Dr. Richard Davidson

So we are using this, I'm sure you know something about it, but actually there are very few groups in the world currently using this.

It's called transcranial electric stimulation with temporal interference, TESTI.

And the basic idea of this is that if you have two electrodes that are stimulating at a very high carrier frequency, say 15 kilohertz, which is essentially from all we know the brain is not responsive to a 15 kilohertz signal,

So that's the carrier frequency and the way it works is we're stimulating one electrode at 15,000 kilohertz and another electrode at 15,001 kilohertz.

So there's just a one hertz offset and the geometry of the targeting is such that we can target deep brain structures where the delta frequency is maximal.

We are targeting structures that are specifically structures where we know slow waves are generated and are therefore an important ingredient in deep sleep.

And the other cool thing about this stimulation is you cannot feel it, it has no subjective sensations.

So it's very different than TMS which is, you know, you feel it big time.

You don't feel a thing.

So we are delivering this during sleep.

People don't know when they're getting stimulated.

They of course know they're being stimulated because they're giving informed consent, but it doesn't wake them up.

We've definitively demonstrated that it increases the density of slow-wave activity during deep sleep.

This is a, yeah, it's a big complicated protocol.

Yeah, and that's exactly what we're doing in this study now.

We're using a, this is a little technical, but we're using a micro-randomized design.

So in a single participant on some nights they get pre-sleep meditation, just before sleep, just a five-minute practice.

And in other nights they do not receive that.

And we are looking at the impact of that on slow-wave sleep and also looking at the synergistic effects of pre-sleep meditation with the TESTI stimulation to increase slow-wave activity.

And we're getting experience sampling measures during the next day to see if the pre-sleep meditation has a demonstrable impact on their mood the next day and how that interacts with our boosting of slow-wave activity.