Assessment of depression in patients with brain pathology: the case of stroke.

The assessment of depression in patients with brain pathologies--a topic of considerable clinical and research interest--is complicated by a variety of factors. Among the most problematic are cognitive consequences of brain injury that can diminish the reliability and validity of information used to diagnose depression, determine its severity, ascertain its predictors, and evaluate its impact. In this article, the authors examine the challenges to depression assessment in patients who have had a stroke, the neurologically impaired population in which it has been most frequently studied. Focusing on poststroke depression research, they describe methodological limitations that may contribute to conflicting outcomes and conclusions and offer suggestions for improving the specificity, consistency, validity, and reliability of assessment methods and procedures when investigating depression in patients with brain pathologies.

A longitudinal study of the psychosocial impact of stroke on primary support persons.

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.

Right hemisphere appreciation of prosodic and linguistic indications of implicit attitude.

Appreciation of attitudes conveyed through prosodic cues and lexical content was examined in subjects with temporal lobe seizure foci. One task involved auditory judgments of the consistency of verbal and intonational meaning of sentences. Errors on judgments of consistent verbal and prosodic stimuli were not only more frequent in the right temporal group than in left temporals or controls but were strongly related to neuropsychological indices associated with extent of right temporal involvement. Answering questions based on written narratives in which multiple attitude markers were either redundant or conflicting comprised the second task. Right temporal patients as a group had difficulty in answering inferential questions about paragraphs with inconsistent indicators of attitude. Even low-scoring right temporals were able, however, to answer inferential and factual questions when the verbal context markers consistently reinforced a particular attitude.

Predictive inferencing in adults with right hemisphere brain damage.

Predictive inferencing was evaluated in 13 adults with right hemisphere damage (RHD) and 11 adults without brain damage (NBD). Brief narrative stimuli that strongly suggested a single outcome were constructed to vary recency of mention of inference-related information. Reading times were recorded for narrative-final sentences that disconfirmed the target inferences. Slowed reading time on the final sentences was an indicator of inference generation. Adults with RHD generated target predictive inferences in contexts with recent mention of strongly biasing inference-related information. This group also evidenced maintenance of inferences over time, but to a lesser degree than participants in the NBD group. Overall, individuals with better auditory comprehension or larger estimated working memory capacity tended to maintain inferences better than did the other participants. The results are discussed in relation to current hypotheses of inferencing and discourse comprehension in adults with RHD.

Mechanisms of discourse comprehension impairment after right hemisphere brain damage: suppression in inferential ambiguity resolution.

This study examined the generality of a previous finding indicating that difficulty suppressing or inhibiting context-inappropriate interpretations is an important predictor of narrative discourse comprehension for adults with right brain damage (RBD) (C. A. Tompkins, A. Baumgaertner, M. T. Lehman, & W. Fassbinder, 2000). Forty adults with RBD and 39 without brain damage listened to two-sentence stimuli and judged whether a probe word fit with the overall stimulus meaning. An ambiguous initial sentence elicited both dominant and less preferred inferences, and the second sentence resolved the ambiguity toward the initially less-likely interpretation. Probes represented the dominant inference for the first sentence and were presented at two poststimulus intervals. Probe judgment response times indicated that neither group suppressed the eventually inappropriate inferences in the time intervals studied. However, multiple regression analysis demonstrated that for individual participants with RBD, the extent of suppression from one interval to the next was a significant predictor of performance on a specialized measure of inference comprehension. The discussion evaluates these findings and identifies directions for future research.

Mechanisms of discourse comprehension impairment after right hemisphere brain damage: suppression in lexical ambiguity resolution.

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.

Recognizing and managing anemia.

Anemia is not an uncommon problem. Knowledge of a few common laboratory tests can be helpful when caring for patients with anemia. By reviewing approaches to classifying, evaluating, and managing patients with common anemias, nurses will be prepared to care for patients with an anemia more confidently.

Effects of scheduling on the communicative assessment of aphasic patients.

This study determined the influence of morning and afternoon scheduling on the assessment of communicative skills of aphasic patients. Eight short-term (3 to 9 months post-onset) and eight long-term (12 or more months post-onset) aphasic subjects were administered 11 tests from the Porch Index of Communicative Ability (PICA) at specified times in the morning (A.M.) and afternoon (P.M.). Order of scheduling (A.M. first, P.M. second; P.M. first, A.M. second) was determined randomly but balanced between groups. Results indicated an absence of significant main effects for onset, scheduling, and test order; however, significant interactions between the scheduling and test-order factors were evidenced on the naming and auditory identification tests and on all overall measures. Analyses of these interactions revealed that patients scheduled first in the A.M. decreased their mean scores when assessed a second time in the P.M., whereas those scheduled first in the P.M., increased their scores when seen a second time in the A.M. Findings suggest that aphasic patients can be expected to do better on morning than afternoon assessments regardless of the order in which they are scheduled. Clinically, this indicates a need for consistency in the scheduling of periodic assessments for individual aphasic patients.

Redundancy enhances emotional inferencing by right- and left-hemisphere-damaged adults.

This study investigated the influence of enhanced textual redundancy on affective interpretations made by unilaterally right or left hemisphere brain-damaged adults and normally aging control subjects. Emotional interferences were drawn from linguistic or prosodic material, and redundancy effects were examined within and across stimulus boundaries. Results indicate that heightened semantic redundancy improved the accuracy of linguistic and prosodic judgements of affect for all groups. Correct prosodic judgements were also made more quickly by a subset of each group when textual redundancy was maximized. The facilitory influence of increased redundancy was not attributable solely to perseveration or response rigidity. Possible mechanisms by which semantic redundancy affects cognitive processing are considered.

Knowledge and strategies for processing lexical metaphor after right or left hemisphere brain damage.

This study was designed to assess how unilateral right hemisphere brain damage (RHD) affects the knowledge and processing of metaphoric aspects of word meaning. Ambiguous adjectives that could convey either a metaphoric or a literal meaning were used as target words in auditory lexical decision tasks. Targets were preceded by primes that were valid (related to the target's metaphoric or literal meaning), neutral, or unrelated. Prime-target pairs were presented in two attention conditions, designed to favor either relatively automatic or relatively effortful mental processing, and reaction time data were gathered. RHD stroke patients performed similarly to left-brain-damaged and normal control subjects in the automatic condition, and when provided with specific processing strategies, indicating that they retained some knowledge of metaphoric word meanings. When left to glean strategies for themselves, however, both brain-damaged groups had difficulty. These results and others from the RHD literature are discussed in terms of attentional resource capacity and attentional allocation models.

Automatic and effortful processing of emotional intonation after right or left hemisphere brain damage.

This study assessed the effects of unilateral right (RHD) or left hemisphere brain damage (LHD) on the knowledge and processing of emotional information imparted by vocal intonation. Semantically neutral statements that conveyed a mood through prosody were used as targets in a mood priming task. These targets were preceded by story primes. The events described in the primes were either congruent with the mood conveyed by the intonation of a target phrase, incongruent with target mood, or emotionally neutral. Prime-target pairs were presented in two attention conditions designed to favor either relatively automatic or effortful mental processing. Response time (RT) data were recorded for accurate judgments of target moods. In the automatic condition, there were no qualitative differences between RHD, LHD, or normally aging control subjects. In the effortful condition, RTs for each group were similarly improved by congruent primes (relative to neutral primes), but RHD subjects were disproportionately slower when targets were preceded by incongruent primes. Results indicate that brain-damaged adults retain knowledge of emotional meanings, and use that knowledge to facilitate effective interpretations in some circumstances. Demands for emotional inference revision were not exclusively responsible for RHD adults' poor performance with incongruent primes, as they successfully revised initial predictions in other conditions. Rather, these subjects' difficulties arose when increased processing demands converged with decreased availability of mental resources. These findings are integrated with those from a related study of lexical metaphor, and are interpreted within a cognitive resource framework.

Identifying behavior associated with verbal self-corrections of aphasic clients.

The purposes of this study were to define certain behaviors associated with verbal self-correction efforts of aphasic clients and to determine the accuracy with which these behaviors might be identified by clinical observers. Seven explicit definitions were written for behaviors associated wih aphasic clients' self-correction attempts on single-word and short-answer language production tasks. To determine the accuracy with which defined behaviors could be identified, observers (N = 7) were asked to view 400 randomly selected speech samples and to code the type of self-correction event for each sample. The accuracy of these judgments was ascertained by calculating the percentages of observers' agreements with judgments made previously by the experimenters. Results showed observers were able to identify explicitly defined behaviors at levels of accuracy ranging from 73%--99%. When observers' judgments did not agree with those of the experimenters, inaccuracies tended to be logical and to cluster in particular categories. Findings suggest a need for further study of behaviors associated with aphasic individuals' self-correction efforts, particularly with reference to the significance of these behaviors to recovery from aphasic, and to aphasic symptomatology in general.

Perception of emotional intonation by brain-damaged adults: the influence of task processing levels.

This research examined perception of moods from the tone-of-voice of semantically neutral phrases following unilateral cerebrovascular accident. It was hypothesized that right hemisphere damage (RHD) would impair even low-level discrimination and recognition of affective prosody, while left hemisphere damage (LHD) would affect performance only as associational-cognitive task demands increased. Thirty-three male subjects, 11 each in RHD, LHD, and normal groups, were given three tasks that varied in presumed amounts of processing undertaken for successful completion. Discrimination of prosodic patterns was expected to require the fewest cognitive operations. An intermediate task involved selecting from two possibilities the label that described moods conveyed prosodically. In the third task, prosodic mood selection was made from four choices, increasing the number of comparisons necessary for accurate judgment. As hypothesized, RHD subjects were inferior to normal subjects in all tasks. LHD subjects were equivalent to normal subjects for the first two tasks, but fell to the level of the RHD group for the third task. These results indicated that the right hemisphere in men was primarily involved in the reception and recognition of emotional prosodic stimuli. Increasing cognitive demands, however, brought about a shift in emphasis from the right hemisphere to both hemispheres. An implication of these findings concerns the need to examine performance levels that invoke changes from expected patterns of hemispheric specialization to advance our knowledge of functional asymmetries.

Contextual mood priming following left and right hemisphere damage.

This research examined the influence of mood-congruent and mood-incongruent contexts on recognizing affective prosody after brain damage. Predictions stemmed from an associative network theory of learning and memory. Thirty-three male subjects, 11 each in right hemisphere damaged (RHD), left hemisphere damaged (LHD), and normal control groups judged moods from the prosody of semantically neutral phrases. In one task, the prosodic stimulus phrases were judged in isolation. In another task, the phrases were preceded by short paragraphs which were either congruent or incongruent in emotional tone with the prosodic stimuli. These paragraphs were designed to prime specific mood choices. As anticipated, LHD subjects' prosodic mood recognition was more accurate when given congruent rather than incongruent affective contexts. Congruent contexts facilitated, and incongruent contexts disrupted, their prosodic mood judgments to the same extent as normals. RHD subjects showed a partial context decrement. They were less accurate than normal or LHD subjects in the congruent condition, and were unaffected by incongruent contexts. When given congruent biasing paragraphs, however, RHD subjects did experience facilitation on a par with that found for the other groups, indicating spared sensitivity to certain contextual factors. The distinction between automatic and effortful processes is offered as a potential explanation for the RHD group's pattern of performance.

On prognostic research in adult neurologic disorders.

This note suggests some changes in variable selection and operationalization for research on prognosis in adult neurologic communicative disorders. The issues raised are relevant to both broad prognostic questions concerning extent of recovery, and focused questions regarding candidacy and treatment efficacy.

The access and processing of familiar idioms by brain-damaged and normally aging adults.

Idiom interpretation tasks are routinely used in the clinical evaluation of adults with brain damage, and idiom processing has received increasing attention in the psycholinguistic literature. Clinical evidence suggests that adults with unilateral right-hemisphere damage (RHD) are insensitive to nonliteral meanings conveyed by idiomatic expressions and other figurative forms. However, this portrayal is derived from their terminal responses to tasks that reflect multiple aspects of mental operations (off-line measures), obscuring the source of poor performance. This study used an on-line word-monitoring task to assess RHD, left-hemisphere-damaged, and normally aging adults' implicit knowledge of familiar idiomatic expressions. Brain-damaged subjects performed similarly to normal controls on this task, even though the clinical subjects fared poorly by comparison on an off-line idiom definition measure. These results suggest that adults with unilateral brain damage can activate and retrieve familiar idiomatic forms, and that their idiom-interpretation deficits most likely reflect impairment at some later stage of information processing. Further, error analysis of idiom-definition performance did not support the customary characterization of RHD adults as excessively literal responders. The paper discusses clinical implications of the nature and use of idiom interpretation tasks.

Aphasic patients in a rehabilitation program: scheduling speech and language services.

Eleven 10-item tests from the Porch Index of Communicative Ability (PICA), were administered to 14 aphasic adults participating in a rehabilitation program. Tests were given once in the morning and once in the afternoon. Results indicate that overall communicative functioning was significantly higher for morning assessments, although some individual patients did better in the afternoon. The primary implication of these results is the importance of consistency in scheduling patient contacts when measuring the effects of treatments rendered. Considerations in determining optimum schedules and aiding individual patients in compensating for reduced efficiency due to time of day are discussed.

Working memory and inference revision in brain-damaged and normally aging adults.

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.