The contribution of injury severity, executive and implicit functions to awareness of deficits after traumatic brain injury (TBI)

Abstract

Deficits in self-awareness are commonly seen after Traumatic Brain Injury (TBI) and adversely affect rehabilitative efforts, independence and quality of life (Ponsford, 2004). Awareness models predict that executive and implicit functions are important cognitive components of awareness though the putative relationship between implicit and awareness processes has not been subject to empirical investigation. (Toglia & Kirk, 2000; Ownsworth, Clare & Morris, 2006; Crosson et al., 1989). Severity of injury, also thought to be a crucial determinant of awareness outcome post-insult, is under-explored in awareness studies (Sherer et al., 1989).The present study measured the contribution of injury severity, IQ, mood state, executive and implicit functions to awareness in head-injured patients assigned to moderate/severe head-injured groups using several awareness, executive and implicit measures. Severe injuries resulted in greater impairments across most awareness, executive and implicit measures compared to moderate injuries, although deficits were still seen in the moderate group. Hierarchical regression results showed that severity of injury, IQ, mood state, executive and implicit functions made significant unique contributions to selective aspects of awareness. Future models of awareness should account for both implicit and executive contributions to awareness and the possibility that both are vulnerable to disruption after neuropathology.

Metamemory following childhood brain injury: A consequence of executive impairment

“…In accordance with previous findings in adults (e.g., Bogod et al, 2003;Ciurli et al, 2010;Morton & Barker, 2010), statistical analyses carried out on the memory selfawareness measure indicate that children with TBI who have a reduced level of executive functioning seem to underestimate the frequency of their memory problems (impaired selfawareness), while those with preserved executive functions appear to understand their own memory functioning as accurately as control children. As with knowledge of memory tasks and strategies, our results seem to confirm that high-level cognitive functions are involved in children's perception and understanding of their own memory strengths and limitations.…”

“…In agreement with previous findings presented in the literature on adults (e.g., Morton & Barker, 2010), we expected children with TBI with poor executive functioning to underestimate the magnitude of their memory problems, compared to those with good executive functioning. Furthermore, we also hypothesized that TBI participants with executive impairment would be less accurate than agematched control participants when they had to estimate the frequency of their memory problems.…”

“…In accordance with previous findings in adults (e.g., Ciurli et al, 2010;Morton & Barker, 2010), the second aim of this research was to explore whether differences in executive impairment can influence the accuracy of the representations that children have of their own memory functioning after a TBI. For this purpose, a one-way ANOVA was carried out to compare the two TBI groups (TBI-High vs. TBI-Low) on the self-other discrepancy score for the memory questionnaire.…”

“…This hypothesis is supported by several neuropsychological studies carried out on adult patients with TBI that highlighted significant (negative) correlations between patients' level of executive functioning and both types of metamemory measures. Specifically, the results of these studies indicated that patients with poor executive functioning underestimate the frequency of their deficits and demonstrate less general knowledge of memory tasks and strategies than patients with good executive functioning (Bivona et al, 2008;Bogod et al, 2003;Ciurli et al, 2010;Morton & Barker, 2010;Ownsworth et al, 2002). Surprisingly however, despite the obvious clinical and theoretical value of this "executive" hypothesis and the fact that its corroboration could improve memory rehabilitation programs, few studies have examined this question from a developmental perspective.…”

Using game authoring platforms to develop screen-based simulated functional assessments in persons with executive dysfunction following traumatic brain injury

“…EDF is extremely common in neurological and neuropsychiatric pathologies with either severe or mild impairments, such as brain tumors [22], traumatic brain injury (TBI) [23], stroke [24], multiple sclerosis [25], Gilles de la Tourette syndrome [26], schizophrenia [27], obsessive-compulsive disorder [28], and neurological patients with frontal pathology [29][30][31][32][33].…”