Stacy M. Harnish

Affected Arm Use and Cortical Change in Stroke Patients Exhibiting Minimal Hand Movement

Background and Purpose . Conventional electrical stimulation modalities are limited by their lack of opportunities for motor learning and, consequently, their impact on function. Other rehabilitative regimens necessitate affected hand and wrist movement for patients to be included, making them implausible for most patients. In light of these challenges, the current study examined the efficacy of a repetitive task-specific training (RTP) regimen using an electrical stimulation neuroprosthesis in stroke patients exhibiting no affected wrist or hand movement. Method. Eight chronic stroke patients (mean = 46.5 months) with moderately affected arm motor deficits participated in 30-minute therapy sessions occurring every weekday for 8 weeks. During the sessions, they wore the neuroprosthesis to enable performance of valued activities identified largely by the patients. To ensure transfer to their real-world environments, most sessions were home based, with the patients coming to the clinic for “tune-up” sessions (eg, adjusting the stimulation parameters, exercises, and/or fit of the device) twice every other week (a total of 8 clinical visits). Outcomes were evaluated using the Action Research Arm Test (ARAT) and the upper extremity section of the Fugl-Meyer Assessment (FM), the amount of use scale of the Motor Activity Log (MAL), and high-field functional magnetic resonance imaging (fMRI). Results. Before the intervention, patients exhibited stable motor deficits. After the intervention, they exhibited ARAT and FM score increases (+2.85 and +2.2, respectively). Postintervention fMRI revealed significant increases in cortical activation, possibly brought about by markedly increased affected arm use patterns on the MAL (+0.97). Conclusions. An affected arm RTP program incorporating NEURSTIM appears to increase affected arm use and elicit neural changes in more impaired patients. These factors may conspire to produce motor changes, although motor changes are smaller in this population than with less impaired patients. The program may act as a “bridge” to other promising regimens.

Motor Cortex Preactivation by Standing Facilitates Word Retrieval in Aphasia

Background and Objectives. A tight link between linguistic functions and activation of motor areas has been consistently reported, indicating that the 2 systems share functional neural resources. Few efforts have been made to explore whether this knowledge could aid the rehabilitation of aphasia. Methods. The authors assessed whether preactivation of the leg motor cortex during standing, compared with sitting, can facilitate language production in patients with chronic aphasia. In a cross-over within-subject design, the authors assessed performance on a picture naming task and controlled for effects on processing speed and simple verbal reaction time. Results. They found that standing compared with sitting had a beneficial effect on the number of semantic self-corrections that resulted in correct naming. In the absence of effects on motor or general processing speed, this points to a specific effect on lexical retrieval and selection. This was further corroborated by an error pattern analysis. Successful semantic self-corrections during standing were only found when there was already partial activation of the target semantic network—that is, when self-corrections were preceded by an incorrect but semantically associated naming response. Discussion. These findings show that preactivation of the motor system, which extends beyond the intrinsic link between manual gestures and language, can facilitate lexical access in chronic aphasia and may open new directions in aphasia rehabilitation.

Lesion Symptom Mapping of Manipulable Object Naming in Nonfluent Aphasia: Can a Brain be both Embodied and Disembodied?

Embodied cognition offers an approach to word meaning firmly grounded in action and perception. A strong prediction of embodied cognition is that sensorimotor simulation is a necessary component of lexical–semantic representation. One semantic distinction where motor imagery is likely to play a key role involves the representation of manufactured artefacts. Many questions remain with respect to the scope of embodied cognition. One dominant unresolved issue is the extent to which motor enactment is necessary for representing and generating words with high motor salience. We investigated lesion correlates of manipulable relative to nonmanipulable name generation (e.g., name a school supply; name a mountain range) in patients with nonfluent aphasia (N = 14). Lesion volumes within motor (BA4, where BA = Brodmann area) and premotor (BA6) cortices were not predictive of category discrepancies. Lesion symptom mapping linked impairment for manipulable objects to polymodal convergence zones and to projections of the left, primary visual cortex specialized for motion perception (MT/V5+). Lesions to motor and premotor cortex were not predictive of manipulability impairment. This lesion correlation is incompatible with an embodied perspective premised on necessity of motor cortex for the enactment and subsequent production of motor-related words. These findings instead support a graded or “soft” approach to embodied cognition premised on an ancillary role of modality-specific cortical regions in enriching modality-neutral representations. We discuss a dynamic, hybrid approach to the neurobiology of semantic memory integrating both embodied and disembodied components.

Dosing of a cued picture naming treatment for anomia

PURPOSE Recent investigations into effects of intensity or distribution of aphasia therapy have provided moderate evidence supporting intensive therapy schedules on aphasia treatment response. The purpose of the present study was to investigate the feasibility of creating an intensive therapy session without extending the amount of daily time a person spends in treatment. METHOD Individuals who presented with chronic anomia poststroke (N = 8) participated in 2 weeks of a computerized, therapist-delivered, cued, picture-naming treatment. Dosing parameters for each session were 8 presentations of 50 pictures, totaling 400 teaching episodes per session. RESULTS Of the 8 participants, 6 achieved significant increases from baseline on trained items after 400 teaching episodes (i.e., 1 treatment hr), and the remaining 2 participants achieved significant increases from baseline after 1200 teaching episodes (i.e., 3 treatment hr). Maintenance data from 7 of the participants indicated that 6 participants maintained significant improvement from baseline on trained items. CONCLUSIONS Given an intensive and saturated context, anomic individuals were surprisingly quick at relearning to produce problematic words successfully. Most participants demonstrated retention of the gains 2 months after treatment ended. The high density of teaching episodes within the treatment session (i.e., the intensive treatment schedule) may have contributed to the behavioral gains.

A Behavioral Manipulation Engages Right Frontal Cortex During Aphasia Therapy

Background. An aphasia treatment was designed to shift laterality from the left to right lateral frontal lobe during word production by initiating word-finding trials with complex left-hand movements. Previous findings indicated successful relateralization. Objective. The current study was designed to ascertain whether the shift was attributable to the left-hand movement. Methods. Using stratified random sampling, 14 subjects were equally divided between Intention (IT) and Control (CT) treatments. CT was identical to IT, except with no left-hand movements. Both treatments trained picture naming (phases 1 and 2) and category-member generation (phase 3), each phase lasting 10 sessions. Functional magnetic resonance imaging of category member generation occurred at pretreatment, posttreatment, and 3-month follow-up. Results. IT shifted lateral frontal activity rightward compared with pretreatment both at posttreatment (t = −2.602, df = 6, P < .05) and 3-month follow-up (t = −2.332, df = 5, P < .05), but CT did not. IT and CT yielded similar changes for all picture-naming and category probes. However, IT patients showed gains for untrained category (t = 3.33, df = 6, P < .01) and picture-naming probes (t = 3.77, df = 5, P < .01), but CT patients did not. Conclusions. The rightward shift in lateral frontal activity for IT was because of the left-hand movements. IT evoked greater generalization than CT.

Nonverbal Working Memory as a Predictor of Anomia Treatment Success

PURPOSE The purpose of the study was to determine (a) reliability of the spatial span as a nonverbal working memory (WM) task in individuals with aphasia, (b) whether participation in anomia treatment changed spatial span scores, and (c) the degree to which visuospatial WM predicted response to anomia treatment. METHOD Eight individuals with chronic aphasia were repeatedly assessed on the forward and backward conditions of the spatial span over 4 weeks while undergoing treatment for anomia. Experiment 1 assessed reliability of the spatial span conditions and determined whether span scores changed after beginning anomia treatment. Experiment 2 investigated the spatial span as a predictor of anomia treatment success. RESULTS Results of Experiment 1 showed that 7 participants demonstrated stability of the forward condition of the spatial span, and 5 participants demonstrated stability of the backward condition across all sessions (p = .05). No participants showed an effect of aphasia treatment on span performance in either condition. Experiment 2 found that the backward span condition significantly predicted anomia treatment effect size, F(1, 6) = 15.202, p = .008. CONCLUSIONS Visuospatial WM abilities were highly predictive of response to anomia treatment, supporting an account of WM that includes a central processing mechanism.

Thinking about better speech: Mental practice for stroke-induced motor speech impairments

Background: Mental practice (MP) is a mind–body technique in which physical movements are cognitively rehearsed. It has shown efficacy in reducing the severity of a number of neurological impairments. Aims: In the present review we highlight recent developments in MP research, and the basis for MP use after stroke-induced motor speech disorders. Main Contribution: In this review we (a) propose a novel conceptual model regarding the development of learned non-use in people with motor speech impairments; (b) review the rationale and efficacy of MP for reducing the severity of stroke-induced impairments; (c) review evidence demonstrating muscular and neural activations during and following MP use; (d) review evidence showing that MP increases skill acquisition, use, and function in stroke; (e) review literature regarding neuroplasticity after stroke, including MP-induced neuroplasticity and the neural substrates underlying motor and language reacquisition; and (f) based on the above, review the rationale and clinical application of MP for stroke-induced motor speech impairments. Conclusions: Support for MP use includes decades of MP neurobiological and behavioural efficacy data in a number of populations. Most recently these data have expanded to the application of MP in neurological populations. Given increasingly demanding managed care environments, efficacious strategies that can be easily administered are needed. We also encounter clinicians who aspire to use MP, but their protocols do not contain several of the elements shown to be fundamental to effective MP implementation. Given shortfalls of some conventional aphasia and motor speech rehabilitative techniques, and uncertainty regarding optimal MP implementation, this paper introduces the neurophysiological bases for MP, the evidence for MP use in stroke rehabilitation, and discusses its applications and considerations in patients with stroke-induced motor speech impairments.

Visual Discrimination Predicts Naming and Semantic Association Accuracy in Alzheimer Disease

ObjectiveLanguage impairment is a common symptom of Alzheimer disease (AD), and is thought to be related to semantic processing. This study examines the contribution of another process, namely visual perception, on measures of confrontation naming and semantic association abilities in persons with probable AD. MethodsTwenty individuals with probable mild-moderate Alzheimer disease and 20 age-matched controls completed a battery of neuropsychologic measures assessing visual perception, naming, and semantic association ability. Visual discrimination tasks that varied in the degree to which they likely accessed stored structural representations were used to gauge whether structural processing deficits could account for deficits in naming and in semantic association in AD. ResultsVisual discrimination abilities of nameable objects in AD strongly predicted performance on both picture naming and semantic association ability, but lacked the same predictive value for controls. Although impaired, performance on visual discrimination tests of abstract shapes and novel faces showed no significant relationship with picture naming and semantic association. These results provide additional evidence to support that structural processing deficits exist in AD, and may contribute to object recognition and naming deficits. ConclusionsOur findings suggest that there is a common deficit in discrimination of pictures using nameable objects, picture naming, and semantic association of pictures in AD. Disturbances in structural processing of pictured items may be associated with lexical-semantic impairment in AD, owing to degraded internal storage of structural knowledge.

Influence of working memory on stimulus generalization in anomia treatment: A pilot study

Abstract Neuropsychological testing of distinct cognitive domains holds promise as a prognostic indicator of aphasia therapy success; however, it is unclear the degree to which cognitive assessments may also predict generalization abilities. The present study aimed to assess the relationship between working memory skills and stimulus generalization from a visual picture-naming treatment to an auditory definition-naming task. Seven individuals with aphasia completed verbal and nonverbal assessments of working memory prior to participating in a cued picture-naming treatment for anomia. After treatment ended, stimulus generalization percentages were calculated for definition naming for the same items that were trained using picture naming. Scores on two nonverbal working memory measures, the backward spatial span and the 1-back, and one verbal working memory assessment, the picture span, were positively correlated with generalization percentage. These results provide preliminary evidence of the relationship between working memory and stimulus generalization. When comparing performance across working memory measures, the spatial span and the picture span were highly correlated in this sample. We propose that despite the verbal and nonverbal distinction, these tasks may have tapped into working memory similarly by relying on a shared central processing mechanism.

Adolescent Summaries of Narrative and Expository Discourse: Differences and Predictors

Purpose Summarizing expository passages is a critical academic skill that is understudied in language research. The purpose of this study was to compare the quality of verbal summaries produced by adolescents for 3 different discourse types and to determine whether a composite measure of cognitive skill or a test of expressive syntax predicted their performance. Method Fifty adolescents listened to, and then verbally summarized, 1 narrative and 2 expository lectures (compare-contrast and cause-effect). They also participated in testing that targeted expressive syntax and 5 cognitive subdomains. Results Summary quality scores were significantly different across discourse types, with a medium effect size. Analyses revealed significantly higher summary quality scores for cause-effect than compare-contrast summaries. Although the composite cognitive measure contributed significantly to the prediction of quality scores for both types of expository summaries, the expressive syntax score only contributed significantly to the quality scores for narrative summaries. Conclusions These results support previous research indicating that type of expository discourse may impact student performance. These results also show, for the first time, that cognition may play a predictive role in determining summary quality for expository but not narrative passages in this population. In addition, despite the more complex syntax commonly associated with exposition versus narratives, an expressive syntax score was only predictive of performance on narrative summaries. These findings provide new information, questions, and directions for future research for those who study academic discourse and for professionals who must identify and manage the problems of students struggling with different types of academic discourse. Supplemental Material https://doi.org/10.23641/asha.6167879.