This study investigated the 'latent deficit' hypothesis in two groups of head-injured patients with predominantly frontal lesions, those injured prior to steep morphological and corresponding functional maturational periods for frontal networks (28 years. The latent deficit hypothesis proposes that early injuries produce enduring cognitive deficits manifest later in the lifespan with graver consequences for behavior than adult injuries, particularly after frontal pathology (Eslinger, Grattan, Damasio & Damasio, 1992). Implicit and executive deficits both contribute to behavioral insight after frontal head injury (Barker, Andrade, Romanowski, Morton, & Wasti, 2006). On the basis of morphological and behavioral data, we hypothesized that early injury would confer greater vulnerability to impairment on tasks associated with frontal regions than later injury. Patients completed experimental tasks of implicit cognition, executive function measures and the DEX measure of behavioral insight (Behavioral Assessment of the Dysexecutive Syndrome: Wilson, Alderman, Burgess, Emslie, & Evans, 1996). The Early Injury group were more impaired on implicit cognition tasks compared to controls that Late Injury patients. There were no marked group differences on most executive function measures. Executive ability only contributed to behavioral awareness in the Early Injury Group. Findings showed that age at injury moderates the relationship between executive and implicit cognition and behavioral insight and that early injuries result in long-standing deficits to functions associated with frontal regions partially supporting the latent deficit hypothesis.

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.

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(2011). Inter-rater reliability of the Dysexecutive Questionnaire (DEX): comparative data from non-clinician respondents -all raters are not equal. Brain Injury, 25 (10), 997-1004. Copyright and re-use policySee http://shura.shu.ac.uk/information.html Sheffield Hallam University Research Archivehttp://shura.shu.ac.ukInter-rater reliability of the Dysexecutive Questionnaire (DEX):Comparative data from non-clinician respondents -all raters are not equalKey Words: executive function, reliability, brain injury.2 AbstractPrimary objective: The Dysexecutive Questionnaire (DEX) is used to obtain information about executive and emotional problems after neuropathology. The DEX is self-completed by the patient (DEX-S) and an independent rater such as a family member (DEX-I). This study examined the level of inter-rater agreement between either two or three non-clinician raters on the DEX-I in order to establish the reliability of DEX-I ratings. Methods and procedures:Family members and/or carers of 60 people with mixed neuropathology completed the DEX-I. For each patient, DEX-I ratings were obtained from either two or three raters who knew the person well prior to brain injury. Main outcomes and results:We obtained two independent-ratings for 60 patients and three independent-ratings for 36 patients. Intra-class correlations revealed that there was only a modest level of agreement for items, subscale and total DEX scores between raters for their particular family member. Several individual DEX items had low reliability and ratings for the emotion sub-scale had the lowest level of agreement.Conclusions: Independent DEX ratings completed by two or more non-clinician raters show only moderate correlation. Suggestions are made for improving the reliability of DEX-I ratings.3

This report describes two tests, verbal and nonverbal, meant for use with adults as a supplement to the more abstract problems of existing tests (Hebb and Morton 2 ). Both "Verbal Situation Series" and "Picture Anomaly Series" concern an understanding of human behavior, and are intended to provide problems of intrinsic adult interest; together they comprise the "McGill Adult Comprehension Examination," but they need not necessarily be used together as a single test. Both are culture-loaded; norms are given for two predominantly urban populations in the provinces of Quebec and Ontario, in Canada; and other norms will be necessary for any markedly different population. Our object is not primarily, however, to provide a test ready standardized for widely different populations (if such a thing is possible), but to provide new material which others may rearrange or restandardize to suit themselves.