Vata-L: Visual-Analogue Test Assessing Anosognosia for Language Impairment

Lack of awareness (anosognosia) for one's own language impairments has rarely been investigated, despite hampering language rehabilitation. Assessment of anosognosia by means of self-report is particularly complex, as a patient's language difficulties may seriously prevent or bias the assessment. Other methods, such as measures of self-correction and error detection, have provided valuable information, although they are an indirect form of assessment of anosognosia and are not exempt from methodological criticisms. In this study we report on a new tool, the VATA-L (Visual-Analogue Test for Anosognosia for Language impairment), geared at assessing explicit anosognosia for aphasia. The VATA-L compares the patient's self-evaluation with caregivers’ evaluations of the patient's verbal communication abilities in a series of common situations. By means of non-verbal support and a system of check questions, this test minimizes some of the methodological limitations of existing diagnostic tools (e.g., structured interviews), enhancing reliability, and enabling assessment of patients with aphasia. Finally, normative data provided in the study allow a clearer interpretation of the patient's performance and facilitate assessment of anosognosia.     

Effects of phonological and semantic deficits on facilitative and inhibitory consequences of item repetition in spoken word comprehension

Repeating a word can have both facilitative and inhibitory effects on subsequent processing. The present study investigated these dynamics by examining the facilitative and inhibitory consequences of different kinds of item repetition in two individuals with aphasia and a group of neurologically intact control participants. The two individuals with aphasia were matched on overall aphasia severity, but had deficits at different levels of processing: one with a phonological deficit and spared semantic processing, the other with a semantic deficit and spared phonological processing. Participants completed a spoken word-to-picture matching task in which they had to pick which of four object images matched the spoken word. The trials were grouped into pairs such that exactly two objects from the first trial in a pair were present on screen during the second trial in the pair. When the second trial's target was the same as the first trial's target, compared to control participants, both participants with aphasia exhibited equally larger repetition priming effects. When the second trial's target was one of the new items, the participant with a phonological deficit exhibited a significantly more negative effect (i.e., second trial response slower than first trial response) than the control participants and the participant with a semantic deficit. Simulations of a computational model confirmed that this pattern of results could arise from (1) normal residual activation being functionally more significant when overall lexical processing is slower and (2) residual phonological activation of the previous trial's target having a particularly strong inhibitory effect specifically when phonological processing is impaired because the task was phonologically-driven (the spoken input specified the target). These results provide new insights into perseveration errors and lexical access deficits in aphasia.     

Testing single‐ and dual‐route computational models of auditory repetition with new data from six aphasic patients

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.     

Verbal and non-verbal working memory in aphasia: What three n-back tasks reveal

Background: Researchers have found that many individuals with aphasia (IWA) present with cognitive deficits that may impact their communication, and perhaps underlie their language-processing deficits (e.g., Erickson et al., 1996 Erickson, E., Goldinger and LaPointe, L. 1996. Auditory vigilance in aphasic individuals: Detecting non-linguistic stimuli with full or divided attention. Brain and Cognition, 30: 244–253. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Murray et al., 1997 Murray, L.L., Holland, A.L. and Beeson, P.M. 1997. Accuracy monitoring and task demand evaluation in aphasia. Aphasiology, 11: 401–414. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; Wright et al., 2003 Wright, H. H., Newhoff, M., Downey, R. and Austerman, S. 2003. Additional data on working memory in aphasia. Journal of International Neuropsychological Society, 9: 302 [Google Scholar]). However, many investigations of cognitive ability in aphasia have included measures that may be considered “language heavy”; they require overt lexical, semantic, and/or phonological processing to follow the task instructions and/or formulate a response. Few have considered the amount of linguistic processing required to perform the task. Subsequently, it is not clear if poorer performance by IWA on cognitive tasks compared to neurologically intact (NI) participants is due to a deficit in the respective cognitive domain or due to the inability of IWA to perform the task because of their language difficulties.

Aims: The purpose of the current study was to explore the effect of varying linguistic processing demands in the context of a dynamic working memory task—an n-back task for participants with and without aphasia.

Method & Procedures: This study compared differences on three different n-back tasks within and across groups for individuals with aphasia and NI matched peers. Participants completed three different n-back tasks; stimuli for the tasks varied in “linguistic load”. For each n-back task participants completed two levels of difficulty: 1-back and 2-back.

Outcomes & Results: The aphasia group performed significantly worse than the NI participants across the n-back tasks. All participants performed significantly better with the stimuli that carried a higher linguistic load (i.e., the fruit), than with the fribbles (semi-linguistic) and blocks (non-linguistic). All participants performed significantly better on the 1-back than the 2-back working memory task. Unlike the NI participants, IWA performed equally poorly with the fribbles and the blocks in the 2-back task.

Conclusions: Overall, the performance of individuals with aphasia on working memory tasks that varied in their linguistic load was similar to the control group but reduced. However, unlike the NI participants, IWA were less skilled at rapidly utilising linguistic knowledge to increase performance on the fribbles, demonstrating the further decrement in working memory that results from a decreased ability to utilise a linguistic strategy to increase performance on verbal working memory tasks. The results of this study indicate that language ability has a significant influence on performance on working memory tasks and should be considered when discussing cognitive deficits in aphasia.     

Performance of individuals with left hemisphere stroke and aphasia and individuals with right brain damage on forward and backward digit span tasks

Background: Working memory (WM) limitations have been suggested as a significant source of the linguistic processing deficits observed in individuals with aphasia (IWA). Digits forward (DF) and digits backward (DB) span tasks are frequently used to study WM in both healthy and clinical populations. Unfortunately only a handful of studies have explored digit span in IWA.

Aims: The purpose of the current study is to measure the DF and DB spans of IWA and compare their digit spans to a group with right brain damage, but no aphasia (RBD). Additionally, DF and DB span is compared within each group to determine if there is indeed a performance differential that may support the idea that DB is a more difficult WM task in these populations.

Methods & Procedures: A total of 17 IWA and 14 individuals with RBD participated in a DF and DB span task. Modifications to the span tasks were implemented to accommodate language deficits. A series of two digits were orally presented to each participant continuing to a maximum of eight digits. There were seven trials per digit series. Participants were asked to point to the correct order of digits on a written one- to nine-digit list provided on individual note cards or to verbally repeat the numbers if the participant was able to do so.

Outcomes & Results: IWA demonstrated shorter digit spans than the RBD group. Both groups performed worse on the DB span tasks than the DF span tasks.

Conclusions: The results are consistent with previous studies suggesting that DB span is shorter than DF span in other populations and that there are differences in performance on digit span tasks between the two groups. The differences between RBD group and IWA may be explained by decreased attentional capacity or inefficient resource allocation in IWA, or alternatively, a deficient phonological loop. Future studies should explore these possibilities.     

Longitudinal study of single‐word comprehension in semantic dementia: A comparison with primary progressive aphasia and Alzheimer's disease

Background: Although semantic dementia (SD) is characterised by a multimodal loss of semantic knowledge, it has been demonstrated that lexical‐semantic representations are not equally disrupted in SD and that some categories may be recognised better than others. Little is known, however, about the pattern of the category‐specific comprehension deficits in SD and whether it differs from that of other forms of progressive aphasias.

Aims: This exploratory study aimed to investigate the evolution of category‐specific deficits of single‐word comprehension in progressive aphasias.

Methods & Procedures: A total of 19 patients with a clinical diagnosis of SD, 25 patients with primary progressive aphasia with agrammatic and relatively nonfluent speech (PPA), and 25 patients with Alzheimer's disease (AD) with aphasia were studied longitudinally with the Western Aphasia Battery (WAB). The Auditory Word Recognition subtest of the WAB was utilised to assess comprehension of words derived from different semantic categories.

Outcomes & Results: The analysis revealed that, over time, category‐specific deficits of single‐word comprehension were seen in all three groups of patients. Participants with SD as well as those with PPA and AD were impaired on both pointing to fingers and the right–left orientation task. However, patients with SD were the only group that showed defective recognition of their own body parts. Interestingly, individuals with SD had no difficulties identifying colours, letters, and numbers, even during the follow‐up testing. In addition, in all three groups the extent of category‐specific deficits was associated with the severity of aphasia.

Conclusions: These results indicate that category‐specific deficits of single‐word comprehension are frequently seen not only in patients with SD but also in individuals with PPA or AD, and that the extent of these deficits is associated with the severity of aphasia. However, the pattern of these deficits is often different in these three forms of neurodegenerative conditions and more dissociations between semantic categories are observed as each of these diseases progresses.     

Communication style before and after aphasia: A study among Finnish population

Background: Communication difficulties in aphasia have a big effect on communicative activity and social participation. Contacts with other people than family become more infrequent because of problems in communicating. Rehabilitation should make a real difference in being able to communicate and in the life of people with aphasia.

Aims: The aim of this study was to explore the impact of aphasia on the communication style of people with aphasia in the Finnish population. The term “communication style” is used to describe how active the person is in communication situations and in participating in social interaction. In addition, a clinical evaluation of the communication style was made 6 months after an intervention concentrating on training total communication and guiding the partner to facilitate the use of different communication methods and support the interaction.

Methods & Procedures: The data were collected during natural rehabilitation courses for people with aphasia and their communication partners. The participants were 38 communication partners of people with aphasia. The courses were carried out in two parts (8 + 4 days) with a 3-month interval. A questionnaire concerning the communication style of people with aphasia was constructed using parts of Green’s questionnaire (1984) and its unpublished Finnish modification. The communication partners estimated the communication style of people with aphasia. At first, they estimated how the communication style was before the onset of aphasia and how it was 2 weeks before the intervention. Six months after the intervention, they estimated the communication style again.

Outcomes & Results: Aphasia has a drastic impact on the communicative activity and social participation of people with aphasia in Finland. Activity in conversations decreases and contacts with people other than family members and relatives become much more infrequent. The social interaction occurs mostly at home. The conversation topics focus on health, home matters and TV programmes when other topics such as work, hobbies, leisure time and plans for the future are discussed much less often.

Conclusion: Aphasia has a drastic impact on communication style, activity in communication and participation in social interaction, also according to this study conducted in Finland. There seems to be a decrease in communication between the people with aphasia and people other than their significant others and outside the home. To be able to have an impact on social participation, interventions also including people other than family members are needed.     

Psychometric properties of the Communication Confidence Rating Scale for Aphasia (CCRSA): Phase 2

Background: The construct of communication confidence was introduced by participants and family members during qualitative post-treatment interviews as part of a research study using a computer programme to deliver language therapy. However, there was no standardised method of evaluating communication confidence. Therefore the Communication Confidence Rating Scale for Aphasia (CCRSA) was developed, asking persons to self-rate communication confidence.

Aims: This study reports data from the second phase of the project in which the CCRSA was revised to include 10 items. This revised 10-item self-rating scale of communication confidence (CCRSA) was evaluated psychometrically.

Methods & Procedures: The revised 10-item questionnaire was administered 94 times to 47 participants with aphasia from a variety of settings. Psychometric properties of the 10-item CCRSA were investigated using rating scale (Rasch) analysis.

Outcomes & Results: Person reliability of the 10-item CCRSA was .81. The four-category rating scale demonstrated monotonic increases in average measures from low to high ratings. However, one item (“How confident are you that you can participate in discussions about your finances?”) slightly misfitted the construct defined by the other items (mean square infit?=?1.54, item-measure correlation?=?.48).

Conclusions: Our findings suggest that the CCRSA is a psychometrically sound tool for assessing participants' self-report of communication confidence. Further evaluation of the CCRSA is warranted to examine sensitivity to change and inter- and intra-rater reliability.