Biomedical subjects

Ton Dijkstra

Publications and source records attributed to Ton Dijkstra.

6 recordsLinked to original sources

PubMed2005

Testing a model for bilingual semantic priming with interlingual homographs: RT and N400 effects.

Using a semantic priming paradigm, this study examines the effects of semantic and lexical-orthographic context on reaction times (RTs) and event-related potentials (ERPs) for interlingual homographs. Dutch-English bilinguals performed an English lexical decision task in which homographs like STEM (meaning "voice" in Dutch) were preceded by primes like ROOT or FOOL that were semantically related or unrelated to the English reading of the target word. Homographs were responded to faster following semantically related primes than following unrelated primes. The responses in both conditions were modulated by the relative frequencies of the two readings of the homographs: responses were faster when their English word frequency was high or when their Dutch word frequency was low. In the ERPs, N400 effects, taken to reflect processes of semantic integration, were found for homographs preceded by related primes. Remarkably, the amplitude of the N400 effect was also modulated by word frequency in both the first (Dutch, L1) and the second (English, L2) language. The observed relationship between lexical and semantic variables supports a model for bilingual semantic priming that extends the language nonselective BIA+ model for bilingual word recognition.

Adult↗

PubMed2005

Theta responses are involved in lexical-semantic retrieval during language processing.

Oscillatory neuronal dynamics, observed in the human electroencephalogram (EEG) during language processing, have been related to the dynamic formation of functionally coherent networks that serve the role of integrating the different sources of information needed for understanding the linguistic input. To further explore the functional role of oscillatory synchrony during language processing, we quantified event-related EEG power changes induced by the presentation of open-class (OC) words and closed-class (CC) words in a wide range of frequencies (from 1 to 30 Hz), while subjects read a short story. Word presentation induced three oscillatory components: a theta power increase (4-7 Hz), an alpha power decrease (10-12 Hz), and a beta power decrease (16-21 Hz). Whereas the alpha and beta responses showed mainly quantitative differences between the two word classes, the theta responses showed qualitative differences between OC words and CC words: A theta power increase was found over left temporal areas for OC words, but not for CC words. The left temporal theta increase may index the activation of a network involved in retrieving the lexical-semantic properties of the OC items.

Adult↗

PubMed2004

Recognizing cognates and interlingual homographs: effects of code similarity in language-specific and generalized lexical decision.

In four experiments, we investigated how cross-linguistic overlap in semantics, orthography, and phonology affects bilingual word recognition in different variants of the lexical decision task. Dutch-English bilinguals performed a language-specific or a generalized lexical decision task including words that are spelled and/or pronounced the same in English and in Dutch and that matched one-language control words from both languages. In Experiments 1 and 3, "false friends" with different meanings in the two languages (e.g., spot) were presented, whereas in Experiments 2 and 4 cognates with the same meanings across languages (e.g., film) were presented. The language-specific Experiments 1 and 2 replicated and qualified an earlier study (Dijkstra, Grainger, & Van Heuven, 1999). In the generalized Experiment 3, participants reacted equally quickly on Dutch-English homographs and Dutch control words, indicating that their response was based primarily on the fastest available orthographic code (i.e., Dutch). In Experiment 4, cognates were recognized faster than English and Dutch controls, suggesting coactivation of the cognates' semantics. The nonword results indicate that the bilingual rejection procedure can, to some extent, be language specific. All results are discussed within the BIA+ (bilingual interactive activation) model for bilingual word recognition.

Adolescent↗

PubMed2003

Recognition of interlingual homophones in bilingual auditory word recognition.

How do bilinguals recognize interlingual homophones? In a gating study, word identification and language membership decisions by Dutch-English bilinguals were delayed for interlingual homophones relative to monolingual controls. At the same time, participant judgments were sensitive to subphonemic cues. These findings suggest that auditory lexical access is language nonselective but is sensitive to language-specific characteristics of the input. In 2 cross-modal priming experiments, visual lexical decision times were shortest for monolingual controls preceded by their auditory equivalents. Response times to interlingual homophones accompanied by their corresponding auditory English or Dutch counterparts were also shorter than in unrelated conditions. However, they were longer than in the related monolingual control conditions, providing evidence for online competition of the 2 near-homophonic representations. Experiment 3 suggested that participants used sublexical cues to differentiate the 2 versions of a homophone after language nonselective access.

Adult↗

PubMed2002

Changes in PTSD patients' narratives during prolonged exposure therapy: a replication and extension.

Following E. B. Foa, C. Molnar, and L. Cashman (1995), narrative changes from the first to the last exposure session were compared for improved and nonimproved PTSD patients on fragmentation, organization, internal, and external events. Improved (n = 8) and nonimproved (n = 12) patients did not differ regarding changes in fragmentation or organized thoughts. However, improved patients showed a greater decrease in disorganized thoughts during treatment. Furthermore, all patients, independent of improvement, showed significant changes in the same direction; a decrease in disorganized thoughts and external events and an increase in internal events. Although previous results were partly replicated, it is concluded that narrative changes may be due to exposure treatment itself rather than to changes in memory representation.

Chronic Disease↗

PubMed2002

Foreign language knowledge can influence native language performance in exclusively native contexts.

In three experiments, we studied the influence of foreign language knowledge on native language performance in an exclusively native language context. Trilinguals with Dutch as their native and dominant language (L1), English as their second language (L2), and French as their third language (L3) performed a word association task (Experiment 1) or a lexical decision task (Experiments 2 and 3) in L1. The L1 stimulus words were cognates with their translations in English, cognates with their translations in French, or were noncognates. In Experiments 1 and 2 with trilinguals who were highly proficient in English and relatively low in proficiency in French, we observed shorter word association and lexical decision times to the L1 words that were cognates with English than to the noncognates. In these relatively low-proficiency French speakers, response times (RTs) for the L1 words that were cognates with French did not differ from those for the noncognates. In Experiment 3, we tested Dutch-English-French trilinguals with a higher level of fluency in French (i.e., equally fluent in English and in French). We now observed faster responses on the L1 words that were cognates with French than on the noncognates. Lexical decision times to the cognates with English were also shorter than those to then oncognates. The results indicate that words presented in the dominant language, to naive participants, activate information in the nontarget, and weaker, language in parallel, implying that the multilinguals' processing system is profoundly nonselective with respect to language. A minimal level of nontarget language fluency seems to be required, however, before any weaker language effects become noticeable in L1 processing.

Adolescent↗