Investigating the neurophysiological correlates of syntactic processing in a visual masked priming paradigm

Language comprehension proceeds rapidly on a millisecond timescale. To achieve such efficiency, our brain must perform specific linguistic computations highly automatically. While automaticity of syntactic processes has been extensively tested in the auditory modality, the generalizability of automaticity to other modalities is still an open issue. In the present EEG study, we examined the neurophysiological correlates of syntactic processing within minimal two-word structures in German using a masked priming paradigm in reading. We found a late positivity (P600) elicited by ungrammatical structures containing a word category violation that was independent of masking, under both masked and unmasked conditions. Our findings suggest that the late error detection mechanism associated with the P600 is robust, while earlier detection processes might be affected by physical input parameters. Overall, the presence of the P600 regardless of masking indicates that the human brain reacts to syntactic errors even unconsciously, suggesting high automaticity of syntactic processes.