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.     

Cued recall and release from proactive interference in Alzheimer's disease

Abstract

Two tasks were administered to 13 mildly to moderately impaired subjects who met clinical research criteria for AD, and 17 controls matched for age and education. In the first task, subjects were administered a cued recall test (Buschke, 1984). AD subjects were found to be variably impaired in their ability to perform the initial stimulus-processing procedure, which involved matching cues with referents. The subsequent cued recall test did not typically facilitate performance. In the second task, subjects were administered a release from proactive interference (PI) paradigm consisting of semantically related and unrelated word lists. AD subjects did not develop the expected proactive interference effect for the semantically related words or show a resulting “release from PI” on related word list recall compared to normal controls. Results are discussed in terms of the role of semantic processing in episodic memory tasks.     

The representation of homophones: Evidence from remediation

Background: This single case study examines the linguistic phenomenon of ambiguous spoken words: homophones. In the psycholinguistic research literature the lexicalisation of homophones is the subject of extensive debate. A common assumption is that these words share one word form but have two grammatical representations (lemmas). An opposing view postulates two separate word form entries for homophones - without assuming a lemma level. Aims: The single case study presented here searches for empirical evidence for the representation of homophones using aphasic speech production. Can aphasic speech production give us some evidence regarding how many processing levels have to be completed prior to articulation? Methods & Procedures: A treatment study with MW, a man with global aphasia and severe anomia, is presented. Treatment comprised an intensive picture-naming training with exclusively phonological cues. Naming was facilitated using the following cueing hierarchy: (i) giving the initial phoneme, (ii) tapping the syllable number, and (iii) giving the target word for repetition. How this pure phonological training would affect naming performance of homophones, semantically and phonologically related words, and unrelated words was investigated. Outcomes & Results: The results showed significant short-term, item-specific effects for treated words and generalisation to untreated homophone words alone. The outcome is discussed with reference to the debate regarding homophone production in psycholinguistics and the debate regarding the facilitatory effects of phonological techniques. Conclusions: The results support the two stage model, with only one word form and two lemma entries for homophones. In addition, the outcome of this phonological treatment supports the common assumption that pure word form training rarely results in long-term improvement or generalisation.     

Effectiveness of contextual repetition priming treatments for anomia depends on intact access to semantics.

Naming of two semantically impaired aphasic patients was treated with the contextual repetition priming technique, which involves repeated repetition of names of pictures that are related semantically, phonologically, or are unrelated. Our previous studies using this technique have suggested that patients with impaired access to lexical-semantic representations benefit in the short-term from this treatment technique, but show no long-term improvement in naming. In contrast, patients with good access to semantics show short- and long-term benefits from this treatment. Here we report two studies of treatment for two individuals with aphasia affecting access to lexical semantics and anomia but spared access to input and output phonology and spared conceptual semantics. We predicted that they would show short-term facilitation from the contextual priming, but no long-term improvements in naming. The results confirmed the prediction. An account of this pattern is offered within the framework of an interactive activation model of word retrieval. Additionally, we discuss alternative techniques for addressing naming deficits when access to semantics is impaired.     

Therapy for naming disorders (Part II): Specifics,surprises and suggestions

Abstract

This paper presents a series of therapy studies aimed at remediation of the word-retrieval deficits of three aphasic patients. All three patients are argued to have semantic deficits and are given semantic therapy in the form of word-to-picture matching tasks. Two of the patients (A.E.R. and T.R.C.) show improved naming as a result of the therapy, with generalization to untreated items. The third patient (P.A.) does not improve as a result of the word-to-picture matching therapy, even though her pattern of deficits appears similar. However, she does show item-specific improvement in naming with a different therapy (lexical therapy). The reasons for the differences between the patients in their response to therapy are discussed. In particular we consider the effect of the production of the word during the therapy, and the patient's ability to perform the task accurately. Additionally, we investigate the role of modality of input and generalization across modality of output, and the use of different types of semantic therapy. The study highlights the importance of analysing tasks in detail, and the need to continuously evaluate the effects of intervention.     

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.     

Cued recall and release from proactive interference in Alzheimer's disease

Two tasks were administered to 13 mildly to moderately impaired subjects who met clinical research criteria for AD, and 17 controls matched for age and education. In the first task, subjects were administered a cued recall test (Buschke, 1984). AD subjects were found to be variably impaired in their ability to perform the initial stimulus-processing procedure, which involved matching cues with referents. The subsequent cued recall test did not typically facilitate performance. In the second task, subjects were administered a release from proactive interference (PI) paradigm consisting of semantically related and unrelated word lists. AD subjects did not develop the expected proactive interference effect for the semantically related words or show a resulting "release from PI" on related word list recall compared to normal controls. Results are discussed in terms of the role of semantic processing in episodic memory tasks.     

Dissociating stimulus-driven semantic and phonological effect during reading and naming

The aim of the present study was to dissociate the neural correlates of semantic and phonological processes during word reading and picture naming. Previous studies have addressed this issue by contrasting tasks involving semantic and phonological decisions. However, these tasks engage verbal short-term memory and executive functions that are not required for reading and naming. Here, 20 subjects were instructed to overtly name written words and pictures of objects while their neuronal responses were measured using functional magnetic resonance imaging (fMRI). Each trial consisted of a pair of successive stimuli that were either semantically related (e.g., "ROBIN-nest"), phonologically related (e.g., "BELL-belt"), unrelated (e.g., "KITE-lobster"), or semantically and phonologically identical (e.g., "FRIDGE-fridge"). In addition, a pair of stimuli could be presented in either the same modality (word-word or picture-picture) or a different modality (word-picture or picture-word). We report that semantically related pairs modulate neuronal responses in a left-lateralized network, including the pars orbitalis of the inferior frontal gyrus, the middle temporal gyrus, the angular gyrus, and the superior frontal gyrus. We propose that these areas are involved in stimulus-driven semantic processes. In contrast, phonologically related pairs modulate neuronal responses in bilateral insula. This region is therefore implicated in the discrimination of similar, competing phonological and articulatory codes. The above effects were detected with both words and pictures and did not differ between the two modalities even with a less conservative statistical threshold. In conclusion, this study dissociates the effects of semantic and phonological relatedness between successive items during reading and naming aloud.     

Treatment of word retrieval deficits with contextual priming

Background: Repetition priming is often a component of treatments for word‐finding disorders. It can facilitate or interfere with naming success depending on a number of factors. Here we investigate the effectiveness of massed priming coupled with semantic or phonological context as a treatment for naming impairments arising from semantic and phonological deficits. Aims: We aimed to determine whether (1) this procedure, used previously in a short‐term facilitation study, would effectively improve word retrieval in a treatment study, and (2) the pattern of facilitation or interference observed in the facilitation study would carry over to the treatment programme. Methods & Procedures: We used a single subject multiple baseline design. There were two participants: LP with a phonological encoding deficit and AS with both semantic and phonological deficits. Treatment involved identifying and repeating the names of words that were related semantically or phonologically, or unrelated. Pre and post measures of naming were used to assess overall effectiveness of the treatment. Acquisition, maintenance, and generalisation were measured with baseline tests at the start of each session. Correct responses and errors on within‐training naming probes were used to measure sensitivity to priming in a particular context. Outcomes & Results: LP benefited from this procedure regardless of the training context. AS showed interference in the semantic context during training and only modest short‐term gains. These outcomes were predicted by their performance on an earlier facilitation study. Conclusions: Contextual repetition priming has different effects on naming and these differences appear to be related to the context of training (semantic or phonological) and the primary source of an individual's naming impairment (semantic or phonological). This procedure is most effective when semantic processing of words is relatively spared.     

Independent Access to Phonological and Orthographic Lexical Representations: A Replication Study

Abstract

Traditionally, it has been assumed that written abilities are completely dependent on phonology (the so-called phonological mediation theory). In this view, the semantic system activates the phonological form of a word, which then activates the corresponding orthographic representation. This hypothesis predicts that in double naming tasks (two temporally close responses to the same picture in the two output modalities), the word selected for a written response will always correspond to the one selected for a spoken output. On the contrary, the orthographic autonomy theory hypothesises the independence of the written output lexicon, which, in the presence of severe damage to conversion procedures, could be directly activated from the semantic system. In this case, the theory predicts that double naming tasks give rise to lexically inconsistent responses.

We describe a non-fluent aphasic patient, RA, with agrammatic speech and severe word- finding difficulties. He also presented with severe damage to the phonology-to-orthography and orthography-to-phonology conversion procedures. His performance on picture naming tasks was significantly worse in the spoken than in the written output modality. Errors were predominantly omissions. Few semantic paraphasias were present. Semantic errors did not arise from a deficit in the semantic system since the patient performed flawlessly on a semantic questionnaire and a word picture matching task and gave correct definitions of the items. Although not predicted by the phonological mediation theory, on double naming tasks the patient gave inconsistent responses (i.e. he correctly wrote the stimulus “z-e-b-r-a” but he orally produced “giraffe”). Taken together, these results further confirm the hypothesis that access to the orthographic form of words can be accomplished independently, without the mediation of phonology (the orthographic autonomy hypothesis).     

Naming Concepts: Evidence of Two Routes

This study examines a parallel distributed processing (PDP) model (partly based on the Wernicke-Lichtheim information processing model) that posits two routes for naming concepts, whole word and phonological. To test the two naming route hypothesis of this model, we performed confrontation naming tests that were either uncued, semantically cued, or phonologically cued in a patient with naming impairment due to Broca’s aphasia. In spoken language and in uncued naming to confrontation, word retrieval was severely impaired and marked by semantic but no phonemic paraphasic errors. With semantic cues, naming behavior was unchanged; however, with phonological cues, naming success was enhanced but frequent phonemic paraphasias were produced. These results suggest that the patient spontaneously engaged the whole word naming route, but when given phonological cues, he engaged an alternative phonological naming route that incorporated phonological sequence knowledge.     

Anomia in patients with left inferior temporal lobe lesions

Background: Damage to left inferior temporal cortex has been associated with naming deficits resulting either from impaired access to phonological word forms (pure anomia) or from degraded semantic knowledge (semantic anomia). Neuropsychological evidence indicates that pure anomia may follow damage to posterior inferior temporal cortex (BA 37), whereas semantic anomia is associated with damage to more anterior temporal lobe regions (BA 20, 21, 38). By contrast, some investigators have suggested that it is the overall severity of anomia, rather than the nature of the underlying cognitive impairment, that is affected by the anterior extent of the lesion. Aims: To examine the naming performance of patients with left inferior temporal lobe damage and determine whether anterior extension of the lesion influences the nature and/or the severity of the naming impairment. Methods & Procedures: Eight participants with focal damage to left inferior temporal cortex completed a battery of language measures that included confrontation naming, semantic processing, and single‐word reading and spelling. Degree and type of anomia was examined relative to anterior lesion extension using both visual inspection and statistical analyses. Outcomes & Results: Naming performance ranged from unimpaired to severely defective, with only two participants demonstrating an additional mild impairment of semantic knowledge. The underlying mechanism of anomia seemed to be degraded access to phonological word forms in all participants, regardless of lesion configuration. The severity of the naming impairment was positively correlated with anterior extension of the lesion towards the temporal pole, although additional analyses suggested that these findings were significantly influenced by participant age. Naming was not correlated with performance on the nonverbal semantic task or any other demographic variable. Conclusions: The behavioural and neuroanatomical findings provide modest support for the hypothesis that a relationship exists between anterior lesion extension and the severity of concomitant anomia in patients with left inferior temporal lobe damage. The data suggest that such lesions may disconnect relatively preserved semantic knowledge from regions critical for access to phonological word forms. However, additional research is needed to discern to what extent age and individual variability temper these effects.     

Lexical retrieval and semantic knowledge in patients with left inferior temporal lobe lesions

Background: It has been proposed that anomia following left inferior temporal lobe lesions may have two different underlying mechanisms with distinct neural substrates. Specifically, naming impairment following damage to more posterior regions (BA 37) has been considered to result from a disconnection between preserved semantic knowledge and phonological word forms (pure anomia), whereas anomia following damage to anterior temporal regions (BAs 38, 20/21) has been attributed to the degradation of semantic representations (semantic anomia). However, the integrity of semantic knowledge in patients with pure anomia has not been demonstrated convincingly, nor were lesions in these cases necessarily confined to BA 37. Furthermore, evidence of semantic anomia often comes from individuals with bilateral temporal lobe damage, so it is unclear whether unilateral temporal lobe lesions are sufficient to produce significant semantic impairment.

Aims: The main goals of this study were to determine whether anomia following unilateral left inferior temporal lobe damage reflected a loss of semantic knowledge or a post‐semantic deficit in lexical retrieval and to identify the neuroanatomical correlates of the naming impairment.

Methods & Procedures: Eight individuals who underwent left anterior temporal lobectomy (L ATL) and eight individuals who sustained left posterior cerebral artery strokes (L PCA) completed a battery of language measures that assessed lexical retrieval and semantic processing, and 16 age‐ and education‐matched controls also completed this battery. High‐resolution structural brain scans were collected to conduct lesion analyses.

Outcomes & Results: Performance of L ATL and L PCA patients was strikingly similar, with both groups demonstrating naming performance ranging from moderately impaired to unimpaired. Anomia in both groups occurred in the context of mild deficits to semantic knowledge, which manifested primarily as greater difficulty in naming living things than nonliving things and greater difficulty in processing visual/perceptual as opposed to functional/associative semantic attributes. Lesion analyses indicated that both patient groups sustained damage to anterior inferior temporal lobe regions implicated in semantic processing.

Conclusions: These results contribute to a better understanding of the cognitive mechanism of naming impairment in patients with temporal lobe damage and support the notion that pure anomia and semantic anomia represent two endpoints along a continuum of semantic impairment. Unilateral left temporal lobe lesions in our patients resulted in relatively mild semantic deficits that were apparent primarily in lexical production tasks, whereas severe semantic impairment likely requires bilateral temporal lobe damage.     

Improved word comprehension in Global aphasia using a modified semantic feature analysis treatment

Limited research has investigated treatment of single word comprehension in people with aphasia, despite numerous studies examining treatment of naming deficits. This study employed a single case experimental design to examine efficacy of a modified semantic feature analysis (SFA) therapy in improving word comprehension in an individual with Global aphasia, who presented with a semantically based comprehension impairment. Ten treatment sessions were conducted over a period of two weeks. Following therapy, the participant demonstrated improved comprehension of treatment items and generalisation to control items, measured by performance on a spoken word picture matching task. Improvements were also observed on other language assessments (e.g. subtests of WAB-R; PALPA subtest 47) and were largely maintained over a period of 12 weeks without further therapy. This study provides support for the efficacy of a modified SFA therapy in remediating single word comprehension in individuals with aphasia with a semantically based comprehension deficit.     

Re-visiting "semantic facilitation" of word retrieval for people with aphasia: facilitation yes but semantic no

Previous research has shown that word-to-picture matching for targets that cannot be named at pre-test results in improved naming relative to untreated control items for people with aphasia. This paper replicates and extends this finding and investigates its source. Is the effect a result of priming of semantic representations, or of post-semantic mechanisms in word retrieval? The first experiment shows that word-to-picture matching with unrelated distractors improves naming at short (2-3 minutes) and long (up to 25 minute) lags. There was no effect of being made aware of the relationship between word-to-picture matching and picture naming. People who have a semantic impairment improve only with a short lag between word-to-picture matching and naming. Participants with less semantic impairment show larger priming effects that are equal at short and long lags between word-to-picture matching and naming. The second experiment shows that the facilitation effect is just as large for word-to-picture matching with unrelated distractors as with semantically-related distractors. Furthermore, overall there was no difference between matching with coordinate items and with associated items. The results of these experiments show that facilitation of naming by word-to-picture matching in people with aphasia cannot be a result of the priming of semantic representations. Instead they are consistent with two effects: word-to-picture matching results in priming at a lemma level for aphasic people with a semantic impairment that is only found with a short lag between word-to-picture matching and naming. Word-to-picture matching causes priming of the lemma to output lexicon entry mapping that benefits participants with less semantic impairment that is evident at both a short and long lag between word-to-picture matching and naming. These findings fit well with previous research on repetition priming of naming with normal subjects.     

Model-oriented naming therapy in semantic dementia: A single-case fMRI study

Background: Studies on anomia treatment in semantic dementia demonstrate that re-learning is possible, but maintenance and generalisation of improvements are limited. Changes in cortical activation associated with anomia treatment have already been demonstrated in aphasic patients after stroke. Recovery of brain functions under the impact of deficit-specific treatment in semantic dementia has not been explored yet. Nevertheless, recent activation studies using language tasks in patients with neurodegenerative diseases report altered activation patterns, involving diverse brain regions ipsi- or contralateral to the primarily affected left hemisphere.

Aims: The purpose of the present study was to investigate if phonological and semantic cueing hierarchies established for naming therapy in aphasia were also effective in a patient with semantic dementia. Moreover, we aimed to examine changes of brain activity associated with anomia treatment.

Methods & Procedures: One individual with semantic dementia participated in the present study. Over a period of 4 weeks the participant received an intensive model-oriented treatment with phonological and semantic cueing hierarchies. Two pre-tests and two post-tests (one immediately after training and one 2 months later) were administered. The second pre-test and both follow-ups were registered inside the scanner.

Outcomes & Results: Behaviourally, both treatments resulted in specific training effects, which subsequently decreased over time. Concerning functional magnetic resonance imaging data, improved naming following therapy was mirrored by changes in cortical activity, predominantly located in right superior and inferior temporal gyrus.

Conclusions: Cueing hierarchies were successful, resulting in specific and immediate treatment effects, corroborating previous treatment studies in semantic dementia. Treatment-induced changes in cortical activity were mainly concentrated in right temporal cortex. Since right-sided modulation of cortical activity was associated with training-induced improvements in task performance, it may reflect right hemispheric compensatory mechanisms in this participant.     

Semantic and Cross-Case Identity Priming in Patients With Parkinson's Disease

Semantic and cross-case identity priming were investigated in nondemented patients with Parkinson's disease (PD) and controls using the Lexical Decision Task. Three conditions were administered that consisted of the presentation of prime and target word pairs. In the semantic priming condition the word pairs were semantically related (e.g., table-CHAIR), in the cross-case identity priming condition the word pairs consisted of the same word (e.g., noise-NOISE), and in the unrelated condition the word pairs were not related semantically (e.g., guns-DEEP). A fourth condition was also administered that consisted of the presentation of a prime word and a pronounceable nonword target (e.g., starved-FORVE). Participants were asked to indicate whether the target was a real word or a nonword. The prime and target were separated by either a short or long (250 ms or 1000 ms) stimulus onset asynchrony (SOA). Results indicated that PD patients displayed normal semantic priming (i.e., faster responding to the target in the semantic condition as compared to the unrelated condition) at both the short and long SOA. Similarly, PD patients displayed normal cross-case identity priming (i.e., faster responding to the target in the identity condition relative to the unrelated condition) at the long SOA. At the short SOA, however, PD patients displayed hyper identity priming relative to controls (134 ms vs. 50 ms). These results suggest that semantic processes are normal in nondemented PD patients but that the processes involved in accessing lexical information may be overly activated in these patients.     

A comparison of drawing and writing on facilitating word retrieval in individuals with aphasia

ABSTRACT

Background: Drawing has long been a focus in aphasia research as a compensatory strategy for improving functional communication in individuals with aphasia, but fewer studies have addressed drawing as a facilitative tool to improve their verbal output.

Aims: The purpose of the current study was to investigate differences in naming accuracy in individuals with aphasia during a drawing versus a writing condition. Two research questions were formed to examine the role of drawing in facilitating naming: 1) Will participants perform better when naming with drawing compared to confrontation naming only or when naming with writing? and 2) Is the quality of the picture drawn related to the naming accuracy?

Methods & Procedures: Across three separate one-hour sessions, fifteen individuals with aphasia (n = 15) aged 44–81 years (M = 61.47, SD = 13.27) were evaluated using two standardized language assessments, the Western Aphasia Battery-Revised and Pyramid and Palm Tree Test, and three naming tasks designed to assess the effect of writing and drawing on naming performance. The three naming conditions consisted of confrontation naming only, naming with drawing, and naming with writing.

Outcomes & Results: A one-way, repeated measures analysis of variance (ANOVA) was computed to analyze the impact of naming conditions on the participants’ naming accuracy. The main effect of naming conditions was statistically significant, F (1, 14) = 5.87, p < 0.05, and Bonferroni correction revealed that the participants performed significantly better in the naming with drawing condition than with writing condition. In addition, no correlation between the quality of the pictures drawn and the participants’ naming performance was found which suggested that the quality of drawing did not affect the accuracy of naming.

Conclusions: When attempting to name a picture along with drawing its representation, the act of drawing may facilitate word retrieval by stimulating the semantic network associated with the word and involving the right cerebral hemisphere in the word retrieval process. Through drawing, these semantic features of the target word are more strongly activated than other related words. When the semantic features are more strongly activated, the probabilities of retrieving the target word may increase. In contrast, writing heavily relies on the left hemisphere and linguistic systems. Thus, naming when attempting to write the associated word may be a more cognitively and linguistically demanding task for individuals with aphasia.     

Analysis of lexical recovery in an individual with acute anomia

Observing recovery of cognitive functions may provide converging evidence about the organization of systems that mediate cognitive functions. We analyzed recovery of lexical abilities in a patient, HH, with an acute onset of anomic aphasia following a cerebral infarction confined to the left temporo-occipital junction (area 37). His initial assessment, described in detail elsewhere (Raymer et al. 1997a), indicated a cross-modal anomia arising at a stage in lexical processing at which semantic information accesses phonological and orthographic lexical mechanisms for speech and writing. We also documented reading and spelling impairments that we attributed to developmental deficits. We now report our patient's follow-up testing at 6 and 15 months post-stroke. Recovery testing demonstrated significant improvements in task performance across recovery phases: word retrieval in naming and spelling tasks recovered in the earlier recovery phase and reading improved at the later testing. Word frequency effects varied across observations. Over time, error patterns evolved from off-target and semantically related responses towards correct responses. The parallel recovery patterns in oral and written naming support our proposal that a common impairment was responsible for the cross-modal anomia. In contrast, recovery of reading and spelling skills contradicts our hypothesis that these problems were developmental in origin.     

Contrasting effects of errorless naming treatment and gestural facilitation for word retrieval in aphasia

We compared the effects of two treatments for aphasic word retrieval impairments, errorless naming treatment (ENT) and gestural facilitation of naming (GES), within the same individuals, anticipating that the use of gesture would enhance the effect of treatment over errorless treatment alone. In addition to picture naming, we evaluated results for other outcome measures that were largely untested in earlier ENT studies. In a single participant crossover treatment design, we examined the effects of ENT and GES in eight individuals with stroke-induced aphasia and word retrieval impairments (three semantic anomia, five phonological anomia) in counterbalanced phases across participants. We evaluated effects of the two treatments for a daily picture naming/gesture production probe measure and in standardised aphasia tests and communication rating scales administered across phases of the experiment. Both treatments led to improvements in naming of trained words (small-to-large effect sizes) in individuals with semantic and phonological anomia. Small generalised naming improvements were noted for three individuals with phonological anomia. GES improved use of corresponding gestures for trained words (large effect sizes). Results were largely maintained at one month post-treatment completion. Increases in scores on standardised aphasia testing also occurred for both ENT and GES training. Both ENT and GES led to improvements in naming measures, with no clear difference between treatments. Increased use of gestures following GES provided a potential compensatory means of communication for those who did not improve verbal skills. Both treatments are considered to be effective methods to promote recovery of word retrieval and verbal production skills in individuals with aphasia.