Dissociating the impact of alexithymia and impaired self-awareness on emotional distress and aggression after traumatic brain injury.

OBJECTIVE: Alexithymia, a deficit in identifying and describing feelings, is prevalent in traumatic brain injury (TBI). Sometimes referred to as "emotional unawareness," we sought to investigate whether alexithymia after TBI was related to, or distinct from, impaired self-awareness (ISA) and whether the two predicted differentiable emotional and aggression profiles. Further, the mediating role of frontal system behaviors (disinhibition, dysexecutive function, apathy) was explored. METHOD: Participants with TBI (N = 40) from diverse backgrounds completed self-report measures of alexithymia, emotional distress, aggression, and frontal system behaviors. For the assessment of ISA, significant other ratings were obtained to identify discrepancies from self-ratings. Data were analyzed quantitatively using independent samples t tests, correlations, partial correlations, and simple mediation. RESULTS: There was a negative correlation between alexithymia and ISA. Alexithymia, but not ISA, was associated with higher expressions of emotional distress and aggression even after controlling for the effects of ISA via partial correlations. Exploratory analyses found that frontal system behaviors mediated the relationships between alexithymia and aggression and alexithymia and emotional distress. CONCLUSIONS: Alexithymia is more accurately conceptualized as an emotional processing deficit than an awareness deficit. Indeed, self-awareness may be a prerequisite for the ability to identify alexithymic tendencies. Negative psychological effects of alexithymia are compounded by poorer executive function and disinhibition and call for the development of TBI-specific alexithymia screening tools and interventions. Alexithymia interventions are best delivered in conjunction with rehabilitation of emotion regulation and executive function. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Impaired auditory selective attention ameliorated by cognitive training with graded exposure to noise in patients with traumatic brain injury.

Patients who suffer traumatic brain injury frequently report difficulty concentrating on tasks and completing routine activities in noisy and distracting environments. Such impairments can have long-term negative psychosocial consequences. A cognitive control function that may underlie this impairment is the capacity to select a goal-relevant signal for further processing while safeguarding it from irrelevant noise. A paradigmatic investigation of this problem was undertaken using a dichotic listening task (study 1) in which comprehension of a stream of speech to one ear was measured in the context of increasing interference from a second stream of irrelevant speech to the other ear. Controls showed an initial decline in performance in the presence of competing speech but thereafter showed adaptation to increasing audibility of irrelevant speech, even at the highest levels of noise. By contrast, patients showed linear decline in performance with increasing noise. Subsequently attempts were made to ameliorate this deficit (study 2) using a cognitive training procedure based on attention process training (APT) that included graded exposure to irrelevant noise over the course of training. Patients were assigned to adaptive and non-adaptive training schedules or to a no-training control group. Results showed that both types of training drove improvements in the dichotic listening and in naturalistic tasks of performance in noise. Improvements were also seen on measures of selective attention in the visual domain suggesting transfer of training. We also observed augmentation of event-related potentials (ERPs) linked to target processing (P3b) but no change in ERPs evoked by distractor stimuli (P3a) suggesting that training heightened tuning of target signals, as opposed to gating irrelevant noise. No changes in any of the above measures were observed in a no-training control group. Together these findings present an ecologically valid approach to measure selective attention difficulties after brain injury, and provide a means to ameliorate these deficits.