Psychological distress and gender predict cognitive complaint after adult civilian mild traumatic brain injury in pre-morbidly healthy adults.

Subjective cognitive symptoms are common after mild traumatic brain injury (mTBI), and are associated with important outcome factors including return to work. This study examined self-reported cognitive symptoms in mTBI and trauma controls (TCs), and explored psychological distress and gender as predictors of these symptoms. Pre-morbidly healthy adults with mTBI (n = 68) and general trauma (n = 40) were prospectively recruited from inpatient hospital wards and assessed 6-10 weeks post-injury. Primary measures included self-reported cognitive symptoms, post-concussion symptoms, and psychological distress. Groups were matched on all background variables, including objective cognitive performance. Within this context, subjective cognitive symptoms were significantly elevated after mTBI relative to TCs (t = 3.396, p = .001). In contrast, there was no difference in post-concussion symptoms between groups (t = 1.275, p = .206). Psychological distress (ß = .536, p < .001) and gender (ß = .253, p = .012) predicted subjective cognitive symptoms in mTBI, with females and those with higher distress reporting greater symptoms. Unlike general post-concussion symptoms, subjective cognitive symptoms were elevated after mTBI relative to TCs, suggesting that mTBI-specific factors underly this elevation. Females and individuals with high psychological distress are important subgroups to consider for potential intervention following mTBI.

Isolating automatic photism generation from strategic photism use in grapheme-colour synaesthesia.

Grapheme-colour synaesthesia is a phenomenon in which ordinary black numbers and letters (graphemes) trigger the experience of highly specific colours (photisms). The Synaesthetic Stroop task has been used to demonstrate that graphemes trigger photisms automatically. In the standard Stroop task, congruent trial probability (CTP) has been manipulated to isolate effects of automaticity from higher-order strategic effects, with larger Stroop effects at high CTP attributed to participants strategically attending to the stimulus word to facilitate responding, and smaller Stroop effects at low CTP reflecting automatic word processing. Here we apply this logic for the first time to the Synaesthetic Stroop task. At high CTP we showed larger Stroop effects due to synaesthetes using their synaesthetic colours strategically. At low CTP Stroop effects were reduced but were still significant. We directly isolate automatic processing of graphemes from strategic effects and conclusively show that, in synaesthesia, viewing black graphemes automatically triggers colour experiences.

Cognitive Symptoms Are Not Associated with Cognitive Performance in Post-Acute mTBI.

OBJECTIVE: Subjective cognitive symptoms are commonly reported after mild traumatic brain injury (mTBI) but are often not associated with objective cognitive performance. This may be due to limitations in traditional cognitive performance measures, which may not be sensitive to subtle variations in cognition in post-acute mTBI. This study explored associations between objective and subjective cognition using computer-based tasks of increasing cognitive load, proposed to be more sensitive to subtle differences in performance. METHOD: Individuals with mTBI (n = 68) and trauma controls (n = 40) were prospectively recruited and assessed approximately 8 weeks post-injury. Participants completed measures of subjective symptom reporting, objective cognitive performance (including two computer-based tasks of increasing cognitive load), and psychological distress. RESULTS: There were no significant associations between subjective and objective cognition reporting in the mTBI group, both in bivariate correlations (|r| = 0.01-0.20, p > .05) and when controlling for psychological distress (|r| = 0.00-0.17, p > .05). A similar pattern of results was observed in trauma controls, suggesting that the limited relationships between objective and subjective cognition in mTBI may not be specific to this population. CONCLUSIONS: Despite employing measures of cognitive performance proposed to be more sensitive than traditional tasks, no significant relationships were observed between objective and subjective cognition in post-acute mTBI, and estimated effect sizes were small to negligible. This provides further evidence that at a group level 8 weeks after mTBI subjective cognitive symptoms primarily reflect factors aside from objective cognition.

Frequency and extent of cognitive complaint following adult civilian mild traumatic brain injury: a systematic review and meta-analysis.

OBJECTIVE: Cognitive symptoms are associated with return to work, healthcare use and quality of life after mild traumatic brain injury (mTBI). Additionally, while overall 'post-concussion' symptoms are often present at similar levels in mTBI and control groups, cognitive complaints may be specifically elevated in mTBI. A systematic review and meta-analysis was conducted to investigate the frequency and extent of cognitive complaints following adult civilian mTBI, and compare it to the frequency and extent of complaints in control populations (PROSPERO: CRD42020151284). METHOD: This review included studies published up to March 2022. Thirteen studies were included in the systematic review, and six were included in the meta-analysis. Data extraction and quality assessment were conducted by two independent reviewers. RESULTS: Cognitive complaints are common after mTBI, although reported rates differed greatly across studies. Results suggested that mTBI groups report cognitive complaints to a significantly greater extent than control groups (Hedges' g = 0.85, 95% CI 0.31-1.40, p = .0102). Heterogeneity between studies was high (τ2 = 0.20, 95% CI 0.04-1.58; I2 = 75.0%, 95% CI 43.4%-89.0%). Between-group differences in symptom reporting were most often found when healthy rather than injured controls were employed. CONCLUSIONS: Cognitive complaints are consistently reported after mTBI, and are present at greater levels in mTBI patients than in controls. Despite the importance of these complaints, including in regards to return to work, healthcare use and quality of life, there has been limited research in this area, and heterogeneity in research methodology is common.