Papers by arturo hernandez
Brain and Language, 2013
At its most basic sense, the sensorimotor/emergentist (S/E) model suggests that early second lang... more At its most basic sense, the sensorimotor/emergentist (S/E) model suggests that early second language (L2) learning is preferentially reliant upon sensory and motor processes, while later L2 learning is accomplished by greater reliance on executive abilities. To investigate the S/E model using fMRI, neural correlates of L2 age of acquisition were examined by employing a past-tense generation task on 22 L2 proficient bilinguals. Early bilinguals preferentially recruited left hemisphere sensorimotor regions involved in motoric control and articulation. In contrast, later learners, to a greater degree, engaged regions involved in executive cognitive control and lexical access. The data support the notion that early L2 learners devote neural resources to motor control during lexical retrieval. In contrast, later L2 learners recruit executive control mechanisms to generate the past tense. These data are consistent with the S/E model of bilingual language learning, and serve as an extension of cognitive control theories.
Aging, Neuropsychology, and Cognition (Neuropsychology, Development and Cognition: Section B), 1999
Language switching was studied with a group of bilingual older adults (65 and older) and college-... more Language switching was studied with a group of bilingual older adults (65 and older) and college-age bilinguals using a cued picture naming paradigm in a blocked (English or Spanish), unpredictable mixed (Spanish and English cues change randomly from trial to trial), and a predictable mixed condition (cues alternate between English and Spanish from trial to trial). Results revealed equivalent error rates and small differences in reaction time (RT) between older adults and college-age participants in the blocked condition. However, older adults showed much slower RTs and made significantly more errors in the mixed conditions. The results are consistent with models that predict deficiencies in task set shifting across the life span.
International Journal of Bilingualism
Aims: The goal of this study was to investigate if phonetic experience with two languages facilit... more Aims: The goal of this study was to investigate if phonetic experience with two languages facilitated the learning of novel speech sounds or if general perceptual abilities independent of bilingualism played a role in this learning. Method: The underlying neural mechanisms involved in novel speech sound learning were observed in groups of English monolinguals (n = 20), early Spanish–English bilinguals (n = 24), and experimentally derived subgroups of individuals with advanced ability to learn novel speech sound contrasts (ALs, n = 28) and individuals with non-advanced ability to learn novel speech sound contrasts (non-ALs, n = 16). Subjects participated in four consecutive sessions of phonetic training in which they listened to novel speech sounds embedded in Hungarian pseudowords. Participants completed two fMRI sessions, one before training and another one after training. While in the scanner, participants passively listened to the speech stimuli presented during training. A repea...
Bilingualism requires individuals to manage their two languages in order to communicate with othe... more Bilingualism requires individuals to manage their two languages in order to communicate with others • Previous imaging and language impairment research has shown evidence of a cogni8ve control network needed for the maintenance of two languages • This network involves the prefrontal, inferior parietal, and anterior cingulate cor8ces, and basal ganglia • The purpose of this study was to examine the cogni8ve control network interac8ons during three condi8ons: naming in Spanish only, English only, and mixed (switching con8nuously between naming in Spanish and English) using Dynamic Causal Modeling (DCM).
• Par5cipants: Forty--five Spanish--English bilinguals • Language background variables:
Journal of speech, language, and hearing research : JSLHR, 1999
The present study investigated developmental changes in lexical production skills in early sequen... more The present study investigated developmental changes in lexical production skills in early sequential bilinguals, in both Spanish (L1) and English (L2), exploring the effects of age, years of experience, and basic-level cognitive processing (specifically the ability to resist interference) within a timed picture-naming task. To assess resistance to interference, naming was compared in low competition (blocked-single language) vs. high competition (mixed-alternating language) conditions. Participants were 100 individuals, 20 at each of 5 different age levels (5-7, 8-10, 11-13, 14-16, & young adults). All had learned Spanish as a first language in the home, with formal English experience beginning at 5 years. Gains were made in both languages across age. However, there was a developmental crossover from Spanish dominance in the youngest children, through a period of relatively balanced Spanish and English skills in middle childhood, culminating in a clear pattern of English dominance ...
Endocrinology, 2002
The mouse Dio3 gene codes for the type 3 iodothyronine deiodinase (D3), a conserved selenocystein... more The mouse Dio3 gene codes for the type 3 iodothyronine deiodinase (D3), a conserved selenocysteine-containing enzyme that inactivates thyroid hormones and is highly expressed during early development. The mouse Dio3 gene and its human homolog map to chromosomal regions that are known to contain imprinted genes. We assessed the allelic expression of the Dio3 using a mouse model in which the gene had been inactivated by the introduction of a critical mutation in the selenocysteine codon. We compared Dio3 gene expression in fetuses that were either wild type or heterozygous (+/-Dio3) for the mutation. D3 enzymatic activities in the head, limbs, liver and body of heterozygous fetuses (E14 to E18) that inherited the mutation from the mother were no different from those found in their wild type littermates. However, D3 activities in heterozygous animals that inherited the mutation from the father were only 18 to 28% of the activities of their wild type littermates in these same tissues. N...
Critical care (London, England), 2006
Refractory septic shock has dismal prognosis despite aggressive therapy. The purpose of the prese... more Refractory septic shock has dismal prognosis despite aggressive therapy. The purpose of the present study is to report the effects of terlipressin (TP) as a rescue treatment in children with catecholamine refractory hypotensive septic shock. We prospectively registered the children with severe septic shock and hypotension resistant to standard intensive care, including a high dose of catecholamines, who received compassionate therapy with TP in nine pediatric intensive care units in Spain, over a 12-month period. The TP dose was 0.02 mg/kg every four hours. Sixteen children (age range, 1 month-13 years) were included. The cause of sepsis was meningococcal in eight cases, Staphylococcus aureus in two cases, and unknown in six cases. At inclusion the median (range) Pediatric Logistic Organ Dysfunction score was 23.5 (12-52) and the median (range) Pediatric Risk of Mortality score was 24.5 (16-43). All children had been treated with a combination of at least two catecholamines at high ...
The American journal of psychology, 2011
Although the age at which a skill is learned (age of acquisition [AoA]) is one of the most studie... more Although the age at which a skill is learned (age of acquisition [AoA]) is one of the most studied predictors of success in domains ranging from language to music, very little work has focused on this factor in sports. In order to uncover how the age at which a skill is learned relates to how athletes cognitively represent that skill, we asked a group of skilled golfers who learned to play golf before (early learners) or after (late learners) the age of 10 to take a series of putts on an indoor putting green. Golfers putted in isolation (single-task condition), while monitoring a stream of words presented over a loudspeaker (dual-task condition), or while being instructed to attend to specific aspects of their golf swing (skill-focused condition). Early and late learners putted equally well in the single-task and dual-task conditions. However, in the skill-focused condition, golfers who learned earlier performed worse than those who learned later. The results are consistent with the...
Physics of life reviews, 2013
For many years, researchers have wondered how two languages are represented in one brain. Of part... more For many years, researchers have wondered how two languages are represented in one brain. Of particular interest is the finding of selective impairment of a single language in bilinguals . Naturally, this leads to the question of what factors might be determining which language is preserved and which is lost. It also leads to the possibility that each language may have different neural representations.
Brain and language, Jan 26, 2015
The present study compared the neural correlates of language processing in children and adult Spa... more The present study compared the neural correlates of language processing in children and adult Spanish-English bilinguals. Participants were asked to perform a visual lexical processing task in both Spanish and English while being scanned with fMRI. Both children and adults recruited a similar network of left hemisphere "language" areas and showed similar proficiency profiles in Spanish. In terms of behavior, adults showed better language proficiency in English relative to children. Furthermore, neural activity in adults was observed in the bilateral MTG. Age-related differences were observed in Spanish in the right MTG. The current results confirm the presence of neural activity in a set of left hemisphere areas in both adult and child bilinguals when reading words in each language. They also reveal that differences in neural activity are not entirely driven by changes in language proficiency during visual word processing. This indicates that both skill development and age...
Uploads
Papers by arturo hernandez