Electrophysiological investigation of active-assisted vs recumbent cycling: A pilot study in healthy older adults.

There is a relationship between acute bouts of aerobic exercise and cognition in adults, yet the exact nature of this relationship remains unclear. The current pilot study aims to investigate how different modes of cycling (active-assisted cycling vs recumbent cycling) at different moderate-to-vigorous physical activity (MVPA) intensity levels (prescribed 65-70% Heart Rate Max and self-selected 12-13 Rate of Perceived Exertion) modulate neurocognitive, and behavioral markers of cognition in healthy older adults. A sample of 10 adults (aged 50-74years) participated in baseline (no exercise), active-assisted, and recumbent cycling interventions at different intensity levels. The P3 event-related potential (ERP), a neural index of executive functions, was recorded at baseline and following each exercise condition during an auditory odd-ball paradigm. Results revealed that greater amplitudes within the P3 ERP component were associated with post-exercise recumbent bike cycling compared to baseline and active-assisted cycling. Further, post-exercise behavioral cognitive measures (i.e., button press accuracy) were significantly greater than baseline for both active-assisted and recumbent bikes at both intensity levels. These findings suggest that exercise modulated both neurocognitive and behavioral measures of executive functions in older healthy adults, and that exercise modalities and intensity levels differentially modulate neurocognitive measures.

Neural Correlates of Morphosyntactic Processing in Spanish-English Bilingual Children: A Functional Near-Infrared Spectroscopy Study.

PURPOSE: The aim of this study was to examine the effects of early bilingual exposure on Spanish-English bilingual children's neural organization of English morphosyntactic structures. This study examines how children's age and language experiences are related to morphosyntactic processing at the neural level. METHOD: Eighty-one children (ages 6-11 years) completed an auditory sentence judgment task during functional near-infrared spectroscopy neuroimaging. The measure tapped into children's processing of early-acquired (present progressive -ing) and later-acquired (past tense -ed and third-person singular -s) English morphosyntactic structures, the primary language of academic instruction. RESULTS: We observed effects of syntactic structure and age. Early-acquired morphemic structures elicited activation in the left inferior frontal gyrus, while the later-acquired structures elicited additional activations in the left middle temporal gyrus and superior temporal gyrus (STG). Younger children had a more distributed neural response, whereas older children had a more focal neural response. Finally, there was a trending association between children's English language use and left STG activation for later-acquired structures. CONCLUSION: The findings inform theories of language and brain development by highlighting the mechanisms by which age and language experiences influence bilingual children's neural architecture for morphosyntactic processing.

Event-Related Potentials in Assessing Visual Speech Cues in the Broader Autism Phenotype: Evidence from a Phonemic Restoration Paradigm.

Audiovisual speech perception includes the simultaneous processing of auditory and visual speech. Deficits in audiovisual speech perception are reported in autistic individuals; however, less is known regarding audiovisual speech perception within the broader autism phenotype (BAP), which includes individuals with elevated, yet subclinical, levels of autistic traits. We investigate the neural indices of audiovisual speech perception in adults exhibiting a range of autism-like traits using event-related potentials (ERPs) in a phonemic restoration paradigm. In this paradigm, we consider conditions where speech articulators (mouth and jaw) are present (AV condition) and obscured by a pixelated mask (PX condition). These two face conditions were included in both passive (simply viewing a speaking face) and active (participants were required to press a button for a specific consonant-vowel stimulus) experiments. The results revealed an N100 ERP component which was present for all listening contexts and conditions; however, it was attenuated in the active AV condition where participants were able to view the speaker's face, including the mouth and jaw. The P300 ERP component was present within the active experiment only, and significantly greater within the AV condition compared to the PX condition. This suggests increased neural effort for detecting deviant stimuli when visible articulation was present and visual influence on perception. Finally, the P300 response was negatively correlated with autism-like traits, suggesting that higher autistic traits were associated with generally smaller P300 responses in the active AV and PX conditions. The conclusions support the finding that atypical audiovisual processing may be characteristic of the BAP in adults.

Neural and Behavioral Differences in Speech Perception for Children With Autism Spectrum Disorders Within an Audiovisual Context.

PURPOSE: Reduced use of visible articulatory information on a speaker's face has been implicated as a possible contributor to language deficits in autism spectrum disorders (ASD). We employ an audiovisual (AV) phonemic restoration paradigm to measure behavioral performance (button press) and event-related potentials (ERPs) of visual speech perception in children with ASD and their neurotypical peers to assess potential neural substrates that contribute to group differences. METHOD: Two sets of speech stimuli, /ba/-"/a/" ("/a/" was created from the /ba/ token by a reducing the initial consonant) and /ba/-/pa/, were presented within an auditory oddball paradigm to children aged 6-13 years with ASD (n = 17) and typical development (TD; n = 33) within two conditions. The AV condition contained a fully visible speaking face; the pixelated (PX) condition included a face, but the mouth and jaw were PX, removing all articulatory information. When articulatory features were present for the /ba/-"/a/" contrast, it was expected that the influence of the visual articulators would facilitate a phonemic restoration effect in which "/a/" would be perceived as /ba/. ERPs were recorded during the experiment while children were required to press a button for the deviant sound for both sets of speech contrasts within both conditions. RESULTS: Button press data revealed that TD children were more accurate in discriminating between /ba/-"/a/" and /ba/-/pa/ contrasts in the PX condition relative to the ASD group. ERPs in response to the /ba/-/pa/ contrast within both AV and PX conditions differed between children with ASD and TD children (earlier P300 responses for children with ASD). CONCLUSION: Children with ASD differ in the underlying neural mechanisms responsible for speech processing compared with TD peers within an AV context.

Where on the face do we look during phonemic restoration: An eye-tracking study.

Face to face communication typically involves audio and visual components to the speech signal. To examine the effect of task demands on gaze patterns in response to a speaking face, adults participated in two eye-tracking experiments with an audiovisual (articulatory information from the mouth was visible) and a pixelated condition (articulatory information was not visible). Further, task demands were manipulated by having listeners respond in a passive (no response) or an active (button press response) context. The active experiment required participants to discriminate between speech stimuli and was designed to mimic environmental situations which require one to use visual information to disambiguate the speaker's message, simulating different listening conditions in real-world settings. Stimuli included a clear exemplar of the syllable /ba/ and a second exemplar in which the formant initial consonant was reduced creating an /a/-like consonant. Consistent with our hypothesis, results revealed that the greatest fixations to the mouth were present in the audiovisual active experiment and visual articulatory information led to a phonemic restoration effect for the /a/ speech token. In the pixelated condition, participants fixated on the eyes, and discrimination of the deviant token within the active experiment was significantly greater than the audiovisual condition. These results suggest that when required to disambiguate changes in speech, adults may look to the mouth for additional cues to support processing when it is available.

The P300 event related potential predicts phonological working memory skills in school-aged children.

The P300 event related potential (ERP) has been cited as a marker of phonological working memory (PWM); however, little is known regarding its relationship to behavioral PWM skills in early school-aged children. The current study investigates the P300 ERP recorded in response to native and non-native (English and Spanish) phoneme contrasts as a predictor of PWM skills in monolingual English-speaking first and second grade children. Thirty-three typically developing children, ages 6-9, completed a battery of phonological processing, language, and cognitive assessments. ERPs were recorded within an auditory oddball paradigm in response to both English phoneme contrasts (/ta/, /pa/) and Spanish contrasts (/t̪a/, /d̪a/). The P300 ERP recorded in response to English phoneme contrasts significantly predicted standard scores on the Nonword Repetition subtest of the Comprehensive Test of Phonological Processing, Second Edition. Spanish contrasts did not elicit a P300 response, nor were amplitude or latency values within the P300 timeframe (250-500 ms) recorded in response to Spanish contrasts related to English nonword repetition performance. This study provides further evidence that the P300 ERP in response to native phonemic contrasts indexes PWM skills, specifically nonword repetition performance, in monolingual children. Further work is necessary to determine the extent to which the P300 response to changing phonological stimuli reflects PWM skills in other populations.

Grammatical Gender in Spoken Word Recognition in School-Age Spanish-English Bilingual Children.

This study investigated grammatical gender processing in school-age Spanish-English bilingual children using a visual world paradigm with a 4-picture display where the target noun was heard with a gendered article that was either in a context where all distractor images were the same gender as the target noun (same gender; uninformative) or in a context where all distractor images were the opposite gender than the target noun (different gender; informative). We investigated 32 bilingual children (ages 5;6-8;6) who were exposed to Spanish since infancy and began learning English by school entry. Along with the eye-tracking experiment, all children participated in a standardized language assessment and told narratives in English and Spanish, and parents reported on their child's current Spanish language use. The differential proportion fixations to target (target - averaged distractor fixations) were analyzed in two time regions with linear mixed-effects models (LME). Results show that prior to the target word being spoken, these bilingual children did not use the gendered articles to actively anticipate upcoming nouns. In the subsequent time region (during the noun), it was shown that there are differences in the way they use feminine and masculine articles, with a lack of use of the masculine article and a potential facilitatory use of the feminine article for children who currently use more Spanish than English. This asymmetry in the use of gendered articles in processing is modulated by current Spanish language use and trends with results found for bilingual and second-language learning adults.

Event-Related Potentials to Speech Relate to Speech Sound Production and Language in Young Children.

This research was funded through the American Speech and Hearing Foundation's 2012 StudentResearch Grant in Early Childhood Language Development awarded to Vanessa Harwood as well as an anonymous generous donation to Haskins Laboratories. Electrophysiological measures of language within early childhood provide important information about neurolinguistic development. We investigated associations between amplitude and latency of the P1 and N2 event-related potential components in response to spoken pseudowords, and clinical measures of language performance within a sample of 58 typically developing children between 24 and 48 months. N2 amplitude differences between repeated and new tokens were correlated with measures of expressive and receptive language and speech sound production. Phonemic sensitivity measured by the N2 component may reflect the integrity of neural networks that are important for speech perception and production in young children.

Production of Spanish Grammatical Forms in U.S. Bilingual Children.

Purpose: The purpose of this analysis was to understand how grammatical morpheme production in Spanish for typically developing Spanish-English bilingual children relates to mean length of utterance in words (MLUw) and the extent to which different bilingual profiles influence order of grammatical morpheme acquisition. Method: Participants included 228 Spanish-English bilingual children ages 4;0-7;6 (years;months). Grammatical morpheme accuracy was evaluated using an experimental version of the Bilingual English-Spanish Assessment (Peña, Gutiérrez-Clellen, Iglesias, Goldstein, & Bedore, 2014). MLUw data were calculated from children's narrative samples. Production accuracy of plural nouns, singular and plural definite articles, preterite tense, imperfect aspect, direct object clitics, prepositions, subjunctive, and conjunctions was calculated and analyzed as a function of MLUw in Spanish. Level of accuracy on these forms was compared for Spanish-dominant and English-dominant groups. Results: Accuracy was significantly associated with MLUw. The relative difficulty of Spanish grammatical morphemes is highly similar across different bilingual profiles. Conclusions: There are common elements of Spanish that are easy (imperfect, plural nouns, singular articles, conjunctions), medium (plural articles, preterite), or hard (prepositions, direct object clitics, subjunctive), regardless of whether a child is a Spanish-dominant or English-dominant bilingual.

Understanding Disorder Within Variation: Production of English Grammatical Forms by English Language Learners.

Purpose: This study examines English performance on a set of 11 grammatical forms in Spanish-English bilingual, school-age children in order to understand how item difficulty of grammatical constructions helps correctly classify language impairment (LI) from expected variability in second language acquisition when taking into account linguistic experience and exposure. Method: Three hundred seventy-eight children's scores on the Bilingual English-Spanish Assessment-Middle Extension (Peña, Bedore, Gutiérrez-Clellen, Iglesias, & Goldstein, 2008) morphosyntax cloze task were analyzed by bilingual experience groups (high Spanish experience, balanced English-Spanish experience, high English experience, ability (typically developing [TD] vs. LI), and grammatical form. Classification accuracy was calculated for the forms that best differentiated TD and LI groups. Results: Children with LI scored lower than TD children across all bilingual experience groups. There were differences by grammatical form across bilingual experience and ability groups. Children from high English experience and balanced English-Spanish experience groups could be accurately classified on the basis of all the English grammatical forms tested except for prepositions. For bilinguals with high Spanish experience, it was possible to rule out LI on the basis of grammatical production but not rule in LI. Conclusions: It is possible to accurately identify LI in English language learners once they use English 40% of the time or more. However, for children with high Spanish experience, more information about development and patterns of impairment is needed to positively identify LI.

Tense marking and spontaneous speech measures in Spanish specific language impairment: a discriminant function analysis.

PURPOSE: To test the proposal that the tense deficit that has been demonstrated for children with specific language impairment (SLI) in other languages is also found in child Spanish and that low performance on tense-related measures can distinguish Spanish-speaking children with SLI from those without. METHOD: The authors evaluated evidence from existing spontaneous production, elicited production, and grammaticality judgment studies of finiteness in child Spanish. They measured the relationship of 7 spontaneous speech measures with previous receptive and expressive measures of finiteness and performed a discriminant function analysis, using tense as the target variable, to classify monolingual child Spanish (n = 55) as representing SLI or as typically developing (TD). RESULTS: Spontaneous speech measures correlated with the results of previous receptive and expressive measures of child Spanish that show a tense deficit. The SLI group was shown to have statistically lower scores than the TD group on 6 of 7 spontaneous speech measures. Multiple discriminant functions, including tense measures by themselves and in combination with spontaneous speech measures, were shown to provide fair to good sensitivity and specificity in the classification of children as having SLI vs. TD. CONCLUSION: The findings support the contention that the tense-marking deficit is a plausible clinical marker of SLI for Spanish-speaking children.