We investigated longitudinally the effects of a stroke on the social support systems and well-being of the patient's primary support person, both acutely and as the condition stabilized. Individuals who had suffered a first stroke and a primary support person participated in two waves of data collection, carried out in 6-month intervals beginning 7 weeks after the stroke. Our data show that the prevalence of depressive symptoms is from 2 1/2 to 3 1/2 times higher than rates found among representative samples of middle-aged and elderly populations. Mean level of depression did not change over time, although level of optimism declined significantly. Multiple regression analyses showed that levels of depression and perceived burden in support persons are highly related to aspects of the stroke such as its severity, and that demographic variables such as age and income play a relatively minor role in attenuating these relations in the acute adjustment phase. However, from 7 to 9 months after the stroke, well-established demographic variables such as health, income, and age were significant predictors of depression. Individuals who were older and who had good health and higher incomes were least depressed.

This study examined the association between estimated working memory (WM) capacity and comprehension of passages that required revision of an initial interpretation. Predictions stemmed from the recently elaborated theory of capacity-constrained comprehension (Just & Carpenter, 1992, Psychological Review, 99 , 122–149), which includes as a major feature the principle that WM influences comprehension only as processing demands approach or exceed the limits of capacity. As anticipated from task analysis, correlations between unilaterally brain-damaged patients’ estimated WM capacity and discourse comprehension performance were minimal for nondemanding measures, and increased in magnitude with task processing requirements. Most notably, a meaningful correlation (/ r / greater than .50) emerged only for the task judged to involve the most demanding comprehension processes, for adults with right hemisphere brain damage. No meaningful associations between estimated WM capacity and task performance were observed for normally aging subjects, who were not expected to have difficulty with any of our comprehension measures. The nature of WM deficits in brain-damaged adults (total capacity, vs. resource allocation, vs. slow or otherwise faulty component processing operations) is considered, and some existing work is interpreted from a cognitive resource perspective. Theoretical implications and clinical applicability of the working memory/resource framework are also discussed.

Background:Immunization of patients with Alzheimer’s disease (AD) with synthetic amyloid-β peptide (Aβ42) (AN1792) was previously studied in a randomized, double-blind, placebo-controlled phase 2a clinical trial, Study AN1792(QS-21)-201. Treatment was discontinued following reports of encephalitis. One year follow-up revealed that AN1792 antibody responders showed improvements in cognitive measures as assessed by the neuropsychological test battery (NTB) and a decrease in brain volume compared with placebo.Methods:A follow-up study, Study AN1792(QS-21)-251, was conducted to assess the long-term functional, psychometric, neuroimaging, and safety outcomes of patients from the phase 2a study 4.6 years after immunization with AN1792. The results were analyzed by comparing patients originally identified as antibody responders in the AN1792 phase 2a study with placebo-treated patients.Results:One hundred and fifty-nine patients/caregivers (30 placebo; 129 AN1792) participated in this follow-up study. Of the 129 AN1792-treated patients, 25 were classified in the phase 2a study as antibody responders (anti-AN1792 titers ≥1:2,200 at any time after the first injection). Low but detectable, sustained anti-AN1792 titers were found in 17 of 19 samples obtained from patients classified as antibody responders in the phase 2a study. No detectable anti-AN1792 antibodies were found in patients not classified as antibody responders in the phase 2a study. Significantly less decline was observed on the Disability Assessment for Dementia scale among antibody responders than placebo-treated patients (p=0.015) after 4.6 years. Significant differences in favor of responders were also observed on the Dependence Scale (p=0.033). Of the small number of patients who underwent a follow-up MRI, antibody responders showed similar brain volume loss during the follow-up period subsequent to the AN1792 phase 2a study compared with placebo-treated patients.Conclusions:Approximately 4.6 years after immunization with AN1792, patients defined as responders in the phase 2a study maintained low but detectable, sustained anti-AN1792 antibody titers and demonstrated significantly reduced functional decline compared with placebo-treated patients. Brain volume loss in antibody responders was not significantly different from placebo-treated patients approximately 3.6 years from the end of the original study. No further cases of encephalitis were noted. These data support the hypothesis that Aβ immunotherapy may have long-term functional benefits.

Normal comprehension skill is linked with the proficiency of a suppression mechanism, which functions to dampen mental activation that becomes irrelevant or inappropriate to a final interpretation. This study investigated suppression and discourse comprehension in adults with right brain damage (RBD). To index suppression function, 40 adults with RBD and 40 without brain damage listened to sentence stimuli that biased the meaning of a sentence-final lexical ambiguity (e.g., SPADE), then judged whether a probe word (e.g., CARDS) fit the overall sentence meaning. Probes represented the contextually inappropriate meanings of the ambiguities and were presented in two conditions: 175 ms and 1000 ms post-stimulus. The same probes were used with unambiguous comparison stimuli. Probe judgment response times indicated that only the group without brain damage suppressed inappropriate interpretations over time. In a multiple regression analysis, suppression function added significantly to predicting performance on a general measure of narrative discourse comprehension for participants with RBD. The discussion addresses how suppression deficits may account more broadly for comprehension difficulties after RBD; it also considers several unresolved issues concerning the suppression construct and the suppression deficit hypothesis.

Persisting difficulties in communication are a serious handicap faced by many after traumatic brain injury (TBI) and a major barrier to community reintegration. Conventional approaches to the study of communication problems after TBI have focused on the form of language production and expression, usually in terms of phonological, semantic, and syntactical features. Most TBI patients, however, perform overall within normal ranges on these conventional indicators. More recently, attention has focused on language in its naturally-occurring form, that is, discourse, which is heavily influenced by linguistic, cognitive and social skills. Because most TBI patients are left with residual deficits in these areas, study of discourse abilities seem to be particularly suited to understanding their problems in communication and facilitating eventual reintegration into the community. This study was designed to determine if and how the conversational discourse of TBI patients differs from a matched non-TBI group and whether any identified variables are related to measures of outcome as measured by community integration and quality of life. Additionally, the study was designed to explore the relationship between TBI and features of discourse across conversational, narrative, procedural genres. TBI patients (n = 30) from an out-patient brain injury programme were compared to matched controls (n = 10) in the three discourse genres. Bivariate and multivariate analyses evaluated 23 measures of discourse efficiency, complexity, topic management, information and pragmatic behaviours in each genre as well as measures of psychosocial adjustment, particularly social integration and quality of life. Results indicated that TBIs were significantly different from controls on several measures of discourse and psychosocial adjustment. A number of other features of discourse were found to correlate significantly with social integration and quality of life. Interestingly, discourse variables appeared to correlate with social integration more strongly than age, gender, education, and other conventional psychosocial factors. Contrary to prediction, features of conversational discourse did not correlate more strongly than other types of discourse with social integration and quality of life. Discussion centred on the apparent comorbidity of features in everyday discourse and psychosocial determinants that were associated with quality of life and social integration.