Raúl Rojas

Behavioral model of chronic tinnitus in rats

An animal model of tinnitus was developed to study chronic salicylate-induced tinnitus in rats. Novel features of the model included oral dosing of salicylate, test stimuli that included a range of pure tones and silence, and assessment of tinnitus for several months. Experimental subjects were given sodium salicylate in their drinking water while control subjects received normal tap water. Subjects were conditioned to press a lever for food in the presence of continuous white noise. At random intervals, offset of the noise was paired with a noxious stimulus, resulting in cessation of lever pressing during the silent test periods. At other randomly scheduled intervals, a test tone was substituted for the white noise, unpaired with noxious stimuli. When the test stimuli were pure tones, the salicylate-treated subjects suppressed less than the control subjects. One explanation for this result is that the experimental subjects sensations of tones were noisier than those of the controls because experimental subjects were experiencing tinnitus.

The Language Growth of Spanish-Speaking English Language Learners.

Although the research literature regarding language growth trajectories is burgeoning, the shape and direction of English Language Learners (ELLs) language growth trajectories are largely not known. This study used growth curve modeling to determine the shape of ELLs language growth trajectories across 12,248 oral narrative language samples (6,516 Spanish; 5,732 English) produced by 1,723 ELLs during the first 3xa0years of formal schooling (M age at first observationxa0=xa05xa0years 7xa0months). Results indicated distinct trajectories of language growth over time for each language differentially impacted by summer vacation and gender, significant intra- and interindividual differences in initial status and growth rates across both languages, and language-specific relations between language growth and initial status. Implications of ELLs language growth are discussed.

Interlocutor differential effects on the expressive language skills of Spanish-speaking English learners

Abstract Purpose: The primary objective of this study was to investigate the relationship between language use with different interlocutors, maternal education level and the expressive language skills of US English learners (ELs) in Spanish and English. Method: Two hundred and twenty-four Spanish-speaking ELs in kindergarten provided narrative language samples in Spanish and English. Parents completed a questionnaire of maternal education level and language use with parents, older siblings and peers. Result: Multiple linear regression analyses demonstrated that language used with different interlocutors and maternal education level had unique effects on participants’ expressive language skills. ELs’ expressive language skills in English were predicted by interactions with older siblings, peers and maternal education level; Spanish expressive language skills were predicted by interactions with older siblings. Conclusion: The findings from this study suggest that the determination of language experience of school-age bilingual children should examine differential language use with multiple interlocutors, particularly interactions with older siblings and peers.

Clinical impact of wordless picture storybooks on bilingual narrative language production: A comparison of the 'Frog' stories.

BACKGROUNDnLanguage sampling, recognized as a gold standard for expressive language assessment, is often elicited using wordless picture storybooks. A series of wordless storybooks, commonly referred to as Frog stories, have been frequently used in language-based research with children from around the globe.nnnAIMSnTo examine the impact that differences in stories have on narrative output by comparing narrative productions across a series of five storybooks produced by 831 bilingual (Spanish-English) children in kindergarten through third grade.nnnMETHODS & PROCEDURESnEach participant produced oral narratives using one of the five Frog storybooks in both English and Spanish. The narratives were recorded, transcribed and coded for a variety of measures of language production.nnnOUTCOMES & RESULTSnNegligible differences were observed in language measures when comparing groups of children who told different stories, with the exception of lexical diversity.nnnCONCLUSIONS & IMPLICATIONSnThe implications of using different storybooks to elicit narrative language samples from children are discussed from the perspectives of research and clinical practice.

Tense Marking in the English Narrative Retells of Dual Language Preschoolers

PurposenThis longitudinal study investigated the emergence of English tense marking in young (Spanish-English) dual language learners (DLLs) over 4 consecutive academic semesters, addressing the need for longitudinal data on typical acquisition trajectories of English in DLL preschoolers.nnnMethodnLanguage sample analysis was conducted on 139 English narrative retells elicited from 39 preschool-age (Spanish-English) DLLs (range = 39-65 months). Growth curve models captured within- and between-individual change in tense-marking accuracy over time. Tense-marking accuracy was indexed by the finite verb morphology composite and by 2 specifically developed adaptations. Individual tense markers were systematically described in terms of overall accuracy and specific error patterns.nnnResultsnTense-marking accuracy exhibited significant growth over time for each composite. Initially, irregular past-tense accuracy was higher than regular past-tense accuracy; over time, however, regular past-tense marking outpaced accuracy on irregular verbs.nnnConclusionsnThese findings suggest that young DLLs can achieve high tense-marking accuracy assuming 2 years of immersive exposure to English. Monitoring the growth in tense-marking accuracy over time and considering productive tense-marking errors as partially correct more precisely captured the emergence of English tense marking in this population with highly variable expressive language skills.nnnSupplemental Materialsnhttps://doi.org/10.23641/asha.5176942.

Child Vocabulary, Maternal Behavior, and Inhibitory Control Development Among Spanish-Speaking Children

Research Findings: The roles of child lexical diversity and maternal sensitivity in the development of young children’s inhibitory control were examined in 100 low-income Hispanic Spanish-speaking children. Child communication utterances at age 2½ years were transcribed from 10-min mother–child interactions to quantify lexical diversity. Maternal behavior was rated independently from the interactions. Inhibitory control was measured with a battery of tasks at ages 2½ and 3½. Greater maternal sensitivity was correlated with higher vocabulary at 2½. Greater vocabulary predicted positive growth in child inhibitory control skills from ages 2½ to 3½ in multivariable regression models that controlled for maternal education, family income, the home environment, and mothering quality. Practice or Policy: These findings suggest that supporting vocabulary development in low-income Spanish-speaking children is important for the development of inhibitory control skills, an important foundation for school readiness and academic success.