after conflict or errors. We tested whether people with obsessive-compulsive disorder (OCD) would show specific proactive control dysfunction in 31 individuals with OCD and 30 psychiatrically-healthy controls. We employed two tasks that differentiate proactive and reactive cognitive control processes: the cued-Stroop and the AX version of a continuous performance task (AX-CPT). There was a 1s or 5s delay between the cue and probe for both tasks to allow for implementation of proactive control processes. Participants also completed a neuropsychological test battery and mood and symptom severity self-report questionnaires. Although there were group-level differences in OCD severity and depression/anxiety symptoms, there were no significant differences in response times (RT) and error rates between groups for delay or condition for the cued-Stroop or for the AX-CPT, indicating similar performance in implementing proactive control strategies. There were also no significant differences between OCD and control participants on neuropsychological test performance. Results suggest a convergence of evidence wherein individuals with OCD are not showing disproportionately altered proactive control abilities.

Day-of-Injury Computed Tomography and Longitudinal Rehabilitation Outcomes: A Comparison of the Marshall and Rotterdam Computed Tomography Scoring Methods.

OBJECTIVE: The aim of the study was to compare the relative predictive value of Marshall Classification System and Rotterdam scores on long-term rehabilitation outcomes. This study hypothesized that Rotterdam would outperform Marshall Classification System. DESIGN: The study used an observational cohort design with a consecutive sample of 88 participants (25 females, mean age = 42.0 [SD = 21.3]) with moderate to severe traumatic brain injury who were admitted to trauma service with subsequent transfer to the rehabilitation unit between February 2009 and July 2011 and who had clearly readable computed tomography scans. Twenty-three participants did not return for the 9-mo postdischarge follow-up. Day-of-injury computed tomography images were scored using both Marshall Classification System and Rotterdam criteria by two independent raters, blind to outcomes. Functional outcomes were measured by length of stay in rehabilitation and the cognitive and motor subscales of the Functional Independence Measure at rehabilitation discharge and 9-mo postdischarge follow-up. RESULTS: Neither Marshall Classification System nor Rotterdam scales as a whole significantly predicted Functional Independence Measure motor or cognitive outcomes at discharge or 9-mo follow-up. Both scales, however, predicted length of stay in rehabilitation. Specific Marshall scores (3 and 6) and Rotterdam scores (5 and 6) significantly predicted subacute outcomes such as Functional Independence Measure cognitive at discharge from rehabilitation and length of stay. CONCLUSIONS: Marshall Classification System and Rotterdam scales may have limited utility in predicting long-term functional outcome, but specific Marshall and Rotterdam scores, primarily linked to increased severity and intracranial pressure, may predict subacute outcomes.

Volumetric analysis of day of injury computed tomography is associated with rehabilitation outcomes after traumatic brain injury.

BACKGROUND: Day-of-injury (DOI) brain lesion volumes in traumatic brain injury (TBI) patients are rarely used to predict long-term outcomes in the acute setting. The purpose of this study was to investigate the relationship between acute brain injury lesion volume and rehabilitation outcomes in patients with TBI at a level one trauma center. METHODS: Patients with TBI who were admitted to our rehabilitation unit after the acute care trauma service from February 2009-July 2011 were eligible for the study. Demographic data and outcome variables including cognitive and motor Functional Independence Measure (FIM) scores, length of stay (LOS) in the rehabilitation unit, and ability to return to home were obtained. The DOI quantitative injury lesion volumes and degree of midline shift were obtained from DOI brain computed tomography scans. A multiple stepwise regression model including 13 independent variables was created. This model was used to predict postrehabilitation outcomes, including FIM scores and ability to return to home. A p value less than 0.05 was considered significant. RESULTS: Ninety-six patients were enrolled in the study. Mean age was 43 ± 21 years, admission Glasgow Coma Score was 8.4 ± 4.8, Injury Severity Score was 24.7 ± 9.9, and head Abbreviated Injury Scale score was 3.73 ± 0.97. Acute hospital LOS was 12.3 ± 8.9 days, and rehabilitation LOS was 15.9 ± 9.3 days. Day-of-injury TBI lesion volumes were inversely associated with cognitive FIM scores at rehabilitation admission (p = 0.004) and discharge (p = 0.004) and inversely associated with ability to be discharged to home after rehabilitation (p = 0.006). CONCLUSION: In a cohort of patients with moderate to severe TBI requiring a rehabilitation unit stay after the acute care hospital stay, DOI brain injury lesion volumes are associated with worse cognitive FIM scores at the time of rehabilitation admission and discharge. Smaller-injury volumes were associated with eventual discharge to home. Volumetric neuroimaging in the acute injury phase may improve surgeons' ultimate outcome predictions in TBI patients. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level V.

Predictors of performance monitoring abilities following traumatic brain injury: the influence of negative affect and cognitive sequelae.

Performance monitoring is a cognitive control process modulated by both cognitive and affective variables. This study examined the relative contributions of negative affect (NA) and cognitive sequelae to performance monitoring dysfunction following severe traumatic brain injury (TBI). We used the error-related negativity (ERN) and post-error positivity (Pe) components of the event-related potential (ERP) to test the hypothesis that NA and cognitive sequelae would predict performance monitoring dysfunction beyond time since injury, and injury severity. Nineteen survivors of severe TBI completed neuropsychological tests, measures of NA, and a computerized Stroop task. Scores on NA and neuropsychological measures were standardized to form magnitude of cognitive sequelae and negative affect composite scores. Separate hierarchical regression analyses with ERN and Pe amplitudes as dependent variables and injury severity, time since injury, magnitude of cognitive sequelae, and NA as independent variables indicated that NA and cognitive sequelae significantly predicted ERN amplitude, with a larger relative contribution of NA than cognitive sequelae. Increased levels of NA were associated with decreased amplitude ERN. Cognitive sequelae, but not NA, predicted Pe amplitude. Injury severity and time since injury were not significant predictors. Results suggest that both NA and cognitive sequelae play critical roles in performance monitoring decrements following TBI and indicate a possible dissociation between the ERN and Pe, with the ERN more related to affective processes and the Pe to cognitive processes.

Temporal stability of the error-related negativity (ERN) and post-error positivity (Pe): the role of number of trials.

The error-related negativity (ERN) and post-error positivity (Pe) components of the event-related potential (ERP) are relatively stable over time. The current study further assessed the temporal reliability of ERN and Pe amplitudes for random samples of 2 to 14 trials per participant and the grand mean over a 2-week retest interval. In a replication of previous results, intraclass and zero-order correlations revealed moderate to good temporal stability for participants' (N=20) grand mean ERN and Pe component amplitudes. Adding trials increased test-retest reliabilities; however, the temporal stability of ERN and Pe amplitudes with 14 or fewer trials were modest at best and considerably lower than that for the grand means. Overall, data support the temporal stability of grand-mean ERN and Pe amplitudes and suggest that more than 14 trials are needed to include in ERN and Pe averages for adequate test-retest reliability.

The relationship between performance monitoring, satisfaction with life, and positive personality traits.

Neural reflections of performance monitoring, including the error-related negativity (ERN) component of the event-related potential (ERP), are modulated by personality and affective constructs. Little is known, however, about the relationship between positive personality traits and neural indices of performance monitoring. We investigated the relationship between measures of positive personality traits, including satisfaction with life, dispositional optimism, and positive affect, and indices of performance monitoring in a sample of 45 neurologically-healthy individuals. Increased satisfaction with life was associated with decreased (i.e., less negative) ERN amplitude. Dispositional optimism and positive affect were not related to ERN amplitude. Results remained consistent when negative affect and measures of positive personality were accounted for using multiple regression. There were no relationships between measures of positive personality and the post-error positivity (Pe) or behavioral indices. Findings are consistent with an affective salience interpretation of the ERN, with errors potentially being less meaningful for individuals with higher satisfaction with life.

Empathy and error processing.

Recent research suggests a relationship between empathy and error processing. Error processing is an evaluative control function that can be measured using post-error response time slowing and the error-related negativity (ERN) and post-error positivity (Pe) components of the event-related potential (ERP). Thirty healthy participants completed two measures of empathy, the Interpersonal Reactivity Index (IRI) and the Empathy Quotient (EQ), and a modified Stroop task. Post-error slowing was associated with increased empathic personal distress on the IRI. ERN amplitude was related to overall empathy score on the EQ and the fantasy subscale of the IRI. The Pe and measures of empathy were not related. Results remained consistent when negative affect was controlled via partial correlation, with an additional relationship between ERN amplitude and empathic concern on the IRI. Findings support a connection between empathy and error processing mechanisms.