Daniela Paolieri

How Does Bilingualism Improve Executive Control? A Comparison of Active and Reactive Inhibition Mechanisms

It has been claimed that bilingualism enhances inhibitory control, but the available evidence is equivocal. The authors evaluated several possible versions of the inhibition hypothesis by comparing monolinguals and bilinguals with regard to stop signal performance, inhibition of return, and the attentional blink. These three phenomena, it can be argued, tap into different aspects of inhibition. Monolinguals and bilinguals did not differ in stop signal reaction time and thus were comparable in terms of active-inhibitory efficiency. However, bilinguals showed no facilitation from spatial cues, showed a strong inhibition of return effect, and exhibited a more pronounced attentional blink. These results suggest that bilinguals do not differ from monolinguals in terms of active inhibition but have acquired a better ability to maintain action goals and to use them to bias goal-related information. Under some circumstances, this ability may indirectly lead to more pronounced reactive inhibition of irrelevant information.

Language switching and language competition

This study examined the asymmetrical language switching cost in a word reading task (Experiment 1) and in a categorization task (Experiment 2 and 3). In Experiment 1, Spanish–English bilinguals named words in first language (L1) and second language (L2) in a switching paradigm. They were slower to switch from their weaker L2 to their more dominant L1 than from L1 to L2. In Experiment 2 and 3, high vs. low English proficiency bilinguals decided whether a word visually presented in their L1 or L2 referred to an animate or to an inanimate entity. In this case, bilinguals did not show asymmetrical cost when they switched between languages. These results suggest that inhibitory processes in bilingual processing as indexed by the asymmetrical language switching cost are only observed when L1 and L2 lexical representations compete for selection (e.g. word naming task). In addition, L2 proficiency did not influence the absence of asymmetrical switching cost.

The Effect of Grammatical Gender on Object Categorization

In 3 experiments, we investigated the effect of grammatical gender on object categorization. Participants were asked to judge whether 2 objects, whose names did or did not share grammatical gender, belonged to the same semantic category by pressing a key. Monolingual speakers of English (Experiment 1), Italian (Experiments 1 and 2), and Spanish (Experiments 2 and 3) were tested in their native language. Italian and Spanish participants responded faster to pairs of stimuli sharing the same gender, whereas no difference was observed for English participants. In Experiment 2, the pictures were chosen in such a way that the grammatical gender of the names was opposite in Italian and Spanish. Therefore, the same pair of stimuli gave rise to different patterns depending on the gender congruency of the names in the languages. In Experiment 3, Spanish speakers performed the same task under an articulatory suppression condition, showing no grammatical gender effect. The locus where meaning and gender interact can be located at the level of the lexical representation that specifies syntactic information: Nouns sharing the same grammatical gender activate each other, thus facilitating their processing and speeding up responses, either to semantically related pairs or to semantically unrelated pairs.

Grammatical gender processing in Italian and Spanish bilinguals

We explored whether the grammatical gender of the native language (L1) affects the production of words in a second language (L2). Evidence from previous studies is contrasting. In the present investigation, Italian–Spanish bilinguals were instructed to name pictures in L2 (Experiments 1 and 2) or to translate words from L1 to L2 (Experiment 3), producing either the bare noun or the noun phrase (article + noun). Half of the nouns had the same gender in the two languages, while the other half had a different gender. In all experiments, responses were faster in the gender-congruent than in the gender-incongruent condition, irrespective of task (L2 picture naming or forward word translation) and syntactic type (bare noun and noun phrase). We propose that in the bilingual system, parallel to the semantic route, a direct lexical, nonsemantic route connects the languages and that the native language interacts at the level of grammatical gender with the lexical representations of the response language.

Is there cross-language modulation when bilinguals process number words?

This study explores the possibility of cross-language activation when bilinguals process number words in their first language (Italian) and their second language (German). Italian monolinguals (Experiment 1), German monolinguals (Experiment 2), and Italian/German bilinguals (Experiment 3) were required to decide the larger of two number words while the unit–decade compatibility effect was examined. For compatible trials the decade and unit comparisons lead to the same response (e.g., 24–67), whereas for incompatible trials the decade and unit comparisons lead to different responses (e.g., 27–64). The regular unit–decade compatibility effect was significant when bilinguals and monolinguals performed the comparison in German. However, this effect was not found when bilinguals and monolinguals performed the task in Italian. In addition, the decade distance played a major role when bilinguals processed in their first language, whereas the unit distance was more important when they worked in their second language. These results indicate that the processing of number words in one language is not modulated by the way bilinguals process number words in their alternative language.

Grammatical gender inhibition in bilinguals

Inhibitory control processes have been recently considered to be involved in interference resolution in bilinguals at the phonological level. In this study we explored if interference resolution is also carried out by this inhibitory mechanism at the grammatical level. Thirty-two bilinguals (Italian-L1 and Spanish-L2) participated. All of them completed two tasks. In the first one they had to name pictures in L2. We manipulated gender congruency between the two languages and the number of presentations of the pictures (1 and 5). Results showed a gender congruency effect with slower naming latencies in the incongruent condition. In the second task, participants were presented with the pictures practiced during the first naming task, but now they were asked to produce the L1 article. Results showed a grammatical gender congruency effect in L1 that increased for those words practiced five times in L2. Our conclusion is that an inhibitory mechanism was involved in the suppression of the native language during a picture naming task. Furthermore, this inhibitory process was also involved in suppressing grammatical gender when it was a source of competition between the languages.

Differential effects of grammatical gender and gender inflection in bare noun production

In a new series of experiments with the picture-word interference paradigm, we replicated the grammatical gender interference effect in bare noun production in Italian: naming times are slower to picture-word noun pairs sharing the same gender. This effect is independent from the morphological transparency for gender, but responses are significantly slower when the distracters are transparent for gender. Overall, the pattern of results supports the assumption that in bare noun production grammatical gender is always selected, at least in languages like Italian. We assume that the differential effects of the nominal endings are due to the mechanisms involved in the recognition of grammatical gender of the distracter nouns which are sensitive to the morphological transparency for gender: lexical representation of transparent written words leads to a higher level of activation, thus resulting in stronger gender interference.

Grammatical gender processing in romance languages: Evidence from bare noun production in Italian and Spanish

The selection of grammatical gender in bare noun production is a controversial topic. In two experiments with the picture–word interference paradigm we confirmed a reliable effect of grammatical gender congruency in bare noun production in Italian and we replicated this effect in Spanish, another Romance language with a gender system analogous to the Italian one. In both Experiments, naming times were slower for picture–word pairs sharing grammatical gender. The results of the present study support the notion that grammatical gender is an intrinsic lexical property and not a pure syntactic feature selected only in noun phrase production. We assume that grammatical gender selection is crucial in languages with a complex morphological structure, like Italian and Spanish, in which the ending vowel is itself marked for grammatical gender.

The role of working memory in inferential sentence comprehension

Existing literature on inference making is large and varied. Trabasso and Magliano (Discourse Process 21(3):255–287, 1996) proposed the existence of three types of inferences: explicative, associative and predictive. In addition, the authors suggested that these inferences were related to working memory (WM). In the present experiment, we investigated whether WM capacity plays a role in our ability to answer comprehension sentences that require text information based on these types of inferences. Participants with high and low WM span read two narratives with four paragraphs each. After each paragraph was read, they were presented with four true/false comprehension sentences. One required verbatim information and the other three implied explicative, associative and predictive inferential information. Results demonstrated that only the explicative and predictive comprehension sentences required WM: participants with high verbal WM were more accurate in giving explanations and also faster at making predictions relative to participants with low verbal WM span; in contrast, no WM differences were found in the associative comprehension sentences. These results are interpreted in terms of the causal nature underlying these types of inferences.

Is naming faces different from naming objects? Semantic interference in a face- and object-naming task

A current debate regarding face and object naming concerns whether they are equally vulnerable to semantic interference. Although some studies have shown similar patterns of interference, others have revealed different effects for faces and objects. In Experiment 1, we compared face naming to object naming when exemplars were presented in a semantically homogeneous context (grouped by their category) or in a semantically heterogeneous context (mixed) across four cycles. The data revealed significant slowing for both face and object naming in the homogeneous context. This semantic interference was explained as being due to lexical competition from the conceptual activation of category members. When focusing on the first cycle, a facilitation effect for objects but not for faces appeared. This result permits us to explain the previously observed discrepancies between face and object naming. Experiment 2 was identical to Experiment 1, with the exception that half of the stimuli were presented as face/object names for reading. Semantic interference was present for both face and object naming, suggesting that faces and objects behave similarly during naming. Interestingly, during reading, semantic interference was observed for face names but not for object names. This pattern is consistent with previous assumptions proposing the activation of a person identity during face name reading.