Mireia Hernández

Bilingualism aids conflict resolution: evidence from the ANT task.

The need of bilinguals to continuously control two languages during speech production may exert general effects on their attentional networks. To explore this issue we compared the performance of bilinguals and monolinguals in the attentional network task (ANT) developed by Fan et al. [Fan, J., McCandliss, B.D. Sommer, T., Raz, A., Posner, M.I. (2002). Testing the efficiency and independence of attentional networks. Journal of Cognitive Neuroscience, 14, 340-347]. This task is supposed to tap into three different attentional networks: alerting, orienting and executive control. The results revealed that bilingual participants were not only faster in performing the task, but also more efficient in the alerting and executive control networks. In particular, bilinguals were aided more by the presentation of an alerting cue, and were also better at resolving conflicting information. Furthermore, bilinguals experienced a reduced switching cost between the different type of trials compared to monolinguals. These results show that bilingualism exerts an influence in the attainment of efficient attentional mechanisms by young adults that are supposed to be at the peak of their attentional capabilities.

On the bilingual advantage in conflict processing: Now you see it, now you don't

We report two experiments exploring more in detail the bilingual advantage in conflict resolution tasks. In particular, we focus on the origin of the bilingual advantage on overall reaction times in the flanker task. Bilingual and monolingual participants were asked to perform a flanker task under different task versions. In Experiment 1, we used two low-monitoring versions where most of the trials were of just one type (either congruent or incongruent). In Experiment 2, we used two high-monitoring versions where congruent and incongruent trials were more evenly distributed. An effect of bilingualism in overall reaction times was only present in the high-monitoring condition. These results reveal that when the task at hand recruits a good deal of monitoring resources, bilinguals outperform monolinguals. This observation suggests that bilingualism may affect the monitoring processes involved in executive control.

The impact of bilingualism on the executive control and orienting networks of attention

The main objective of this article is to provide new evidence regarding the impact of bilingualism on the attentional system. We approach this goal by assessing the effects of bilingualism on the executive and orienting networks of attention. In Experiment 1, we compared young bilingual and monolingual adults in a numerical version of the Stroop task, which allowed the assessment of the executive control network. We observed more efficient performance in the former group, which showed both reduced Stroop Interference and larger Stroop Facilitation Effects relative to the latter. Conversely, Experiment 2, conducted with a visual cueing task in order to assess the orienting network, revealed similar Cueing Facilitation and Inhibition (Inhibition of Return – IOR) Effects for both groups of speakers. The implications of the results of these two experiments for the origin and boundaries of the bilingual impact on the attentional system are discussed.

Escaping capture: Bilingualism modulates distraction from working memory

We ask whether bilingualism aids cognitive control over the inadvertent guidance of visual attention from working memory and from bottom-up cueing. We compare highly-proficient Catalan-Spanish bilinguals with Spanish monolinguals in three visual search conditions. In the working memory (WM) condition, attention was driven in a top-down fashion by irrelevant objects held in WM. In the Identify condition, attention was driven in a bottom-up fashion by visual priming. In the Singleton condition, attention was driven in a bottom-up fashion by including a unique distracting object in the search array. The results showed that bilinguals were overall faster than monolinguals in the three conditions, replicating previous findings that bilinguals can be more efficient than monolinguals in the deployment of attention. Interestingly, bilinguals were less captured by irrelevant information held in WM but were equally affected by visual priming and unique singletons in the search displays. These observations suggest that bilingualism aids top-down WM-mediated guidance of attention, facilitating processes that keep separate representations in WM from representations that guide visual attention. In contrast, bottom-up attentional capture by salient yet unrelated input operates similarly in bilinguals and monolinguals.

The organisation of nouns and verbs in bilingual speakers: A case of bilingual grammatical category-specific deficit

Abstract We report the naming performance of an early and highly proficient Catalan–Spanish bilingual woman (LPM) suffering from Alzheimers disease (AD). LPMs performance in several naming tasks revealed a disproportionate deficit for nouns in comparison to verbs. Further analyses revealed that this dissociation does not seem to be caused by damage to her semantic system, but rather by damage at the lexical level. Interestingly, the patients performance in her first and second language revealed comparable noun–verb dissociation both in terms of the magnitude of the effect and in terms of error types. These results suggest that the principles governing the organisation of lexical representations in the brain are similar for the two languages of a bilingual.

Grammatical category-specific deficits in bilingual aphasia

We report the naming performance of an early and highly proficient Spanish-Catalan bilingual (JPG) suffering from Primary Progressive Aphasia (PPA). JPGs performance revealed a grammatical category-specific deficit, with worse performance in naming verbs than nouns. This dissociation was present in oral and written naming and in his two languages, and it seems to stem from damage to, at least, the lexical level. Despite the fact that JPGs performance was qualitatively very similar across languages, his second language seemed to be more affected than his first language. These results indicate that the cortical organization of the two languages of highly proficient bilinguals follow similar organizational principles, one of this principles being grammatical class.

Lexical processing in the bilingual brain: Evidence from grammatical/morphological deficits

Background: A few studies have recently documented cases of proficient bilingual individuals who, subsequent to neural injury, suffered selective deficits affecting specific aspects of lexical processing. These cases involved disruption affecting the production of words from a specific grammatical category (verbs or nouns) or the production of irregular versus regular verb forms. Critically, these selective deficits were manifested in a strikingly similar manner across the two languages spoken by each of the individuals. Aims: The present study aims at reviewing these cases of selective cross‐linguistic deficits and discussing their implications for theories concerning lexical organisation in the bilingual brain. Methods & Procedures: The studies reviewed here employed a variety of behavioural tests that were specifically designed to investigate the availability in aphasic patients of lexical information concerning nouns and verbs and their morphological characteristics. Outcomes & Results: The brain‐damaged bilingual speakers reviewed in the present study exhibited selective deficits for nouns, verbs, or irregularly inflected verbs in both of their languages. Conclusions: The selectivity and cross‐language nature of the deficits reviewed here indicates that at least certain language substrates are shared in proficient bilingual people. The fact that these deficits affect grammatical class distinctions and verb inflections—information that is part of the lexicon—further indicates that shared neural substrates support lexical processing in proficient bilingual people.

The size of an attentional window affects working memory guidance.

We ask whether attentional guidance from working memory (WM) is influenced by the size of an attentional window. Participants adopted either a focused or a diffuse attentional window when responding to a search display. Prior to the search display an initial cue had to be held in memory (Experiment 1A, visual WM; Experiment 1C, verbal WM) or merely identified (Experiment 1B, identification). In all cases, search performance was affected by the re-presentation of the cue in the search display, with the cuing effects (either cost or benefit) being larger when the cue was held in memory than when it was merely identified. Critically, the magnitude of the cuing benefit increased when participants adopted a diffuse attentional window. This held for effects that are based on items held in WM and for effects that are based only on item priming. The results suggest that variations in the size of an attentional window modulate top-down (both WM conditions) as well as bottom-up guidance of attention (identification condition).

Category-specific semantic deficits in Alzheimer's disease : A semantic priming study

Category-specific semantic deficits in individuals suffering brain damage after relatively focal lesions provide an important source of evidence about the organization of semantic knowledge. However, whether Alzheimers disease (AD), in which the brain damage is more widespread, affects semantic categories to a different extent is still controversial. In the present study, we assess this issue by means of the semantic priming technique. AD patients with a mild impairment of their semantic knowledge showed comparable priming effects to that of controls for the categories of animals and artifacts. Interestingly, however, patients with a moderate impairment of their semantic knowledge showed a normal priming effect for animals but a very reduced priming effect (if any) for artifacts. These results reveal that AD may affect the semantic knowledge of different semantic categories to a different extent. The implications of this observation for current theoretical accounts of semantic representation in the brain are discussed.

On the parallel deterioration of lexico-semantic processes in the bilinguals’ two languages: Evidence from Alzheimer's disease

In this article we aimed to assess how Alzheimers disease (AD), which is neurodegenerative, affects the linguistic performance of early, high-proficient bilinguals in their two languages. To this end, we compared the Picture Naming and Word Translation performances of two groups of AD patients varying in disease progression (Mild and Moderate) with that of bilingual individuals diagnosed with mild cognitive impairment (MCI). The results revealed that the linguistic deterioration caused by AD affected the two languages similarly. We also found that cognate status and word frequency were two major determinants of language performance in all three groups of participants. These results are consistent with the notion of a common neural substrate recruited to represent and process the two languages of high-proficient bilinguals.