Neurobiology of Language -
"Right now, Sophie *swims in the pool?!" Temporal information is processed different from semantic and morpho-syntactic relations
Given its contribution to the meaning of a sentence (temporal interpretation) and its marked morphosyntactic form (morphological marking on the verb), the question arises: how is grammatical aspect processed as reflected in event-related brain potentials (ERPs). Do ERPs of aspect processing resemble those typically associated with semantic processing (the N400 component) and/or morpho-syntactic processing (the P600)? Or is this interface phenomenon characterized by a distinct pattern entirely?
In an experiment conducted by Monique Flecken and colleagues, English native speakers read sentences on a computer screen while their EEG was recorded. First, they read questions providing a temporal context that was progressive (What is Sophie doing in the pool, right now?) or habitual (What does Sophie do in the pool every Monday?). Following a lead-in sentence context, such as Right now, Sophie... we measured ERPs time-locked to verb phrases in four different conditions: e.g. a) is swimming (control); (b) *is cooking (semantic violation); c) *are swimming (morpho-syntactic violation); or d) ?swims (aspect mismatch); ... in the pool.
ERPs show typical N400 and P600 effects for semantics and morpho-syntax, while aspect processing elicited an Early Negativity (a negative going waveform, peaking between 250-350ms after onset of the verb phrase), thus representing a different pattern. In a second experiment, participants overtly judged the grammaticality of aspect mismatch sentences and overall accepted these instances as grammatically correct. These findings suggest that, overtly, disagreement of temporal context and verbal aspect is largely considered acceptable. In the brain, however, these mismatches are detected rapidly, resulting in the Early Negativity, but they do not require any further repair or processing costs.
Flecken, M., Walbert, K., & Dijkstra, T. (2015). ‘Right Now, Sophie ∗Swims in the Pool?!’: Brain Potentials of Grammatical Aspect Processing. Frontiers in Psychology, 6: 1764. doi:10.3389/fpsyg.2015.01764.