Janet Nicol

Syntactically based sentence processing classes: Evidence from event-related brain potentials

Theoretical considerations and diverse empirical data from clinical, psycholinguistic, and developmental studies suggest that language comprehension processes are decomposable into separate subsystems, including distinct systems for semantic and grammatical processing. Here we report that event-related potentials (ERPs) to syntactically well-formed but semantically anomalous sentences produced a pattern of brain activity that is distinct in timing and distribution from the patterns elicited by syntactically deviant sentences, and further, that different types of syntactic deviance produced distinct ERP patterns. Forty right-handed young adults read sentences presented at 2 words/sec while ERPs were recorded from over several positions between and within the hemispheres. Half of the sentences were semantically and grammatically acceptable and were controls for the remainder, which contained sentence medial words that violated (1) semantic expectations, (2) phrase structure rules, or (3) WH-movement constraints on Specificity and (4) Subjacency. As in prior research, the semantic anomalies produced a negative potential, N400, that was bilaterally distributed and was largest over posterior regions. The phrase structure violations enhanced the N125 response over anterior regions of the left hemisphere, and elicited a negative response (300-500 msec) over temporal and parietal regions of the left hemisphere. Violations of Specificity constraints produced a slow negative potential, evident by 125 msec, that was also largest over anterior regions of the left hemisphere. Violations of Subjacency constraints elicited a broadly and symmetrically distributed positivity that onset around 200 msec. The distinct timing and distribution of these effects provide biological support for theories that distinguish between these types of grammatical rules and constraints and more generally for the proposal that semantic and grammatical processes are distinct subsystems within the language faculty.

On the Distinctiveness, Independence, and Time Course of the Brain Responses to Syntactic and Semantic Anomalies.

We evaluated the distinctiveness, independence, and relative time courses of the event-related brain potentials (ERPs) elicited by syntactically and semantically anomalous words. ERPs were recorded from 13 scalp electrodes while subjects read sentences, some of which contained a selectional restriction violation (semantically anomalous), a verb tense violation (syntactically anomalous), or a doubly anomalous word that violated both selectional restriction and verb tense constraints. Semantic anomalies elicited a monophasic increase in N400 amplitude, whereas syntactic anomalies elicited a late positive shift with an onset around 500 msec and a duration of several hundred msec. Doubly anomalous words elicited both an increase in N400 amplitude and a late positive wave, and these effects summated in an approximately (but not perfectly) linear manner. These results are discussed with respect to the hypotheses that syntactic and semantic processes are separable and independent.

Using cross-modal lexical decision tasks to investigate sentence processing

Recent investigations of sentence processing have used the cross-modal lexical decision task to show that the antecedent of a phonologically empty noun phrase (specifically, WH-trace) is reactivated at the trace position. G. McKoon, R. Ratcliff, and G. Ward (1994) claimed that (a) a design feature concerning the choice of related and unrelated targets is a possible confound in this work and (b) the conclusions drawn from this previous research are therefore called into question. These claims are considered in light of both McKoon et al.s experimental findings and results of our own experiments in which we test their linguistic materials. We argue that their results may be due to the nature of their materials. Additionally, we argue that a follow-up experiment reported by G. McKoon and R. Ratcliff (1994) used a technique that is not comparable to the cross-modal lexical decision task. It is concluded that current evidence supports the claim that structural information is using during on-line sentence processing and that the cross-modal technique is sensitive to this.

Semantic Category Effects in Second Language Word Learning.

The present study addresses a long-standing assumption in the field of applied linguistics: that presenting new second language (L2) vocabulary in semantically grouped sets is an effective method of teaching. Participants learned 32 new L2 labels for concepts from four different semantic categories in either a related or unrelated condition. At test, participants translated words in both translation directions. We found a semantic interference effect both during the encoding of information into memory and during the retrieval of information in translation. We discuss these findings in terms of theoretical models of L2 lexical representation and development, as well as in more practical terms of L2 curriculum design and vocabulary instruction.

Clausal intonation after unilateral brain damage.

Thirteen right-handed adult speakers, including five patients with unilateral left-hemisphere damage, four patients with unilateral right-hemisphere damage, and four patients with non-neurological damage, read aloud sentences designed to test influences of clause and utterance length on two acoustical measures of intonation, fundamental voice frequency (F o) and timing. Patients with unilateral damage to the left-hemisphere exhibited more abnormality in F o and speech timing than did patients with right-hemisphere damage.

Children's knowledge of binding and coreference: evidence from spontaneous speech

In experiments requiring sentence comprehension, young children sometimes appear to accept coreference in sentences such as Thelma touched her. This has motivated the claim that 4- and 5-year-olds lack knowledge of the principles of binding and coreference. Another option, however, is that the requisite principles are present from the very start and childrens poor performance is due to performance factors. We test this claim through a longitudinal analysis of the spontaneous speech of three children, analyzing their usage of the pronoun me and the reflexive myself. Even 2- and 3-year-olds virtually always use these forms in accord with the adult grammar-they will say John hit me and not John hit myself (obeying Principle A) and I hit myself and not I hit me (obeying Principle B). We argue that the best explanation for these results is that children understand the principles of binding and coreference at the earliest stages of language development.*

The Relation Between Gender and Number Agreement Processing

We report an experiment in which we test the relationship between gender and number in subject-predicate agreement. We also test the link between two different number-agreement relations—subject-verb and subject-predicative adjective. Participants saw first an unmarked adjective and then a sentence fragment consisting of a complex subject with a head noun and a modifier containing a second noun and were asked to make a whole sentence using the adjective with the proper gender and number markings. The gender of the subject head and the gender and number of the attractor noun were manipulated. Number errors in the verb and number and gender errors in the predicative adjective were measured. The results suggest gender agreement is computed independently of number agreement. In contrast, subject-verb number agreement and subject-predicative adjective number agreement are a unitary process. The implications for psycholinguistic and linguistic theories of gender and number are discussed.

Learning the Phonological Forms of New Words: Effects of Orthographic and Auditory Input.

We investigated the relationship between the phonological and orthographic representations of new words for adult learners. Three groups of native English speakers learned a set of auditorily-presented pseudowords along with pictures indicating their “meanings”. They were later tested on their memory of the words via an auditory word—picture matching test. While all three groups of participants heard the same auditory stimuli and saw the same pictures, the groups differed with respect to the written stimuli that accompanied each item during training. Some participants were presented with written forms for the auditory labels that were consistent with English spelling conventions (e.g., spelled form , auditory form [k m d]), while others saw written forms that were not consistent with English spelling conventions (e.g., spelled form , auditory form [k m d]), and a third group of participants was presented with no written forms. Participants who saw written forms that were not consistent with English spelling conventions showed interference from the words’ spelled forms at test. This finding provides evidence for a relationship between orthographic and phonological representations for newly-learned words.

Processing syntactically ambiguous sentences - Evidence from semantic priming

In this paper, we report the results of a study which investigates the processing of syntactically ambiguous sentences. We examined the processing of sentences in which an embedded clause is interpretable as either a complement clause or as a relative clause, as in, for example,“The receptionist informed the doctor that the journalist had phoned about the events.” The embedded clause in such sentences is typically analyzed as a complement to the verbinformed, rather than as a relative clause modifyingthe doctor. A number of models parsing predict this is the only analysis ever considered, while others predict that both interpretations are computed in parallel. Using a cross-model semantic priming technique, we probed for activation ofdoctor just after the embedded verb. Since only the relative clause analysis contains a connection betweenthe doctor and the embedded verb, we expected reactivation ofdoctor at that point only if the relative clause analysis were a viable option. Our results suggest that this is the case: Compared to priming in an ambiguous control sentence, a significant reactivation effect was obtained. These results are argued to support a model of parsing in which attachment of a clause may be delayed.

Deeper than shallow: Evidence for structure-based parsing biases in second-language sentence processing

This study examines the reading patterns of native speakers (NSs) and high-level (Chinese) nonnative speakers (NNSs) on three English sentence types involving temporarily ambiguous structural configurations. The reading patterns on each sentence type indicate that both NSs and NNSs were biased toward specific structural interpretations. These results are interpreted as evidence that both first-language and second-language (L2) sentence comprehension is guided (at least in part) by structure-based parsing strategies and, thus as counterevidence to the claim that NNSs are largely limited to rudimentary (or “shallow”) syntactic computation during online L2 sentence processing.