Aiming a wearable seems super hard. Even if it's adhered to the skin, people's skin can easily move enough to misalign aim by several centimeters right?
> And my current guess is, from the data points we do have (which will be covered in a later post) that whether you get an excitatory or inhibitory effect on neurons depends on the ultrasound protocol (frequency, intensity, duty cycle, etc) rather than the brain region.
Angle of stimulation could influence which group of neurons stimulated and which type of neurons are stimulated matters to effect excitation or inhibition. The distribution of excitatory/inhibitory neurons vary across cortical layers in any region. There is a good chance that neurons within layers could be responsive to different frequencies.
Brain regions, especially in prefrontal cortex, often rely on a mixture of excitatory and inhibitory effects downstream of it. These effects are likely to be highly context sensitive. So the notion of exciting or inhibiting a particular brain region is likely to be an ill-posed effect. In the language of causal inference, we would call it a violation of consistency assumption.
Timing matters! When you stimulate with respect to a preconditioning stimulus can result in either excitatory or inhibitory effects. The TMS literature uses protocols that involve paired pulse stimulation to induce either short-interval intracortical facilitation or long interval cortical inhibition to study such phenomenon.
I'm much more willing to bet that what we will need is patterned stimulation in context-specific ways across multiple brain regions to achieve most desired goals in the future. Neurostimulation/modulation of a particular brain region is better thought of as a mixture of somewhat uncontrolled effects. For current practical purposes, we don't care what it does as long as it disrupts some areas that are therapeutically useful to disrupt.
Aiming a wearable seems super hard. Even if it's adhered to the skin, people's skin can easily move enough to misalign aim by several centimeters right?
> And my current guess is, from the data points we do have (which will be covered in a later post) that whether you get an excitatory or inhibitory effect on neurons depends on the ultrasound protocol (frequency, intensity, duty cycle, etc) rather than the brain region.
Angle of stimulation could influence which group of neurons stimulated and which type of neurons are stimulated matters to effect excitation or inhibition. The distribution of excitatory/inhibitory neurons vary across cortical layers in any region. There is a good chance that neurons within layers could be responsive to different frequencies.
Brain regions, especially in prefrontal cortex, often rely on a mixture of excitatory and inhibitory effects downstream of it. These effects are likely to be highly context sensitive. So the notion of exciting or inhibiting a particular brain region is likely to be an ill-posed effect. In the language of causal inference, we would call it a violation of consistency assumption.
Timing matters! When you stimulate with respect to a preconditioning stimulus can result in either excitatory or inhibitory effects. The TMS literature uses protocols that involve paired pulse stimulation to induce either short-interval intracortical facilitation or long interval cortical inhibition to study such phenomenon.
I'm much more willing to bet that what we will need is patterned stimulation in context-specific ways across multiple brain regions to achieve most desired goals in the future. Neurostimulation/modulation of a particular brain region is better thought of as a mixture of somewhat uncontrolled effects. For current practical purposes, we don't care what it does as long as it disrupts some areas that are therapeutically useful to disrupt.