Naming In Aphasia Research Articles

Masked repetition priming effects on naming in aphasia: A Phase I treatment study

Background: It has been suggested that lexical access deficits in aphasia may be the result of impaired automatic activation of the networks that support language processing, a system that operates implicitly, outside conscious awareness. This raises the question of whether there might be a way to address rebuilding these implicit networks directly, rather than through the explicit treatment protocols that are typical of aphasia therapy. Masked priming is one method by which the language system can be automatically activated, while limiting or preventing the influence of conscious, explicit processing. Aims: This Phase I study was undertaken to investigate the potential effectiveness of masked repetition priming as a treatment for anomia. Methods & Procedures: This study used a single-participant, ABA, multiple-baseline repeated-probe design. A total of 22 training sessions were completed across 4 weeks. Training involved repeated presentation of masked repetition primes paired with target pictures prior to attempts at naming those pictures. Untrained items were presented an equal number of times, but without prime words. Repeated naming probes administered before, during, and after treatment were used to measure effects of training (naming trained stimuli) and generalisation (naming within and across semantic categories). Pre- and post-training assessment with broader tests of language function and conversation were also completed. Outcomes & Results: Results revealed a small effect of training on naming of trained items in one category, as well as a pattern of improvement in the other category that did not quite meet the criterion for a small effect. There was also a medium cross- category generalisation effect, although no generalisation effect was seen to untrained items within semantic categories. Improvements were seen on some measures of general language function. Conclusions: Masked priming can elicit changes in naming ability over time, and may have potential as a tool for improving word retrieval in individuals with anomia. Results warrant further investigation.

“Penguins don't fly”: An investigation into the effect of typicality on picture naming in people with aphasia

Background: Previous research has highlighted psycholinguistic variables influencing naming ability for individuals with aphasia, including: familiarity, frequency, age of acquisition, imageability, operativity, and length (Nickels & Howard, 1995) and a potential link between typicality and generalisation to untreated items in intervention (Kiran, Sandberg, & Sebastian, 2011). However, the effect of concept typicality (the extent to which an item can be considered a prototype of a category) on naming in aphasia warrants further examination. Aims: To investigate first whether typicality can be reliably rated across a range of natural semantic categories and second whether, and if so in which direction, typicality influences naming performance for people with aphasia. To provide quantitative and qualitative information on typicality for a set of stimuli for use in future research. Methods & Procedures: Typicality ratings were obtained and the results compared with those in the existing literature. The influence of typicality on picture naming was investigated employing both matched sets (high and low typicality matched for other psycholinguistic variables) and logistic regression analyses for the group and individual participants with aphasia (n = 20). Outcomes & Results: Typicality rating correlated strongly with ratings obtained in previous research (Rosch, 1975: r = .798, N = 35, p < .001; Uyeda & Mandler, 1980: r = .844, N = 47, p < .001). Typicality was a significant predictor of picture naming for the group and some individuals, with generally better performance for typical items. This was demonstrated in both matched sets and regression analyses. However, other psycholinguistic variables proved more strongly related to naming success, particularly age of acquisition. Conclusions: Typicality can be rated reliably and should be considered alongside other psycholinguistic variables when investigating word retrieval and intervention in aphasia. Further research is necessary to accurately model the direction of typicality effects found in word retrieval. Finally, the differing nature, size, and internal structure of categories require further exploration when investigating typicality effects.

Investigating the Role of Somatotopy on Verb Naming in Aphasia

Investigating the Role of Somatotopy on Verb Naming in Aphasia

Across-session Consistency of Performance and Stability of Error Constraints in Aphasic Naming

Across-session Consistency of Performance and Stability of Error Constraints in Aphasic Naming

Neural mechanisms underlying the facilitation of naming in aphasia using a semantic task: an fMRI study

BackgroundPrevious attempts to investigate the effects of semantic tasks on picture naming in both healthy controls and people with aphasia have typically been confounded by inclusion of the phonological word form of the target item. As a result, it is difficult to isolate any facilitatory effects of a semantically-focused task to either lexical-semantic or phonological processing. This functional magnetic resonance imaging (fMRI) study examined the neurological mechanisms underlying short-term (within minutes) and long-term (within days) facilitation of naming from a semantic task that did not include the phonological word form, in both participants with aphasia and age-matched controls.ResultsBehavioral results showed that a semantic task that did not include the phonological word form can successfully facilitate subsequent picture naming in both healthy controls and individuals with aphasia. The whole brain neuroimaging results for control participants identified a repetition enhancement effect in the short-term, with modulation of activity found in regions that have not traditionally been associated with semantic processing, such as the right lingual gyrus (extending to the precuneus) and the left inferior occipital gyrus (extending to the fusiform gyrus). In contrast, the participants with aphasia showed significant differences in activation over both the short- and the long-term for facilitated items, predominantly within either left hemisphere regions linked to semantic processing or their right hemisphere homologues.ConclusionsFor control participants in this study, the short-lived facilitation effects of a prior semantic task that did not include the phonological word form were primarily driven by object priming and episodic memory mechanisms. However, facilitation effects appeared to engage a predominantly semantic network in participants with aphasia over both the short- and the long-term. The findings of the present study also suggest that right hemisphere involvement may be supportive rather than maladaptive, and that a large distributed perisylvian network in both cerebral hemispheres supports the facilitation of naming in individuals with aphasia.

Use of Orthography in Spoken Naming in Aphasia

An unusual pattern of responding by a woman with aphasia was analyzed with respect to cognitive neuropsychologic models of language processing. Spontaneous spelling aloud in spoken naming tasks has been reported in a small number of earlier cases. C.P. exhibited this behavior and, in addition, produced attempts at assembled phonologic naming that reflected errors in oral spelling. Assessment on a variety of single word-processing tasks and analysis of variables' underlying performance were carried out. The assessment revealed greater impairment to phonologic than to orthographic output lexical representations, and a less errorful route to spoken responses by spelling aloud and by assembling responses from grapheme-to-phoneme conversion. C.P.'s skills changed over time, and when written naming ceased to hold an advantage over spoken naming, the use of orthographic information in spoken naming ceased. C.P.'s performance supports the existence of separate orthographic and phonological lexicons, argues against the phonological mediation of spelling, and, as orthography in spoken naming seemed to be used strategically, shows some limits on the interaction of components within models of single word processing.

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.

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.

A comparison of word versus sentence cues as therapy for verb naming in aphasia

Background: Improving verb naming in people with aphasia should enable expession of a wider range of sentence types and meanings, and may have wider benefits for connected speech. Estableshing the optimal therapy methods for improving verb naming is, therefore, of substantial clinical importance. Aims: This study investigated whether cueing sentence production would improve verb‐naming accuracy to a greater extent than the more typical, single‐word verb‐cueing therapies. A second aim was to examine the extent to which verb picture naming improvements would generalise to naming of the same items in dynamic videos. Methods & Procedures: Seven participants with chronic aphasia including word retrieval impairment took part in a case‐series study. Decreasing cues were used to devise two therapies to improve verb naming: word cue therapy and sentence cue therapy. A total of 60 verbs that had not been named accurately in baseline testing on three presentations were collated for each participant. These were split into three sets of 20 verbs: set A was used in word cue therapy, set B in sentence cue therapy, and set C served as control items undergoing no therapy. The sets were matched for significant psycholinguistic variables such as word frequency, imageability, length, and number of noun arguments. Therapy consisted of 10 sessions over 5 weeks. Post‐therapy assessments consisted of an immediate naming assessment (1 week following therapy) and a follow‐up assessment 5 weeks later. Naming of the target verbs in set A for each participant was also assessed using a dynamic video presentation. Outcomes & Results: Both therapies resulted in highly significant gains in naming accuracy for treated verbs with little, if any, carry‐over to untreated verbs. There were no significant differences between the therapies for individual participants. At the group level there was a significantly greater benefit for word cue over sentence cue therapy at the follow‐up naming assessment. The gains in verb naming post therapy generalised from the static depictions used in therapy to naming of the same items in the dynamic video presentation format. Conclusions: Both word and sentence cue therapy for verb naming were effective in improving naming accuracy. Gains from word cue therapy can generalise to naming of very different exemplars of the same verb targets. Word cue therapy resulted in significantly greater gains than sentence cues at the level of the group, but the difference was not substantial enough to be significant at the individual participant level. Generalisation, as an effect following intervention, can be examined in terms of naming different exemplars of a word, as well as its more typical meaning of generalisation from treated to untreated items in therapy.

The influence of word frequency on semantic word substitutions in aphasic naming

Background: Semantic word substitutions are frequent errors of aphasic speakers when naming a picture. The role of word frequency in the generation of these semantic errors provides an important testing ground for models of lexical access. The discrete two‐stage model of Levelt, Roelofs, and Meyer (1999) predicts that frequency should not play a role in semantic errors. In contrast, cascading and interactive models of lexical access allow for an influence of frequency on lexical selection. Aims: To assess the role of word frequency in the generation of semantic substitutions. Methods & Procedures: We re‐analysed a large corpus of aphasic semantic word substitutions in response to target words from carefully controlled semantic categories. Frequency of these errors was compared to randomly selected pseudo‐errors from the same semantic category. Outcomes & Results: Errors were more frequent than randomly selected competitors from the same semantic category. Conclusions: The results support interactive or cascading models of lexical access and speak against the discrete two‐stage model of lexical access. The data are discussed with regard to models of lexical access and to previous studies that failed to find a frequency effect for aphasic semantic naming errors. We would like to thank the aphasic patients for participating in this research, and the speech therapists for referring the patients to us. The idea to compare word frequency of the actual semantic errors and randomly chosen competitors came from an anonymous reviewer of a previous paper of our group. We are very grateful for this suggestion. We would like to thank Myrna Schwartz and an anonymous reviewer for helpful comments on a previous version of this paper.

Using a written cueing hierarchy to improve verbal naming in aphasia

Background: For some individuals with aphasia, writing has been used as an alternative modality for communicating (e.g., Clausen & Beeson, 2003; Lustig & Tompkins, 2002). In some investigations where writing ability was treated; post‐treatment and/or anecdotal reports indicated that verbal naming ability also improved for participants with aphasia (e.g., Beeson, Rising, & Volk, 2003; Kiran, 2005). In some recent studies, investigators have reported that written naming cueing can improve verbal naming ability (DeDe, Parris, & Waters, 2003; Hillis, 1989). This investigation was conducted as a master's thesis by the third author. The authors are especially grateful to the participants for their time and commitment in participating in the study. Aims: The purpose of the present study was to examine the effects of a written cueing treatment programme on verbal naming ability in two adults with aphasia. Method & Procedures: Treatment involved using a written cueing hierarchy, which was modelled after Copy and Recall Treatment (CART; Beeson, 1999) and included verbal and writing components. A modified multiple probe across behaviours design was used to document individual participants' response to treatment. The design was replicated across each participant and included baseline, treatment, probe, and maintenance conditions. Outcomes & Results: Both participants improved their verbal naming ability for the target items over the course of treatment, but they responded differently to the treatment. One participant (P2) maintained verbal naming performance for the treated items 4 weeks after treatment ended and generalised to the untrained items; whereas the other participant (P1) did not. Conclusions: Results support and extend previous findings that treating in one modality improves performance in a different modality. Further, participants responded differently to the treatment, suggesting that underlying differences in the participants' deficits may account for why they responded differently to the same treatment.

Homographic and heterographic homophones in speech production: Does orthography matter?

This paper investigates homophone naming performance in an individual with impaired word retrieval. The aim of the study is to investigate the status of homophone representations using treatment of homophone picture naming in aphasia. The focus of this paper is the representation of heterographic homophones (words which sound the same but are spelled differently, e.g., ‘knight’ vs. ‘night’). Additionally, we replicate and expand previous findings regarding homographic homophones of Biedermann and Nickels (2008) in English and Biedermann et al. (2002), in German. Two theoretical positions about the mental representation of homophones are tested. First, do homophones – regardless of whether they are spelled the same or differently – share a phonological word form (e.g., Levelt et al., 1999; Dell, 1990)? Or second, do they have independent phonological word forms? (e.g., Caramazza et al., 2001; Miozzo and Caramazza, 2005)? In addition, might it be the case that homographic and heterographic homophones behave differently in word production reflecting different word form representations? These theoretical accounts are put to the test by looking at the generalisation of improvement following the treatment of homophone naming in aphasia, in particular, whether picture naming improves for both homophone meanings if only one is treated using a phonological cueing hierarchy. Treated and untreated homophones improved significantly, regardless of their spelling. Homographic and heterographic homophones showed the same pattern of generalisation. There was no generalisation for phonologically related controls. The pattern of generalisation extends our previous findings (Biedermann et al., 2002; Biedermann and Nickels, 2008) by showing evidence that heterographic homophones benefit to the same extent as homographic homophones. These results are interpreted as favouring a theory where both homographic and heterographic homophones share a single phonological representation. It is inferred that facilitation of naming takes place at the level of phonological representations, where orthography seems to have no influence.

The representation of homophones: More evidence from the remediation of anomia

This paper compares two theoretical positions regarding the mental representation of homophones: first, that homophones have one phonological word form but two grammatical representations (lemmas, e.g., Levelt et al., 1999; Dell, 1990), or second, that they have two separate phonological word forms (e.g., Caramazza et al., 2001). The adequacy of these two theoretical accounts for explaining the pattern of generalisation obtained in the treatment of homophone naming in aphasia is investigated. Two single cases are presented, where phonological treatment techniques are used to improve word retrieval. Treatment comprised picture naming of one member of a homophone pair using a phonological cueing hierarchy. A significant improvement in word retrieval was found for both the treated and the untreated homophones, while there was no improvement for phonologically and semantically related controls. It is argued that the data support a shared representation for homophones at the word form level. However, current theories cannot explain the pattern of generalisation found without the addition of a mechanism for repetition priming (e.g., suggested by Wheeldon and Monsell, 1992) and feedback between word form and lemmas to explain the results.

Noun–verb naming in aphasia: a voxel-based lesion-symptom mapping study

Single case and anatomo-correlative studies of aphasic participants have indicated that lesions in temporal regions cause predominant noun impairment, whereas lesions in frontal areas affect verb processing. These studies, however, relied mostly on arbitrary cut-offs, grouping participants according to whether or not they showed a noun or a verb deficit. Here, instead, we applied a recent anatomo-correlation technique, voxel-based lesion symptom mapping (VLSM) to a group of 16 left-hemisphere stroke participants tested on noun and verb naming tasks. Behavioral and lesion data were collected continuously without establishing a priori two different groups of participants. Noun naming was associated with regions located in the left superior temporal areas, whereas verb naming involved a larger region extending from the left prefrontal to the superior temporal areas. The differences and similarities of the two networks are discussed.

Model‐oriented naming therapy: Testing predictions of a connectionist model

Background: The two versions of the connectionist model of Dell and colleagues offer alternative explanations of aphasic naming disorders (Dell, Schwartz, Martin, Saffran, & Gagnon, 1997; Foygel & Dell, 2000). The semantic‐phonological (SP) model hypothesises impairments in lexical‐semantic or lexical‐phonological connections, and the weight‐decay (WD) model assumes global impairments in either connection weights or activation decay. In each version, a patient's error pattern in picture naming is simulated to assess the underlying disorder (connectionist “diagnosis”). A systematic comparison of both model versions in model‐oriented naming therapy has not yet been performed. Moreover, if the normalisation of the error pattern during recovery is lesion‐specific, as suggested in the SP model (Schwartz, Dell, Martin, Gahl, & Sobel, 2006), this should be observable in the patient data. Aims: Predictions were made and tested regarding the relation between (1) connectionist diagnosis and therapy outcome, and (2) connectionist diagnosis and error pattern development. For example, patients with phonological disorders in the SP model should (1) benefit more from phonological as compared to semantic therapy, and (2) present a decrease of nonwords in their naming responses. Methods & Procedures: The connectionist diagnosis and a 4‐week therapy with cueing hierarchies (Howard, 2000; Wambaugh et al., 2001) were administered to 10 German‐speaking aphasic patients with naming disorders. Six patients, who had been diagnosed by the SP model, received semantic and phonological therapy. The other four patients, diagnosed by the WD model, received increasing and vanishing therapy (Abel, Schultz, Radermacher, Willmes, & Huber, 2005). Outcomes & Results: Cueing therapy was generally effective for 9 of 10 patients. The trend of improvement was always found in the direction predicted by the connectionist diagnosis, except for two patients diagnosed by the SP model who presented a numerical trend in the opposite direction. Nevertheless, the SP model offered a more plausible explanation of lesion‐specific therapy outcomes, and it properly predicted the error pattern development. Moreover, the errorless learning procedure applied in vanishing therapy was favourable for patients with phonological (SP model) or weight (WD model) lesions, and this may be attributed to their characteristic error types and an impairment of editorial processes. Conclusions: Models can be informative about the effectiveness of potential therapies and error pattern developments. Data from therapy studies can test competing models.

Omissions and semantic errors in aphasic naming: Is there a link?

Within a discrete two-stage model of lexicalization, semantic errors and errors of omission are assumed to be independent events. In contrast, cascading and interactive models allow for an influence of word form on lexical selection and thus for an inherent relationship in accounting for both error types. A group of 17 aphasic patients was assessed with a naming test controlling for semantic competition of the target items. Semantic errors were more frequent for targets with many competitors than for targets with few competitors while omissions were more frequent when few competitors were available. However, the overall sums of errors in both item groups were comparable. These results imply a common source of both error types and thus speak against a strictly serial model of naming.

The Influence of Neuropsychological Functioning on Neuropsychiatric Problems in Dementia

The Influence of Neuropsychological Functioning on Neuropsychiatric Problems in Dementia

Treating perseveration improves naming in aphasia

Treating perseveration improves naming in aphasia

A case-series test of the interactive two-step model of lexical access: Evidence from picture naming

Many facts about aphasic and nonaphasic naming are explained by models that use spreading activation to map from the semantics of a word to its phonology. The implemented model of picture naming discussed here achieves this by coupling interactive feedback with two selection steps. The model’s structure and default parameters were set up to match the normal naming profile; and aphasic naming is simulated by altering “lesionable” parameters away from default settings. Past studies within this framework have used different sets of lesionable parameters. Here, in the largest and most representative case-series ever modeled, we show the superiority of the version of the model that allows lesions to weaken semantic and/or phonological connections. Pairing this approach to lesions with the assumptions of interactivity and two-step selection equips the model to explain the wide variation in individual naming response profiles and key facts about lexical and sublexical errors.

Generative naming in aphasia during conditions of quiet and cafeteria noise distraction

Aphasia theory is evolving to include aspects of cognitive resource allocation including the performance of individuals during dual task paradigms as well as during interference, competition, and distraction (Erickson, Goldinger, & LaPointe, 1996; LaPointe & Erickson, 1991; McNeil, 1997; Murray, 1999). Signal extraction from competing stimuli has been shown to be influenced by such factors as arousal, motivation, effort, task demands, and nervous system integrity. Limited capacity cognitive systems require parsing and distribution of selective attention among the cascade of attended and unattended stimuli that surround communicators, but few studies of individuals with aphasia have considered or controlled efficiency of these stimulus variables during communication attempts.