Karen Sage

Coherent concepts are computed in the anterior temporal lobes

In his Philosophical Investigations, Wittgenstein famously noted that the formation of semantic representations requires more than a simple combination of verbal and nonverbal features to generate conceptually based similarities and differences. Classical and contemporary neuroscience has tended to focus upon how different neocortical regions contribute to conceptualization through the summation of modality-specific information. The additional yet critical step of computing coherent concepts has received little attention. Some computational models of semantic memory are able to generate such concepts by the addition of modality-invariant information coded in a multidimensional semantic space. By studying patients with semantic dementia, we demonstrate that this aspect of semantic memory becomes compromised following atrophy of the anterior temporal lobes and, as a result, the patients become increasingly influenced by superficial rather than conceptual similarities.

The treatment of anomia using errorless learning.

In the contemporary literature, errorless learning is thought to have benefits over more traditional trial-and-error methods. The most prominent investigations of errorless learning are those designed for rehabilitation of severe memory impairments, including numerous demonstrations of effective amelioration of word-finding difficulties (Baddeley & Wilson, 1994; Clare, Wilson, Breen, & Hodges, 1999; Clare et al., 2000; Evans et al., 2000). Despite this, there are very few reports on the application of purely errorless learning to people with aphasia (Fillingham, Hodgson, Sage, & Lambon Ralph, 2003). The aim of this study was to compare directly the efficacy of errorless and errorful learning in a case series of 11 aphasic people with pronounced word-finding difficulties. Previous studies of errorless learning and, more recently, studies of rehabilitation have suggested that cognition is an important factor for determining outcome (Helm-Estabrooks, 2002; Robertson & Murre, 1999). Therefore, a thorough language and neuropsychological assessment battery was completed with each participant. Naming therapy was carried out to contrast errorless and errorful therapy in a case series analysis. Errorless learning proved to be as effective as the more traditional, errorful approach in the majority of cases in terms of both immediate improvement and at follow up assessment. Without exception, the patients preferred the errorless learning therapy. Strikingly, it was found that language skill did not predict therapy outcome. Participants who responded better overall, had better recognition memory, executive/problem solving skills and monitoring ability. This replicates recent findings that frontal executive skills are crucial for rehabilitation (Robertson & Murre, 1999). Also, participants who did better at errorful treatment were those with the best working and recall memory, and attention. It is probable that these factors are essential cognitive components for providing effective monitoring and feedback systems to a more general learning mechanism. Department of Psychology, The University of Manchester, Oxford Road, Manchester M13 9PL. E-mail: matt.lambon-ralph@man.ac.uk

Errorless and errorful therapy for verb and noun naming in aphasia

Background: The aphasiological literature has provided an extensive body of research on verb impairments but many fewer verb therapy studies. Verbs display particular complexity at various levels of linguistic analysis: phonological, morphological, semantic, and syntactic. Verb impairments can arise at any of these processing levels as well as from cognitive sources. Verb-naming therapies may therefore be relatively more vulnerable to errors, which could reduce their effectiveness. Errorless learning has been used with positive results for noun therapies. Aims: Given the high linguistic and cognitive demands of verb processing, this study investigated whether errorless therapy would be more effective for verb naming than more traditional hierarchical cueing (relatively errorful) therapy. Methods & Procedures: Nine participants with word-finding difficulties as a part of their chronic aphasia took part in the study. Outcomes & Results: For the dependent variable of naming accuracy, as in previous studies, we found that errorless therapy was as effective as errorful therapy for both verb and noun naming. Three participants with most severe aphasia showed significantly greater gains in noun as opposed to verb naming. The remaining participants exhibited comparable gains in both nouns and verb naming. There was no lasting generalisation from treated to untreated therapy items. The prediction that errorless therapy would be more effective for verb naming was not upheld; errorless and errorful approaches were as effective as one another. Conclusions: An errorless-learning approach to verb and noun naming was a time-efficient therapy, and one that was as effective as an errorful/hierarchical cueing method in improving naming accuracy, for a range of participants with varying naming skills and types of aphasia.

Relearning and retention of verbal labels in a case of semantic dementia

Background: Previous studies looking at relearning and retention of word labels in people with semantic dementia have shown some improvement in naming immediately after the period of learning but this has not usually been maintained. Studies have also shown rigid learning of names, in the order of presentation and to the picture exemplars only, with no generalisation of learning. Aims: This study aimed to explore relearning of a small vocabulary set in a person with semantic dementia (CUB) and to examine her ability to generalise this learning. In addition, it aimed to find out how long the learning persisted after therapy was completed given that semantic dementia is a progressive disorder. Methods & Procedures: A single‐case design was used where CUB was asked to learn 28 words while a further 28 were left as controls. A “look and say” method was used daily for 1 month. As well as examining learning of the therapy and control set, CUB was asked to name 168 other exemplars of the learning set to see whether there had been any transfer of her learning from the therapy set. Outcomes & Results: CUB not only relearned a set of picture names but retained these without deliberate practice over a 6‐month period. She was also able to generalise this learning to other visually similar exemplars in testing and in daily use. The maintenance of relearning was achieved despite severe deterioration in her semantic memory. Conclusions: Possible reasons are explored as to why CUB was able to relearn and retain these words and why this may differ from all previously reported cases. Differences in amount of time spent relearning, number of items learned, therapy methods, the severity of semantic memory impairment, the degree of atrophy, and the behavioural profiles of people with semantic dementia do not provide adequate explanations for our individuals differential ability to retain her learning over 6 months. The most plausible explanation is that the person with semantic dementia generalised her learning to her everyday speech and this provided the source of maintenance for the relearned names. This work was supported by a Royal Society Travel Fellowship awarded to K. Sage. We are grateful to Dr Tomás Ojea from the Hospital Carlos Haya, Málaga for referring CUB to us, and most importantly to CUB and her family for their collaboration throughout.

Towards theory‐driven therapies for aphasic verb impairments: A review of current theory and practice

Background: This review is intended for both theoretically and clinically motivated audiences with an interest in aphasic verb impairments. This work is supported by a Research Bursary from the Stroke Association (TSAB 2004/01). Aims: Building from previous reviews, our aim is to provide a concise summary of the relevant theoretical research and perspectives on verbs, and from this theoretical foundation to explore which aspects have been incorporated and tested in therapy studies. Main Contribution: In the theoretical domain, the review first considers the patterns of verb and noun impairments in aphasic syndromes. Second, an overview of the linguistic differences between verbs and nouns is provided, differences that occur at various levels of linguistic analysis: phonological, morphological, semantic, and syntactic. This is followed by a detailed account of the psycholinguistic perspective on verb–noun differences. Specifically, this section examines the role of variables such as imageability and frequency, and the issue of depiction of actions in static picture versus dynamic video format. Evidence from neuroimaging studies as well as neurodegenerative conditions such as semantic dementia is also reviewed. Finally, the psycholinguistic account further discusses the question of whether verbs (and nouns) serve as primary ordering principles in the cognitive architecture of language processing or whether they should be more accurately viewed as points on an overarching psycholinguistic continuum. Also within the psycholinguistic discussion, event perception is described as a theoretical account with implications for verb processing. Despite the importance of verbs in their pivotal role in connected speech, there is a very limited body of literature on verb therapies and only a small number of the theoretical issues/perspectives have penetrated approaches to treating verb impairments. Ten published papers are described. Two of these directly compare verb and noun therapies, reflecting the many comparisons of noun vs verb impairments in the theoretical literature. The remaining eight consist of purely verb‐focused therapies, which also examined the effects of increased verb retrieval skills on related sentence production (reflecting the pivotal role of verbs in connected speech). These eight studies are subdivided between four that targeted verb retrieval only and four that also investigated aspects of verb argument structure and sentence production. Conclusions: The general discussion notes possible new approaches to the treatment of verb deficits that arise from the many factors noted in the theoretical literature which are yet to be fully explored in therapy studies.

The effects of decreasing and increasing cue therapy on improving naming speed and accuracy for verbs and nouns in aphasia

Background: Verb impairments in aphasia have generated considerable theoretical interest in the literature (Druks, 2002; Druks & Masterson, 2003; Marshall, 2003) but this is not reflected in the number of studies investigating therapies for verb impairments (Conroy, Sage, & Lambon Ralph, 2006). Recent anomia therapy studies have compared errorless and errorful techniques (Abel, Schultz, Radermacher, Willmes, & Huber, 2005; Fillingham, Hodgson, Sage, & Lambon Ralph, 2003; Fillingham, Sage, & Lambon Ralph, 2005a, 2005b, 2006). Decreasing cues have been proposed as the optimal interaction of low error and sustained effort in therapy in the amnesia literature (Komatsu, Mimura, Kato, Wakamatsu, & Kashima, 2000). Following on from Conroy, Sage, and Lambon Ralph (2008), we predicted that decreasing cue therapy would result in greater effects in terms of both naming accuracy and speed relative to increasing cues. Aims: The present study aimed to answer the following questions: (1) Would naming therapy consisting of decreasing cues result in greater naming accuracy for verb and noun targets than therapy consisting of increasing cues? (2) Would decreasing cues result in speedier naming responses to verb and noun targets than increasing cues? Methods & Procedures: A case‐series study that utilised decreasing versus increasing cues as naming therapy for verbs and nouns was implemented with seven participants with aphasia of various sub‐types and degrees of severity. A total of 120 target words were collated for each participant, divided into three sets, each consisting of 20 verbs and 20 nouns. Set A was used in decreasing cues therapy, set B in increasing cues therapy, and set C served as control items. Ten sessions of therapy were delivered to each therapy set concurrently. The speed of post‐therapy naming responses as well as accuracy was recorded. Outcomes & Results: All participants showed significant therapy gains after both decreasing and increasing cue therapies, with little or no change in naming of control sets. The two therapies were equivalent in the degree to which participants improved in naming accuracy and yielded almost identical overall speed of naming responses. Naming speeds for successfully named items, post‐therapy, were faster for nouns than verbs (perhaps reflecting their shorter length), and faster at immediate than follow‐up assessment. Conclusions: Decreasing cues are as effective in naming therapy as increasing cues, in terms of both accuracy and speed of naming for verbs and nouns.

Lexical influences in graphemic buffer disorder

Abstract We report the case of patient BH, who misspelled about half of the words she attempted and showed the characteristic features of “graphemic buffer disorder” (an effect of letter length on spelling accuracy, errors involving the substitution, omission, addition, and movement of letters that affect the middles more than the ends of words). Speech comprehension and production were good. Reading of words was, at most, only mildly impaired, though reading of nonwords was more affected. Words were spelled more accurately than nonwords, and BHs ability to spell words correctly was influenced by their imageability, age of acquisition, frequency, and number of orthographic neighbours (N). The effect of length was much reduced once these factors (especially N) were controlled. BHs spelling pattern is discussed in terms of top-down lexical influences on the graphemic buffer. We argue that such effects may be more widespread than has previously been acknowledged.

Wernicke's Aphasia Reflects a Combination of Acoustic-Phonological and Semantic Control Deficits: A Case-Series Comparison of Wernicke's Aphasia, Semantic Dementia and Semantic Aphasia.

Wernickes aphasia (WA) is the classical neurological model of comprehension impairment and, as a result, the posterior temporal lobe is assumed to be critical to semantic cognition. This conclusion is potentially confused by (a) the existence of patient groups with semantic impairment following damage to other brain regions (semantic dementia and semantic aphasia) and (b) an ongoing debate about the underlying causes of comprehension impairment in WA. By directly comparing these three patient groups for the first time, we demonstrate that the comprehension impairment in Wernickes aphasia is best accounted for by dual deficits in acoustic-phonological analysis (associated with pSTG) and semantic cognition (associated with pMTG and angular gyrus). The WA group were impaired on both nonverbal and verbal comprehension assessments consistent with a generalised semantic impairment. This semantic deficit was most similar in nature to that of the semantic aphasia group suggestive of a disruption to semantic control processes. In addition, only the WA group showed a strong effect of input modality on comprehension, with accuracy decreasing considerably as acoustic-phonological requirements increased. These results deviate from traditional accounts which emphasise a single impairment and, instead, implicate two deficits underlying the comprehension disorder in WA.

Implementing and evaluating aphasia therapy targeted at couples' conversations: A single case study

Background: In recent years conversation has become an area of interest for aphasia therapy, with several studies using conversation analysis (CA) to target and evaluate therapy. Most of these studies have focused on the main conversation partner of the person with aphasia, and in particular have targeted the partners pedagogic behaviours in relation to the person with aphasia. Evaluations of therapy have primarily taken the form of qualitative analyses of change in conversational behaviours. Aims: This single-case intervention study aims to advance research into interaction-focused intervention for aphasia in the following ways: by targeting intervention at the person with aphasia and the main conversation partner as a couple; by focusing on conversational behaviours where the person with aphasia can be seen to be restricted by the conversational actions of the conversation partner, in particular by recurrent questioning using closed questions and yes/no interrogatives; and by using a novel combination of qualitative and quantitative approaches to evaluate the intervention. Methods & Procedures: CA was used to target and evaluate interaction-focused intervention for a couple where one partner has aphasia. Evidence for change was evaluated using qualitative and quantitative evidence of change in conversational behaviours; evidence from naïve raters of pre- and post-intervention conversation extracts; and interview/other feedback from the conversation partner. Outcomes & Results: There was evidence that the intervention had changed the couples conversational behaviours. In particular, the conversational behaviours of the non-aphasic partner were in general less restricting for the person with aphasia in that she was now using fewer questions and more instance of other types of turns, such as paraphrases. Following intervention the person with aphasia had also changed in that he was now producing turns that had more sentences, or attempts at sentences, and which developed the topic of talk across several of his turns. Conclusions: The study provides evidence that directly targeting the conversational behaviours of the person with aphasia and/or a main conversational partner can produce positive change, and can achieve this in a way that is ecologically valid. In particular, it highlights the usefulness of targeting conversational behaviours that are proving to be maladaptive for the participants. It provides further evidence that creating change in the non-aphasic partners conversational behaviour may facilitate change in the person with aphasias conversational and linguistic performance.

How intensive does anomia therapy for people with aphasia need to be

The intensity of aphasia therapy has been a key clinical question. The aim of this case-series study was to compare the outcome of intensive and non-intensive therapy in the relearning of words for people with aphasia. Eight participants took part in a study comparing the intensity of delivery of the therapy. Participants received two courses of the same therapy (each lasting 10 sessions) delivered either intensively or non-intensively. Therapy consisted of confrontation naming with progressive phonemic and orthographic cues. Post-therapy assessments were carried out immediately after the study and one month later. Performance was also monitored during each therapy session. Immediately post-therapy, both types of therapy had improved naming accuracy considerably and there was no significant difference between the two interventions. One month later, seven out of eight participants showed a small yet significant difference in naming accuracy, favouring non-intensive over intense therapy. There were no differences in the learning patterns during the therapy sessions between the intensive and non-intensive therapies. For the majority of people with aphasia post-stroke, both intense and non-intense therapy for anomia leads to improved naming performance. Retention at one-month post therapy is relatively superior after non-intensive therapy.