In SSEP, which electrode is closest to the post-central gyrus?

In Somatosensory Evoked Potentials (SSEP), the electrode placed nearest to the post-central gyrus is typically the one that is involved in phase reversal, which is most commonly located over the somatosensory cortex. This region corresponds to the processing area for sensory information and is crucial for the interpretation of SSEP signals.

When phase reversal occurs, it indicates a change in the polarity of the recorded potential at that specific site, highlighting that the electrode is positioned directly over the area where sensory information is being processed. Therefore, confirming the electrode's positioning in relation to the post-central gyrus.

The other locations mentioned may relate to other electrodes used in the SSEP setup but do not directly correlate to the area that is closest to the post-central gyrus when considering functional mapping and potential reversal effects. The vertex, multiple locations relative to the central sulcus, or proximal to the nasal region would not provide the same specificity in relation to evoked potentials and sensory processing as the phase-reversing electrode.