[nabla9]

I think the author means single channel and not single electrode. At least the picture suggests that there are three electrodes (one to the skull two white ear clips for ground/reference). For bipolar electrodes you need three: channel, ground and reference. For unipolar electrodes, just two.

You can remove artifacts like eye and muscle movements with prepossessing, not as well as with electrodes, but still.

I'm more worried about electrode connections and electrode quality in these amateur EEG applications. You also want high quality active electrodes if you take EEG outside laboratory. I'm also skeptical about these dry skin electrodes (no alcohol scrubbing and conductive paste). NeuroSky devices are surprisingly cheap. I would be very interested to know how well they work in practice.

[nonbel]

Thanks. It said one electrode and after glancing at the picture I thought the ear clips were headphones for some reason.