The Cortical Organization of Syntactic Processing Is Supramodal: Evidence from American Sign Language

Areas within the left-lateralized neural network for language have been found to be sensitive to syntactic complexity in spoken and written language. Previous research has revealed that these areas are active for sign language as well, but whether these areas are specifically responsive to syntactic complexity in sign language independent of lexical processing has yet to be found. To investigate the question, we used fMRI to neuroimage deaf native signers' comprehension of 180 sign strings in American Sign Language (ASL) with a picture-probe recognition task. The ASL strings were all six signs in length but varied at three levels of syntactic complexity: sign lists, two-word sentences, and complex sentences. Syntactic complexity significantly affected comprehension and memory, both behaviorally and neurally, by facilitating accuracy and response time on the picture-probe recognition task and eliciting a left lateralized activation response pattern in anterior and posterior superior temporal sulcus (aSTS and pSTS). Minimal or absent syntactic structure reduced picture-probe recognition and elicited activation in bilateral pSTS and occipital-temporal cortex. These results provide evidence from a sign language, ASL, that the combinatorial processing of anterior STS and pSTS is supramodal in nature. The results further suggest that the neurolinguistic processing of ASL is characterized by overlapping and separable neural systems for syntactic and lexical processing.

Indeterminate and Enriched Propositions in Context Linger: Evidence From an Eye-Tracking False Memory Paradigm

A sentence such as We finished the paper is indeterminate with regards to what we finished doing with the paper. Indeterminate sentences constitute a test case for two major issues regarding language comprehension: (1) how we compose sentence meaning; and (2) what is retained in memory about what we read in context over time. In an eye-tracking experiment, participants read short stories that were unexpectedly followed by one of three recognition probes: (a) an indeterminate sentence (Lisa began the book), that is identical to the one in the story; (b) an enriched but false probe (Lisa began reading the book); and (c) a contextually unrelated probe (Lisa began writing the book). The probes were presented either at the offset of the original indeterminate sentence in context or following additional neutral discourse. We measured accuracy, probe recognition time, and reading times of the probe sentences. Results showed that, at the immediate time point, participants correctly accepted the identical probes with high accuracy and short recognition times, but that this effect reversed to chance-level accuracy and significantly longer recognition times at the delayed time point. We also found that participants falsely accept the enriched probe at both time points 50% of the time. There were no reading-time differences between identical and enriched probes, suggesting that enrichment might not be an early, mandatory process for indeterminate sentences. Overall, results suggest that while context produces an enriched proposition, an unenriched proposition true to the indeterminate sentence also lingers in memory.

The role of non-categorical relations in establishing focus alternative sets

ABSTRACTCategorisation is arguably the most important organising principle in semantic memory. However, elements that are not in a categorical relation can be dynamically grouped together when the context provides a common theme for these elements. In the field of sentence (and discourse) comprehension, alternatives to a focused element can be thought of as a set of elements determined by a theme given in the utterance context. According to Alternative Semantics (Rooth, 1985, 1992), the main function of linguistic focus is to introduce a set of alternatives to the focused element within an utterance. Here, we will investigate the contribution of the utterance context to the composition of focus alternative sets. Specifically, we test whether a focus alternative set can contain elements that belong to different taxonomic categories (i.e., that are not closely semantically related). Using a behavioural probe recognition experiment, we show that participants activate elements from another taxonomic category than the focused element as part of sentence comprehension. This finding suggests that the composition of a focus alternative set is not simply based on semantic relations between the members of the set and the focused element, but that contextual relations also play a crucial role.

The effect of stereotype activation on spontaneous inferences

We adopted the probe recognition paradigm to examine the effect of stereotype activation on spontaneous inferences among Chinese undergraduates (N = 48). First, behavioral sentences involving trait-implying behavior and corresponding situational information were simultaneously presented. We then selected stereotype labels of the actor's behavior that were consistent or inconsistent with the behavior, and which were activated either supraliminally or subliminally. The results showed that whether a stereotype was activated supraliminally or subliminally, the influence on spontaneous inferences was the same. Specifically, when the stereotype was inconsistent with the actor's behavior, spontaneous situational inferences were facilitated, and when the stereotype was consistent with the actor's behavior, spontaneous trait inferences were not facilitated. As Chinese people may be more prone to spontaneous (vs. trait) inferences, this indicates that human inferences are deeply influenced by culture.

Hierarchical structure and memory retrieval mechanisms in agreement attraction

Speakers occasionally cause the verb to agree with an element that is not the subject, a so-called ‘attractor’; likewise, comprehenders occasionally fail to notice agreement errors when the attractor agrees with the verb. Cross-linguistic studies converge in showing that attraction is modulated by the hierarchical position of the attractor in the sentence structure. We report two experiments exploring the link between structural position and memory representations in attraction. The method used is innovative in two respects: we used jabberwocky materials to control for semantic influences and focus on structural agreement processing, and we used a Speed-Accuracy Trade-off (SAT) design combined with a memory probe recognition task, as classically used in list memorization tasks. SAT allowed us to investigate the full time-course of processing and it enabled the joint measurement of retrieval speed and retrieval accuracy. Experiment 1 first established that attraction arises in jabberwocky sentences, to a similar extent and following the same structure-dependency as in natural sentences. Experiment 2 showed a close alignment between the attraction profiles found in Experiment 1 and memory parameters. Results support a content-addressable architecture of memory representations for sentences in which nouns’ accessibility depends on their syntactic position, while subjects are kept in the focus of attention.