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Working Memory Capacity and its Relation to Passive Sentence Comprehension in Persons with Mild Cognitive Impairment
No full textThe purpose of the study was to investigate working memory capacity (WMC) and its relation to Korean passive sentence (PS) comprehension in persons with mild cognitive impairment (MCI). Results revealed that persons with MCI performed significantly more poorly than normal elderly individuals (NEI) in PS compared to active sentences with intransitive verbs. However, the group differences were not significant between PS and active sentences with transitive verbs. WMC significantly predicted performance on PS for both groups. The current study indicated that Korean-speaking persons with MCI could use information of case markers and WMC was related to PS comprehension abilities
Comprehension of Who and Which-NP questions: Which Account do the Data Support?
No full textThis study investigated the comprehension of various types of Wh-questions in unimpaired adults and those with Broca’s aphasia. Using an eye tracking-while listening method, we examined four specific hypotheses. Our initial results for our healthy controls revealed offline support for a Word Order Hypothesis – object-extracted Who and Which-NP questions took longer to resolve than subject-extracted versions. Our results using eye gaze data, however, revealed support for a Retrieval Hypothesis – Which-NP questions that contain more specific information yielded fewer looks to the correct referent than their Who-question counterparts. These patterns set the stage for our ongoing aphasia study
Concurrent validation of an eyetracking-based method for assessing attention allocation
Get PDFSeveral authors have reported that individuals with aphasia have greater difficulty allocating attention according to task demands than people without neurological disorders (Hula & McNeil, 2008; LaPointe & Erickson, 1991; McNeil et al., 2004; McNeil et al., 2005; Murray, Holland, & Beeson, 1997; Robin & Rizzo, 1988). Studying how attention deficits contribute to neurogenic language deficits is important for clinical practice and research. However, existing methods for indexing attention allocation in people with aphasia pose serious methodological challenges, including demands on comprehension abilities for understanding of dual-task instructions prior to an experiment, and response requirements that may impact participants’ performance. Eyetracking methods have great potential to address such challenges. Such methods do not require a) understanding of complex instructions; b) responding verbally, in writing, or with gestures; or c) manipulating devices, such as a computer mouse or joystick (Hallowell, Wertz, & Kruse, 2002). These features reduce critical response confounds and improve the validity of assessment tools for indexing attention allocation (Heuer & Hallowell, 2013).
Heuer and Hallowell (2013) developed an eyetracking method to assess attention allocation using a dual-task paradigm in individuals with and without aphasia. The dual-task method included a visual search task, in which participants were trained to find a visual target in a display that included one target and three nontarget foils, and an auditory linguistic processing task, in which sentences were presented auditorally. Attention demands were manipulated by varying the complexity of each of the two tasks. Changes in attention demands were indexed through performance on the visual search task using eyetracking measures. Results indicated that the method is sensitive to differences between people with and without aphasia, and that it captures response variations associated with task demands and stimulus complexity. While those results were valuable in establishing the construct validity of the novel eyetracking-based measures, no conclusions could be drawn about the concurrent validity of the method because no previously validated measure of attention allocation had been administered
Feedback and Feedforward Control in Speech Production in Apraxia of Speech and Aphasia
No full textApraxia of speech (AOS) is considered to be a speech motor planning impairment (e.g., McNeil et al., 2009), but the nature of this impairment remains poorly understood. The present study was designed to test two hypotheses about the nature of AOS, framed in the DIVA model (Guenther et al., 2006). The DIVA model assumes that speech targets are regions in auditory space, and combines two control mechanisms to reach those targets: feedback control and feedforward control. The feedback mechanism generates corrective motor commands when the actual speech sound deviates from the intended speech sound. The feedforward mechanism generates predictive motor commands based on past experiences with the speech target.
In the context of the DIVA model, we developed two hypotheses about possible underlying deficits in AOS. The Feedforward Control Impairment (FF) hypothesis states that feedforward control is impaired in AOS, with consequently a greater reliance on feedback control (Jacks, 2008). The Feedback Control Impairment (FB) hypothesis states that feedback control is impaired in AOS; concurrent feedback may be disruptive (cf. Ballard & Robin, 2007).
We tested these hypotheses by measuring acoustic vowel contrast in two conditions: normal listening and auditory feedback masking. Under masking conditions, unimpaired speakers maintain segmental contrast (suggesting adequate feedforward commands to support speech without auditory feedback) even though contrast is somewhat reduced (suggesting on-line use of auditory feedback) (Perkell et al., 2007). The FF hypothesis predicts a greater reduction of segmental contrast with feedback masking in speakers with AOS than in controls, because effective removal of the auditory feedback control strategy will reveal the impaired feedforward commands. The FB hypothesis, in contrast, predicts increased segmental contrast with feedback masking, because removal of auditory feedback will allow the intact feedforward commands to produce adequate contrasts. One previous study that used feedback masking in AOS examined vowel duration and found longer vowels with masking in AOS and controls (Rogers et al., 1996); the present study also examined vowel duration
Measuring quality of life for an economic evaluation of aphasia: First steps
No full textHealth economists typically use the Quality Adjusted Life Year (QALY) when conducting economic evaluations of healthcare investments. We have begun investigating methods to obtain QALYs for aphasia by developing a pictographic version of the Time Trade-Off methodology (picTTO) in an attempt to circumvent language barriers. A convenience sample of 50 adults with aphasia participated in reliability and validity testing of the picTTO. Analysis suggests that while the picTTO itself has face validity, results demonstrated poor to moderate test-retest reliability which we plan to improve by optimizing the study design
Progressive Apraxia of Speech: Might There Be Subtypes?
No full textThis study examined speech and language characteristics of three groups of individuals with neurodegenerative disease: (1) primary progressive apraxia of speech (AOS) without aphasia (N=18), (2) agrammatic primary progressive aphasia (agPPA) less severe than AOS (N=10), and (3) agPPA more severe than AOS (N=9). Findings indicate that differences in the predominant characteristics of AOS (predominance of articulatory versus prosodic abnormalities) distributed differently among the three groups, independent of AOS severity. Neuroimaging findings also differed among the groups. Results suggest that neurodegenerative AOS may include perceptually distinguishable subtypes that are related to the presence or absence of aphasia and neuroimaging findings
Word-finding pauses in primary progressive aphasia (PPA): Effects of lexical category
No full textWord-finding pauses are common in logopenic primary progressive aphasia (PPA-L). However, no previous research investigated the distribution of word-finding pauses in PPA or their specificity to PPA-L. We coded pauses preceding nouns and verbs in narrative speech samples from participants with PPA-L, agrammatic (PPA-G) and semantic PPA (PPA-S), and controls, hypothesizing that frequent word-finding pauses, if present, should match previously-observed lexical category deficits (noun deficits in PPA-L and PPA-S; verb deficits in PPA-G).The PPA-L group paused more frequently before nouns than verbs, whereas no other group exhibited lexical category effects, suggesting that frequent word-finding pauses are specific to PPA-L
Effort Invested in Cognitive Tasks by Adults with Aphasia: A Pilot Study
No full textThe objective of this study was to quantify cognitive effort IWA and control participants dedicate to verbal compared with spatial working memory tasks using HRV. Researchers have found that non-brain injured adults’ physiological stress response is not affected by task type (Callister, Suwarno, & Seals, 1992), but by task difficulty (Fairclough & Houston, 2004; Gendolla & Richter, 2006; Iani, et al., 2004; Ryu & Myung, 2005). Assuming IWA have an impaired ability to allocate effort to the tasks, it was predicted that they would demonstrate no change in HRV from baseline to task for either verbal or spatial tasks. Further, a significant positive relationship between change in HRV and task performance was predicted for control participants, but none was expected for IWA
iPractice: The effectiveness of a tablet-based home program in aphasia treatment
No full textThe iPad and other tablet devices have enormous potential for personalized home practice to augment aphasia rehabilitation. The current study investigates the utility of an iPad-based home practice program, implemented post intensive therapy, for people with chronic aphasia. Six of eight subjects are participating in the home program. All participants maintained advances made on words trained during the intensive treatment and additionally were able to learn new words solely by practicing on the iPad. The results have implications for the use of home programs and tablet devices in people with chronic aphasia. Selecting appropriate candidates for tablet-based technology is discussed
Learning ability as a predictor of success with therapy
Get PDFResearch has shown that therapy can significantly improve the communicative success of patients with aphasia. In spite of progress made in the field of aphasia rehabilitation, questions remain regarding the influence of factors such as severity of aphasia and measures of cognitive and linguistic ability on language recovery. A major limitation currently facing clinicians is the inability to predict therapy outcomes or tailor treatment to individuals.
We aim to introduce a fundamentally new approach that looks beyond language, proposing that the answer to developing efficacious, individually tailored therapies lies in a better understanding of the supporting systems and networks of general learning. Learning is integral to the processes of forming associations, recalling information and applying rules (Seger & Miller, 2010 for review). Learning requires attention, strategy use, feedback monitoring and integration, skills likely to contribute to the process of achieving gains through therapy. Thus, we suggest that predicting whether a patient will improve following therapy instruction may depend more upon that individual’s ability to learn new information in general than upon a specific ability to relearn or re-access language.
In support of this hypothesis are recent neuroimaging studies that have found success with language therapy to be associated with structures and functional networks associated with learning and memory; rather than with structures considered essential to language (Goldenberg & Spatt, 1994; Meinzer et al., 2010; Menke et al., 2009). In addition, a recent study by Vallila-Rohter & Kiran (2013) suggests that patients with aphasia vary in their ability to learn non-linguistic categories.
We propose that learning ability is yet another factor that contributes to treatment outcomes. In the current study we explore the relationship between learning ability and progress with language therapy. We hypothesize that non-verbal learning phenotype (learning slope) will be positively associated with treatment outcomes