How to engage the right brain hemisphere in aphasics without even singing: evidence for two paths of speech recovery

Early Boost of Linguistic Skills? Individualized Non-Invasive Brain Stimulation in Early Postacute Aphasia

Non-invasive brain stimulation, such as transcranial direct current stimulation (tDCS), has been shown to increase the outcome of speech and language therapy (SLT) in chronic aphasia. Only a few studies have investigated the effect of add-on tDCS on SLT in the early stage of aphasia; this may be due to methodological reasons, in particular the influence of spontaneous remission and the difficulty of establishing stimulation protocols in clinical routines. Thirty-seven participants with subacute aphasia (PwA) after stroke (23 men, 14 women; mean age 62 ± 12 years; mean duration 49 ± 28 days) were included in two consecutive periods of treatment lasting two weeks each. During the first period (P1) the participants received 10 sessions of SLT, during the second period (P2) the aphasia therapy was supplemented by anodal left hemispheric 2 mA tDCS over the left hemisphere. Severity-specific language tests (Aachen Aphasia Test (AAT), n = 27 and Bielefeld Aphasia Screening-Reha (BIAS-R), n = 10) were administered before P1, between P1 and P2, and after P2. Where information was available, the results were corrected for spontaneous remission (AAT sample), and the therapy outcomes of P1 and P2 were compared. Participants' overall language abilities improved significantly during P1 and P2. However, improvement-as measured by the AAT profile level or the BIAS-R mean percentage value-during P2 (with tDCS) was significantly higher than during P1 (p < 0.001; AAT sample and p = 0.005; BIAS-R sample). Thus, tDCS protocols can be implemented in early aphasia rehabilitation. Despite the limitations of the research design, which are also discussed from an implementation science perspective, this is preliminary evidence that an individually tailored anodal tDCS can have a significant add-on effect on the outcome of behavioral aphasia therapy in subacute aphasia.

The Effect of Prosodic Timing Structure on Unison Production in People With Aphasia

PURPOSE

Unison production is a common aphasia treatment technique in which the clinician and the person with aphasia (PWA) produce phrases aloud together. It can be implemented using a typical "conversational," syntax-influenced prosodic timing structure, or with a "metrical," beat-based timing structure, but to date no study has directly compared these two approaches. This study compared the effects of metrical versus conversational prosodic timing during unison production on the (a) accuracy of participants' spoken output and (b) timing alignment of participants' productions with the stimuli.

METHOD

PWAs and controls listened to conversationally timed and metrically timed sentences and repeated them in unison with audio recordings. Productions were transcribed and scored in two ways: (a) Accuracy was calculated as the percentage of correctly produced syllables, and (b) timing alignment was determined by extracting the voice onset moment of identical target syllables in the unison stimuli and participant productions in both conditions and comparing the corresponding time points.

RESULTS

Metrical timing yielded a greater number of accurate syllables in both groups, with larger effect in PWAs than in controls. Both groups exhibited more anticipatory, less variable timing when speaking along with metrical stimuli, though evidence of such prediction was also present in the conversational condition.

CONCLUSIONS

Results suggest that unison production works via entrainment-a process that utilizes prediction to guide synchronous production of spoken output. Metrically regular stimuli may facilitate this process as they are more rhythmically predictable. Future work will examine key behavioral variables that predict benefit from unison production and metrical timing.

Examining cortical tracking of the speech envelope in post-stroke aphasia

Introduction

People with aphasia have been shown to benefit from rhythmic elements for language production during aphasia rehabilitation. However, it is unknown whether rhythmic processing is associated with such benefits. Cortical tracking of the speech envelope (CTenv) may provide a measure of encoding of speech rhythmic properties and serve as a predictor of candidacy for rhythm-based aphasia interventions.

Methods

Electroencephalography was used to capture electrophysiological responses while Spanish speakers with aphasia (n = 9) listened to a continuous speech narrative (audiobook). The Temporal Response Function was used to estimate CTenv in the delta (associated with word- and phrase-level properties), theta (syllable-level properties), and alpha bands (attention-related properties). CTenv estimates were used to predict aphasia severity, performance in rhythmic perception and production tasks, and treatment response in a sentence-level rhythm-based intervention.

Results

CTenv in delta and theta, but not alpha, predicted aphasia severity. Neither CTenv in delta, alpha, or theta bands predicted performance in rhythmic perception or production tasks. Some evidence supported that CTenv in theta could predict sentence-level learning in aphasia, but alpha and delta did not.

Conclusion

CTenv of the syllable-level properties was relatively preserved in individuals with less language impairment. In contrast, higher encoding of word- and phrase-level properties was relatively impaired and was predictive of more severe language impairments. CTenv and treatment response to sentence-level rhythm-based interventions need to be further investigated.

Melodic Intonation Therapy for aphasia: A multi-level meta-analysis of randomized controlled trials and individual participant data

Melodic Intonation Therapy (MIT) is a prominent rehabilitation program for individuals with post-stroke aphasia. Our meta-analysis investigated the efficacy of MIT while considering quality of outcomes, experimental design, influence of spontaneous recovery, MIT protocol variant, and level of generalization. Extensive literature search identified 606 studies in major databases and trial registers; of those, 22 studies-overall 129 participants-met all eligibility criteria. Multi-level mixed- and random-effects models served to separately meta-analyze randomized controlled trial (RCT) and non-RCT data. RCT evidence on validated outcomes revealed a small-to-moderate standardized effect in noncommunicative language expression for MIT-with substantial uncertainty. Unvalidated outcomes attenuated MIT's effect size compared to validated tests. MIT's effect size was 5.7 times larger for non-RCT data compared to RCT data (g̅case report = 2.01 vs. g̅RCT = 0.35 for validated Non-Communicative Language Expression measures). Effect size for non-RCT data decreased with number of months post-stroke, suggesting confound through spontaneous recovery. Deviation from the original MIT protocol did not systematically alter benefit from treatment. Progress on validated tests arose mainly from gains in repetition tasks rather than other domains of verbal expression, such as everyday communication ability. Our results confirm the promising role of MIT in improving trained and untrained performance on unvalidated outcomes, alongside validated repetition tasks, and highlight possible limitations in promoting everyday communication ability.

Singing for the Rehabilitation of Acquired Neurogenic Communication Disorders: Continuing the Evidence Dialogue with a Survey of Current Practices in Speech-Language Pathology

Therapeutic applications of singing (e.g., melodic intonation therapy) for acquired neurogenic communication disorders (ANCD) such as post-stroke aphasia, dysarthria, or neurodegenerative diseases have emerged from innovations by clinical speech-language pathologists (SLPs). However, these specialists have never been systematically consulted about the use of singing in their practices. We report a survey of 395 SLPs in France using an online questionnaire (September 2018-January 2019). Most (98%) knew that singing could be a therapeutic tool. A wide variety of uses emerged in our data. Some practices (e.g., song games) have not yet been investigated in research settings. Melodic therapy, which is supported by scientific evidence, is familiar to clinicians (90%), but they lack training and rarely follow a full protocol. Over half of respondents (62%) recognize group singing for various benefits, but do not often use it, mainly due to the lack of adapted or welcoming choirs in their area. These results provide key information for continued dialogue between researchers, clinicians, and the community. Considering the aging population and the associated increase in the prevalence of ANCD, access to group singing in particular could be facilitated for these patients from a social prescription perspective with further research evidence.

Get in Sync: Active Ingredients and Patient Profiles in Scripted-Sentence Learning in Spanish Speakers With Aphasia

PURPOSE

Script training is a well-established treatment for aphasia, but its evidence comes almost exclusively from monolingual English speakers with aphasia. Furthermore, its active ingredients and profiles of people with aphasia (PWA) that respond to this treatment remain understudied. This study aimed to adapt a scripted-sentence learning protocol to Colombian Spanish speakers with aphasia, investigate speech entrainment (i.e., unison production of sentences) as an active ingredient for scripted-sentence learning, and identify patient profiles associated with better scripted-sentence learning.

METHOD

Fourteen monolingual Spanish speakers with aphasia learned a set of 30 sentences. To examine speech entrainment as an active ingredient for scripted-sentence learning, we investigated whether sentences containing externally added rhythmic cues (involving stress-aligned vs. metronomic rhythmic cues) would result in better scripted-sentence learning compared with control sentences. Learning was measured via postsession probes and analyzed using mixed-effects logistic regression models. The relationship between scripted-sentence learning and baseline language and rhythmic processing measures was also examined.

RESULTS

Significant scripted-sentence learning over time indicated a successful adaptation of a script-training protocol to Spanish. PWA learned significantly more scripted sentences in the rhythmically enhanced conditions compared with the control condition. There were no differences between rhythmically enhanced conditions (stress-aligned vs. metronomic). In terms of patient profiles, it was found that PWA with more severe aphasia demonstrated larger learning gains, but rhythmic processing showed little association with learning estimates.

CONCLUSIONS

To our knowledge, this study provides the first adaptation of a scripted-sentence learning protocol for monolingual Spanish speakers with aphasia, demonstrating cross-linguistic benefits of script training interventions. Highlighting rhythmic features during speech entrainment facilitated scripted-sentence learning in Spanish speakers with aphasia, suggesting that speech entrainment may be an active ingredient for scripted-sentence learning. More severe aphasia was associated with better scripted-sentence learning, suggesting that more severely impaired individuals are likely to benefit most from this treatment.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19241847.

Melodic Intonation Therapy on Non-fluent Aphasia After Stroke: A Systematic Review and Analysis on Clinical Trials

Melodic intonation therapy (MIT) is a melodic musical training method that could be combined with language rehabilitation. However, some of the existing literature focuses on theoretical mechanism research, while others only focus on clinical behavioral evidence. Few clinical experimental studies can combine the two for behavioral and mechanism analysis. This review aimed at systematizing recent results from studies that have delved explicitly into the MIT effect on non-fluent aphasia by their study design properties, summarizing the findings, and identifying knowledge gaps for future work. MIT clinical trials and case studies were retrieved and teased out the results to explore the validity and relevance of these results. These studies focused on MIT intervention for patients with non-fluent aphasia in stroke recovery period. After retrieving 128 MIT-related articles, 39 valid RCT studies and case reports were provided for analysis. Our summary shows that behavioral measurements at MIT are excessive and provide insufficient evidence of MRI imaging structure. This proves that MIT still needs many MRI studies to determine its clinical evidence and intervention targets. The strengthening of large-scale clinical evidence of imaging observations will result in the clear neural circuit prompts and prediction models proposed for the MIT treatment and its prognosis.

Evaluating Cognitive-Linguistic Approaches to Interventions for Aphasia Within the Rehabilitation Treatment Specification System

The Rehabilitation Treatment Specification System (RTSS) provides a framework to identify specific components of treatments developed within various rehabilitation disciplines (eg, physical, occupational, or speech-language therapy). Furthermore, this framework offers the opportunity to identify the target and active ingredients of a therapy approach as well as the mechanism of action by which it is hypothesized to effect change in abilities or functions. In this article, we apply the RTSS framework to the characterization of a sample of treatments for aphasia that are based on cognitive-linguistic models of language processing. Our discussion of these applications centers on the benefits of this classification system and additional criteria to consider when evaluating cognitive-linguistic treatments for aphasia.

Adaptation of Melodic Intonation Therapy to Greek: A Clinical Study in Broca's Aphasia With Brain Perfusion SPECT Validation

Melodic intonation therapy (MIT) is one of the most well-known treatment methods which is based on pitch and rhythm and was developed to increase verbal output in adults with non-fluent aphasia. Although MIT has been adapted to several languages, in Greece it is almost unknown. The aim of the proposed study is twofold: (1) to translate and adapt the MIT to the Greek language, and (2) to conduct an experimental study in order to examine the effect of MIT on Greek patients with Broca’s aphasia. To this aim, a 64-year-old, right-handed male who had a 6-year primary school education level, no musical abilities and poor performance on the recognition of prosody attended the MIT intervention program almost two and a half years after the event of suffering an ischemic stroke. The MIT intervention was administered three times per week for a 12-week period, in which each session lasted from 30 to 40 min. The patient underwent three assessments all using both the Boston Diagnostic Aphasia Examination–Short Form (BDAE-SF) and brain perfusion single-photon emission computed tomography (SPECT); (1) before the MIT, (2) immediately after, and (3) 3 months after the completion of MIT. The results from the BDAE-SF revealed an impressive improvement on both trained and prepositional speech production, immediately after the completion of the MIT, and a stable improved performance 3 months after MIT. The SPECT scan revealed reactivation of the perilesional areas of the left hemisphere, and considerably improved perfusion of the frontal lobe, the anterior temporal lobe, and the upper part of the parietal lobe of the right hemisphere. The improvement persisted and even expanded 3 months after MIT. Therefore, MIT is a promising intervention program and its positive effects last for at least 3 months after the completion of the intervention.

Neural plasticity: The substratum of music-based interventions in neurorehabilitation

BACKGROUND

The plastic nature of the human brain lends itself to experience and training-based structural changes leading to functional recovery. Music, with its multimodal activation of the brain, serves as a useful model for neurorehabilitation through neuroplastic changes in dysfunctional or impaired networks. Neurologic Music Therapy (NMT) contributes to the field of neurorehabilitation using this rationale.

OBJECTIVE

The purpose of this article is to present a discourse on the concept of neuroplasticity and music-based neuroplasticity through the techniques of NMT in the domain of neurological rehabilitation.

METHODS

The article draws on observations and findings made by researchers in the areas of neuroplasticity, music-based neuroplastic changes, NMT in neurological disorders and the implication of further research in this field.

RESULTS

A commentary on previous research reveal that interventions based on the NMT paradigm have been successfully used to train neural networks using music-based tasks and paradigms which have been explained to have cross-modal effects on sensorimotor, language and cognitive and affective functions.

CONCLUSIONS

Multimodal gains using music-based interventions highlight the brain plasticity inducing function of music. Individual differences do play a predictive role in neurological gains associated with such interventions. This area deserves further exploration and application-based studies.

Treatment dose in post-stroke aphasia: A systematic scoping review

Little is known about how the amount of treatment a person with aphasia receives impacts aphasia recovery following stroke, yet this information is vital to ensure effective treatments are delivered efficiently. Furthermore, there is no standard dose terminology in the stroke rehabilitation or aphasia literature. This scoping review aims to systematically map the evidence regarding dose in treatments for post-stroke aphasia and to explore how treatment dose is conceptualized, measured and reported in the literature. A comprehensive search was undertaken in June 2019. One hundred and twelve intervention studies were reviewed. Treatment dose (amount of treatment) has been conceptualized as both a measure of time and a count of discrete therapeutic elements. Doses ranged from one to 100 hours, while some studies reported session doses of up to 420 therapeutic inputs per session. Studies employ a wide variety of treatment schedules (i.e., session dose, session frequency, and intervention duration) and the interaction of dose parameters may impact the dose-response relationship. High dose interventions delivered over short periods may improve treatment efficiency while maintaining efficacy. Person- and treatment-level factors that mediate tolerance of high dose interventions require further investigation. Systematic exploration of dose-response relationships in post-stroke aphasia treatment is required.

Auditory rhyme processing in expert freestyle rap lyricists and novices: An ERP study

Music and language processing share and sometimes compete for brain resources. An extreme case of such shared processing occurs in improvised rap music, in which performers, or 'lyricists', combine rhyming, rhythmic, and semantic structures of language with musical rhythm, harmony, and phrasing to create integrally meaningful musical expressions. We used event-related potentials (ERPs) to investigate how auditory rhyme sequence processing differed between expert lyricists and non-lyricists. Participants listened to rhythmically presented pseudo-word triplets each of which terminated in a full-rhyme (e.g., STEEK, PREEK; FLEEK), half-rhyme (e.g., STEEK, PREEK; FREET), or non-rhyme (e.g., STEEK, PREEK; YAME), then judged each sequence in its aesthetic (Do you 'like' the rhyme?) or technical (Is the rhyme 'perfect'?) aspect. Phonological N450 showed rhyming effects between conditions (i.e., non vs. full; half vs. full; non vs. half) similarly across groups in parietal electrodes. However, concurrent activity in frontocentral electrodes showed left-laterality in non-lyricists, but not lyricists. Furthermore, non-lyricists' responses to the three conditions were distinct in morphology and amplitude at left-hemisphere electrodes with no condition difference at right-hemisphere electrodes, while lyricists' responses to half-rhymes they deemed unsatisfactory were similar to full-rhyme at left-hemisphere electrodes, and similar to non-rhyme at right-hemisphere electrodes. The CNV response observed while waiting for the second and third pseudo-word in the sequence was more enhanced to aesthetic rhyme judgments tasks than to technical rhyme judgment tasks in non-lyricists, suggesting their investment of greater effort for aesthetic rhyme judgments. No task effects were observed in lyricists, suggesting that aesthetic and technical rhyme judgments may engage the same processes for experts. Overall, our findings suggest that extensive practice of improvised lyricism may uniquely encourage the neuroplasticity of integrated linguistic and musical feature processing in the brain.

A Case Study Using a Multimodal Approach to Melodic Intonation Therapy

PURPOSE

The purpose of this study was to assess the efficacy. of increasing spontaneous expressive language using a modified melodic intonation therapy (MIT) approach with a male participant diagnosed with acquired aphasia and apraxia who was 10 years post onset.

METHOD

A therapeutic protocol consisting of vocal and linguistic tasks was administered. The participant attended two 50-min individual sessions and a 4-hr/week socialization program for three 12-week semesters. Measures of speech and language were administered before intervention and at the completion of each of the 3 semesters.

RESULTS

At the completion of the study, the participant demonstrated reduced apraxia of speech as measured by The Apraxia Battery for Adults, Second Edition (Dabul, 2000). He also showed improvements in auditory comprehension skills as measured on the Boston Diagnostic Aphasia Evaluation (Goodglass, Kaplan, & Barresi, 2000). His spontaneous utterances were characterized by an increased number of complete sentences and questions. Several language parameters including mean length of utterance, total number of spontaneous (untrained) utterances, and number of different words spoken were also improved as revealed through language analysis.

CONCLUSIONS

Integration of melodic intonation therapy through the addition of musical elements may result in improved speech and expressive language skills when administered over a 9-month period in conjunction with a group socialization program.

Please don't stop the music: Song completion in patients with aphasia

Aphasia, an acquired language disorder resulting from brain damage, affects over one million individuals in the United States alone. Many persons with aphasia (PWA), particularly those with non-fluent aphasia, have been observed to be able to sing the lyrics of songs more easily than they can speak the same words. Remarkably, even humming a melody can facilitate speech output in PWA, and this has been capitalized on in therapies such as Melodic Intonation Therapy. The current study examined PWA's ability to complete phrases from songs by either singing, speaking, or intoning them in an experimental stem-completion format. Twenty PWA of varying severity, all but one of whom had aphasia as a result of stroke, and 20 age-matched healthy controls participated in the task. The task consisted of three conditions (sung, spoken, and melodic) each consisting of 20 well-known songs. Participants heard the first half of a phrase that was either sung in its original format (sung condition), spoken (spoken condition), or intoned on the syllable "bum," (melodic condition) and were asked to complete the phrase according to the format in which the stimulus was presented. PWA achieved the highest accuracy in the sung condition, followed by the spoken and then melodic conditions, while controls scored comparably in the sung and spoken condition and much lower in the melodic condition. PWA and controls were better able to access and produce both the melody and lyrics of songs in the sung condition (when both components were presented together), compared to when the melody and lyrics of songs were presented in isolation. Here, melody confers an advantage for word retrieval for PWA, as lyric production is better in a sung context, and these results substantiate the theoretical framework of MIT. Additionally, the present results may be attributed to the integration hypothesis, which postulates that the text and tune of a song are integrated in memory. Interestingly, a subset of the most severe PWA scored higher in the melodic condition relative to the spoken condition, while this pattern was not found for less severe PWA and for controls. Taken together, our results suggest that singing appears to influence PWA when trying to access the lyrics of songs; access to melody is preserved in PWA even while they exhibit profound and diverse language impairments. Findings may have implications for using music as a more widely implemented tool in speech therapy for PWA.

The Affective Nature of Formulaic Language: A Right-Hemisphere Subcortical Process

Formulaic expressions naturally convey affective content. The unique formal and functional characteristics of idioms, slang, expletives, proverbs, conversational speech formulas, and the many other conventional expressions in this repertory have been well-described: these include unitary form, conventionalized and non-literal meanings, and reliance on social context. Less highlighted, but potent, is the intrinsic presence of affective meaning. Expletives, for example, signal strong emotion. Idioms, too, inherently communicate emotional connotations, and conversational speech formulas allow for empathetic bonding and humor. The built-in affective content of formulaic expressions, in combination with their other unique characteristics, is compatible with the proposal that brain structures other than those representing grammatical language are in play in producing formulaic expressions. Evidence is presented for a dual process model of language, whereby a right hemisphere-subcortical system modulates formulaic language.

Exploring the efficacy of melodic intonation therapy with Broca's aphasia in Arabic

BACKGROUND

 Even though the efficacy of melodic intonation therapy (MIT) with persons with aphasia (PWA) has been explored in different languages, the efficacy of MIT with Arabic-speaking PWA has never been explored. Aims: To explore the efficacy of MIT, adapted to Arabic, in promoting the expressive abilities of a 70-year-old Jordanian Arabic-speaking male subject with severe Broca's aphasia 3 months post-onset. Methods: An 8-week MIT therapy programme with tapping (1.5 h daily, 6 days a week) was used in a multiple baseline design across two types of trained phrases (i.e. automatic and self-generated phrases). Outcome measures included accuracy of production of trained (at the end of each session) and untrained phrases (at the end of each week). Pre- and post-treatment measures used, were the bilingual aphasia test, the American Speech-Language Hearing Association Functional Assessment of Communicative Skills, the communicative effectiveness index and the American Speech and Hearing Association Quality of Communication Life Scale. Accuracy of production for the trained and untrained phrases was also measured 2 weeks and 4 weeks after the treatment programme was finished. Results: The patient, (MK), improved his expressive productions post-treatment in automatic and self-generated phrases. Automatic phrases exceeded the established 75% accuracy criterion, whereas the self-generated phrases reached criterion and remained constant at follow-up. Moreover, MK gradually started improving on the generalisation stimuli, once the treatment on the self-generated phrases started and maintained the gains 2 weeks and 4 weeks post-treatment. Conclusion: MIT appears to be a viable treatment option for Jordanian Arabic-speaking persons with Broca's aphasia. However, more research is needed with larger groups of Jordanian Arabic-speaking persons with Broca's aphasia to provide more support to the present findings. Moreover, future studies might focus on the efficacy of MIT with persons with Broca's aphasia from different Arab countries and from countries where Arabic is part of the multicultural structure like South Africa and other countries on the African continent.

Melodic Intonation Therapy in Chronic Aphasia: Evidence from a Pilot Randomized Controlled Trial

Melodic Intonation Therapy (MIT) is a language production therapy for severely non-fluent aphasic patients using melodic intoning and rhythm to restore language. Although many studies have reported its beneficial effects on language production, randomized controlled trials (RCT) examining the efficacy of MIT are rare. In an earlier publication, we presented the results of an RCT on MIT in subacute aphasia and found that MIT was effective on trained and untrained items. Further, we observed a clear trend in improved functional language use after MIT: subacute aphasic patients receiving MIT improved considerably on language tasks measuring connected speech and daily life verbal communication. Here, we present the results of a pilot RCT on MIT in chronic aphasia and compare these to the results observed in subacute aphasia. We used a multicenter waiting-list RCT design. Patients with chronic (>1 year) post-stroke aphasia were randomly allocated to the experimental group (6 weeks MIT) or to the control group (6 weeks no intervention followed by 6 weeks MIT). Assessments were done at baseline (T1), after 6 weeks (T2), and 6 weeks later (T3). Efficacy was evaluated at T2 using univariable linear regression analyses. Outcome measures were chosen to examine several levels of therapy success: improvement on trained items, generalization to untrained items, and generalization to verbal communication. Of 17 included patients, 10 were allocated to the experimental condition and 7 to the control condition. MIT significantly improved repetition of trained items (β = 13.32, p = 0.02). This effect did not remain stable at follow-up assessment. In contrast to earlier studies, we found only a limited and temporary effect of MIT, without generalization to untrained material or to functional communication. The results further suggest that the effect of MIT in chronic aphasia is more restricted than its effect in earlier stages post stroke. This is in line with studies showing larger effects of aphasia therapy in earlier compared to later stages post stroke. The study was designed as an RCT, but was underpowered. The results therefore have to be interpreted cautiously and future larger studies are needed.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, identifier NTR 1961.

Improved Neural Processing Efficiency in a Chronic Aphasia Patient Following Melodic Intonation Therapy: A Neuropsychological and Functional MRI Study

Melodic intonation therapy (MIT) is a treatment program for the rehabilitation of aphasic patients with speech production disorders. We report a case of severe chronic non-fluent aphasia unresponsive to several years of conventional therapy that showed a marked improvement following intensive 9-day training on the Japanese version of MIT (MIT-J). The purpose of this study was to verify the efficacy of MIT-J by functional assessment and examine associated changes in neural processing by functional magnetic resonance imaging. MIT improved language output and auditory comprehension, and decreased the response time for picture naming. Following MIT-J, an area of the right hemisphere was less activated on correct naming trials than compared with before training but similarly activated on incorrect trials. These results suggest that the aphasic symptoms of our patient were improved by increased neural processing efficiency and a concomitant decrease in cognitive load.

Play along: effects of music and social interaction on word learning

Learning new words is an increasingly common necessity in everyday life. External factors, among which music and social interaction are particularly debated, are claimed to facilitate this task. Due to their influence on the learner's temporal behavior, these stimuli are able to drive the learner's attention to the correct referent of new words at the correct point in time. However, do music and social interaction impact learning behavior in the same way? The current study aims to answer this question. Native German speakers (N = 80) were requested to learn new words (pseudo-words) during a contextual learning game. This learning task was performed alone with a computer or with a partner, with or without music. Results showed that music and social interaction had a different impact on the learner's behavior: Participants tended to temporally coordinate their behavior more with a partner than with music, and in both cases more than with a computer. However, when both music and social interaction were present, this temporal coordination was hindered. These results suggest that while music and social interaction do influence participants' learning behavior, they have a different impact. Moreover, impaired behavior when both music and a partner are present suggests that different mechanisms are employed to coordinate with the two types of stimuli. Whether one or the other approach is more efficient for word learning, however, is a question still requiring further investigation, as no differences were observed between conditions in a retrieval phase, which took place immediately after the learning session. This study contributes to the literature on word learning in adults by investigating two possible facilitating factors, and has important implications for situations such as music therapy, in which music and social interaction are present at the same time.

Bilateral brain reorganization with memantine and constraint-induced aphasia therapy in chronic post-stroke aphasia: An ERP study

Changes in ERP (P100 and N400) and root mean square (RMS) were obtained during a silent reading task in 28 patients with chronic post-stroke aphasia in a randomized, double-blind, placebo-controlled trial of both memantine and constraint-induced aphasia therapy (CIAT). Participants received memantine/placebo alone (weeks 0-16), followed by drug treatment combined with CIAT (weeks 16-18), and then memantine/placebo alone (weeks 18-20). ERP/RMS values (week 16) decreased more in the memantine group than in the placebo group. During CIAT application (weeks 16-18), improvements in aphasia severity and ERP/RMS values were amplified by memantine and changes remained stable thereafter (weeks 18-20). Changes in ERP/RMS occurred in left and right hemispheres and correlated with gains in language performance. No changes in ERP/RMS were found in a healthy group in two separated evaluations. Our results show that aphasia recovery induced by both memantine alone and in combination with CIAT is indexed by bilateral cortical potentials.

The Role of Rhythm in Speech and Language Rehabilitation: The SEP Hypothesis

For thousands of years, human beings have engaged in rhythmic activities such as drumming, dancing, and singing. Rhythm can be a powerful medium to stimulate communication and social interactions, due to the strong sensorimotor coupling. For example, the mere presence of an underlying beat or pulse can result in spontaneous motor responses such as hand clapping, foot stepping, and rhythmic vocalizations. Examining the relationship between rhythm and speech is fundamental not only to our understanding of the origins of human communication but also in the treatment of neurological disorders. In this paper, we explore whether rhythm has therapeutic potential for promoting recovery from speech and language dysfunctions. Although clinical studies are limited to date, existing experimental evidence demonstrates rich rhythmic organization in both music and language, as well as overlapping brain networks that are crucial in the design of rehabilitation approaches. Here, we propose the “SEP” hypothesis, which postulates that (1) “sound envelope processing” and (2) “synchronization and entrainment to pulse” may help stimulate brain networks that underlie human communication. Ultimately, we hope that the SEP hypothesis will provide a useful framework for facilitating rhythm-based research in various patient populations.

Insight into the neurophysiological processes of melodically intoned language with functional MRI

BACKGROUND

Melodic Intonation Therapy (MIT) uses the melodic elements of speech to improve language production in severe nonfluent aphasia. A crucial element of MIT is the melodically intoned auditory input: the patient listens to the therapist singing a target utterance. Such input of melodically intoned language facilitates production, whereas auditory input of spoken language does not.

METHODS

Using a sparse sampling fMRI sequence, we examined the differential auditory processing of spoken and melodically intoned language. Nineteen right-handed healthy volunteers performed an auditory lexical decision task in an event related design consisting of spoken and melodically intoned meaningful and meaningless items. The control conditions consisted of neutral utterances, either melodically intoned or spoken.

RESULTS

Irrespective of whether the items were normally spoken or melodically intoned, meaningful items showed greater activation in the supramarginal gyrus and inferior parietal lobule, predominantly in the left hemisphere. Melodically intoned language activated both temporal lobes rather symmetrically, as well as the right frontal lobe cortices, indicating that these regions are engaged in the acoustic complexity of melodically intoned stimuli. Compared to spoken language, melodically intoned language activated sensory motor regions and articulatory language networks in the left hemisphere, but only when meaningful language was used.

DISCUSSION

Our results suggest that the facilitatory effect of MIT may - in part - depend on an auditory input which combines melody and meaning.

CONCLUSION

Combined melody and meaning provide a sound basis for the further investigation of melodic language processing in aphasic patients, and eventually the neurophysiological processes underlying MIT.

The Combination of Rhythm and Pitch Can Account for the Beneficial Effect of Melodic Intonation Therapy on Connected Speech Improvements in Broca's Aphasia

Melodic intonation therapy (MIT) is a structured protocol for language rehabilitation in people with Broca's aphasia. The main particularity of MIT is the use of intoned speech, a technique in which the clinician stylizes the prosody of short sentences using simple pitch and rhythm patterns. In the original MIT protocol, patients must repeat diverse sentences in order to espouse this way of speaking, with the goal of improving their natural, connected speech. MIT has long been regarded as a promising treatment but its mechanisms are still debated. Recent work showed that rhythm plays a key role in variations of MIT, leading to consider the use of pitch as relatively unnecessary in MIT. Our study primarily aimed to assess the relative contribution of rhythm and pitch in MIT's generalization effect to non-trained stimuli and to connected speech. We compared a melodic therapy (with pitch and rhythm) to a rhythmic therapy (with rhythm only) and to a normally spoken therapy (without melodic elements). Three participants with chronic post-stroke Broca's aphasia underwent the treatments in hourly sessions, 3 days per week for 6 weeks, in a cross-over design. The informativeness of connected speech, speech accuracy of trained and non-trained sentences, motor-speech agility, and mood was assessed before and after the treatments. The results show that the three treatments improved speech accuracy in trained sentences, but that the combination of rhythm and pitch elicited the strongest generalization effect both to non-trained stimuli and connected speech. No significant change was measured in motor-speech agility or mood measures with either treatment. The results emphasize the beneficial effect of both rhythm and pitch in the efficacy of original MIT on connected speech, an outcome of primary clinical importance in aphasia therapy.

Neurobiological, cognitive, and emotional mechanisms in melodic intonation therapy

Singing has been used in language rehabilitation for decades, yet controversy remains over its effectiveness and mechanisms of action. Melodic Intonation Therapy (MIT) is the most well-known singing-based therapy; however, speculation surrounds when and how it might improve outcomes in aphasia and other language disorders. While positive treatment effects have been variously attributed to different MIT components, including melody, rhythm, hand-tapping, and the choral nature of the singing, there is uncertainty about the components that are truly necessary and beneficial. Moreover, the mechanisms by which the components operate are not well understood. Within the literature to date, proposed mechanisms can be broadly grouped into four categories: (1) neuroplastic reorganization of language function, (2) activation of the mirror neuron system and multimodal integration, (3) utilization of shared or specific features of music and language, and (4) motivation and mood. In this paper, we review available evidence for each mechanism and propose that these mechanisms are not mutually exclusive, but rather represent different levels of explanation, reflecting the neurobiological, cognitive, and emotional effects of MIT. Thus, instead of competing, each of these mechanisms may contribute to language rehabilitation, with a better understanding of their relative roles and interactions allowing the design of protocols that maximize the effectiveness of singing therapy for aphasia.

Melodic intonation therapy: back to basics for future research

We present a critical review of the literature on melodic intonation therapy (MIT), one of the most formalized treatments used by speech-language therapist in Broca's aphasia. We suggest basic clarifications to enhance the scientific support of this promising treatment. First, therapeutic protocols using singing as a speech facilitation technique are not necessarily MIT. The goal of MIT is to restore propositional speech. The rationale is that patients can learn a new way to speak through singing by using language-capable regions of the right cerebral hemisphere. Eventually, patients are supposed to use this way of speaking permanently but not to sing overtly. We argue that many treatment programs covered in systematic reviews on MIT's efficacy do not match MIT's therapeutic goal and rationale. Critically, we identified two main variations of MIT: the French thérapie mélodique et rythmée (TMR) that trains patients to use singing overtly as a facilitation technique in case of speech struggle and palliative versions of MIT that help patients with the most severe expressive deficits produce a limited set of useful, readymade phrases. Second, we distinguish between the immediate effect of singing on speech production and the long-term effect of the entire program on language recovery. Many results in the MIT literature can be explained by this temporal perspective. Finally, we propose that MIT can be viewed as a treatment of apraxia of speech more than aphasia. This issue should be explored in future experimental studies.

The Efficacy and Timing of Melodic Intonation Therapy in Subacute Aphasia

Background. Little is known about the efficacy of language production treatment in subacute severe nonfluent aphasia. Although Melodic Intonation Therapy (MIT) is a language production treatment for this disorder, until now MIT effect studies have focused on chronic aphasia. Purpose. This study examines whether language production treatment with MIT is effective in subacute severe nonfluent aphasia. Methods. A multicenter, randomized controlled trial was conducted in a waiting-list control design: patients were randomly allocated to the experimental group (MIT) or the control group (control intervention followed by delayed MIT). In both groups, therapy started at 2 to 3 months poststroke and was given intensively (5 h/wk) during 6 weeks. In a second therapy period, the control group received 6 weeks of intensive MIT. The experimental group resumed their regular treatment. Assessment was done at baseline (T1), after the first intervention period (T2), and after the second intervention period (T3). Efficacy was evaluated at T2. The impact of delaying MIT on therapy outcome was also examined. Results. A total of 27 participants were included: n = 16 in the experimental group and n = 11 in the control group. A significant effect in favor of MIT on language repetition was observed for trained items, with mixed results for untrained items. After MIT there was a significant improvement in verbal communication but not after the control intervention. Finally, delaying MIT was related to less improvement in the repetition of trained material. Conclusions. In these patients with subacute severe nonfluent aphasia, language production treatment with MIT was effective. Earlier treatment may lead to greater improvement.