Reacción a "Electrodes capable of evoking vision and adapting in real time are implanted in the brains of two blind people"

This paper addresses an important issue in the field of visual prosthesis development. While increasing electrode counts make it possible to convey more visual details directly to the brain using electrical stimulation, it comes at the cost of having to do a much more elaborate calibration procedure to figure out the ideal stimulation parameters for each of these electrodes. The conventional way of asking the patient about their experience while optimizing each electrode is then indcredibly tedious and not very user-friendly. Here, an alternative approach is presented that uses neural recordings rather than patient reports to fine-tune the stimulation based on ongoing brain activity. This new approach opens the door for fully automated mass-calibration of the stimulation parameters for all electrodes. 

The paper presents unique and valuable data from blind volunteers that are implanted with electrodes in their visual cortex, allowing the researchers to both stimulate and record, while getting detailed feedback about the perceptual experience evoked by stimulation. Of course there are limitations in how such an experiment can be run. In experimental animals one would be able to do a similar thing but explore the parameter space in a much more systematic way. However, such animals wouldn't be able to describe their perception, making the the interpretation of data much more challenging. 

While automated calibration of stimulation thresholds sounds great, one thing the paper doesn't really discuss is the perceptual experience of such process. In the current experiments the volunteering patients seem really engaged with the researchers to perform well in these experiments. In a non-experimental setting, calibration of the electrodes inevitably involves many repetitions of stimulation with differnet parameters and a substantial subset of these will evoke phosphene percepts. It should be carefully considered how such a system would be incorporated and communicated to patients. If done correctly it would be an important step towards more functional, user-friendly visual prostheses.