Loss of regional accent after damage to the speech production network

Abstract

Lesion-symptom mapping studies reveal that selective damage to one or more components of the speech production network can be associated with foreign accent syndrome, changes in regional accent (e.g., from Parisian accent to Alsatian accent), stronger regional accent, or re-emergence of a previously learned and dormant regional accent. Here, we report loss of regional accent after rapidly regressive Broca’s aphasia in three Argentinean patients who had suffered unilateral or bilateral focal lesions in components of the speech production network. All patients were monolingual speakers with three different native Spanish accents (Cordobés or central, Guaranítico or northeast, and Bonaerense). Samples of speech production from the patient with native Córdoba accent were compared with previous recordings of his voice, whereas data from the patient with native Guaranítico accent were compared with speech samples from one healthy control matched for age, gender, and native accent. Speech samples from the patient with native Buenos Aires’s accent were compared with data obtained from four healthy control subjects with the same accent. Analysis of speech production revealed discrete slowing in speech rate, inappropriate long pauses, and monotonous intonation. Phonemic production remained similar to those of healthy Spanish speakers, but phonetic variants peculiar to each accent (e.g., intervocalic aspiration of /s/ in Córdoba accent) were absent. While basic normal prosodic features of Spanish prosody were preserved, features intrinsic to melody of certain geographical areas (e.g., rising end F0 excursion in declarative sentences intoned with Córdoba accent) were absent. All patients were also unable to produce sentences with different emotional prosody. Brain imaging disclosed focal left hemisphere lesions involving the middle part of the motor cortex, the post-central cortex, the posterior inferior and/or middle frontal cortices, insula, anterior putamen and supplementary motor area. Our findings suggest that lesions affecting the middle part of the left motor cortex and other components of the speech production network disrupt neural processes involved in the production of regional accent features.

Neuroanatomical profiles of bilingual children

“…Neural activity has also been reported in the left putamen in response to degraded speech (Meyer, Steinhauer, Alter, Friederici, & von Cramon, 2004) and in late talkers (Preston et al, 2010). Moreover, left putaminal damage has been associated with foreign accent syndrome (Berthier et al, 2015).…”

“…Neural activity has also been reported in the left putamen in response to degraded speech (Meyer, Steinhauer, Alter, Friederici, & von Cramon, ) and in late talkers (Preston et al., ). Moreover, left putaminal damage has been associated with foreign accent syndrome (Berthier et al., ). And finally, a recent study found that children with poor phonological skills in the L1 and L2 have less gray matter density in the putamen, bilaterally (Cherodah, Rao, Midha, & Sumathi, ).…”

The role of the supplementary motor area for speech and language processing

“…In part, lesions of SMA proper and pre-SMA may also to be involved in the development of the "foreign accent syndrome" (Berthier et al, 2015).…”

Foreign Accent Syndrome: A Rare Sequelae after Orthognathic Surgery

“…In this study all patients had damage to the left pre-central gyrus. 7 However, damage to the basal ganglia, frontal lobe white matter, and parietal lobe have all been reported. 8,9 In addition to case reports detailing left temporal involvement, functional MRI data has also shown largely left hemisphere activation during speech in a patient with FAS.…”