Microcontroller-Based Low Latency Audio System to Study Cortical Auditory Evoked Potentials: Applications with Intraoperative Language Mapping

Language processing in the brain comprises complex neurophysiology involving multiple regions and multimodal functions like cognition, memory, speech, etc. Recent studies show language processing is not restricted within anatomically established cortical language regions, and there is considerable inter-person variability. Clinically intraoperative functional language mapping is critical for studying patient-specific language processing and identifying the eloquent cortex to retain language functionalities during resection surgeries. Cortical auditory evoked potential (CAEP) induced by different auditory stimuli can provide a profound understanding of language processing. In this study, we present a low-cost, low-latency microcontroller-based audio system to induce and analyze CAEP. The system is established using off the shelf components; a 32bit Teensy (3.2) microcontroller, Teensy (3) audio shield etc. which makes it easily replicable. The Teensy can generate digital trigger locked to auditory stimulus onset to interface the system with biosignal amplifiers to record and study neural data simultaneously. The presented hardware tools enable the analysis of neural signals aligned with the audio stimuli with sub-millisecond temporal precision. Implementation of the system can provide a flexible platform to observe and analyze real-time cortical CAEP in the clinical settings. The system also provides great customization opportunities to study not only CAEP but also complex language processing tasks.