Study of Elastin, Hydrolyzed Collagen and Collagen-like Products in a Tri-Layered Chitosan Membrane to Test Anti-Aging Skin Properties.

The use of animal testing in the cosmetic industry is already prohibited in more than 40 countries, including those of the EU. The pressure for it to be banned worldwide in the future is increasing, so the need for animal alternatives is of great interest today. In addition, using animals and humans in scientific research is ethically reprehensible. This study aimed to prove some of the anti-aging properties of elastin (EL), hydrolyzed collagen (HC), and two vegan collagen-like products (Veg Col) in a tri-layered chitosan membrane that was ionically crosslinked with sodium tripolyphosphate (TPP). In the first approach, as a way of representing different layers of a biological system, such as the epidermis and the two dermis sublayers, EL, HC, or Veg Col were independently introduced into the two inner layers (2L(i+b)). Their effects were compared with those of their introduction into three layers (3L). Different experiments were performed on the membrane to test its elasticity, hydration, moisture retention, and pore reduction at different concentrations of EL, HC, and Veg Col, and the results were normalized vs. a blank membrane. This new alternative to animal or human testing can be suitable for proving certain efficacy claims for active ingredients or products in the pharmaceutical, nutritional, and cosmetic fields.

Creation of Chemically Tri-Layered Collagen Crosslinked Membranes and Their Comparison with Ionically Tri-Layered Chitosan Crosslinked Membranes to Study Human Skin Properties.

In 2009, a new European regulation came into force that forbade the use of animals in the cosmetics industry. As a result, new alternatives were sought, taking into account the new ethical considerations. The main objective of this article is to continue a line of research that aims to build a physical model of skin from a biomaterial scaffold composed of collagen, chitosan or a combination to investigate whether they offer similar behavior to human skin. Collagen, the major component in the dermis, was crosslinked with glutaraldehyde (GTA) to develop three formulations for studying some properties of the skin through rheological tests like swelling index, elasticity or water loss. In addition, this article makes a comparison with the results obtained in the previous article where the membranes were made of chitosan and tripolyphosphate (TPP). The results obtained highlight that the tri-layered membranes scaffold better than the mono-layered ones to increase the elastic modulus (G') and the permeability. Furthermore, they offer a protective effect against water loss compared to mono-layered membranes. As regards chitosan membranes, these have a higher G' modulus than collagen membranes when the degree of deacetylation (DDA) is 85%. However, collagen membranes are more elastic when the DDA of chitosan is 76%, and their linear viscoelastic limit (LVL) doubles that of chitosan membranes, both for the degree of acetylation of 76 and 85%.

Influence of Gesture and Linguistic Experience on Sign Perception.

In the past years, there has been a significant increase in the number of people learning sign languages. For hearing second language (L2) signers, acquiring a sign language involves acquiring a new language in a different modality. Exploring how L2 sign perception is accomplished and how newly learned categories are created is the aim of the present study. In particular, we investigated handshape perception by means of two tasks, identification and discrimination. In two experiments, we compared groups of hearing L2 signers and groups with different knowledge of sign language. Experiment 1 explored three groups of children-hearing L2 signers, deaf signers, and hearing nonsigners. All groups obtained similar results in both identification and discrimination tasks regardless of sign language experience. In Experiment 2, two groups of adults-Catalan sign language learners (LSC) and nonsigners-perceived handshapes that could be permissible (either as a sign or as a gesture) or not. Both groups obtained similar results in both tasks and performed significantly different perceiving handshapes depending on their permissibility. The results obtained here suggest that sign language experience is not a determinant factor in handshape perception and support other hypotheses considering gesture experience.

How does the bilingual experience sculpt the brain?

The ability to speak two languages often marvels monolinguals, although bilinguals report no difficulties in achieving this feat. Here, we examine how learning and using two languages affect language acquisition and processing as well as various aspects of cognition. We do so by addressing three main questions. First, how do infants who are exposed to two languages acquire them without apparent difficulty? Second, how does language processing differ between monolingual and bilingual adults? Last, what are the collateral effects of bilingualism on the executive control system across the lifespan? Research in all three areas has not only provided some fascinating insights into bilingualism but also revealed new issues related to brain plasticity and language learning.

The dynamics of human cognition: Increasing global integration coupled with decreasing segregation found using iEEG.

Cognitive processing requires the ability to flexibly integrate and process information across large brain networks. How do brain networks dynamically reorganize to allow broad communication between many different brain regions in order to integrate information? We record neural activity from 12 epileptic patients using intracranial EEG while performing three cognitive tasks. We assess how the functional connectivity between different brain areas changes to facilitate communication across them. At the topological level, this facilitation is characterized by measures of integration and segregation. Across all patients, we found significant increases in integration and decreases in segregation during cognitive processing, especially in the gamma band (50-90 Hz). We also found higher levels of global synchronization and functional connectivity during task execution, again particularly in the gamma band. More importantly, functional connectivity modulations were not caused by changes in the level of the underlying oscillations. Instead, these modulations were caused by a rearrangement of the mutual synchronization between the different nodes as proposed by the "Communication Through Coherence" Theory.

The neural basis of free language choice in bilingual speakers: Disentangling language choice and language execution.

For everyday communication, bilingual speakers need to face the complex task of rapidly choosing the most appropriate language given the context, maintaining this choice over the current communicative act, and shielding lexical selection from competing alternatives from non-target languages. Yet, speech production of bilinguals is typically flawless and fluent. Most of the studies available to date constrain speakers' language choice by cueing the target language and conflate language choice with language use. This left largely unexplored the neural mechanisms underlying free language choice, i.e., the voluntary situation of choosing the language to speak. In this study, we used fMRI and Multivariate Pattern Analysis to identify brain regions encoding the target language when bilinguals are free to choose in which language to name pictures. We found that the medial prefrontal cortex encoded the chosen language prior to speaking. By contrast, during language use, language control recruited a wider brain network including the left inferior frontal lobe, the basal ganglia, and the angular and inferior parietal gyrus bilaterally. None of these regions were involved in language choice. We argue that the control processes involved in language choice are different from those involved in language use. Furthermore, our findings confirm that the medial prefrontal cortex is a domain-general region critical for free choice and that bilingual language choice relies on domain general processes.

The cortical dynamics of speaking: Lexical and phonological knowledge simultaneously recruit the frontal and temporal cortex within 200 ms.

Language production models typically assume that retrieving a word for articulation is a sequential process with substantial functional delays between conceptual, lexical, phonological and motor processing, respectively. Nevertheless, explicit evidence contrasting the spatiotemporal dynamics between different word production components is scarce. Here, using anatomically constrained magnetoencephalography during overt meaningful speech production, we explore the speed with which lexico-semantic versus acoustic-articulatory information of a to-be-uttered word become first neurophysiologically manifest in the cerebral cortex. We demonstrate early modulations of brain activity by the lexical frequency of a word in the temporal cortex and the left inferior frontal gyrus, simultaneously with activity in the motor and the posterior superior temporal cortex reflecting articulatory-acoustic phonological features (+LABIAL vs. +CORONAL) of the word-initial speech sounds (e.g., Monkey vs. Donkey). The specific nature of the spatiotemporal pattern correlating with a word's frequency and initial phoneme demonstrates that, in the course of speech planning, lexico-semantic and phonological-articulatory processes emerge together rapidly, drawing in parallel on temporal and frontal cortex. This novel finding calls for revisions of current brain language theories of word production.

Thinking More or Feeling Less? Explaining the Foreign-Language Effect on Moral Judgment.

Would you kill one person to save five? People are more willing to accept such utilitarian action when using a foreign language than when using their native language. In six experiments, we investigated why foreign-language use affects moral choice in this way. On the one hand, the difficulty of using a foreign language might slow people down and increase deliberation, amplifying utilitarian considerations of maximizing welfare. On the other hand, use of a foreign language might stunt emotional processing, attenuating considerations of deontological rules, such as the prohibition against killing. Using a process-dissociation technique, we found that foreign-language use decreases deontological responding but does not increase utilitarian responding. This suggests that using a foreign language affects moral choice not through increased deliberation but by blunting emotional reactions associated with the violation of deontological rules.

Language Control in Bilinguals: Monitoring and Response Selection.

Language control refers to the cognitive mechanism that allows bilinguals to correctly speak in one language avoiding interference from the nontarget language. Bilinguals achieve this feat by engaging brain areas closely related to cognitive control. However, 2 questions still await resolution: whether this network is differently engaged when controlling nonlinguistic representations, and whether this network is differently engaged when control is exerted upon a restricted set of lexical representations that were previously used (i.e., local control) as opposed to control of the entire language system (i.e., global control). In the present event-related functional magnetic resonance imaging study, we investigated these 2 questions by employing linguistic and nonlinguistic blocked switching tasks in the same bilingual participants. We first report that the left prefrontal cortex is driven similarly for control of linguistic and nonlinguistic representations, suggesting its domain-general role in the implementation of response selection. Second, we propose that language control in bilinguals is hierarchically organized with the dorsal anterior cingulate cortex/presupplementary motor area acting as the supervisory attentional system, recruited for increased monitoring demands such as local control in the second language. On the other hand, prefrontal, inferior parietal areas and the caudate would act as the response selection system, tailored for language selection for both local and global control.

Semantic interference and its control: A functional neuroimaging and connectivity study.

During picture naming, the ease with which humans generate words is dependent upon the context in which they are named. For instances, naming previously presented items results in facilitation. Instead, naming a picture semantically related to previous items displays persistent interference effects (i.e., cumulative semantic interference, CSI). The neural correlates of CSI are still unclear and it is a matter of debate whether semantic control, or cognitive control more in general, is necessary for the resolution of CSI. We carried out an event-related fMRI experiment to assess the neural underpinnings of the CSI effect and the involvement and nature of semantic control. Both left inferior frontal gyrus (LIFG) and the left caudate nucleus (LCN) showed a linear increase of BOLD response positively associated with the consecutive number of presentations of semantically related pictures independently of task-load. The generalized psychophysiological interaction analysis showed that LIFG demonstrated a quantitative neural connectivity difference with the left supramarginal and angular gyri for increases of task-load and with the fusiform gyri for linear CSI increases. Furthermore, seed-to-voxel functional connectivity showed that LIFG activity coupled with different regions involved in cognitive control and lexicosemantic processing when semantic interference was elicited to a minimum or maximum degree. Our results are consistent with the lexical-competitive nature of the CSI effect, and we provide novel evidence that semantic control lies upon a more general cognitive control network (i.e., LIFG and LCN) responsible for resolving interference between competing semantically related items through connectivity with different brain areas in order to guarantee the correct response. Hum Brain Mapp 37:4179-4196, 2016. © 2016 Wiley Periodicals, Inc.

Can Faces Prime a Language?

Bilinguals have two languages that are activated in parallel. During speech production, one of these languages must be selected on the basis of some cue. The present study investigated whether the face of an interlocutor can serve as such a cue. Spanish-Catalan and Dutch-French bilinguals were first familiarized with certain faces, each of which was associated with only one language, during simulated Skype conversations. Afterward, these participants performed a language production task in which they generated words associated with the words produced by familiar and unfamiliar faces displayed on-screen. When responding to familiar faces, participants produced words faster if the faces were speaking the same language as in the previous Skype simulation than if the same faces were speaking a different language. Furthermore, this language priming effect disappeared when it became clear that the interlocutors were actually bilingual. These findings suggest that faces can prime a language, but their cuing effect disappears when it turns out that they are unreliable as language cues.

Numerical representations and intuitions of probabilities at 12 months.

Recent research shows that preverbal infants can reason about single-case probabilities without relying on observed frequencies, adapting their predictions to relevant dynamic parameters of the situation (Téglás, Vul, Girotto, Gonzalez, Tenenbaum & Bonatti, ; Téglás, Girotto, Gonzalez & Bonatti, ). Here we show that intuitions of probabilities may derive from the ability to represent a limited number of possibilities. After watching a scene containing moving objects of two ensembles, 12-month-olds looked longer at an unlikely than at a likely single-case outcome when the objects were within the parallel individuation range. However, they did not do so when the scene contained the same ratio between ensembles but a larger number of objects. At the same time, they could form rational expectations about single-case outcomes in scenes containing the same large number of objects when they could exploit subtle physical parameters induced by the objects' movements and their spatial configuration. Our findings demonstrate that at early stages of development the mental representations involved in probability estimations of future individual situations are powerful and sophisticated, but at the same time they depend on infants' overall cognitive architecture, being constrained by the numerical representations spontaneously induced by the situations.

Language switching makes pronunciation less nativelike.

It is well known that multilingual speakers' nonnative productions are accented. Do these deviations from monolingual productions simply reflect the mislearning of nonnative sound categories, or can difficulties in processing speech sounds also contribute to a speaker's accent? Such difficulties are predicted by interactive theories of production, which propose that nontarget representations, partially activated during lexical access, influence phonetic processing. We examined this possibility using language switching, a task that is well known to disrupt multilingual speech production. We found that these disruptions extend to the articulation of individual speech sounds. When native Spanish speakers are required to unexpectedly switch the language of production between Spanish and English, their speech becomes more accented than when they do not switch languages (particularly for cognate targets). These findings suggest that accents reflect not only difficulty in acquiring second-language speech sounds but also the influence of representations partially activated during on-line speech processing.

Losing control of your languages: a case study.

Bilingual speakers are usually quite good at restricting their lexicalization output to the desired language while preventing all sorts of language intrusions from the language not in use. However, brain damage can affect these abilities of language control, leading to striking and flagrant linguistic behaviours, such as pathological language mixing (pLM) and pathological switching (pLS). In this paper we report the performance of a Catalan-Spanish bilingual individual (R.R.T.) who, due to a neuroinflammatory disease and subcortical lesions, shows pLS. We tested R.R.T. in several tasks of language production and control, such as picture naming (objects and actions), word translation, blocked naming, and language switching task. R.R.T. was also tested in executive control (EC) tasks, such as task switching and a flanker task. We found several interesting results. First, cross-language intrusions were present much more frequently when R.R.T. was asked to speak in her first (and dominant) language (Catalan) than when she was asked to do so in the nondominant language (Spanish). Second, the results provide evidence suggesting that damage to certain subcortical structures may lead to problems in controlling the language output during verbalization in bilingual speakers. Third, we observed that R.R.T. seemed to show more difficulties in language control with verbs. Fourth, R.R.T. showed impaired performance compared to controls in both task switching and a flanker task. The results are discussed in relation to other findings of pLM and pLS in published single-case reports and in relation to EC deficits.

Reconciling phonological neighborhood effects in speech production through single trial analysis.

A crucial step for understanding how lexical knowledge is represented is to describe the relative similarity of lexical items, and how it influences language processing. Previous studies of the effects of form similarity on word production have reported conflicting results, notably within and across languages. The aim of the present study was to clarify this empirical issue to provide specific constraints for theoretical models of language production. We investigated the role of phonological neighborhood density in a large-scale picture naming experiment using fine-grained statistical models. The results showed that increasing phonological neighborhood density has a detrimental effect on naming latencies, and re-analyses of independently obtained data sets provide supplementary evidence for this effect. Finally, we reviewed a large body of evidence concerning phonological neighborhood density effects in word production, and discussed the occurrence of facilitatory and inhibitory effects in accuracy measures. The overall pattern shows that phonological neighborhood generates two opposite forces, one facilitatory and one inhibitory. In cases where speech production is disrupted (e.g. certain aphasic symptoms), the facilitatory component may emerge, but inhibitory processes dominate in efficient naming by healthy speakers. These findings are difficult to accommodate in terms of monitoring processes, but can be explained within interactive activation accounts combining phonological facilitation and lexical competition.

Bilingualism tunes the anterior cingulate cortex for conflict monitoring.

Monitoring and controlling 2 language systems is fundamental to language use in bilinguals. Here, we reveal in a combined functional (event-related functional magnetic resonance imaging) and structural neuroimaging (voxel-based morphometry) study that dorsal anterior cingulate cortex (ACC), a structure tightly bound to domain-general executive control functions, is a common locus for language control and resolving nonverbal conflict. We also show an experience-dependent effect in the same region: Bilinguals use this structure more efficiently than monolinguals to monitor nonlinguistic cognitive conflicts. They adapted better to conflicting situations showing less ACC activity while outperforming monolinguals. Importantly, for bilinguals, brain activity in the ACC, as well as behavioral measures, also correlated positively with local gray matter volume. These results suggest that early learning and lifelong practice of 2 languages exert a strong impact upon human neocortical development. The bilingual brain adapts better to resolve cognitive conflicts in domain-general cognitive tasks.

The poor helping the rich: how can incomplete representations monitor complete ones?

Pickering & Garrod (P&G) propose that inner speech monitoring is subserved by predictions stemming from fast forward modeling. In this commentary, we question this alignment of language prediction with the inner speech monitor. We wonder how the speech monitor can function so efficiently if it is based on incomplete representations.

Languages and Psychotherapy: The Effect of Foreign Language on Fear Extinction.

BACKGROUND: Using a foreign language can influence emotion modulation, but whether different psychotherapy processes would be affected by a foreign language is still unclear. The current study explored the foreign language effect on the extinction of fear. METHOD: During the conditioning phase, part of the neutral stimuli presented to the participants were associated with a threat, while they performed a countdown task in their native language. In the extinction phase, participants performed the same task either in their native/foreign language and were informed that the threat would no longer appear. We collected self-reports of fear, and pupil dilation and electrodermal activity as physiological measures of arousal. RESULTS: Extinction was successful, indicated by greater self-reported fear and pupil dilation during the threat condition compared to neutral in the conditioning phase, but no significant differences during extinction. Although the foreign language group presented higher arousal, fear extinction occurred regardless of the linguistic context. CONCLUSIONS: Fear extinction via verbal instructions is equally effective in a foreign and a native language context. These results indicate that evidence should be continue to be gathered on the role of foreign languages using basic paradigms with clinical applications.