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Word Retrieval Measures with the AphasiaBank Stimuli: Test-Retest Reliability Proposal for CAC 2014
No full textResearch into treatment for improving word retrieval ability in aphasia is increasingly focused on assessing outcomes at a discourse level. For example, the AphasiaBank project (http://talkbank.org/AphasiaBank/ ) uses a number of tasks to elicit discourses from individuals with aphasia. The discourses can then be analyzed with a set of analysis tools from the Computerized Language Analysis (CLAN) system. MacWhinney, Fromm, Holland, Forbes, & Wright (2010) have suggested that the AphasiaBank tools can be used to study recovery from aphasia and the effects of aphasia treatments. The AphasiaBank protocol is promising because of its ability to quickly and accurately perform a number of analyses that are time-consuming, cumbersome, and vulnerable to error when performed manually. However, except for a report on VOCD, a measure of lexical diversity that is part of the CLAN system (Boyle, 2013), there have been no reports about the test-retest reliability of the various language measures included in CLAN when they are used with the elicitation stimuli that are part of the AphasiaBank protocol.
Test-retest reliability refers to the assessment of whether a test produces the same results on repeated application when the participants who are being tested have not changed on the domain that is being measured (Fitzpatrick, Davey, Buxton, & Jones, 1998). Before a measure is used as an outcome assessment, its test-retest reliability must be established, otherwise it is impossible to assert that changes on the measure are related to treatment rather than to spurious, day-to-day variability inherent in the measurement or the behavior it is measuring (Brookshire & Nicholas, 1994; Herbert, Hickin, Howard, Osborne, & Best, 2008). Test-retest reliability is as important for measures used to evaluate impairments as it is for those that measure change, since measures that are not stable will not provide valid or reliable assessments of impairments.
Several measures available in the CLAN System can be used to assess word retrieval difficulty. To use CLAN, the discourses must first be transcribed and coded for errors and other behaviors of interest using a format specified in the CHAT Manual (http://talkbank.org/AphasiaBank/). CLAN can then be used to analyze the transcripts for the occurrence of the coded errors as well as for other language parameters. Word-finding problems that can be coded in CHAT include phonemic paraphasias, semantic paraphasias, neologisms, false starts, time fillers, and repetitions. The purpose of this investigation was to provide preliminary information about the test-retest reliability of these measurements in narrative discourses elicited with the AphasiaBank stimuli from speakers with aphasia
Exploratory Study on Hearing, Cognition, and Memory in Aging
No full textPrevious studies have shown a connection between hearing status, memory, and cognitive decline in older adults. The current exploratory study investigates the effects of unaided hearing loss on cognition and recall for auditory versus written expository text passages in normal hearing young adults, normal hearing older adults, and older adults with hearing loss. Although all participants performed better on the recall of auditory information regardless of group, hearing loss was associated with several cognitive measures. Findings indicate a need for continued collaborative research into sensory deficits and their effects on cognition and memory, in order to inform clinical practice
Modeling the relationship between discourse and confrontation naming
Full text linkThe cardinal deficit of people with aphasia (PWA) is anomia (Goodglass & Wingfield, 1997). In single word retrieval, as in picture naming tasks, this deficit is believed to be indicative of disruption in two cognitive processes: (i) accessing a semantic description of the target concept, and/or (ii) retrieval of a fully phonologically specified representation (e.g., Dell, 1986). During discourse, in addition to these core processes that serve word retrieval of single words, production also depends on “…factors external to the lexicon…” (p. 169, Wilshire & McCarthy, 2002). The latter processes might influence the selection of lexical items based on syntactic, structural, and/or pragmatic criteria that can be either automatic or meta-cognitive. The current study investigates the implicit assumption that performance in single-word, picture naming tasks is directly and strongly related to word retrieval performance during discourse production.
To establish a diagnosis and quantify its severity, and determine the effect of treatment in various communication disorders, speech language pathologists often use confrontation naming tests (CNTs). In CNT’s, basic drawings or pictures are presented to the PWA who is asked to name its target. The results of the test are then used to determine what steps should be taken post-injury to support the client’s word-production/word retrieval process and which therapeutic approach may maximize the rehabilitation outcome.
However, according to Herbert, et al (2008) CNTs may not fully take into account their non-native disposition. First, in typical conversation speakers do not name pictured objects. Also, in CNTs, examinees name bare nouns or verbs and there are no elements in which to attach these words (i.e. not conversational context). Second, the main ideas communicated in discourse may not be necessarily planned: based on Dell’s model, access to word specific semantic features, retrieval of the word form, and encoding the corresponding phonemes of that word are all part of the natural steps that occur, typically without premeditated action in the healthy, non-injured brain (Martin, 2012). Based on these premises authors have argued that decontextualized tasks such as CNT’s may “… [bear] little resemblance to the online, multifaceted word retrieval required during conversation” (Mayer & Murray, 2003, p. 482). This position carries significant clinical and research implications because it directly challenges the idea of using CNT’s to make inferences about discourse production; and, argues that perhaps the decontextualized nature of such tests may mislead professionals when diagnosing and treating PWA if they are to rely solely upon them to make inferences about discourse production.
The specific aims of this study were:
1. To assess whether there is a relationship between performance in CNT’s and the proportion of paraphasias in three different types of discourse when accounting for construct irrelevant variance (i.e. random noise and irrelevant systematic variance).
2. To determine the magnitude of the relationship between error free estimates of word retrieval at the single and discourse level.
3. To determine the relationship between observed scores in CNT’s and number of paraphasias in discourse
On-line sentence reading in people with aphasia: Evidence from eye tracking
No full textPeople with aphasia (PWA) often exhibit impaired sentence comprehension. According to the Lexical Bias Hypothesis (e.g., Gahl, 2002), these comprehension impairments may emerge due to conflicts between sentence structure and the biases of the words in the sentence. It is unclear whether this hypothesis can be extended to include biases – or expectations – based on the relative frequency of different syntactic structures. For example, there is a lot of evidence that PWA have more difficulty understanding structurally complex sentences (e.g., object clefts - example 2) compared to simpler sentences (e.g., subject clefts - example 1). In this case, structural complexity reflects a variety of features, including deviation from the typical subject-verb-object word order of English. However, subject clefts also occur more frequently than object clefts. Thus, it is possible that both structural complexity and frequency affect how PWA process these sentences types.
1. Subject Cleft: It was the father that entertained the baby during the party last week.
2. Object Cleft: It was the baby that the father entertained during the party last week.
Recent work identified patterns of reading times associated with both building a complex structure and violations of syntactic expectations (Staub, 2010). Staub reported slower reading times for college-age adults for both the embedded verb and the second noun phrase in sentences with object versus subject relative clauses. Longer reading times for the verb in object relatives are typically interpreted as evidence of operations associated with building a more complex syntactic structure. However, the second noun phrase is the first point in the sentence at which the object relative structure can be detected. On this basis, Staub claimed that processing disruptions at the second noun phrase occurred because the participants’ expectation for the more common structure (i.e., the subject relative) was violated. The present study asked whether PWA would show effects of complexity and frequency when reading object and subject cleft sentences, as would be expected if the Lexical Bias Hypothesis can be extended to syntactic biases
Patterns of Decline on Language Testing in Primary Progressive Aphasia
No full textThe aim of this study was to investigate patterns of decline on language testing in subtypes of primary progressive aphasia (PPA) and to examine the effects of other variables on rate of decline. Forty-six patients with PPA (mean age = 66.9 + 6.6; 27 female; mean education = 16.4 + 2.8) completed language testing. PPA subtypes were not distinguishable by rapidity of decline; however, there were different patterns of performance on language testing. Age and education did not affect rate of decline on any test. These results have implications for patient/family education regarding language deterioration and future planning
Family ratings of communication largely reflect expressive language and conversation-level ability in people with aphasia
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Using Masked Repetition Priming in Treatment of Anomia – A Phase 2 Study
No full textIndividuals with anomia often demonstrate preserved lexical knowledge, even when they are unable to produce a lexical item. An interactive spreading activation model of lexical processing explains this dichotomy by suggesting that impaired lexical access can result from deficits in the spread of activation between levels of processing or from the maintenance of activation of target representations long enough for them to be selected [1]. In either case, impaired spreading activation is implicated in lexical retrieval impairments.
Spreading activation is a fundamental component of the implicit (unconscious) processing system that supports the rapid, accurate use of language. Implicit and explicit (conscious) processes and representations interact in language production [2], and there is some evidence that the interaction between them may also be impaired in aphasia. For instance, many people with aphasia demonstrate implicit lexical knowledge and/or implicit lexical processing even if they cannot explicitly produce those same items. Most established methods of treatment for anomia are highly explicit, having clients consciously consider a word’s meaning, use, or form. If the implicit processing system and/or the interface between explicit and implicit systems is impaired, however, anomia treatment could benefit from finding ways to also address the implicit system more directly.
All treatment approaches recruit both implicit and explicit processes to some extent, due to the highly integrated, interactive nature of the language processing system. The treatment approach described here, however, shifts the therapeutic target from the explicit to the implicit end of the spectrum. We do this by using visual masking to make prime items implicit, and presenting them several times before asking for a naming response to pictures that are presented. While the naming response is an explicit response, the intent of the masked primes is to pre-activate the appropriate implicit lexical representation adequately so that the target word is more readily available when an explicit response is required. This has been demonstrated in principle by a study conducted with a single individual with anomia [3], which showed improved naming when masked primes were presented. The single-subject, multiple baseline study reported here for two participants extends this idea to investigate the effects of masked priming over repeated exposures on 1) trained items; 2) untrained items in the same semantic category; and 3) untrained items across semantic categories.
This is an ongoing project. At this time, data have been collected and analyzed for two participants, reported here. Additional participants will be enrolled in the project in early 2014, with those data included in the conference presentation, as well
How difficult is it? How well Adults with Aphasia Perceive Task Demands
No full textResearchers investigating self-ratings of task difficulty and effort allocated to lexical decision tasks in adults with aphasia indicated a mismatch between their perceptions and behavioral performance (e.g. Clark & Robin, 1995; Murray et al., 1997a; Murray et al., 1997b). That is, although participants with aphasia performed more poorly on the language tasks, they did not rate the tasks as more difficult (Murray et al., 1997a, 1997b) or as requiring more effort (Clark & Robin, 1995) compared to control participants. Murray et al., (1997a) reported that this impaired relationship between performance and perceptions was only found for difficulty ratings and not for ratings of perceived accuracy, leading them to conclude that individuals with aphasia are impaired in their ability to perceive the demands of the tasks.
The purpose of the current study was to extend these findings by including both pre- and post-task ratings of difficulty for verbal and spatial tasks. We hypothesized that if participants with aphasia are misperceiving the demands of the tasks, the relationship between performance and ratings of difficulty would be less for the pre-task ratings compared to the post-task ratings. Comparing the relationship between difficulty ratings and performance on non-verbal (spatial) and verbal tasks would further reveal whether any deficits in perceiving the task demands are specific to verbal stimuli or a domain-general deficit in evaluating task demands
Design Principles and Outcomes of "Aphasia House" an University Intensive Comprehensive Aphasia Program (ICAP)
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Neurobehavioral response to increased treatment dosage in chronic, mild aphasia
Full text linkIntensive aphasia treatment has been employed with equivocal results likely due to variability in the severity of participants as well as in the parameters that comprise intensity (e.g., session duration). Constraint Induced Language Therapy (CILT; Pulvermüller et al., 2001) is an intensive aphasia therapy that has been replicated successfully and also tends to use similar dosage parameters across replication studies (e.g., Barthel, et al, 2008; Maher, 2006). Meinzer and colleagues (2008; 2007) found that it was their most severely affected participants who tended to benefit most from treatment of CILT, positing that those who had withdrawn from verbal communication the most were those most likely to benefit from the forced use inherent to CILT. It is also possible that since CILT and associated treatment materials was designed for more impaired participants; those more mildly affected may have been insufficiently challenged during the treatment period. If so, it follows that that neural change would be less likely.
The present study employed a multiple probe technique (McReynolds & Kearns, 1983) in which CILT was delivered at a dosage of three hours per day for twenty days. A hierarchy of complex stimuli was created to pose adequate challenge for two individuals with mild aphasia. Discourse analysis and naming response time were used to quantify changes in language efficiency. In addition, fMRI scanning was performed at four time points throughout the treatment process in order to compare potential language changes to changes in neural activation patterns. These results are expected to add to the limited fMRI data currently available for intensive aphasia treatment