Viorica Marian

Competing activation in bilingual language processing: Within- and between-language competition

Two eye-tracking experiments examined spoken language processing in Russian-English bilinguals. The proportion of looks to objects whose names were phonologically similar to the name of a target object in either the same language (within-language competition), the other language (between-language competition), or both languages at the same time (simultaneous competition) was compared to the proportion of looks in a control condition in which no objects overlapped phonologically with the target. Results support previous findings of parallel activation of lexical items within and between languages, but suggest that the magnitude of the between-language competition effect may vary across first and second languages and may be mediated by a number of factors such as stimuli, language background, and language mode.

Cross Talk Between Native and Second Languages: Partial Activation of an Irrelevant Lexicon

Bilingualism provides a unique opportunity for exploring hypotheses about how the human brain encodes language. For example, the “input switch” theory states that bilinguals can deactivate one language module while using the other. A new measure of spoken language comprehension, headband-mounted eyetracking, allows a firm test of this theory. When given spoken instructions to pick up an object, in a monolingual session, late bilinguals looked briefly at a distractor object whose name in the irrelevant language was initially phonetically similar to the spoken word more often than they looked at a control distractor object. This result indicates some overlap between the two languages in bilinguals, and provides support for parallel, interactive accounts of spoken word recognition in general.

Shared and separate systems in bilingual language processing: Converging evidence from eyetracking and brain imaging

The neurological and cognitive aspects of bilingual language processing were examined in late Russian-English bilinguals using headband-mounted eyetracking and functional neuroimaging. A series of three eyetracking studies suggested that, at early stages of word recognition, bilinguals can activate both languages in parallel, even when direct linguistic input is in one language only. A functional neuroimaging study suggested that, although the same general structures are active for both languages, differences within these general structures are present across languages and across levels of processing. For example, different centers of activation were associated with first versus second language processing within the left Inferior Frontal Gyrus, but not within the Superior Temporal Gyrus. We suggest that parallel activation (as found with eyetracking) and shared cortical structures (as found with fMRI) may be characteristic of early stages of language processing (such as phonetic processing), but the two languages may be using separate structures at later stages of processing (such as lexical processing).

Language-dependent recall of autobiographical memories.

Two studies of autobiographical memory explored the hypothesis that memories become more accessible when the linguistic environment at retrieval matches the linguistic environment at encoding. In Experiment 1, Russian-English bilinguals were asked to recall specific life experiences in response to word prompts. The results supported the hypothesis of language-dependent recall: Participants retrieved more experiences from the Russian-speaking period of their lives when interviewed in Russian and more experiences from the English-speaking period of their lives when interviewed in English. In Experiment 2, the language of the interview was varied independently from the language of the word prompts. Both variables were found to influence autobiographical recall. These findings show that language at the time of retrieval, like other forms of context, plays a significant role in determining what will be remembered.

Bilingual and monolingual processing of competing lexical items

Performance of bilingual Russian–English speakers and monolingual English speakers during auditory processing of competing lexical items was examined using eye tracking. Results revealed that both bilinguals and monolinguals experienced competition from English lexical items overlapping phonetically with an English target item (e.g., spear and speaker). However, only bilingual speakers experienced competition from Russian competitor items overlapping crosslinguistically with an English target (e.g., spear and spichki, Russian for matches). English monolinguals treated the Russian competitors as they did any other filler items. This difference in performance between bilinguals and monolinguals tested with exactly the same sets of stimuli suggests that eye movements to a crosslinguistic competitor are due to activation of the other language and to between-language competition rather than being an artifact of stimulus selection or experimental design. With the majority of the world’s population speaking more than one language (Romaine, 1995), studying bilingualism and multilingualism can provide valuable insights into human cognition and language. The capability of one cognitive system to successfully manage two languages is striking. Do bilinguals use the two languages independently, alternating between them by turning them on and off, or do they constantly keep both languages active and process the two in parallel at all times? The traditional language switch hypothesis, according to which bilinguals are able to selectively activate and deactivate their two languages (Gerard & Scarborough, 1989; MacNamara & Kushnir, 1971), has been challenged by a number of recent findings. Parallel activation has been inferred from early studies using the bilingual Stroop task (Chen & Ho, 1986; Preston & Lambert, 1969), code switching (Grainger, 1993; Grainger & Dijkstra, 1992; Li, 1996; Soares & Grosjean, 1984), interlingual homographs (Dijkstra, Timmermans, & Schriefers, 1997; Dijkstra, van Jaarsveld, & ten Brinke, 1998), cog

The bilingual advantage in novel word learning.

The present study examined whether bilingualism facilitates acquisition of novel words in adults with different language histories. Word-learning performance was tested in monolingual English speakers, early English—Spanish bilinguals, and early English—Mandarin bilinguals. Novel words were phonologically unfamiliar to all participants, and they were acquired in association with their English translations. At testing, both bilingual groups outperformed the monolingual group. These findings indicate that bilingualism facilitates word-learning performance in adults, and they suggest a general bilingual advantage for novel word learning.

Subcortical encoding of sound is enhanced in bilinguals and relates to executive function advantages

Bilingualism profoundly affects the brain, yielding functional and structural changes in cortical regions dedicated to language processing and executive function [Crinion J, et al. (2006) Science 312:1537–1540; Kim KHS, et al. (1997) Nature 388:171–174]. Comparatively, musical training, another type of sensory enrichment, translates to expertise in cognitive processing and refined biological processing of sound in both cortical and subcortical structures. Therefore, we asked whether bilingualism can also promote experience-dependent plasticity in subcortical auditory processing. We found that adolescent bilinguals, listening to the speech syllable [da], encoded the stimulus more robustly than age-matched monolinguals. Specifically, bilinguals showed enhanced encoding of the fundamental frequency, a feature known to underlie pitch perception and grouping of auditory objects. This enhancement was associated with executive function advantages. Thus, through experience-related tuning of attention, the bilingual auditory system becomes highly efficient in automatically processing sound. This study provides biological evidence for system-wide neural plasticity in auditory experts that facilitates a tight coupling of sensory and cognitive functions.

Bilingualism influences inhibitory control in auditory comprehension

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among four pictures while their eye-movements were tracked. Each target picture (e.g., hamper) appeared together with a similar-sounding within-language competitor picture (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming probe trials indexed residual activation of target words, and residual inhibition of competitor words. Eye-tracking showed similar within-language competition across groups; priming showed stronger competitor inhibition in monolinguals than in bilinguals, suggesting differences in how inhibitory control was used to resolve within-language competition. Notably, correlation analyses revealed that inhibition performance on a nonlinguistic Stroop task was related to linguistic competition resolution in bilinguals but not in monolinguals. Together, monolingual-bilingual comparisons suggest that cognitive control mechanisms can be shaped by linguistic experience.

Constraints on parallel activation in bilingual spoken language processing: Examining proficiency and lexical status using eye-tracking

During spoken word-recognition, bilinguals have been shown to access their two languages simultaneously. The present study examined effects of language proficiency and lexical status on parallel language activation. Language proficiency was manipulated by testing German-native and English-native bilingual speakers of German and English. Lexical status was manipulated by presenting target words that either overlapped in form across translation equivalents (cognate words) or did not overlap in form across translation equivalents (English-specific words). Participants identified targets (such as hen) from picture-displays that also included similar-sounding German competitor words (such as Hemd, “shirt”). Eye-movements to German competitors were used to index co-activation of German. Results showed that both bilingual groups co-activated German while processing cognate targets; however, only German-native bilinguals co-activated German while processing English-specific targets. These findings indicate that high language proficiency and cognate status boost parallel language activation in bilinguals.

CLEARPOND: Cross-Linguistic Easy-Access Resource for Phonological and Orthographic Neighborhood Densities

Past research has demonstrated cross-linguistic, cross-modal, and task-dependent differences in neighborhood density effects, indicating a need to control for neighborhood variables when developing and interpreting research on language processing. The goals of the present paper are two-fold: (1) to introduce CLEARPOND (Cross-Linguistic Easy-Access Resource for Phonological and Orthographic Neighborhood Densities), a centralized database of phonological and orthographic neighborhood information, both within and between languages, for five commonly-studied languages: Dutch, English, French, German, and Spanish; and (2) to show how CLEARPOND can be used to compare general properties of phonological and orthographic neighborhoods across languages. CLEARPOND allows researchers to input a word or list of words and obtain phonological and orthographic neighbors, neighborhood densities, mean neighborhood frequencies, word lengths by number of phonemes and graphemes, and spoken-word frequencies. Neighbors can be defined by substitution, deletion, and/or addition, and the database can be queried separately along each metric or summed across all three. Neighborhood values can be obtained both within and across languages, and outputs can optionally be restricted to neighbors of higher frequency. To enable researchers to more quickly and easily develop stimuli, CLEARPOND can also be searched by features, generating lists of words that meet precise criteria, such as a specific range of neighborhood sizes, lexical frequencies, and/or word lengths. CLEARPOND is freely-available to researchers and the public as a searchable, online database and for download at http://clearpond.northwestern.edu.