Research in the CNL Lab is focused on understanding the neurocognition of real-time language comprehension and adult language learning.  Short synopses of some of our work appear below.

Much of our work involves recording event-related brain potentials (ERPs). ERPs reflect the summed, simultaneously occurring postsynaptic activity in cortical pyramidal neurons.  For a brief primer on ERPs, click here.

Form and meaning

The human brain responds differently to anomalies involving sentence form (syntax) and sentence meaning (semantics).  Semantic anomalies elicit an N400 effect in the ERP, and our lab was the first to show that syntactic errors  elicit a large positive wave  (the P600 effect). Our past work has shown that this result generalizes across anomaly type, subjects' task, and languages. Here, we show that this result also generalizes to situations in which the anomalies are embedded in naturalistic prose.

 

Second-language word learning

Although second-language (L2) learning is often claimed to be slow and difficult, little is known about the rate of second-language word learning.  We report here that adult learners' brain activity discriminated between L2 words and non-words after just 14 hours of classroom L2 instruction.  This occurred even though the learners were at chance when consciously deciding if the stimuli were words or not.  Apparently, some aspects of second-language learning occur with amazing speed.  We have extended this research to studies investigating second-language.  In subsequent work, we have investigated the acquisition of L2 morphosyntax (click here). 

Meaning can "drive" sentence comprehension

Given that separate syntactic and semantic processes exist, one question is how we coordinate syntactic and semantic knowledge when processing a sentence.  The standard theory holds that syntax alone determines how words are initially combined to form phrases and clauses:  Syntactic structure is computed first, and sentence meaning is derived second.  Kim & Osterhout (2005) tested this theory by presenting anomalous sentences such as "The mysterious crime had been solving ...".  The syntactic cues in the sentence require that the noun crime be the Agent of the verb solving. If syntax drives sentence processing, then the verb solving would be perceived to be semantically anomalous, as crime is a poor Agent for the verb solve, and therefore should elicit an N400 effect. However, although crime is a poor Agent, it is an excellent Patient  (as in solved the crime).  The Patient role can be accommodated simply by changing the inflectional morpheme at the end of the verb ("The mysterious crime had been solved . . .").  Therefore, if meaning drives sentence processing, then the verb solving would be perceived to be in the wrong syntactic form, and should therefore elicit a P600 effect. We report that verbs like solving elicited a P600 effect, showing that a strong semantic attraction between a predicate and an argument can determine how words are combined, even when the semantic attraction contradicts unambiguous syntactic cues.