Platinum microwire for subdural electrocorticography over human neocortex: millimeter-scale spatiotemporal dynamics

Area of Science:

• Neuroscience
• Biomedical Engineering
• Electrophysiology

Background:

• Platinum microwire grids offer high-resolution recording of cortical surface potentials.
• FDA-approved grids with 75 μm wires and 1 mm spacing are suitable for exploring spatiotemporal dynamics.

Purpose of the Study:

• To characterize the recording properties of platinum microwire grids.
• To analyze signal correlation and spread in human cortex.
• To investigate the scale of information processing in speech-related cortical areas.

Main Methods:

• Electrochemical impedance spectroscopy for electrode characterization.
• Electrical modeling of micro-electrodes.
• Analysis of human subdural electrocorticography data.
• Modeling the effect of cerebrospinal fluid on signal spread.

Main Results:

• Developed a frequency-dependent electrical model for micro-electrodes.
• Established relationships between signal correlation and electrode separation distance.
• Identified spatial variations in speech decoding performance across cortical areas.
• Demonstrated millimeter-scale dynamics in human subdural electrocorticography.

Conclusions:

• Millimeter-scale dynamics are significant in human subdural electrocorticography.
• These findings are vital for optimizing neural prosthetic applications.
• High-density microwire grids provide insights into cortical information processing scales.