This protocol requires 2 channel Lensware
The influence of the Vagus nerve on neurological as well as physiological function is a dynamic area of scientific and clinical research [Read more]. It is interesting to note that all LENS protocols are by default performed in relation to vagus nerve function. This is because there is a branch of the Vagus Nerve (as well as the Trigeminal and Auricular nerves) where the reference electrode is clipped to the earlobe. If there was no electrical activity at this connection point, the EEG would be sensing the electrical activity at whatever head site was being monitored. However, there is a great deal of activity at this site, and the EEG is actually sampling the difference1 between the electrical activity at the ear and the head site. There is no way around this, but given the relevance of vagus nerve function, this may be as much an asset as a liability. (A side note is the facile quality of studies of specific EEG biofeedback parameter correlations (amplitude/frequency to cognition) that use an ear clip reference2.) The apparent influence of the Vagus Nerve on conscious cognitive processes motivates exploration of integration of vagus nerve stimulation with neocortical neurofeedback.
Using 2 Channel Lensware, it is possible to provide neurofeedback to the Vagus Nerve in conjunction with the head sites. My experience of doing this on myself and clients is that it deepens the corrections3. There is good access to the Vagus Nerve at the point indicated in the diagram. This point offers a good >2″ separation between the sensor and reference, and seems to offer the best access to efferent and afferent vagus nerve signals. My sense is that working the Vagus Nerve while working a head site strengthens the reference for that head site. It is important that the reference is connected to the right earlobe.
A deficit of this protocol is that it trashes the session data. The second channel requires that a head site be selected, corrupting the data for that head site, in the same way BodyLENS does. I have been deleting the sessions to avoid corrupting the maps. (It would be a useful update to the software to add a checkbox to record / ignore the channel data)
1: The input into the EEG is known as a differential amplifier (Op Amp) [Read more]. This circuit multiplies the difference between two input voltages (site electrode and reference electrode). If at the instant a sample is measured the site electrode measured 10mV, and the reference measured 5mV, the output would be a multiple of 5mV. If the reference was 2mV, the output would be a multiple of 8mV.
2: As far as I know there is no “clean” electrical reference point on the body. The sample voltage recorded is the Beat Frequency between head site and reference. If the head site is 10Hz and the reference is 12Hz, the EEG will record a 2Hz head site signal. From a therapeutic perspective this seems to work just fine, but the interference obscurs analytical inquiry into the method of efficacy.
3: I think what I have experienced is the release of control of parasympathetic functions by the Sympathetic Nervous System. It feels like my breathing is completely fluid and uncontrolled, and somewhat weirdly as if I can feel myself breathing into my joints, especially my finger joints. The effect mostly diminished, but is still easy to access.