Using mixture modeling to examine differences in perceptual decision-making as a function of the time and method of participant recruitment.

We examine whether perceptual decision-making differs as a function of the time in the academic term and whether the participant is an undergraduate participating for course credit, a paid in-person participant, or a paid online participant recruited via Amazon Mechanical Turk. We use a mixture modeling approach within an evidence accumulation framework that separates stimulus-driven responses from contaminant responses, allowing us to distinguish between performance when a participant is engaged in the task and the consistency in this task focus. We first report a survey showing cognitive psychologists expect performance and response caution to be lower among undergraduate participants recruited at the end of the academic term compared to those recruited near the start, and highest among paid in-person participants. The findings from two experiments using common paradigms revealed very little evidence of time-of-semester effects among course credit participants on accuracy, response time, efficiency of information processing (when engaged in the task), caution, and non-decision time, or consistency in task focus. However, paid in-person participants did tend to be more accurate than the other two groups. Groups showed similar effects of speed/accuracy emphasis on response caution and of discrimination difficulty on information processing efficiency, but the effect of speed/accuracy emphasis on information processing efficiency was less consistent among groups. We conclude that online crowdsourcing platforms can provide quality perceptual decision-making data, but recommend that mixture modeling be used to adequately account for data generated by processes other than the psychological phenomena under investigation.

Development and psychometric evaluation of the mental readiness for military transition scale (MT-Ready).

BACKGROUND: The transition to civilian life following separation from military service is associated with increased risk of mental health disorders, suicide, and poor adjustment. No measure currently enables pre-separation screening to assess mental readiness for transition and identify personnel most at risk of poor outcomes. The Mental Readiness for Military Transition Scale (MT-Ready) was developed to identify psychosocial factors predictive of post-separation psychological adjustment and mental health. METHODS: Phase I was a qualitative study including transitioned veterans (n = 60), partners of transitioned veterans (n = 20) and mental health clinicians (n = 20) which enabled development of candidate items that were subsequently piloted with a current serving Australian Defence Force (ADF) sample (n = 19). Phase II included evaluation of the factor structure, psychometric properties, and scale refinement of the initial pool of 50 items with a convenience sample of transitioning ADF personnel (n = 345). Analyses included exploratory factor analysis, evaluation of test-retest reliability, internal consistency, convergent, divergent, discriminant and predictive validity. Receiver Operating Characteristic Curve Analysis was also conducted to determine an optimal cut-off score. RESULTS: Exploratory factor analysis resulted in a 15-item, three-factor solution that explained 62.2% of the variance: Future focus and optimism; Anger and perceived failure; Civilian connections and social support. Reliability and convergent, divergent, and discriminant validity was established. Receiver Operating Characteristic Curve Analysis determined a cut-off score of 55. MT-Ready scores significantly differentiated those reporting adjusting versus not adjusting to civilian life 3.7 months post-separation, and predicted post-separation outcomes including symptoms of Posttraumatic Stress Disorder, depression, anxiety, psychological adjustment and quality of life. CONCLUSIONS: This evaluation provides promising evidence the MT-Ready is a valid, reliable measure of mental readiness for transition, with predictive capability and considerable potential to assist prevention of poor post-separation outcomes among military personnel.

Posttraumatic sleep disturbances in veterans: A pilot randomized controlled trial of cognitive behavioral therapy for insomnia and imagery rehearsal therapy.

OBJECTIVES: Posttraumatic stress disorder (PTSD) is associated with sleep disturbances including insomnia and nightmares. This study compared cognitive behavioral therapy for insomnia (CBT-I) with CBT-I combined with imagery rehearsal therapy (IRT) for nightmares to evaluate if the combined treatment led to greater reductions in trauma-related sleep disturbances in Australian veterans. METHODS: Veterans with diagnosed PTSD, high insomnia symptom severity, and nightmares (N = 31) were randomized to eight group CBT-I sessions or eight group CBT-I + IRT sessions. Self-reported sleep, nightmare, and psychological measures (primary outcome: Pittsburgh Sleep Quality Index), and objective actigraphy data were collected; the effect of obstructive sleep apnea (OSA) risk on treatment outcomes was also examined. RESULTS: No treatment condition effects were detected for the combined treatment compared to CBT-I alone, and no moderating effect of OSA risk was detected. On average, participants from both groups improved on various self-report measures over time (baseline to 3 months posttreatment). Despite the improvements, mean scores for sleep-specific measures remained indicative of poor sleep quality. There were also no significant differences between the groups on the actigraphy indices. CONCLUSIONS: The findings indicate that there is potential to optimize both treatments for veterans with trauma-related sleep disturbances.

Compassionate mind training for ex-service personnel with PTSD and their partners.

Posttraumatic stress disorder (PTSD) is a significant issue for a substantial proportion of Australian ex-service personnel. In addition to the functional impact on individuals, PTSD can have a significant impact on intimate partner relationships. Research has demonstrated that practicing compassion and self-compassion may be an important component of psychological therapy for survivors of trauma, while also demonstrating benefits to intimate relationships. This pilot study aimed to investigate the utility of a Compassionate Mind Training intervention for ex-service personnel with PTSD and their partners. An uncontrolled, within-subjects, longitudinal design was utilized with assessment at pre-intervention, post-intervention and 3-month follow-up. Twenty-four participants attended 12 biweekly group sessions. Self-report measures of compassion, quality of life and psychological symptoms were administered at each time point. Findings demonstrated a significant reduction in fears of compassion and PTSD symptoms for ex-service personnel at 3-month follow-up and a reduction in depressive symptoms and increase in quality-of-life and social safeness at post-intervention. Additionally, significant reductions in anxiety, stress, external shame and self-criticism at 3-month follow-up were found, and couples reported significant increases in relationship satisfaction. Findings from this pilot study demonstrate promising outcomes, warranting further investigation in a larger randomized controlled trial of Compassionate Mind Training for ex-service personnel and their partners.

The relationship between chronic PTSD, cortical volumetry and white matter microstructure among Australian combat veterans.

BACKGROUND: Posttraumatic stress disorder (PTSD) has been associated with volumetric and white matter microstructural changes among general and veteran populations. However, regions implicated have greatly varied and often conflict between studies, potentially due to confounding comorbidities within samples. This study compared grey matter volume and white matter microstructure among Australian combat veterans with and without a lifetime diagnosis of PTSD, in a homogenous sample assessed for known confounding comorbidities. METHODS: Sixty-eight male trauma-exposed veterans (16 PTSD-diagnosed; mean age 69 years) completed a battery of psychometric assessments and underwent magnetic resonance and diffusion tensor imaging. Analyses included tract-based spatial statistics, voxel-wise analyses, diffusion connectome-based group-wise analysis, and volumetric analysis. RESULTS: Significantly smaller grey matter volumes were observed in the left prefrontal cortex (P = 0.026), bilateral middle frontal gyrus (P = 0.021), and left anterior insula (P = 0.048) in the PTSD group compared to controls. Significant negative correlations were found between PTSD symptom severity and fractional anisotropy values in the left corticospinal tract (R2 = 0.34, P = 0.024) and left inferior cerebellar peduncle (R2 = 0.62, P = 0.016). No connectome-based differences in white matter properties were observed. CONCLUSIONS: Findings from this study reinforce reports of white matter alterations, as indicated by reduced fractional anisotropy values, in relation to PTSD symptom severity, as well as patterns of reduced volume in the prefrontal cortex. These results contribute to the developing profile of neuroanatomical differences uniquely attributable to veterans who suffer from chronic PTSD.

Assessing psychological adjustment and cultural reintegration after military service: development and psychometric evaluation of the post-separation Military-Civilian Adjustment and Reintegration Measure (M-CARM).

BACKGROUND: The transition out of military service and subsequent reintegration to civilian life has been established as a period associated with an increased risk of psychological adjustment difficulties, psychiatric disorders and suicide risk, yet no tool exists to measure cultural and psychological adjustment following permanent separation from the military. This study describes the two-phase mixed-methods development and validation of the self-report Military-Civilian Adjustment and Reintegration Measure (M-CARM). METHODS: In Phase I, four focus groups (n = 20) and semi-structured one-on-one interviews (n = 80) enabled thematic analysis and generation of 53 initial items that were reviewed by an expert multidisciplinary panel (n = 12) and piloted for clarity and relevance in an Australian service-veteran sample (n = 11). In Phase II, psychometric properties of the 47 items resulting from Phase I were evaluated with online assessment of a convenience sample of transitioned Australian Defence Force veterans (n = 725). Analyses included exploratory and confirmatory factor analyses, as well as evaluation of test-retest reliability, internal consistency, and convergent, divergent and discriminant validity. RESULTS: Exploratory factor analysis on a randomized split-half sample (n = 357), resulted in a 21-item, five-factor solution of Purpose and Connection, Help seeking, Beliefs about civilians, Resentment and regret, and Regimentation, explaining 53.22% of the variance. Confirmatory factor analysis (n = 368) verified this factor structure without modification (χ2 = 304.96, df = 160; CFI = .96, TLI = .94, NFI = .91, RMSEA = .05). Strong convergent, divergent and discriminant validity was demonstrated as M-CARM scores significantly correlated with related constructs assessed by standardised clinical measures as well as differentiated groups based on three binary reintegration items, with large effect sizes (d = > 1). Strong test-retest reliability for the total score (n = 186, r = .93) and excellent internal consistency (n = 725, a = .90) were also found. CONCLUSIONS: Results provide promising evidence the M-CARM is a valid, reliable measure of psychological and cultural reintegration to civilian life, with potential for considerable clinical and research application.

Public Opinions on Strategies for Managing Stray Cats and Predictors of Opposition to Trap-Neuter and Return in Brisbane, Australia.

A survey of Brisbane residents was undertaken to investigate community attitudes toward urban stray cats and their management. Surveys were distributed to 84 medical and dental practices across Brisbane City, and were completed by 305 patients and staff. Practices were targeted to achieve a sample of respondents from a representative distribution of socioeconomic backgrounds. After being informed about trap, neuter, and return (TNR) programs for management of urban stray cats, most respondents (79%), chose TNR as their preferred management strategy, while a lesser proportion (18%) expressed a preference to continue the current Brisbane City Council lethal control program (catching and culling ~1,000 cats annually), and 3.4% selected to leave the cats alone. Differences in beliefs and attitudes toward urban stray cats as a function of demographic variables were investigated. Statistical analyses indicated that respondents who were male, older, non-cat owners, those who believed euthanasia of stray cats was humane, and that urban stray cats spread disease to humans were significantly more likely to express a preference for lethal control, as opposed to non-lethal population management. Based on these findings, we recommend that information is disseminated to mitigate these concerns or negative beliefs, where warranted. Ultimately, findings from this study demonstrate that current Queensland legislation does not reflect public views and opinions on stray cat management and should be reviewed. Formal research evaluating the efficacy of TNR programs for urban stray cats in Australia would be in the public interest.