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4_Aphasia Rehabilitation- Does Generalisation From Anomia Therapy Occur and is It Predictable_ A

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Articulo sobre Anomia
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  Research report  Aphasia rehabilitation: Does generalisation from anomiatherapy occur and is it predictable? A case series study Wendy Best  a, *, Alison Greenwood  b , Jennie Grassly  a,b , Ruth Herbert  c , Julie Hickin  d andDavid Howard  e a Psychology & Language Sciences, UCL, London, UK b Amersham Hospital, Buckinghamshire, UK c Department of Human Communication Sciences, University of Sheffield, UK d School of Health and Human Services, Central Queensland University, Rockhampton, Australia e School of Education, Communication and Language Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK a r t i c l e i n f o Article history: Received 17 May 2012Reviewed 17 July 2012Revised 31 October 2012Accepted 3 December 2012Action editor Roberto CubelliPublished online 4 February 2013 Keywords: AphasiaAnomiaRehabilitationTherapyGeneralisation a b s t r a c t Introduction:  The majority of adults with acquired aphasia have anomia which can respondto rehabilitation with cues. However, the literature and clinical consensus suggest changeis usually limited to treated items. We investigated the effect of an experimentallycontrolled intervention using progressive cues in the rehabilitation of noun retrieval/pro-duction in 16 participants with chronic aphasia. Method:  Participants were sub-divided relative to the group according to performance onsemantic tasks (spoken/written word to picture matching) and phonological output pro-cessing (presence/absence of word length effect and proportion of phonological errors inpicture 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 15/16participants, 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 asemantic difficulty  and  more of a phonological output deficit demonstrated generalisationto untreated items. Outcome did not relate to traditional aphasia classification. Conclusion:  A cueing hierarchy can improve word retrieval/production for adults withaphasia. In some cases generalisation to untreated items also occurs. The study demon-strates that the results of behavioural testing can be used to guide predictions of recoverywith intervention. ª  2013 Elsevier Ltd.*  Corresponding author.  UCL Division of Psychology and Language Sciences, Chandler House, 2 Wakefield Street, London WC1,United Kingdom.E-mail address: w.best@ucl.ac.uk (W. Best).  Available online at www.sciencedirect.com Journal homepage:  www.elsevier.com/locate/cortex cortex 49 (2013) 2345 e 2357 0010-9452 ª  2013 Elsevier Ltd.http://dx.doi.org/10.1016/j.cortex.2013.01.005 Open access under CC BY license.Open access under CC BY license.  1. Introduction The majority of people with aphasia have difficulty in finding or producing words and this can be a significant cause of breakdown in conversation (e.g., Perkins et al., 1999). There isa large and growing body of evidence demonstrating thatintervention can help improve word retrieval or word pro-duction (see Nickels, 2002 for a review). However,the majorityof interventions result in change primarily on treated items(e.g., Abel et al., 2005; Fillingham et al., 2006; Laganaro et al., 2003; Wisenburn and Mahoney, 2009). Given these fairly consistent findings a key question of bothclinicaland theoreticalimportance arises:whatpattern(/s) of strengths and difficulties leads to generalisation to un-treated items? The answer to this question may inform clin-ical practice and our understanding of how intervention isaltering word retrieval/production. 1.1. Models and levels of impairment There are several models of ‘speech production’, morerecently and accurately termed ‘language production’ ranging from classic ‘box and arrow’ models (Ellis and Young, 1988;Kay et al., 1992) to connectionist models (Dell et al., 1997; Goldrick and Rapp, 2002; Levelt et al., 1999). While the models vary considerably in their specification, in relationto retrieving single words for production, all require thefollowing three stages:(1) Lexical-semantic processing or accessing word meaning (sometimes termed ‘lexical semantics’ and usuallydistinguished from ‘conceptual semantics’)(2) Accessing abstract phonological word form (the ‘phono-logical output lexicon’ in box and arrow models; the‘phonological level’ in Dell’s account)(3) Phonological encoding (or ‘phonological assembly’ in boxand arrow models, commonly also termed ‘post-lexical’processing).In this paper ‘word (or, for connected speech, language)production’ will be used to refer to all three stages of pro-cessing. Thus, ‘word production’ incorporates retrieving theword’s meaning and form and abstract phonological encod-ing. ‘Word production’ is more general than specific diffi-cultieswithwordfindingor wordretrieval, sometimes usedtorefer exclusively to stage (2) above. All these occur prior tomotor programming for speech (Ziegler, 2002).Detailed single case studies link aphasic individuals’ pat-ternsoflanguagestrengthsandweaknessestodifficultieswitha particular level of processing. For example, E.E. (Howard,1995) was held to have a deficit within the phonologicaloutputlexicon:hewasconsistentintheitemshewasunabletoretrieve and was not helped by phonological cues. Howardsuggests items were lost from his lexicon. Franklin et al. (2002)describeM.B.whoseoutputincludedmanyphonologicalerrorsand whose performance was better on short than long words.M.B.’s difficulty was in assembling phonemes for production.There is a confound in much of the research to datebetweenthelevelofdeficitandthetargetofintervention.Thisstudy employs the same intervention with participants withdifferent levels of deficit enabling us to investigate the rela-tionship between the level of impairment and outcome, inparticular any generalisation to untreated items. 1.2. Linking outcome to background findings In a seminal study, Hillis (1989) investigated a cueing therapydesigned to improve written naming in two participants withsevere aphasia. The participant with more lexical-semanticdifficulty (stage 1 on the model above and common toaccessing both written and spoken forms for production)improved and the change generalised to untreated items (andspokennaming).Thesecondparticipant,withwrittennaming difficulties arising from an orthographic equivalent to level 2,improved only on written naming of treated items. Hillisargued it is important to determine the source of an in-dividual’s naming difficulty in order to predict the outcome of intervention.However, more recently, Lorenz and Ziegler (2009) did notfind a direct relationship between the nature of the deficit andtreatment approach. Participants with post-semantic anomia(stages2or3above)benefitedfromsemanticintervention andalso participants with semantic anomia (stage 1 on the modeloutlined above) benefitted from phonological/orthographic(word form) approach. Neither of these findings would bepredicted from a straightforward link between interventionapproach and breakdown in level of word production.Fillingham et al. (2006) compared errorless learning witherrorful learning. All participants completed a detailed lan-guage and neuropsychological assessment battery prior tointervention. Fillingham et al. found strong relationships be-tween response to therapy and underlying neuropsychologi-cal profiles, with participants who responded better overall toboth types of therapy having better recognition memory, ex-ecutive/problem solving skills and monitoring ability. Strik-ingly, however, there was no clear relationship betweenlanguage skill and therapy outcome.What might be the reasons for the difficulty in relating language profile to the outcome of intervention? Firstly, peo-ple with aphasia rarely have a single clearly identifiable levelof impairment in language production. For example, the sameindividualoftenmakesbothsemanticandphonologicalerrorsin word retrieval. Furthermore, individuals’ word productionis often influenced by variables held to reflect different levelsof processing. Secondly, almost all interventions involveparticipants in producing the target word thereby strength-ening links from word meaning to word form (Howard, 2000)and potentially benefiting everyone with difficulty at somestage(s) in word production. 1.3. Generalisation in word production interventions The findings from therapy studies for spoken word-production deficits are somewhat mixed with regards to theextent of the effect of treatment.Limited or no generalisation to untreated items is theresult across the majority of intervention studies including those investigating: errorless learning (Fillingham et al., 2006), cortex 49 (2013) 2345 e 2357 2346  production of nouns and verbs (Raymer et al., 2007), a cueing hierarchy (Thompson et al., 2006) and contextual priming (Renvall et al., 2007).There are a few exceptions to this pattern. Interventionsfocused on process, particularly those with a semanticcomponent (Renvall et al., 2003; Coelho et al., 2000; Boyle, 2004) are held to influence production of untreated items tosome extent. Phonological Feature Analysis (Leonard et al.,2008) also resulted in generalisation to untreated items for 3/10 participants. Generalisation to homophones of targets hasbeen found from intervention with a cueing hierarchy(Biedermann and Nickels, 2008) but not to phonologically orsemantically related control items.The distinction between therapy for semantic deficits(which targets this level) and semantic therapy for word pro-duction is important. In the former, ‘semantic’ tasks such ascategorisation or semantic feature judgements are employedwith the aim of improving a person’s semantic processing;this should influence comprehension and production. In thelatter, while meaning is involved in the task, e.g., throughpictures, the intervention facilitates word production ratherthan semantic processing itself. An example is the study by,Howard et al. (2006) who demonstrated that manipulating the‘depth’ of semantic processing did not influence naming outcome. Participants that benefited the most from semantictherapy for word production had a deficit in the links betweenword meaning and form (stage 2 on the model of word pro-duction outlined above). These results combined suggest thisintervention is not actually operating at a semantic level butrather strengthening links between meaning and form.Thus, there is consensus that repeatedly activating thelinks between an item’s meaning and form [stages (1) and (2)above] often results in item specific improvement in naming (Howard,2000),andthisisthelikelyfocusforchangeinalargenumber of therapy studies. However, the picture may not beas bleak as it first appears.In a review of therapy for naming disorders, Nickels (2002)makes a distinction between approaches involving ‘repair’and those that involve ‘strategy’.In the first case there is held to be a change in the in-dividual’simpairment.Whenthestudieswithmethodologicalweaknesses were excluded, then 11 of the 44 people givenphonological or orthographic information showed somegeneralisation to untreated items. Thus, around a quarter of participants in thesestudies improved on untreatedas wellastreated items. Findings from approaches involving ‘strategy’and aimed at re-organising processes, such as orthographicself-cueing, were even more encouraging. Thirteen of nine-teen cases showed some generalisation. Such approaches are,however, suitable for only some individuals with particularstrengths (e.g., in retrieving orthographic knowledge). Inter-estingly, in a case series intervention using written cues,sixteen of eighteen participants improved on written naming,and four oftheseshowedtransferto untreated items(Delocheet al., 1997; see also Carlomagno et al., 2001). This mirrors Nickels’ review in suggesting around one quarter maydemonstrate generalisation in word production.There are several experimentally controlled single casestudies with participants with deficits in post-lexical process-ing where intervention resulted in improvement on bothtreated and untreated items (Fisher et al., 2009; Franklin et al., 2002; Robson et al., 1998) For example, Fisher et al. (2009) worked with a man with ‘mild phonological encoding impair-ment’.Heshowedsignificantgeneralisationtountreateditemsfrom an intervention which involved attempting to namepictures with unrelated names or with shared phonology(magnet,mattress,macaroni).Incontrast,Waldronetal.(2011)found no generalisation to untreated items, despite employing a previously successful intervention (Franklin et al., 2002). Theparticipants in Waldron’s study had a combination of lexical(stage 2) and post-lexical (stage 3) impairments. Raymer et al.(2012), in a study investigating errorless naming treatmentand gestural facilitation of naming did not obtain generalisa-tion to untrained items for the three participants with se-mantic anomia, but obtained some generalisation in naming forthreeoffiveparticipantswithphonologicalanomia.Finally,studies using orthographic cueing aids demonstrateconvincing generalisation to untreated items (Best et al., 1997;Bruce and Howard, 1987; Howard and Harding, 1998). 1.4. Aims We aimed to explore the effects of a cueing hierarchy, espe-cially generalisation to untreated items, and to relate theoutcome to level of breakdown in naming.Specifically, we ask:(i) Can a cueing therapy improve word production (i.e.,retrieval of meaning and form and phonological encod-ing) in participants with aphasia?(ii) Do some participants show improvement on untreateditems?(iii) Can any generalisation to untreated items be related tothe participants’ language profiles?From previous studies we predicted:(a) those with a post-semantic deficit, stage 2, with relativestrengths in semantic and phonological output processing and a specific deficit in retrieving lexical forms will showitem specific changes in naming (following e.g., Howardet al., 2006; Raymer et al., 2007) (b) those with a post-lexical deficit, stage 3, with relativestrengths in semantic processing and weakness inphonological output processing will show effects of intervention which generalise to untreated items(following e.g., Franklin et al., 2002; Fisher et al., 2009). 1.5. Value The study is of theoretical importance. Evidence for a linkbetween the nature of the impairment and change withintervention can inform our understanding of improvementmechanisms. In rehabilitation for word production, anyintervention which involves pictures and producing spokenwords will necessarily activate all the representations andlevelsofprocessing inthemodeloutlinedabove.Thequestioniswhethertherapycanoperateatdifferentlevelsandwhethergeneralisationreflectsthelevelat whichchangeinthesystemis occurring. cortex 49 (2013) 2345 e 2357  2347  This investigation is also of clinical importance. Thosepeople who show generalised improvement to untreateditems are likely to be benefiting more than those who showchanges limited to treated items, although item specificchanges may also impact on everyday life (e.g., Best et al.,2008; Raymer et al., 2007). For those who improve only on treated items, selection of these items to be of maximumfunctional benefit to each individual is crucial. Finally, thestudy is of clinical relevance because we include ‘all comers’.Rather than including only those with clearly identifiableimpairments at a single level, we included everyone referredto the study who met the general criteria.Prognosis in aphasia is generally linked to stroke relatedvariables (initial aphasia severity, nature of lesion, e.g., Sauret al., 2010) rather than patient related variables (gender,handedness, education, e.g., Plowman et al., 2011). Pederson et al. (2004) found language outcome was related to aphasiaseverity but not type of aphasia. Thus, from both the detailedsingle case cognitive neuropsychological and the broaderprognosis literature, our hypothesis is that generalisation tountreated items may not be predicted by participants’ tradi-tional aphasia classification, but rather by language scoresfrom behavioural testing. 2. Method 2.1. Participants Sixteen participants with varying profiles and severity of aphasia were recruited. Criteria for inclusion were minimisedin order for participants to better reflect the clinical populationrather than, for example, selecting those most likely to benefitfrom rehabilitation (e.g., highly motivated participants). Allthose who met the criteria were included; all had word finding difficultiesasasignificantpartofaphasiaandweremorethanayearpost-onset.Allparticipantshadaphasiaduetoasingleleftcerebrovascular accident (CVA). Participants gave informedconsent via an aphasia friendly form and process (Osborneet al., 1998). Results from two intervention studies were com-bined to provide the data for this investigation.Participants ranged from one to eight years post-onset atthe time of the study and from 42 to 77 years. Participants’aphasia type was agreed by the research clinicians, all of whom are experienced speech and language therapists; therewas complete agreement as to the categorisation of partici-pantsasfluentornon-fluent.Whereatraditionalaphasiasub-type is shown in Table 1 there was also agreement as to thecategory as determined by background language profiles andconnected speech. Eight participants had fluent aphasia andeight had non-fluent aphasia. 2.2. Background assessments Naming was assessed using a set of 200 black and white linedrawings (for which there is 95% name agreement from oldercontrolparticipants).Theinfluenceofpsycholinguisticvariableson naming was investigated and the nature of participants’ er-rors was coded. A phonological error was counted where theattempt was a word or non-word for which 50% or more of thetarget phonemes were in the response or 50% or more of thephonemes in the response were in the target. Participants’comprehensionofsinglewordswasassessedusingspokenandwritten word to picture matching from the ComprehensiveAphasia Test (CAT; Swinburn et al., 2004). Single word reading and repetition were assessed using the same set of 152 items. 2.3. Intervention The data from this study come from two separate but stronglyrelated projects: the Tavistock study and the Buckinghamshirestudy. The Tavistock study used phonological and ortho-graphic cues in the treatment of word finding difficulties inaphasia(Bestetal.,2002;Hickinetal.,2002;Herbertetal.,2003). Inthisstudytheeightparticipantswereprovidedwithachoiceof phonological cues or a choice of orthographic cues intreatment. The Buckinghamshire study was a collaborativeproject with therapists working in NHS and academic settings Table1 e Participantdetails,attimeofstudy.ThefirsteightparticipantswereintheTavistockStudy(Universitybased)andthe final eight were in the Buckinghamshire (Health Service based) replication. Participant Gender Years post-onset Age Aphasia type Occupation attime of CVA H.M. M 6 45 NF Broca’s Cabinet makerP.H. F 3 77 F Anomic HomemakerS.C. M 5 65 F Mixed/Wernicke’s RetiredD.C. F 5 70 F Anomic RetiredO.L. F 2 65 F Anomic RetiredN.K. M 3 52 F Anomic AccountantI.K. M 3 68 NF Broca’s Retired, ran a businessK.R. F 8 38 NF Broca’s HomemakerT.E. M 1 69 F Anomic Ran building businessF.A. F 2 64 NF some apraxia Personal assistantG.B. M 3 71 NF Retired floristC.M. M 5 52 NF PlumberC.V. F 2 56 NF Florist/gardenerD.J. F 1 65 F VolunteerP.P. F 2 75 F Wernicke’s HomemakerL.M. F 7 42 NF Broca’s Homemaker cortex 49 (2013) 2345 e 2357 2348
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