Rhythm in disguise: why singing may not hold the key to recovery from aphasia

Abstract

The question of whether singing may be helpful for stroke patients with non-fluent aphasia has been debated for many years. However, the role of rhythm in speech recovery appears to have been neglected. In the current lesion study, we aimed to assess the relative importance of melody and rhythm for speech production in 17 non-fluent aphasics. Furthermore, we systematically alternated the lyrics to test for the influence of long-term memory and preserved motor automaticity in formulaic expressions. We controlled for vocal frequency variability, pitch accuracy, rhythmicity, syllable duration, phonetic complexity and other relevant factors, such as learning effects or the acoustic setting. Contrary to some opinion, our data suggest that singing may not be decisive for speech production in non-fluent aphasics. Instead, our results indicate that rhythm may be crucial, particularly for patients with lesions including the basal ganglia. Among the patients we studied, basal ganglia lesions accounted for more than 50% of the variance related to rhythmicity. Our findings therefore suggest that benefits typically attributed to melodic intoning in the past could actually have their roots in rhythm. Moreover, our data indicate that lyric production in non-fluent aphasics may be strongly mediated by long-term memory and motor automaticity, irrespective of whether lyrics are sung or spoken.

Choral singing therapy following stroke or Parkinson’s disease: an exploration of participants’ experiences

“…Participants described how they watched the choir leader for cues, and used group flow and rhythm to entrain to melody and words; similar to other therapies suggested for Broca's aphasia and dysarthria [95,96]. This lends support for rhythm as a therapeutic agent in music [18,97], rhythmic cueing for word production in song [36], and the benefits of singing in synchrony with an auditory model (provided by the choir and choir leader) [98]. While the descriptions varied, some people with aphasia described how confidence, fluency, and vocabulary in conversation had improved since participating in CST.…”

Song and speech: Examining the link between singing talent and speech imitation ability

“…This depends on the fact that language is based on timbre and music is based on pitch (Patel, 2008;Reiterer et al, 2008). In fact, several researchers favor a dual memory store for song (e.g., Bonnel et al, 2001;Peretz et al, 2004;Racette and Peretz, 2007;Stahl et al, 2011). The basic acoustic properties of music and speech (pitch and timbre) are more salient on the level of acoustic-perception.…”

“…On a very fundamental level, song consists of one or both of the following: melody and lyrics (Crowder et al, 1990). However, the question as to whether being able to memorize or recall a song involves a dual system of storage, lyrics, and melody being stored independently, remains unanswered and a topic that continues to be discussed at length (Bonnel et al, 2001;Steinke et al, 2001;Peretz et al, 2004;Racette and Peretz, 2007;Stahl et al, 2011).…”

Music and Health

“…Music therapy can help to improve and restore many functions e.g. motor capacities in patients with Parkinson's disease (Bernatzky et al, 2011).Melody intonation therapy is a common method of treating aphasia (Stahl et al, 2011). Music therapy in stroke patients increases rate of recovery of emotional and social deficits.…”