Where, When and Why Brain Activation Differs for Bilinguals and Monolinguals during Picture Naming and Reading Aloud

Using functional magnetic resonance imaging, we found that when bilinguals named pictures or read words aloud, in their native or nonnative language, activation was higher relative to monolinguals in 5 left hemisphere regions: dorsal precentral gyrus, pars triangularis, pars opercularis, superior temporal gyrus, and planum temporale. We further demonstrate that these areas are sensitive to increasing demands on speech production in monolinguals. This suggests that the advantage of being bilingual comes at the expense of increased work in brain areas that support monolingual word processing. By comparing the effect of bilingualism across a range of tasks, we argue that activation is higher in bilinguals compared with monolinguals because word retrieval is more demanding; articulation of each word is less rehearsed; and speech output needs careful monitoring to avoid errors when competition for word selection occurs between, as well as within, language

The impact of second language learning on semantic and nonsemantic first language reading

The relationship between orthography (spelling) and phonology (speech sounds) varies across alphabetic languages. Consequently, learning to read a second alphabetic language, that uses the same letters as the first, increases the phonological associations that can be linked to the same orthographic units. In subjects with English as their first language, previous functional imaging studies have reported increased left ventral prefrontal activation for reading words with spellings that are inconsistent with their orthographic neighbors (e.g., PINT) compared with words that are consistent with their orthographic neighbors (e.g., SHIP). Here, using functional magnetic resonance imaging (fMRI) in 17 Italian--English and 13 English--Italian bilinguals, we demonstrate that left ventral prefrontal activation for first language reading increases with second language vocabulary knowledge. This suggests that learning a second alphabetic language changes the way that words are read in the first alphabetic language. Specifically, first language reading is more reliant on both lexical/semantic and nonlexical processing when new orthographic to phonological mappings are introduced by second language learning. Our observations were in a context that required participants to switch between languages. They motivate future fMRI studies to test whether first language reading is also altered in contexts when the second language is not in use

Two Tongues, One Brain: Imaging Bilingual Speech Production

This review considers speaking in a second language from the perspective of motor–sensory control. Previous studies relating brain function to the prior acquisition of two or more languages (neurobilingualism) have investigated the differential demands made on linguistic representations and processes, and the role of domain-general cognitive control systems when speakers switch between languages. In contrast to the detailed discussions on these higher functions, typically articulation is considered only as an underspecified stage of simple motor output. The present review considers speaking in a second language in terms of the accompanying foreign accent, which places demands on the integration of motor and sensory discharges not encountered when articulating in the most fluent language. We consider why there has been so little emphasis on this aspect of bilingualism to date, before turning to the motor and sensory complexities involved in learning to speak a second language as an adult. This must involve retuning the neural circuits involved in the motor control of articulation, to enable rapid unfamiliar sequences of movements to be performed with the goal of approximating, as closely as possible, the speech of a native speaker. Accompanying changes in motor networks is experience-dependent plasticity in auditory and somatosensory cortices to integrate auditory memories of the target sounds, copies of feedforward commands from premotor and primary motor cortex and post-articulatory auditory and somatosensory feedback. Finally, we consider the implications of taking a motor–sensory perspective on speaking a second language, both pedagogical regarding non-native learners and clinical regarding speakers with neurological conditions such as dysarthria

Magnetic resonance imaging of the brain and vocal tract:Applications to the study of speech production and language learning

The human vocal system is highly plastic, allowing for the flexible expression of language, mood and intentions. However, this plasticity is not stable throughout the life span, and it is well documented that adult learners encounter greater difficulty than children in acquiring the sounds of foreign languages. Researchers have used magnetic resonance imaging (MRI) to interrogate the neural substrates of vocal imitation and learning, and the correlates of individual differences in phonetic “talent”. In parallel, a growing body of work using MR technology to directly image the vocal tract in real time during speech has offered primarily descriptive accounts of phonetic variation within and across languages. In this paper, we review the contribution of neural MRI to our understanding of vocal learning, and give an overview of vocal tract imaging and its potential to inform the field. We propose methods by which our understanding of speech production and learning could be advanced through the combined measurement of articulation and brain activity using MRI – specifically, we describe a novel paradigm, developed in our laboratory, that uses both MRI techniques to for the first time map directly between neural, articulatory and acoustic data in the investigation of vocalisation. This non-invasive, multimodal imaging method could be used to track central and peripheral correlates of spoken language learning, and speech recovery in clinical settings, as well as provide insights into potential sites for targeted neural interventions

Grapheme-phoneme learning in an unknown orthography: a study in typical reading and dyslexic children

In this study, we examined the learning of new grapheme-phoneme correspondences in individuals with and without dyslexia. Additionally, we investigated the relation between grapheme-phoneme learning and measures of phonological awareness, orthographic knowledge and rapid automatized naming, with a focus on the unique joint variance of grapheme-phoneme learning to word and non-word reading achievement. Training of grapheme-phoneme associations consisted of a 20-min training program in which eight novel letters (Hebrew) needed to be paired with speech sounds taken from the participant's native language (Dutch). Eighty-four third grade students, of whom 20 were diagnosed with dyslexia, participated in the training and testing. Our results indicate a reduced ability of dyslexic readers in applying newly learned grapheme-phoneme correspondences while reading words which consist of these novel letters. However, we did not observe a significant independent contribution of grapheme-phoneme learning to reading outcomes. Alternatively, results from the regression analysis indicate that failure to read may be due to differences in phonological and/or orthographic knowledge but not to differences in the grapheme-phoneme-conversion process itself

Reanalyzing language expectations: Native language knowledge modulates the sensitivity to intervening cues during anticipatory processing

Issue Online:21 September 2018We investigated how native language experience shapes anticipatory language processing. Two groups of bilinguals (either Spanish or Basque natives) performed a word matching task (WordMT) and a picture matching task (PictureMT). They indicated whether the stimuli they visually perceived matched with the noun they heard. Spanish noun endings were either diagnostic of the gender (transparent) or ambiguous (opaque). ERPs were time-locked to an intervening gender-marked determiner preceding the predicted noun. The determiner always gender agreed with the following noun but could also introduce a mismatching noun, so that it was not fully task diagnostic. Evoked brain activity time-locked to the determiner was considered as reflecting updating/reanalysis of the task-relevant preactivated representation. We focused on the timing of this effect by estimating the comparison between a gender-congruent and a gender-incongruent determiner. In the WordMT, both groups showed a late N400 effect. Crucially, only Basque natives displayed an earlier P200 effect for determiners preceding transparent nouns. In the PictureMT, both groups showed an early P200 effect for determiners preceding opaque nouns. The determiners of transparent nouns triggered a negative effect at similar to 430 ms in Spanish natives, but at similar to 550 ms in Basque natives. This pattern of results supports a "retracing hypothesis" according to which the neurocognitive system navigates through the intermediate (sublexical and lexical) linguistic representations available from previous processing to evaluate the need of an update in the linguistic expectation concerning a target lexical item.Spanish Ministry of Economy and Competitiveness (MINECO), Agencia Estatal de Investigación (AEI), Fondo Europeo de Desarrollo Regional (FEDER) (grant PSI2015‐65694‐P to N. M.), Spanish Ministry of Economy and Competitiveness “Severo Ochoa” Programme for Centres/Units of Excellence in R&D (grant SEV‐2015‐490

The Influence of Literacy on Speech. The Orthographic Consistency Effect in Auditory Language Perception and Language Production

136 p.The present thesis presents a series of experiments that explore of the Orthographic Consistency Effect (OCE) in auditory language perception and production. The OCE is a psycholinguistic effect that shows a facilitation in processing words with sounds that can be spelled in only one way (e.g., /t/ in French or Spanish) in comparison to words with sounds that can be spelled in multiple ways (e.g., /k/ in French or Spanish). The OCE can be considered as a by-product of literacy since it is displayed by people who know how to read and write. In Experiment 1, the OCE in auditory language perception in L1-French and L1-Spanish adults was investigated by means of an auditory lexical decision task (LDT). Experiment 2 investigated the OCE in Spanish seven-year-olds, who are at an early stage of reading acquisition, in auditory language perception using the same paradigm as in Experiment 1. Experiment 3 investigated the time course and the brain correlates of the OCE in auditory language perception. L1-Spanish adults were tested in an auditory LDT and a passive listening task. Experiment 4 explored the OCE in language production of French and Spanish adults by means of reading aloud and picture naming tasks. Experiment 5 replicated Experiment 4 but with Spanish seven-year-olds. Overall, this work showed that literacy can strategically influence language perception and production.The project that gave rise to these results received the support of a fellowship from ”la Caixa” Foundation (ID 100010434). The fellowship code is LCF/BQ/IN18/11660068. This project has also received funding from the European Union´s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 713673. The research was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 819093)

Suprasegmental speech perception, working memory and reading comprehension in Cantonese-English bilingual children

This study set out to examine (a) lexical tone and stress perception by bilingual and monolingual children, (b) interrelationships between lexical pitches perception, general acoustic mechanism and working memory, and (c) the association between lexical tone awareness and Chinese text reading comprehension. Experiment 1 tested and compared the perception of Cantonese lexical tones, English lexical stress and nonlinguistic pitch between Cantonese-English bilingual and English monolingual children. The relationships between linguistic pitch perception, non-linguistic pitch perception and working memory were also examined among Cantonese-English bilingual children. Experiment 2 explored the relationship between Cantonese tone awareness and Chinese text reading comprehension skills. Results of this study illustrate differential performances in tone perception but similar performances in stress perception between bilinguals and monolinguals. In addition, inter-correlations were found between linguistic pitches perception, general acoustic mechanism, working memory and reading comprehension. These findings provide new insight to native and non-native perception of lexical pitches, and demonstrate an important link that exists between lexical tone awareness and reading comprehension.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science