Facing the music: three issues in current research on singing and aphasia

Speech pauses in speakers with and without aphasia: A usage-based approach

Pauses in speech are indicators of cognitive effort during language production and have been examined to inform theories of lexical, grammatical and discourse processing in healthy speakers and individuals with aphasia (IWA). Studies of pauses have commonly focused on their location and duration in relation to grammatical properties such as word class or phrase complexity. However, recent studies of speech output in aphasia have revealed that utterances of IWA are characterised by stronger collocations, i.e., combinations of words that are often used together. We investigated the effects of collocation strength and lexical frequency on pause duration in comic strip narrations of IWA and non-brain-damaged (NBD) individuals with part of speech (PoS; content and function words) as covariate. Both groups showed a decrease in pause duration within more strongly collocated bigrams and before more frequent content words, with stronger effects in IWA. These results are consistent with frameworks which propose that strong collocations are more likely to be processed as holistic, perhaps even word-like, units. Usage-based approaches prove valuable in explaining patterns of preservation and impairment in aphasic language production.

Can rhythm-mediated reward boost learning, memory, and social connection? Perspectives for future research

Studies of rhythm processing and of reward have progressed separately, with little connection between the two. However, consistent links between rhythm and reward are beginning to surface, with research suggesting that synchronization to rhythm is rewarding, and that this rewarding element may in turn also boost this synchronization. The current mini review shows that the combined study of rhythm and reward can be beneficial to better understand their independent and combined roles across two central aspects of cognition: 1) learning and memory, and 2) social connection and interpersonal synchronization; which have so far been studied largely independently. From this basis, it is discussed how connections between rhythm and reward can be applied to learning and memory and social connection across different populations, taking into account individual differences, clinical populations, human development, and animal research. Future research will need to consider the rewarding nature of rhythm, and that rhythm can in turn boost reward, potentially enhancing other cognitive and social processes.

A Review on Music Interventions for Frontotemporal Aphasia and a Proposal for Alternative Treatments

Frontotemporal dementia (FTD) is a rare neurodegenerative disease, characterized by behavioral and language impairments. Primary progressive aphasia (PPA) is the linguistic variant of this heterogeneous disorder. To date, there is a lack of consensus about which interventions are effective in these patients. However, several studies show that music-based interventions are beneficial in neurological diseases. This study aims, primarily, to establish the state of the art of music-based interventions designed for PPA due to FTD and, secondarily, to inform the planning of PPA-dedicated future interventions for Italian neurological institutions. The first aim is fulfilled by a review which critically screens the neurological studies examining the effects of music- and/or rhythm-based interventions, especially, on language rehabilitation in aphasic FTD. We found that only two papers fulfilled our criteria and concerned specifically aphasic patients due to FTD. Of those, one paper reported a study conducted in an Italian institution. Most of the reviewed studies focused, instead, on aphasia in post-stroke patients. The results of our review invite further studies to investigate the role of music as a valuable support in the therapy for neurodegenerative patients with language problems and in particular to PPA due to FTD. Moreover, based on this initial work, we can delineate new music-based interventions dedicated to PPA for Italian institutions.

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 (g̅_{case report} = 2.01 vs. g̅_RCT = 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.

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.

"You Should Praise" - "You Should Kill": The Contingent Negative Variation Indicates Moral Goodness and Badness

Moral advice (how to behave in life) is often conveyed by short, simple sentence constructions: "You - should - (plus verb with moral meaning)." Yet how moral prescriptions are processed has never been studied from a neurocognitive perspective. The results of this study suggest that the contingent negative variation (CNV) serves as a neural correlate for moral (and immoral) predictive phrases. In step 1, the original CNV paradigm (S1-S2-motor response) was extended using action-demanding three-word phrases taken from everyday contexts (e.g., "Ready-Set-Go"). In step 2, these commands were replaced by abstract words, each phrase then including a verb of moral or immoral meaning (e.g., "You should hope," "You should praise," and "You should lie"). During recording, each phrase type (e.g., moral or immoral) was presented blockwise. The task varied according to block order: Participants (n = 19) had to either listen attentively or respond with a finger tap immediately after the final word of a phrase. Electroencephalogram (EEG) data were bandpass filtered (0.1-30 Hz) and analyzed at the onset of the second word, yielding two independent responses: a bilateral CNV and a bilateral motor-related negativity, both decreasing from anterior to posterior. The results show that the CNV is sensitive to phrase constructions of moral resp. immoral valence. Thus, transfer to remote semantic fields seems possible. Importantly, this transfer is combined with a change of time frames, from restricted and highly pragmatic (as in the original paradigm) to indefinite and vague. Thus, a CNV may indicate not only preparation to action but also general guidelines for social life. An N400 occurring as an additional, task-dependent result cannot be sufficiently explained on the basis of the present data.

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.

Temporal variability in sung productions of adolescents who stutter

Singing has long been used as a technique to enhance and reeducate temporal aspects of articulation in speech disorders. In the present study, differences in temporal structure of sung versus spoken speech were investigated in stuttering. In particular, the question was examined if singing helps to reduce VOT variability of voiceless plosives, which would indicate enhanced temporal coordination of oral and laryngeal processes. Eight German adolescents who stutter and eight typically fluent peers repeatedly spoke and sang a simple German congratulation formula in which a disyllabic target word (e.g., /'ki:ta/) was repeated five times. Every trial, the first syllable of the word was varied starting equally often with one of the three voiceless German stops /p/, /t/, /k/. Acoustic analyses showed that mean VOT and stop gap duration reduced during singing compared to speaking while mean vowel and utterance duration was prolonged in singing in both groups. Importantly, adolescents who stutter significantly reduced VOT variability (measured as the Coefficient of Variation) during sung productions compared to speaking in word-initial stressed positions while the control group showed a slight increase in VOT variability. However, in unstressed syllables, VOT variability increased in both adolescents who do and do not stutter from speech to song. In addition, vowel and utterance durational variability decreased in both groups, yet, adolescents who stutter were still more variable in utterance duration independent of the form of vocalization. These findings shed new light on how singing alters temporal structure and in particular, the coordination of laryngeal-oral timing in stuttering. Future perspectives for investigating how rhythmic aspects could aid the management of fluent speech in stuttering are discussed.

LEARNING OUTCOMES

Readers will be able to describe (1) current perspectives on singing and its effects on articulation and fluency in stuttering and (2) acoustic parameters such as VOT variability which indicate the efficiency of control and coordination of laryngeal-oral movements. They will understand and be able to discuss (3) how singing reduces temporal variability in the productions of adolescents who do and do not stutter and 4) how this is linked to altered articulatory patterns in singing as well as to its rhythmic structure.

Ultrasonic vocalization changes and FOXP2 expression after experimental stroke

Speech impairments affect one in four stroke survivors. However, animal models of post-ischemic vocalization deficits are limited. Male mice vocalize at ultrasonic frequencies when exposed to an estrous female mouse. In this study we assessed vocalization patterns and quantity in male mice after cerebral ischemia. FOXP2, a gene associated with verbal dyspraxia in humans, with known roles in neurogenesis and synaptic plasticity, was also examined after injury. Using a transient middle cerebral artery occlusion (MCAO) model, we assessed correlates of vocal impairment at several time-points after stroke. Further, to identify possible lateralization of vocalization deficits induced by left and right hemispheric strokes were compared. Significant differences in vocalization quantity were observed between stroke and sham animals that persisted for a month after injury. Injury to the left hemisphere reduced early vocalizations more profoundly than those to the right hemisphere. Nuclear expression of Foxp2 was elevated early after stroke (at 6h), but significantly decreased 24h after injury in both the nucleus and the cytoplasm. Neuronal Foxp2 expression increased in stroke mice compared to sham animals 4 weeks after injury. This study demonstrates that quantifiable deficits in ultrasonic vocalizations (USVs) are seen after stroke. USV may be a useful tool to assess chronic behavioral recovery in murine models of stroke.