THE SYNTACTIC POSITIVE SHIFT (SPS) AS AN ERP MEASURE OF SYNTACTIC PROCESSING

This paper presents event-related brain potential (ERP) data from an e xperiment on syntactic processing. Subjects read individual sentences containing one of three different kinds of violations of the syntactic constraints of Dutch. The ERP results provide evidence for an electro physiological response to syntactic processing that is qualitatively d ifferent from established ERP responses to semantic processing. We ref er to this electrophysiological manifestation of parsing as the Syntac tic Positive Shift (SPS). The SPS was observed in an experiment in whi ch no task demands, other than to read the input, were imposed on the subjects. The pattern of responses to the different kinds of syntactic violations suggests that the SPS indicates the impossibility for the parser to assign the preferred structure to an incoming string of word s irrespective of the specific syntactic nature of this preferred stru cture. The implications of these findings for further research on pars ing are discussed.