Nonbrain-damaged Subjects Research Articles

On the presence and absence of that in aphasia

Background: Deficits in the production of complex structures have been widely documented in non-fluent forms of aphasia. Nevertheless, the data available on fluent deficits are scarcer. In both cases, reduced complexity is attributed to syntactic factors. In the related field of syntactic theory, there exist a number of studies on the production of non-brain damaged (NBD) subjects which try to account for the existence of two alternative constructions in embedded complement clauses in English (as in I think that the situation will improve/I think the situation will improve). The absence of that in the embedded clauses of verbs like say, know or think in colloquial English is very frequent and this suggests that verbs of this type may select a clause lacking a complementiser phrase (CP) layer, namely tense phrase (TP). The presence of that is taken to be the result of insertion, which is triggered by cues associated to contextual factors like register.Aims: To compare the presence and absence of the complementiser that in the speech of English subjects diagnosed with aphasia with the same phenomenon in NBD subjects with the objective of clarifying the nature of the phenomenon of that-omission.Methods & Procedures: We carried out an analysis of spontaneous speech that included the performance of 200 individuals brought together by the AphasiaBank project. Two groups were included in the study, an experimental group comprising 100 individuals diagnosed as aphasic according to the standards of the Western Aphasia Battery (WAB), and a control group including 100 non-brain damaged control subjects ( NBDs).Outcomes & Results: This study shows that the asymmetries across populations (NBDs vs. subjects with aphasia) are restricted to the number of occurrences of subordinate clauses. NBD subjects produce more embeddings than subjects diagnosed with fluent aphasia (although they do produce embedded clauses and crucially prefer the “omission” option) and subjects with non-fluent aphasia.Conclusions: Our results confirm the findings on fluent aphasias as for the presence of deficits with complex constructions. These results may be regarded as evidence for the claim that TP is the default selection for the verbs analysed.

Intrasubject variability of cognitive and word retrieval performance across six sessions

Florida State University, Tallahassee, FL 32306, USAA burgeoning interest appears to be developing in understandingthe nature and interactions between aphasia and nonlinguistic cogni-tive factors such as attention and working memory (Caspari, Parkin-son, LaPointe, & Katz, 1998; Erickson, Goldfinger, & LaPointe, 1996;Helm-Estabrooks, 2002; LaPointe & Erickson, 1991; Murray, 1999).Others (Hoffmann, 2001; Hochstenbach, Mulder, van Limbeek,Donders, & Schoonderwaldt, 1998) have noted the strong presence ofcognitive decline after stroke and commented on how marked slownessof information processing could impact linguistic performance.Some researchers (McNeil et al., 1991) have integrated disturbancesof cognitive processing into cognitive resource allocation models ofaphasia and suggested that the intrasubject variability of languageperformance seen in aphasia might be explained by fluctuating cog-nitive performance. Disturbances in word retrieval and lexical-se-mantic processing remains one of the hallmarks of aphasia andexplanations of variability across these domains also have been enig-matic (Moreno, Buchanan, & Van Orden, 2002; Nespoulous, Villiard,& Lecours, 1989). Despite the growing archive of research on cogni-tive-linguistic interactions, the sources of variability in aphasia remainelusive and unclearly understood. More elementally, the nature andrelationship of intrasubject variability on cognitive and word retrievaltasks across repeatedsessions of assessmentis relatively unstudied. Thepurpose of this study is twofold:1. To describe the variability of four individuals with aphasia on in-depth tasks of word retrieval and cognitive processing performanceacross six sessions of assessment.2. To explore the pattern of correlation and variability among wordretrieval and cognitive processing tasks across six sessions to deter-mine if changes in word retrieval across test sessions can be pre-dicted by changes in cognitive processing performance.MethodsParticipantsFour individuals with aphasia were recruited for this study andvolunteered to participate in six assessment sessions each. Our parti-cipants all suffered a single, left hemisphere thromboembolic CVA andwere mildly to moderately impaired in language as measured by theWestern Aphasia Battery and other standardized measures of languageimpairment. Participants were classified as having non-fluent, Broca’s-type aphasia. They ranged in age from 34 to 66 with a mean of 58.6.All were right handed pre-morbidly, were judged to be neurologicallystable beyond the acute epoch, and ranged in time post onset from 3months to several years. All participants were male.MeasuresSerialperformanceontheprinciplemeasuresincludedthefollowing:Cognitive measure: A computerized assessment protocol was se-lectedthatmeasuresthefollowingcognitiveskillsinthevisualmodality:• simple reaction time• choice reaction time• serial pattern matching• lexical discrimination• visual selective attention• response reversal with rapid visual scanning• abstract form discriminationThis measure has been standardized on a large group of non-braindamaged subjects and a variety of clinical populations (Miller, 1990;1995). The battery measures and records reaction times in millisecondsas well as accuracy across the 10 subtests of the full battery. Signaldetection analysis and accuracy corrected for false positives is alsorecorded and summarized.Word retrieval measure: The Test of Adolescent/Adult WordFinding (TAWF) (German, 1990). The complete TAWF batterymeasures naming nouns, verbs, sentence completion, naming to de-scription, and naming categories. Accuracy as well as latency of re-sponses is recorded.The measures were administered in counterbalanced order. The sixsessions for each participant were accomplished with approximatelyweekly sessions over a six-week period.ResultsFig. 1 presents the group means for the word retrieval scores (totalperformance for all TAWF subtests) as well as the group means for allof the CalCap cognitive processing subtests across the six sessions ofadministration. Description and analysis of performance across theindividual subtests and for individual subjects also will be presented.Spearman’s coefficient of correlation for word retrieval (groupTAWF total scores) and group CalCap reaction times was ).886(p = .028). Spearman’s r value for word retrieval and CalCap accuracywas ).08 (n.s.).

Relative sensitivity of the WAIS-R subtests and selected HRNB measures to the effects of brain damage

Reitan has argued that Halstead-Reitan Neuropsychological Battery measures are more sensitive to the effects of brain damage than are measures from the Wechsler intelligence scales. This proposal was investigated in groups of 65 brain-damaged subjects and 45 nonbrain-damaged controls equated for age and level of education and subgroups of 34 brain-damaged subjects and 34 nonbrain-damaged controls closely matched on age and WAIS-R full Scale IQ. Differences on Halstead-Reitan measures found in the larger groups were not found in the subgroups matched on age and IQ. Further, discriminant analyses showed that 11 Halstead-Reitan measures were equivalent to the 11 WAIS-R subtests in discriminating brain-damage and nonbrain-damaged subjects. Thus, the proposal for poorer sensitivity of the WAIS-R subtests was not supported.

Differential sensitivity of the WMS to the effects of IQ and brain damage

The sensitivity of the Wechsler Memory Scale with Russell's Revision to the effects of IQ and brain damage was assessed in groups of brain-damaged (N = 64) and nonbrain-damaged (N = 64) subjects. Brain-damaged and nonbrain-damaged subjects were divided into subgroups equated on age and IQ for each of three IQ ranges (80-89, 90-99, 100-109). Some Wechsler Memory Scale subtests were affected only by IQ, others were affected by IQ and brain-damage status, and still others were affected only by brain-damage status. Measures of recall efficiency were most useful in discriminating brain-damaged and nonbrain-damaged subjects. We concluded that specific Wechsler Memory Scale subtests are useful in assessing memory deficits in brain-damaged patients.

Attenuated late positivity in the visual evoked potential in aphasia induced by lesions in anterior speech area.

Seven anterior aphasics, 7 nonbrain-damaged subjects and 7 normal controls were tested for their visual evoked potentials. Aphasics showed an attenuation of the long latency positivity related to interest in the stimulus. The attenuation may indicate the subject's failure to signal communicative intention. Thus the attenuated positivity may be a physiological correlate of a behavioral state (aphasia) induced by brain lesions.

Revised administration and scoring procedures for the Boston Naming test and norms for non-brain-damaged adults

Abstract Standard administration, response coding and scoring procedures were developed for the 60-item Boston Naming Test (BNT). Standard prompts to be given following certain types of incorrect responses were also developed. The BNT was administered to 60 non-brain-damaged adults using these standard procedures. Our results show that examiners can reliably carry out the revised test procedures reported in this paper. Our results also show that two response categories (Related Name and Don't Know) accounted for nearly 80% of incorrect responses. Several BNT test pictures frequently elicited a consistent name other than the one specified in the test. Prompting for an additional response following Related Name and Multiple Attempts responses frequently elicited the correct BNT name. Prompts following other types of error responses usually did not elicit the correct name. Neither the age nor education of our nonbrain-damaged subjects was strongly related to their total BNT score.

Category concept generation in aphasia: The influence of context

Abstract The influence of context on the generation of category concepts for ad hoc and common categories was examined in adults with fluent and nonfluent aphasia and nonbrain-damaged controls. Common categories are natural object concepts, such as ‘furniture’. Ad hoc categories are those that are constructed for use in specialized contexts and are considered instrumental in achieving goals. An example of an ad hoc category is ‘things not to eat on a diet’. Both types of categories have a graded structure which indicates that all members of a category are not equally representative of the category, with some members being better examples than others. Subjects performed a category concept generation task in which they were required to generate category labels for groups of category exemplars presented in isolation or preceded by a contextual vignette. Both groups with aphasia were able to utilize context as effectively as nonbrain-damaged subjects to prime category labels for the ad hoc categories. There w...

Nonverbal competency in aphasic stroke patients' conversation

Abstract This study investigated whether or not aphasic patients use more nonverbal behaviour than nonaphasic adults. Fifteen aphasic and 15 nonaphasic stroke subjects and 15 nonbrain-damaged subjects were videotaped in conversation. Nonverbal behaviours were identified in each modality then each behaviour was coded according to function and effectiveness. Aphasic subjects produced significantly more nonverbal behaviours. They also produced significantly more ineffective behaviours, though these represented a small proportion of all behaviours. Significant increases were observed in the hand/arm modality and in behaviours with symbolic and regulatory functions. It was concluded that aphasic patients retain a degree of competency in the nonverbal channel and it was suggested that this be measured as part of an assessment of communicative competence.

A meta-analysis of Halstead-Reitan test performances of non-brain damaged subjects

Eighteen studies reporting Halstead-Reitan (HR) Neuropsychological Battery test performances for over 1000 non-brain damaged subjects were reviewed. Substantial empirical normative data is available only for a group of middle-aged adults characterized by relatively high intelligence and education. Serious methodological flaws in Halstead's original work, changes in the administration of HR Battery over the years, as well as variations in subsequent normative data suggest the traditional Halstead cutting scores are inappropriate. Norms for a composite “meta-sample” were reported. Noting that the HR test scores are valid concommitants of neuropsychological dysfunction, specific areas needing empirical elucidation are outlined.

Perception of sequences of visual temporal and auditory spatial stimuli by aphasic, right hemisphere damaged, and non-brain damaged subjects

Twenty-four aphasic subjects with left hemisphere brain damage, fifteen subjects with right hemisphere brain damage and twenty control subjects with no brain damage participated in visual temporal and auditory spatial sequencing tasks. In the visual temporal task, four colored lights were flashed in various sequences, and subjects reported the order of the lights by operating colored pushbuttons. In the auditory spatial task, bursts of noise were delivered in various sequences to four speakers placed in an arc around the subject, and subjects reported the order of the sounds by operating push-buttons under each of the speakers. Both groups of brain damaged subjects performed less well on both tasks than the group of normal subjects, and both groups of brain damaged subjects performed less well on the auditory temporal task than the visual spatial task. Further investigations to specify the functions served by the two hemispheres are proposed.