Bipolar and Laplacian montages are suitable for high-gamma modulation language mapping with stereoelectroencephalography.

Objective: To determine the optimal montage and vocalization conditions for high-gamma language mapping using stereoelectroencephalography. Methods: We studied 12 epilepsy patients who underwent invasive monitoring with depth electrodes and measurement of auditory-naming related highgamma modulations. We determined the effects of electrode montage and vocalization conditions of the response on the high-gamma (60–140  Hz) amplitudes. Results: Compared to common average reference montage, bipolar and Laplacian montages effectively reduced the degree of auditory naming-related signal deflections in the white matter during the stimulus and response phases (mixed model estimate: −21.2 to −85.4%; p  <  0.001), while maintaining those at the cortical level (−4.4 to +7.8%; p  =  0.614 to 0.085). They also reduced signal deflections outside the brain parenchyma during the response phase (−90.6 to −91.2%; p  <  0.001). Covert responses reduced signal deflections outside the brain parenchyma during the response phase (−17.0%; p  =  0.010). Conclusion: On depth electrode recording, bipolar and Laplacian montages are suitable for measuring auditory naming-related high-gamma modulations in gray matter. The covert response may highlight the gray matter activity. Significance: This study helps establish the practical guidelines for high-gamma language mapping using stereoelectroencephalography. [ABSTRACT FROM AUTHOR]