Layer 7 cortical interface · Grey Matter

The Layer 7 cortical interface is Precision Neuroscience's electrode film for the surface of the brain: a sheet thinner than a hair, carrying 1,024 small electrodes, slid onto the cortex through a narrow slit in the skull, and the first part of a next-generation brain-computer interface to receive regulatory clearance.

Layer 7 cortical interface. The Layer 7 cortical interface is Precision Neuroscience's electrode film for the surface of the brain: a sheet thinner than a hair, carrying 1,024 small electrodes, slid onto the cortex through a narrow slit in the skull, and the first part of a next-generation brain-computer interface to receive regulatory clearance.

It is a high-density version of electrocorticography. Clinical ECoG grids carry a few dozen contacts millimetres wide and a centimetre apart; Layer 7 places 1,024 electrodes of 50 to 380 µm in a flexible film that conforms to the folds of the cortex without penetrating it. The film is inserted through a slit under a millimetre wide in the skull and dura, which avoids a full craniotomy, and several films can be tiled to cover a larger area.

It has a cleared use today. The US clearance of April 2025 covers recording, monitoring and stimulating on the brain's surface for up to 30 days, which lets it be used in surgery to map the cortex before removing a tumour or an epileptic focus.

Its data come from surgery. The company has recorded with it in dozens of patients during operations they were having anyway, building decoding data before any permanent implant.

It reads populations at fine grain. Surface electrodes cannot isolate single neurons, but dense, small contacts capture high-frequency activity that tracks local firing, the signal that drives speech decoders built on ECoG.

Layer 7 bets that the surface is enough if it is read densely.

It leaves the cortex unpierced and gains back resolution with electrode count.

Questions: What makes consent delicate when a brain interface is tested during an operation the patient needs anyway? Much early human data for brain interfaces, including Precision's recordings in dozens of patients and Paradromics's first ten-minute implant, comes from people already undergoing brain surgery for a tumour or for epilepsy. The research adds time and a device to an operation they need for their own care, and it is agreed while they are facing that operation and depend on the same team for their treatment. Consent has to separate the two clearly, so that refusing the research changes nothing about the treatment, and has to say what will be done with recordings made of their brain. What does Precision Neuroscience's 30-day clearance allow, and why does it matter? The April 2025 clearance allows the Layer 7 film, 1,024 electrodes on a sheet thinner than a hair, to be placed on the brain's surface for recording, monitoring and stimulation for up to 30 days. That covers a real clinical market today, mapping the cortex during and around brain surgery, so the company can sell and improve the device before any permanent implant is approved. Each use also produces high-resolution human recordings, data that a future permanent interface will need.