Skip to main content
2025 Neural Interfaces Meeting Main banner
Unparalleled proactive care. Optimizing the SCS experience. Website: neuro.biotronik.com

(65) Ultra-High-Resolution ECoG Microelectrode Arrays Reveal Complex Spatiotemporal Dynamics

Thursday, June 12, 2025
5:50 PM - 6:30 PM ET
Location: Grand Foyer
Introduction: Brain-computer interfaces (BCI) hold potential to transform the lives of individuals with paralysis and chronic disease by directly translating brain signals into a desired outcome such as robotic limb movement or suppression of epileptic activity. In recent years, there has been a trend toward higher channel count neural interfaces for improved brain signal acquisition. These higher-resolution devices open a wide range of possibilities for the BCI world toward reliable solutions to mobility constraints, as well as for clinical use in diagnosis, neuromonitoring, and neuromodulation.

Methods: In this study, we develop and use parylene-C-based ultra-high-resolution electrocorticography (ECoG) devices with contact diameters down to 20 um, inter-contact spacing down to 31 um, channel counts from 1024 to 4224 channels, and high conformality to the brain surface. Using these customizable electrode arrays, we record stimulation-evoked potentials (SEPs) in the rat barrel cortex and the pig rostrum gyrus. The rat SEPs are evoked from stimulation of 8 whiskers individually via 1 Hz puffs of air and with 3 different angles of approach to the whisker. The pig SEPs are recorded during delivery of small puffs of air at 1 Hz in a randomized sequence to the contralateral snout region within a 16 mm^2 area. We perform further human recordings during simple arm and hand movements to investigate the feasibility of our devices for neuroprosthetic control.

Results: We find that as electrode resolution increases, there is yet more information to be gleaned from the surface of the brain. We resolve cortical columns and unique signal features in response to different directions of rat whisker stimulation, suggesting the presence of the macrocolumns corresponding to whisking direction that are visible from the brain surface using our high-resolution grids. Furthermore, we observe modulating dynamics in the pig rostrum gyrus with sub-mm cortical areas activating in unique patterns as the location of snout stimulation changes. These novel high-resolution ECoG grids uncover previously unseen dynamics that may only appear as a few pixels lighting up at lower resolution.

Conclusion: This study quantifies the benefits of using high channel count electrodes for understanding the complex spatiotemporal patterns of data. As electrode diameters and spacing get into the tens of micrometer range, we demonstrate that microscale somatotopic arrangement can be delineated from the brain surface with our ECoG grid technology. These high-resolution ECoG grids can aid in clearer and more accurate functional mapping and brain-computer interface applications in the future.