DSpace Angular :: Browsing by Author "Pena, Marcela"

Browsing by Author "Pena, Marcela"

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A brief tablet-based intervention benefits linguistic and communicative abilities in toddlers and preschoolers
(2024) Pena, Marcela; Vasquez-Venegas, Constanza; Cortes, Patricia; Pittaluga, Enrica; Herrera, Mitzy; Pino, Esteban J.; Escobar, Raul G.; Dehaene-Lambertz, Ghislaine; Guevara, Pamela
Young children's linguistic and communicative abilities are foundational for their academic achievement and overall well-being. We present the positive outcomes of a brief tablet-based intervention aimed at teaching toddlers and preschoolers new word-object and letter-sound associations. We conducted two experiments, one involving toddlers ( similar to 24 months old, n = 101) and the other with preschoolers ( similar to 42 months old, n = 152). Using a pre-post equivalent group design, we measured the children's improvements in language and communication skills resulting from the intervention. Our results showed that the intervention benefited toddlers' verbal communication and preschoolers' speech comprehension. Additionally, it encouraged vocalizations in preschoolers and enhanced long-term memory for the associations taught in the study for all participants. In summary, our study demonstrates that the use of a ludic tablet-based intervention for teaching new vocabulary and pre-reading skills can improve young children's linguistic and communicative abilities, which are essential for future development.
Bias and noise in proportion estimation: A mixture psychophysical model
(2021) Gouet, Camilo; Jin, Wei; Naiman, Daniel Q.; Pena, Marcela; Halberda, Justin
The importance of proportional reasoning has long been recognized by psychologists and educators, yet we still do not have a good understanding of how humans mentally represent proportions. In this paper we present a psychophysical model of proportion estimation, extending previous approaches. We assumed that proportion representations are formed by representing each magnitude of a proportion stimuli (the part and its complement) as Gaussian activations in the mind, which are then mentally combined in the form of a proportion. We next derived the internal representation of proportions, including bias and internal noise parameters -capturing respectively how our estimations depart from true values and how variable estimations are. Methodologically, we introduced a mixture of components to account for contaminating behaviors (guessing and reversal of responses) and framed the model in a hierarchical way. We found empirical support for the model by testing a group of 4th grade children in a spatial proportion estimation task. In particular, the internal density reproduced the asymmetries (skewedness) seen in this and in previous reports of estimation tasks, and the model accurately described wide variations between subjects in behavior. Bias estimates were in general smaller than by using previous approaches, due to the model's capacity to absorb contaminating behaviors. This property of the model can be of especial relevance for studies aimed at linking psychophysical measures with broader cognitive abilities. We also recovered higher levels of noise than those reported in discrimination of spatial magnitudes and discuss possible explanations for it. We conclude by illustrating a concrete application of our model to study the effects of scaling in proportional reasoning, highlighting the value of quantitative models in this field of research.
Brain Oscillations during Spoken Sentence Processing
(2012) Pena, Marcela; Melloni, Lucia
Spoken sentence comprehension relies on rapid and effortless temporal integration of speech units displayed at different rates. Temporal integration refers to how chunks of information perceived at different time scales are linked together by the listener in mapping speech sounds onto meaning. The neural implementation of this integration remains unclear. This study explores the role of short and long windows of integration in accessing meaning from long samples of speech. In a cross-linguistic study, we explore the time course of oscillatory brain activity between 1 and 100 Hz, recorded using EEG, during the processing of native and foreign languages. We compare oscillatory responses in a group of Italian and Spanish native speakers while they attentively listen to Italian, Japanese, and Spanish utterances, played either forward or backward. The results show that both groups of participants display a significant increase in gamma band power (55-75 Hz) only when they listen to their native language played forward. The increase in gamma power starts around 1000 msec after the onset of the utterance and decreases by its end, resembling the time course of access to meaning during speech perception. In contrast, changes in low-frequency power show similar patterns for both native and foreign languages. We propose that gamma band power reflects a temporal binding phenomenon concerning the coordination of neural assemblies involved in accessing meaning of long samples of speech.
Earlier Speech Exposure Does Not Accelerate Speech Acquisition
(2012) Pena, Marcela; Werker, Janet F.; Dehaene-Lambertz, Ghislaine
Critical periods in language acquisition have been discussed primarily with reference to studies of people who are deaf or bilingual. Here, we provide evidence on the opening of sensitivity to the linguistic environment by studying the response to a change of phoneme at a native and nonnative phonetic boundary in full-term and preterm human infants using event-related potentials. Full-term infants show a decline in their discrimination of nonnative phonetic contrasts between 9 and 12 months of age. Because the womb is a high-frequency filter, many phonemes are strongly degraded in utero. Preterm infants thus benefit from earlier and richer exposure to broadcast speech. We find that preterms do not take advantage of this enriched linguistic environment: the decrease in amplitude of the mismatch response to a nonnative change of phoneme at the end of the first year of life was dependent on maturational age and not on the duration of exposure to broadcast speech. The shaping of phonological representations by the environment is thus strongly constrained by brain maturation factors.
How Modality Specific Is the Iambic-Trochaic Law? Evidence From Vision
(2011) Pena, Marcela; Bion, Ricardo A. H.; Nespor, Marina
The iambic-trochaic law has been proposed to account for the grouping of auditory stimuli: Sequences of sounds that differ only in duration are grouped as iambs (i.e., the most prominent element marks the end of a sequence of sounds), and sequences that differ only in pitch or intensity are grouped as trochees (i.e., the most prominent element marks the beginning of a sequence). In 3 experiments, comprising a familiarization and a test phase, we investigated whether a similar grouping principle is also present in the visual modality. During familiarization, sequences of visual stimuli were repeatedly presented to participants, who were asked to memorize their order of presentation. In the test phase, participants were better at remembering fragments of the familiarization sequences that were consistent with the iambic trochaic law. Thus, they were better at remembering fragments that had the element with longer duration in final position (iambs) and fragments that had the element with either higher temporal frequency or higher intensity in initial position (trochees), as compared with fragments that were inconsistent with the iambic-trochaic law or that never occurred during familiarization.
Investigating the neural correlates of continuous speech computation with frequency-tagged neuroelectric responses
(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2009) Buiatti, Marco; Pena, Marcela; Dehaene Lambertz, Ghislaine
In order to learn an oral language, humans have to discover words from a continuous signal. Streams of artificial monotonous speech can be readily segmented based on the statistical analysis of the syllables' distribution. This parsing is considerably improved when acoustic cues, such as subliminal pauses, are added suggesting that a different mechanism is involved. Here we used a frequency-tagging approach to explore the neural mechanisms underlying word learning while listening to continuous speech. High-density EEG was recorded in adults listening to a concatenation of either random syllables or tri-syllabic artificial words, with or without subliminal pauses added every three syllables. Peaks in the EEG power spectrum at the frequencies of one and three syllables occurrence were used to tag the perception of a monosyllabic or trisyllabic structure, respectively. Word streams elicited the suppression of a one-syllable frequency peak, steadily present during random streams, suggesting that syllables are no more perceived as isolated segments but bounded to adjacent syllables. Crucially, three-syllable frequency peaks were only observed during word streams with pauses, and were positively correlated to the explicit recall of the detected words. This result shows that pauses facilitate a fast, explicit and successful extraction of words from continuous speech, and that the frequency-tagging approach is a powerful tool to track brain responses to different hierarchical units of the speech structure. (C) 2008 Elsevier Inc. All rights reserved.
Language acquisition in premature and full-term infants
(NATL ACAD SCIENCES, 2010) Pena, Marcela; Pittaluga, Enrica; Mehler, Jacques
We tested healthy preterm (born near 28 +/- 2 weeks of gestational age) and full-term infants at various different ages. We compared the two populations on the development of a language acquisition landmark, namely, the ability to distinguish the native language from a rhythmically similar one. This ability is attained 4 months after birth in healthy full-term infants. We measured the induced gamma-band power associated with passive listening to (i) the infants' native language (Spanish), (ii) a rhythmically close language (Italian), and (iii) a rhythmically distant language (Japanese) as a marker of gains in language discrimination. Preterm and full-term infants were matched for neural maturation and duration of exposure to broadcast speech. We found that both full-term and preterm infants only display a response to native speech near 6 months after their term age. Neural maturation seems to constrain advances in speech discrimination at early stages of language acquisition.
Neural indicators of articulator-specific sensorimotor influences on infant speech perception
(2021) Choi, Dawoon; Dehaene-Lambertz, Ghislaine; Pena, Marcela; Werker, Janet F.
While there is increasing acceptance that even young infants detect correspondences between heard and seen speech, the common view is that oral-motor movements related to speech production cannot influence speech perception until infants begin to babble or speak. We investigated the extent of multimodal speech influences on auditory speech perception in prebabbling infants who have limited speech-like oral-motor repertoires. We used event-related potentials (ERPs) to examine how sensorimotor influences to the infant's own articulatory movements impact auditory speech perception in 3-mo-old infants. In experiment 1, there were ERP discriminative responses to phonetic category changes across two phonetic contrasts (bilabial-dental /ba/-/da/; dental-retroflex /da/-/cia/) in a mismatch paradigm, indicating that infants auditorily discriminated both contrasts. In experiment 2, inhibiting infants' own tongue-tip movements had a disruptive influence on the early ERP discriminative response to the /da/-/cia/ contrast only. The same articulatory inhibition had contrasting effects on the perception of the /ba/-/da/ contrast, which requires different articulators (the lips vs. the tongue) during production, and the /da/-/cia/ contrast, whereby both phones require tongue-tip movement as a place of articulation. This articulatory distinction between the two contrasts plausibly accounts for the distinct influence of tongue-tip suppression on the neural responses to phonetic category change perception in definitively prebabbling, 3-mo-old, infants. The results showing a specificity in the relation between oral-motor inhibition and phonetic speech discrimination suggest a surprisingly early mapping between auditory and motor speech representation already in prebabbling infants.
Neuroanatomical basis of behavioral disturbances in patients with prefrontal lesions
(2006) Slachevsky, Andrea; Pena, Marcela; Perez, Carolina; Bravo, Eduardo; Alegria, Patricia
The role of the frontal lobe in control of behavioral and cognitive abilities is explored in a group of 34 patients with brain lesions restricted to the prefrontal cortex. The scores in both structured behavioral questionnaires and standard neuropsychological tests were analyzed using the injured area of the frontal lobe as the independent variable. Our results show that patients with simultaneous lesions in supero- and inferomedial areas of the prefrontal cortex exhibit higher behavioral disturbances. Bilateral lesions also are associated with greater behavioral troubles. On the contrary. cognitive abilities are globally impaired in prefrontal patients. Results are discussed in relation to Current models of the organization of the prefrontal cortex and its role on behavior control.
Phonological acquisition in preterm infants
(REVISTA DE NEUROLOGIA, 2010) Pena, Marcela; Pittaluga, Enrica; Farkas, Chamarrita
Introduction. The stock of phonemes used in the mother tongue is mostly acquired towards the end of the first year of life. Systematic exposure to speech begins, maintains and enhances the learning of native phonemes and lowers sensitivity to non-native ones. Speech deprival gives rise to serious problems in the infant's phonological development, yet little is known about the effects that premature exposure to speech can have on this learning. This study explores this issue by comparing the phonological discrimination of full-term and preterm infants at 12 months of age (corrected age in the preterm infants).
Synchronization of neural activity across cortical areas correlates with conscious perception
(SOC NEUROSCIENCE, 2007) Melloni, Lucia; Molina, Carlos; Pena, Marcela; Torres, David; Singer, Wolf; Rodriguez, Eugenio
Subliminal stimuli can be deeply processed and activate similar brain areas as consciously perceived stimuli. This raises the question which signatures of neural activity critically differentiate conscious from unconscious processing. Transient synchronization of neural activity has been proposed as a neural correlate of conscious perception. Here we test this proposal by comparing the electrophysiological responses related to the processing of visible and invisible words in a delayed matching to sample task. Both perceived and nonperceived words caused a similar increase of local (gamma) oscillations in the EEG, but only perceived words induced a transient long-distance synchronization of gamma oscillations across widely separated regions of the brain. After this transient period of temporal coordination, the electrographic signatures of conscious and unconscious processes continue to diverge. Only words reported as perceived induced (1) enhanced theta oscillations over frontal regions during the maintenance interval, (2) an increase of the P300 component of the event-related potential, and (3) an increase in power and phase synchrony of gamma oscillations before the anticipated presentation of the test word. We propose that the critical process mediating the access to conscious perception is the early transient global increase of phase synchrony of oscillatory activity in the gamma frequency range.
The "soul" of language does not use statistics: Reflections on vowels and consonants
(ELSEVIER MASSON, CORP OFF, 2006) Mehler, Jacques; Pena, Marcela; Nespor, Marina; Bonatti, Luca
This paper reviews studies of language processing with the aim of establishing whether any type of statistical information embedded in linguistic signals can be exploited by the language learner. The constraints as to the information that can be so used, we will argue, should be used to inform theories of language acquisition.
The Role of Audiovisual Processing in Early Conceptual Development
(2011) Pena, Marcela; Mehler, Jacques; Nespor, Marina

Browsing by Author "Pena, Marcela"

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