Intracortical microstimulation: Evoking artificial perception and engaging plasticity-based modulation

ICMS can also be used in the visual cortex. Stimulation of the primary visual cortex can produce phosphenes - perceived spots or lines of light - and carefully coordinated stimulation across multiple electrodes can create recognizable shapes and letters. Experiments in blind participants have demonstrated simple two-dimensional visual patterns and object-localization tasks.

These results suggest that ICMS is moving beyond producing a single artificial sensation toward constructing structured sensory information. However, the researchers note that current visual prosthesis studies remain limited to relatively simple shapes, letters and localization tasks. Predicting phosphene responses, determining effective electrode combinations and maintaining stable stimulation over long periods remain major challenges.

However, the authors emphasize that these applications remain largely experimental. Reliable biomarkers, reproducible stimulation parameters, implantation safety and durable therapeutic benefits all require further validation before clinical translation.

Flexible electrodes can reduce some of these problems, but they cannot completely overcome the biological barrier between implanted devices and living neural tissue.

BNIs take a further step by incorporating living biological components, such as neural stem cells, neural progenitor cells and other neural cells, into neural interfaces. These approaches aim to improve tissue integration and may enable living neural tissue to participate in signal transmission. More advanced designs can also guide axon growth, creating connections between biological tissue and electronic devices. The potential of BNIs may extend beyond improving electrode performance to repairing damaged neural circuits.

The researchers therefore call for coordinated advances in electrode design, stimulation encoding, closed-loop calibration and safety evaluation. Future studies should include longer follow-up, cross-species validation, standardized safety assessments and reproducible behavioral and neural-network outcomes.

Rather than replacing existing neuromodulation technologies, ICMS may ultimately become a complementary tool that offers much finer control over local neural populations. Its long-term potential could lie in bringing together several capabilities: delivering artificial sensory information, allowing the brain to learn new information channels, reshaping dysfunctional circuits and integrating electronic devices more naturally with living neural tissue.

As the review authors conclude, translating ICMS from experimental microstimulation into durable BCI systems will require progress not in a single technology, but across interface reliability, stimulation encoding, closed-loop control, safety and biohybrid integration.

Authors of the paper include Pengfei Hu, Chong Chen, Yunliang Zang, Xiaohong Li, and Dong Ming.

This work was supported by the National Key Research and Development Program of China (2023YFF1204200), the Major Program of the National Natural Science Foundation of China (T2596044), and the National Natural Science Foundation of China (82571593).

Source:

Beijing Institute of Technology

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