Gateway to Syntax: On the Neural Origins of the Left Anterior Negativity and Their Functional Implications

The neural origins of the Left Anterior Negativity (LAN) component of the Event-Related brain Potentials (ERP) have never been directly probed although this information is of the highest interest for a comprehensive view of the neural foundation of language. The LAN emerges specifically after morphosyntactic violations and is affected by both linguistic and extralinguistic, non-syntactic information. Here, we explored the neural sources of the LAN by analyzing data from three previously published ERP data sets obtained from canonical morphosyntactic violation conditions. The neuroelectric source analyses were based on LAN data from N = 76 participants and comprised two distributed source algorithms: sLORETA (standardized low-resolution brain electromagnetic tomography), and CLARA (classical LORETA analysis recursively applied), and a discrete dipole model (BESA, brain electrical source analysis). The results indicate that the most acceptable candidate as primary neural source of the LAN is the left frontal operculum (LFO), though the right FO might also be implicated. Considering its location, functions and connections, we speculate that the FO may be monitoring articulatory (morphological or morphophonological) predictions during language comprehension. The direct links between the FO and the anterior temporal pole might also account for nonlinguistic influences on the LAN.