Concurrently with EEG electrode implant research, less invasive ECoG chip research was being conducted.

University of Pittsburgh had a monkey feeding itself by robotic arm in 2008, using an EECoG implant.

VIDEO: 1 min. 4 sec. In this video, from the University of Pittsburgh in 2008, a monkey is feeding himself marshmallows using a robotic arm following commands from his mind.

This experiment was not using electrode implantation, but rather utilized a chip array placed not subdurally as would an ECoG (electrocorticograph) but epidurally, on the brain surface, as an EECoG (epidural electrocorticograph).

Previously, Washington University had utilized EECoG to treat epileptic patients in human trials in 2004, but since then moved to monkey trials.

The EcoG/EECoG technology was also utilized by Daniel Moran at Washington University in St. Louis, Missouri. In 2004, the Moran group utilized this technique to treat epileptic patients. However, since that time, their research has been conducted on monkeys, an example of which is shown above. The method relies on picking up activity not of single microneurons but of large groups of neurons.

In recent years, researchers have found ways to capture electrical signals from the brain without having to poke any thing into the brain tissue. Daniel Moran of Washington University in St. Louis is among the scientists tapping into these signals.

The approach is based on electrocorticography, or ECoG, a method used by doctors to detect electrical activity in the brain. Making an incision in the scalp and removing a portion of the skull are still required; surgeons then place the electrode grids directly on the surface of the dura mater, a thin leatherlike membrane covering the brain.

From this location, about two centimeters below the skull, the electrodes can’t record from single neurons. They can, however pick up the electrical activity of groups of neurons. These neural assemblies – thousands of neurons per group – have synchronized activity that produces what are called local field potentials, broadcasting what the brain is doing.

For more detail about the advantages and disadvantages of this BCI technique, see this link.

Returning to the EEG and electrode implantation research of Dr. Nicolelis, by 2011, sensory neurons were accessed in a monkey’s brain to utilize sensations as clues to select an appropriate object with a computer cursor.

To see a demonstration of the addition of sensory feedback to the brain, adding a feedback dimension to BCI technology, visit the next page.