Learning and maintaining new vocabulary in persons with aphasia: Two controlled case studies

Background: Novel word learning of persons with aphasia is little studied, even though a better understanding of learning processes would inform development of effective treatment strategies. Recent evidence suggests some remaining verbal learning capacity in persons with aphasia. Long-term maintenance of newly learned active vocabulary has not been reported previously in persons with aphasia.

Aims: To explore learning and long-term maintenance of novel words in persons with aphasia.

Methods & Procedures: Two English-speaking males with chronic anomic aphasia and two age-matched controls were taught novel names of 20 unfamiliar objects. Half of the words were taught with semantic information (definition) and half without. Participants were instructed to learn the names. The experiment included four training sessions, one post-training test and four follow-up tests administered 1 week, 4 weeks, 8 weeks, and 6 months post-training. We tested explicit learning of the new names through visual confrontation naming. In addition, incidental learning of semantic information was probed over the follow-up period.

Outcomes & Results: The two participants with aphasia learned 6–8 of the 20 novel names during the training. However, this new vocabulary dissipated during the 6-month follow-up. As expected, the controls showed better performance both in acquisition and in maintenance of the new vocabulary over the follow-up period. As regards the accuracy of semantic information, the aphasic participant with semantic impairment demonstrated worse incidental learning of semantic information than controls and the participant with intact lexical semantics.

Conclusions: Some new vocabulary can be acquired even in chronic aphasia but the ability to spontaneously retrieve the newly learned words gradually dissipates over the weeks following learning. Our results also indicate an interaction between the level of lexical-semantic processing skills and incidental learning of new lexical-semantic knowledge in aphasia.     

Lexicality effects in word and nonword recall of semantic dementia and progressive nonfluent aphasia

Background: Verbal working memory is an essential component of many language functions, including sentence comprehension and word learning. As such, working memory has emerged as a domain of intense research interest both in aphasiology and in the broader field of cognitive neuroscience. The integrity of verbal working memory encoding relies on a fluid interaction between semantic and phonological processes. That is, we encode verbal detail using many cues related to both the sound and meaning of words. Lesion models can provide an effective means of parsing the contributions of phonological or semantic impairment to recall performance.

Methods & Procedures: We employed the lesion model approach here by contrasting the nature of lexicality errors incurred during recall of word and nonword sequences by three individuals with progressive nonfluent aphasia (a phonological dominant impairment) compared to that of two individuals with semantic dementia (a semantic dominant impairment). We focused on psycholinguistic attributes of correctly recalled stimuli relative to those that elicited a lexicality error (i.e., nonword → word OR word → nonword).

Outcomes & Results: Patients with semantic dementia showed greater sensitivity to phonological attributes (e.g., phoneme length, wordlikeness) of the target items relative to semantic attributes (e.g., familiarity). Patients with PNFA showed the opposite pattern, marked by sensitivity to word frequency, age of acquisition, familiarity, and imageability.

Conclusions: We interpret these results in favour of a processing strategy such that in the context of a focal phonological impairment patients revert to an over-reliance on preserved semantic processing abilities. In contrast, a focal semantic impairment forces both reliance on and hypersensitivity to phonological attributes of target words. We relate this interpretation to previous hypotheses about the nature of verbal short-term memory in progressive aphasia.     

Word discrimination therapy: A new technique for the treatment of a phonologically based word‐finding impairment

Background: The majority of cognitive neuropsychological treatments for impairments in phonological encoding utilise some form of phonological cueing or support. Most commonly, the participant is provided with supporting information about the phonological form of a particular word (either partial or complete, auditory or written), and must then generate the word orally. The provision of target phonology facilitates initial production of the word, which can then be repeatedly trained in order to induce relearning of the appropriate lexical–phonological associations.

Aims: The aim of the current case study was to examine the effectiveness of an indirect cueing technique for the treatment of mild impairments in phonological encoding. In this treatment the participant must name pictures without assistance, but the picture names themselves share a phonological relationship (e.g., magnet, mattress, macaroni). These phonologically similar triplets incorporate a form of phonological cueing; however, the cues do not involve the direct provision of the word form.

Methods & Procedures: The case reported here, patient TV, suffers from a mild phonological encoding impairment: he produces phonemic paraphasias and other form‐related errors on longer and/or less frequent words in spontaneous speech and other spoken word production tasks. In the treatment, TV was asked to name triplets of pictures whose names were either phonologically related (sharing either initial or final phonemes) or unrelated. This procedure was repeated across 12 therapy sessions, all of which trained the same set of words. TV's pre‐treatment naming accuracy on the training words was assessed using a repeated baseline design, and was continuously reassessed throughout treatment, and also at 3 months post‐therapy. The key comparison was between words trained within phonologically related triplets and control words trained in unrelated triplets. The design also included multiple assessments on an untrained set of words to assess generalisation.

Outcomes & Results: For this mild case, naming accuracy for all words trained improved significantly. However, gains were significantly faster for the words that were trained within phonologically related triplets than those trained in unrelated triplets. Significant generalisation to untreated items was also observed, and gains on both treatment items and generalisation effects were maintained at 3 months post therapy.

Conclusion: Results from this case study suggest that this type of indirect cueing technique may be a particularly efficient method for treating mild impairments in phonological coding.     

Improved effects of word‐retrieval treatments subsequent to addition of the orthographic form

Background: The participant, an individual with moderate–severe Wernicke's aphasia, had not benefited from two word‐retrieval cueing treatments in a previous investigation. The participant insisted that her performance would have been improved if the written word had been provided as part of the cueing process.

Aims: The purpose of this investigation was to examine the effects of adding the orthographic form of targeted action names to a semantic cueing treatment (SCT) and a phonologic cueing treatment (PCT).

Methods & Procedures: The participant received SCT and PCT applied to the retrieval of action names. The treatments both provided the written word form paired with the pictured action in conjunction with cueing hierarchies. Two, sequential multiple baseline designs across behaviours were employed to examine the acquisition and response generalisation effects of treatment.

Outcomes & Results: Improved accuracy of action naming was found for both treatments. Gains were limited to trained items; no changes were observed in naming of untrained actions.

Conclusions: It appeared that the participant utilised the orthographic word form to develop associations between the visual object recognition system and the orthographic input lexicon, thus facilitating access to the phonological output lexicon.     

Phonological and orthographic cueing therapy: A case of generalised improvement

Background: Phonological and orthographic cues can both be effective in the treatment of anomia, and are often used clinically. However, studies using phonological and orthographical cues in aphasia therapy have tended to be equivocal about their benefits, and most demonstrate improvements limited to treated items. Few previous studies investigate change in conversation or in people's own views of their aphasia.

Aims: The aim of the study was to investigate the effect of a weekly delivered therapy, using combined phonological and orthographic cues, on word retrieval, connected speech, conversation, and on the participant's own views of his aphasia.

Methods & Procedures: A person with anomia (TE) is presented as a detailed single-case study. Two baselines, 8 weeks apart, were followed by two 8-week phases of therapy, delivered weekly in a clinical setting. The first phase involved the use of combined phonological and orthographic cues to aid retrieval of a targeted set of words. The second phase encouraged the use of targeted words in connected speech and conversation. TE was reassessed after each phase of therapy and again 2 months later, after a period of no therapy. The study involved controls for improvement due to regular contact but without intervention (the baseline phase) and investigated generalisation to untreated items (treated and untreated sets were used, balanced for performance prior to therapy). Finally non-specific effects of therapy were determined by testing throughout the study on a set of language control tasks (predicted to be unaffected by the therapy).

Outcome & Results: TE demonstrated significant and enduring improvements in picture naming, which had generalised to untreated items. Significant improvements were also demonstrated in the broader measures of connected speech, aspects of conversation, and his own views of his aphasia, while performance on control tasks remained fairly stable. There was a significant relationship between changes in word finding and changes in TE's views of his communication activity across the course of the study, with a pattern of stability over baseline and change with intervention, particularly the first phase of therapy, i.e., using cues.

Conclusions: These findings demonstrate that a combined phonological and orthographic cueing therapy targeting word retrieval can have lasting benefits, not just on targeted items but also on untreated words, connected speech, and the views of the person with aphasia. Furthermore, such improvements can be achieved within a prevalent service delivery model.     

Effects of phonological neighbourhood on the treatment of naming in aphasia

Background: Phonological treatments to improve naming ability in aphasia focus on re-strengthening connections within the phonological system. Nonetheless, the efficacy of phonological treatments is still being explored with particular consideration of cognitive neuropsychological perspectives. Clinicians may also need to consider lexical factors that interact with the word retrieval process. Researchers have shown that phonological neighbourhood density influences normal language recognition and production, but limited evidence exists for how phonological neighbourhoods may affect the treatment of word retrieval deficits in individuals with aphasia.

Aims: The present study explored if manipulating the emphasis on phonological neighbourhood during treatment has an effect on naming ability, particularly in an individual with predominantly phonologically based deficits. We hypothesised that training front- and end-matched words in a condition that emphasised phonological neighbourhood would result in greater naming improvements than training front- and end-matched words in a condition that does not emphasise neighbourhood.

Methods & Procedures: In this case study, participant AH had a moderate phonologically based word naming deficit following a stroke. He produced phonemic paraphasias and neologisms in spontaneous speech and other spoken word production tasks. In treatment, AH was asked to name triplets of pictures of items that were phonologically related, sharing initial or final phonemes, or unrelated. Items were from either high- or low-density phonological neighbourhoods. High-density items were trained largely in the context of neighbours, therefore emphasising neighbourhood. Low-density items were not trained within a condition that emphasise neighbourhood. The treatment was administered for 9 weeks (27 sessions), with each condition, front-matched, end-matched and unrelated, trained for 8 consecutive sessions. AH’s naming accuracy on training words was assessed using a basic withdrawal design with three probe naming tests during the treatment phase and at 1-month post-therapy. Naming accuracy was also recorded during treatment sessions.

Outcomes & Results: Front-matched words, in a condition that emphasises phonological neighbourhoods, had the greatest treatment effects, with a medium effect size when comparing pre- versus post-measures. A small treatment effect was observed for front-matched items where neighbourhood was not emphasised.

Conclusions: Results suggest that front-matched triplets trained within a condition that emphasises phonological neighbourhoods may lead to the greatest treatment effect. Clinicians should be aware that stimulus parameters, such as phonological neighbourhood, may interact with the effectiveness of treatment protocols.     

Generalisation of personalised cueing to enhance word finding in natural settings

Background: Personalised cueing is a treatment method for naming deficits in patients with aphasia. As part of the treatment patients choose their own cues to help recall a target word. These cues usually include personally relevant semantic information, which is hypothesised to enhance long-term naming abilities. Previous research has shown that personalised cueing can improve long-term naming accuracy in persons with aphasia. However, no research has shown that personalised cueing carries over to improved naming in natural settings.

Aims: The study aimed to examine the long-term generalisation of improved word finding using the personalised cueing method.

Methods & Procedures: Three individuals participated in 12 training trials using the personalised cueing method; 40 unnamed stimulus items were chosen for each participant. Pre-training measures of the Sentence Production Task (SPT) and Message Exchange Task (MET) were administered for each participant. Of the 40 stimulus items, 20 were then trained using the personalised cueing method across 12 training sessions. Post-training measures of the SPT and MET were then collected, along with measures on a Caregiver Partner Rating scale to assess naming accuracy in natural settings. The 20 untrained stimulus items were also probed to assess generalisation to untrained stimuli.

Outcomes & Results: Two of the three participants showed improvement in naming trained items in natural settings, but little improvement was noted on the untrained stimulus items. Results for these patients were consistent with other studies on the personalised cueing method. The third participant demonstrated a slight increase in naming accuracy over time. Shortly after this study that participant was diagnosed with Alzheimer's disease.

Conclusions: Results suggest that personalised cueing is an effective method of improving naming in certain individuals with aphasia. It also suggests that the effects of personalised cueing are maintained over time and are evident in natural settings.     

A contextual approach to facilitating word retrieval in agrammatic aphasia

Background: Although virtually all individuals with aphasia demonstrate problems with word retrieval, this symptom might arise for different reasons in individuals with different types of aphasia. A trade‐off of dependence on semantic and syntactic information is hypothesised to underlie dissociations in word retrieval shown by fluent anomic and non‐fluent agrammatic speakers. This division of labour predicts that strengthening semantic input will improve word retrieval for those with anomic aphasia, whereas strengthening syntactic input through contextual cues will improve word retrieval for those with agrammatic aphasia.

Aims: To explore the outcome of a new treatment approach that proposes to improve word retrieval in individuals with agrammatic aphasia by implicitly strengthening the links between target words and associated words which co‐occur in a connected speech context.

Methods & Procedures: The outcomes of two therapy approaches were examined in two participants with agrammatic aphasia. One therapy approach focused on explicitly training semantic features of target words; the other, more novel, approach focused on implicitly strengthening contextual associations through story telling and retelling. It was predicted that the latter approach would result in greater benefits for the two agrammatic participants.

Outcomes & Results: Although both therapy approaches appeared to be effective, the predicted advantage of the contextually based approach was not found. The evolution of the error patterns throughout the treatment was examined to help understand the mechanisms underlying the improvements shown for each participant.

Conclusions: A novel treatment involving training words in a story context was shown to result in improved word retrieval for two participants with agrammatic aphasia. The merits of the approach are discussed, relative to more traditional explicit word retrieval therapy approaches.     

Facilitating and disrupting speech perception in word deafness

Background: Word deafness is a rare condition where pathologically degraded speech perception results in impaired repetition and comprehension but otherwise intact linguistic skills. Although impaired linguistic systems in aphasia resulting from damage to the neural language system (here termed central impairments) have consistently been shown to be amenable to external influences such as linguistic or contextual information (e.g., cueing effects in naming), it is not known whether similar influences can be shown for aphasia arising from damage to a perceptual system (here termed peripheral impairments).

Aims: This study aimed to investigate the extent to which pathologically degraded speech perception could be facilitated or disrupted by providing visual as well as auditory information.

Methods & Procedures: In three word repetition tasks, the participant with word deafness (AB) repeated words under different conditions: words were repeated in the context of a pictorial or written target, a distractor (semantic, unrelated, rhyme, or phonological neighbour) or a blank page (nothing). Accuracy and error types were analysed.

Outcomes & Results: AB was impaired at repetition in the blank condition, confirming her degraded speech perception. Repetition was significantly facilitated when accompanied by a picture or written example of the word and significantly impaired by the presence of a written rhyme. Errors in the blank condition were primarily formal, whereas errors in the rhyme condition were primarily miscues (saying the distractor word rather than the target).

Conclusions: Cross-modal input can both facilitate and further disrupt repetition in word deafness. The cognitive mechanisms behind these findings are discussed. Both top-down influence from the lexical layer on perceptual processes and intra-lexical competition within the lexical layer may play a role.     

Aphasia rehabilitation: Does generalisation from anomia therapy occur and is it predictable? A case series study

Introduction

The majority of adults with acquired aphasia have anomia which can respond to rehabilitation with cues. However, the literature and clinical consensus suggest change is usually limited to treated items. We investigated the effect of an experimentally controlled intervention using progressive cues in the rehabilitation of noun retrieval/production in 16 participants with chronic aphasia.

Method

Participants were sub-divided relative to the group according to performance on semantic tasks (spoken/written word to picture matching) and phonological output processing (presence/absence of word length effect and proportion of phonological errors in picture naming) in order to investigate outcome in relation to language profile. Cueing therapy took place weekly for 8 weeks.

Results

Intervention resulted in significant improvement on naming treated items for 15/16 participants, with stable performance on control tasks. Change occurred at the point of intervention and not during pre-therapy assessments. We predicted particular patterns of generalisation which were upheld. Only participants classified as having relatively less of a semantic difficulty and more of a phonological output deficit demonstrated generalisation to untreated items. Outcome did not relate to traditional aphasia classification.

Conclusion

A cueing hierarchy can improve word retrieval/production for adults with aphasia. In some cases generalisation to untreated items also occurs. The study demonstrates that the results of behavioural testing can be used to guide predictions of recovery with intervention.     

Single‐word semantic judgements in semantic dementia: Do phonology and grammatical class count?

Background: Listeners make active use of phonological regularities such as word length to facilitate higher‐level syntactic and semantic processing. For example, nouns are longer than verbs, and abstract words are longer than concrete words. Patients with semantic dementia (SD) experience conceptual loss with preserved syntax and phonology. The extent to which patients with SD exploit phonological regularities to support language processing remains unclear.

Aims: We examined the ability of patients with SD (1) to perceive subtle acoustic–phonetic distinctions in English, and (2) to bootstrap their accuracy of lexical‐semantic and syntactic judgements from regularities in the phonological forms of English nouns and verbs.

Methods and Procedures: Four patients with SD made minimal pair judgements (same/different) for auditorily presented stimuli selectively varied by voice, place, or manner of the initial consonant (e.g., pa –ba). In Experiment 2 patients made forced‐choice semantic judgements (abstract or concrete) for single words varied by (1) concreteness (abstract or concrete); (2) grammatical class (noun or verb); and (3) word length (one‐ or three‐syllable words).

Outcomes and Results: The most semantically impaired patients paradoxically showed the highest accuracy of minimal pair phonologic discrimination. Judgements of word concreteness were less accurate for verbs than nouns. Among verbs, accuracy was worse for concrete than abstract items (e.g., eat was worse than think). Patients were more likely to misclassify longer concrete words (e.g., professor) as abstract, demonstrating sensitivity to an underlying phonologically mediated semantic property in English.

Conclusions: Single‐word semantic judgements were sensitive to both grammatical class and phonological properties of the words being evaluated. Theoretical and clinical implications are addressed in the context of an anatomically constrained model of SD that assumes increasing reliance on phonology as lexical‐semantic knowledge degrades.     

Learning and forgetting new names and objects in MCI and AD

We studied how subjects with mild cognitive impairment (MCI), early Alzheimer's disease (AD) and age-matched controls learned and maintained the names of unfamiliar objects that were trained with or without semantic support (object definitions). Naming performance, phonological cueing, incidental learning of the definitions and recognition of the objects were tested during follow-up. We found that word learning was significantly impaired in MCI and AD patients, whereas forgetting patterns were similar across groups. Semantic support showed a beneficial effect on object name retrieval in the MCI group 8 weeks after training, suggesting that the MCI patients’ preserved semantic memory can compensate for impaired episodic memory. The MCI group performed equally well as the controls in the tasks measuring incidental learning and recognition memory, whereas the AD group showed impairment in this respect. Both the MCI and the AD group benefited less from phonological cueing than the controls. Our findings indicate that word learning is compromised in both MCI and AD, whereas long-term retention of newly learned words is not affected to the same extent. Incidental learning and recognition memory seem to be well preserved in MCI.     

The use of the picture–word interference paradigm to examine naming abilities in aphasic individuals

Background: Although naming deficits are well documented in aphasia, on‐line measures of naming processes have been little investigated. The use of on‐line measures may offer further insight into the nature of aphasic naming deficits that would otherwise be difficult to interpret when using off‐line measures.

Aims: The temporal activation of semantic and phonological processes was tracked in older normal control and aphasic individuals using a picture–word interference paradigm. The purpose of the study was to examine how word interference results can augment and/or corroborate standard language testing in the aphasic group, as well as to examine temporal patterns of activation in the aphasic group when compared to a normal control group.

Methods & Procedures: A total of 20 older normal individuals and 11 aphasic individuals participated. Detailed measures of each aphasic individual's language and naming skills were obtained. A visual picture–word interference paradigm was used in which the words bore either a semantic, phonological, or no relationship to 25 pictures. These competitor words were presented at stimulus onset asynchronies of ?300 ms,?+300 ms, and 0 ms.

Outcomes & Results: Analyses of naming RTs in both groups revealed significant early semantic interference effects, mid‐semantic interference effects, and mid‐phonological facilitation effects. A matched control‐aphasic group comparison revealed no differences in the temporal activation of effects during the course of naming. Partial support for this RT pattern was found in the aphasic naming error pattern. The aphasic group also demonstrated greater SIEs and PFEs compared to the matched control group, which indicated disruptions of the phonological processing stage. Analyses of behavioural performances of the aphasic group corroborated this finding.

Conclusions: The aphasic naming RTs results were unexpected given the results from the priming literature, which has supported the idea of slowed or reduced patterns of activation in aphasic individuals. However, analyses of naming RTs also confirmed the behavioural finding of a disruption surrounding phonological processes; thus, the analyses of naming latencies offers another potential means of pinpointing breakdowns of lexical access in individuals with aphasia.     

Immediate and short‐term effects of contextual priming on word retrieval in aphasia

Background: Many therapy techniques for word retrieval disorders use some form of priming to improve access to words. Priming can facilitate or interfere with naming under different circumstances. We examined effects of priming when combined with semantic or phonological context (training words in groups that are semantically or phonologically related) and how these effects interact with the type of naming impairment (semantically or phonologically based). Aims: We addressed three questions (1) Are word retrieval impairments differentially sensitive to priming with semantic or phonological contexts? (2) Would such differences be systematically related to deficits of semantic versus phonological processing? (3) Do effects of priming evolve from immediate interference to short‐term facilitation, as predicted by an interactive activation model of word retrieval? Methods & Procedures: A total of 11 chronic English‐speaking aphasic subjects with varied types of aphasia participated in this experiment. Background measures of semantic and phonological processing ability were administered to determine the nature of each subject's naming impairment. The experiment involved one‐session facilitation treatments for each of three context conditions (semantic, phonological, and unrelated), plus three replications (nine subjects) or one replication (two subjects). Ten pictures in each condition were tested before and after treatment. Five pictures were trained and five served as controls. Participants repeated the name of each picture four times (repetition priming) and then attempted to name each picture individually (naming probe). Repetition priming and naming probes were repeated eight times. We used McNemar tests to compare rates of correct responses before and after priming, and chi square analyses of correct responses and contextual errors on naming probes obtained during the priming sessions. Outcome & results: Our predictions were borne out in the data. Participants varied in their sensitivity to the semantic and phonological contexts. The error data suggest that interference during training is more likely when the context (semantic or phonological) and underlying source of the word processing impairment (semantic or phonological) match. Additionally, we found two sequential effects of contextual priming: immediate interference followed short‐term facilitation. Conclusions: These data have theoretical implications regarding the time course of priming effects, but also have important clinical implications. The present contextual priming procedure is relatively short and could be used as a predictor of performance patterns in a long‐term treatment protocol that uses this approach or other tasks that employ priming.     

CASE STUDY Effectiveness of personalised and phonological cueing on long‐term naming performance by aphasic subjects: A clinical investigation

Background: Personalised cueing is a treatment for aphasic word‐finding deficits that has been shown to have long‐term effects on naming accuracy. However, prior investigations of personalised cueing used novel visual stimuli instead of the more traditional pictures and drawings used in clinical settings. Consequently, the clinical effectiveness of personalised cueing was unclear. Aims: This study compared the effects of personalised cueing and phonological cueing on aphasic individuals' long‐term naming accuracy using stimuli that are typical of those used in clinical treatments. Methods & Procedures: Using a single‐subject, alternating treatments design, this study trained three individuals with moderately severe aphasia on the names of 60 common objects. The training sessions were followed by naming probes administered 1 week, 1 month, 2 months, and 3 months after the completion of training. Outcomes & Results: The results showed that the three participants had significantly higher levels of naming accuracy in the personalised cue condition up to 3 months post training compared to the phonological cue condition and an untrained control condition. Conclusions: This study suggests that personalised cueing can be used as a simple, time‐efficient treatment for the word‐finding deficits associated with aphasia of moderate severity.     

Dynamic-intentional thalamic aphasia: a failure of lexical-semantic self-activation

Background: Previous research has described patients with aphasia from thalamic lesions, some of whom were non-fluent with intact comprehension, others who were fluent with impaired comprehension, and some of whom are non-fluent with impaired comprehension. Whereas these three subtypes usually have normal repetition, they had impaired naming, suggesting a deficit in lexical (phonological word forms)-semantic processing. We report a patient with a left thalamic hemorrhage in which lexical-semantic representations appear to be intact but the patient demonstrates an inability to spontaneously activate his lexical-semantic system Methods: A 82-year-old, right-handed man presented with decreased verbal fluency and memory loss following a thalamic hemorrhage. Neuropsychological assessment revealed significant decrements in verbal fluency with intact naming, comprehension, repetition and vocabulary. Conclusions: To the best of our knowledge this pattern of language disturbance, which mirrors dynamic aphasia induced by frontal lesions, has not previously been described with thalamic injury. The thalamus has strong connections with the frontal lobe and rather than degradation of lexical-semantic representations, this patient's thalamic lesion probably induced frontal lobe dysfunction with a failure to spontaneously active lexical semantic representations.     

Phonological and orthographic facilitation of word-retrieval in aphasia: Immediate and delayed effects

In the literature on repetition priming of word-production in normal participants, long-lasting effects can be found from a single prime. This contrasts with the findings with adults with anomia (as part of their aphasia) where phonological cues, such as first sound or rhyme, have been shown to have very short-lasting effects on word retrieval (Patterson, Purell, & Morton, 1983). In addition, the research into treatment of anomia suggests that semantic techniques produce longer-lasting effects than phonological techniques (Howard et al., 1985b). One difference between phonological and semantic techniques is in the element of choice available. Typically phonological cues are simply provided. This contrasts with semantic techniques where a choice is available, for example selecting from a set of pictures to match a word. This study, using a case series design, set out to replicate the finding, that phonological techniques have only short-lasting effects on word retrieval in aphasia and to investigate the influence of providing a choice of cues. Items that participants with aphasia were unable to name after 5 seconds were allocated to one of three conditions: extra time (control condition), single cue, and choice of two cues. Naming was assessed immediately and at a delay (over 10 minutes later). Four different cue types were used: whole word, spoken CV, written CV, and rime. The results were surprising. The cues influenced immediate naming, as predicted. However, this effect was still significant a delayed naming. Additionally, the benefits from a choice of cues were generally similar to those from a single cue. Different patterns of cue effectiveness were found for different participants. Further investigations shed some light on the mechanisms of cueing, orthographic cueing in particular.     

Facilitation of picture-naming in anomic subjects: Sound vs mouth shape

Background: Phonological cueing is often applied to assist spoken word retrieval in anomia. Phonological cues usually comprise auditory and visual information. Yet while the auditory channel provides full information about a cued phoneme, the mouth shape only contains information about certain features of a segment, e.g., place of articulation.

Aims: This study aimed to investigate the immediate effectiveness of visual phonological information in anomic participants, as compared with auditory cueing, in assisting spoken word retrieval.

Methods & Procedures: In a group of 16 anomic participants, spoken picture-naming tasks were administered using mouth shapes of initial segments of target words as visual cues, and initial phonemes as auditory cues.

Outcomes & Results: Reaction time analyses revealed significant facilitation effects for both the visual and the auditory cues. Single-case analyses revealed selective effects: participants benefited either from auditory or from visual phonological information.

Conclusions: Visually based phonetic feature information specifying the initial phoneme of a word can be sufficient to facilitate word retrieval. The cognitive neurolinguistic factors predicting the effectiveness of visual vs auditory-segmental cueing remain unresolved.     

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.