Presentations

Abstract

Differences in native and nonnative sentence processing may surface most clearly around parameters that are not shared between L1 and L2. We investigated whether differences between Spanish-Basque bilinguals exist in processing related to the particular constraints of the ergative-absolutive case system of Basque, which is not present in Spanish, but not in processing related to number agreement which occurs in both languages. In an event-related FMRI experiment, we tested this hypothesis by examining the cortical networks recruited for reading in Spanish-Basque bilinguals. Highly proficient nonnative and native speakers of Basque read sentences containing violations of ergative case assignment or violations of number agreement as well as correct sentences (e.g., “Gizonak lehiatilan jaso ditu sarrerek/sarrera/sarrerak goizean”, respectively, approximate translation: “The man at the box office has received the tickets-erg/ticket/tickets in the morning”) while performing an acceptability judgment task. Preliminary results (6 nonnative and 16 native speakers) showed that ergative case violations and number violations similarly elicited activation increases compared to correct sentences in the right inferior parietal lobule and the precuneus while number violations elicited additional activation increases in middle and inferior frontal cortex, consistent with reports for morphosyntactic agreement errors. Compared to native speakers, nonnative speakers engaged the medial prefrontal cortex more strongly while processing ergative case violations and number violations, suggesting that they engaged additional cognitive resources to arrive at the same behavioral outcome. These latter effects, however, did not seem to differ between the ergative case and number violations. Thus, our preliminary results support the hypothesis that while morphosyntactic processing is quantitatively different in the two groups, native and nonnative speakers do not show qualitatively different responses when processing morphosyntactic features that are specific of the L2.

Abstract

In general, language comprehension is surprisingly reliable. Listeners very rapidly extract meaning from the unfolding speech signal, on a word-by-word basis, and usually successfully. Research on ‘semantic illusions’ however suggests that under certain conditions, people fail to notice that the linguistic input simply doesn’t make sense. In the current event-related brain potentials (ERP) study we examined whether listeners would spontaneously detect an anomaly in which a human character central to the story at hand (e.g. “a tourist”) was suddenly replaced by an inanimate object (e.g. “a suitcase”). Because this replacement introduced a very powerful coherence break, we expected listeners to immediately notice the anomaly and generate the standard ERP effect associated with incoherent language, the N400 effect. However, instead of the standard N400 effect, anomalous words elicited a differential ERP effect from about 500-700 ms onwards. The absence of an N400 effect indicates that subjects did not immediately notice the anomaly, and that for a few hundred milliseconds the comprehension system has converged on an apparently coherent but factually incorrect interpretation. The presence of the later ERP effect indicates that subjects were processing for comprehension and did ultimately detect the anomaly. Therefore, we take our results to reflect a temporary semantic illusion. Our results also show that even attentive listeners sometimes fail to notice a radical change in the nature of a story character, and therefore demonstrate a case of short-lived ‘change deafness’ in language comprehension.

Abstract

n two ERP-experiments we examined whether discourse context could overrule a local semantic violation. In both experiments, subjects listened to stories in which a person was engaged in conversation with an inanimate object. In experiment 1, story-initial animacy violations reflected in an N400 effect were completely neutralized further down the story. In experiment 2, canonical but story-irrelevant inanimate predicates assigned to the inanimate object elicited an N400 effect, compared to contextually appropriate animate predicates.