One category depends upon external triggers in order to experience the localized sensation and its associated feelings, which typically originates in the head, often reaching down the neck and sometimes the upper back. The other category can intentionally augment the sensation and feelings through attentional control, without dependence upon external stimuli, or 'triggers', in a manner compared by some subjects to their experience of meditation.
Allen verified in a 2016 interview that she purposely selected these terms because they were more objective, comfortable, and clinical than alternative terms for the sensation. Allen explained she selected the word meridian to replace the word orgasm due to its meaning of point or period of greatest prosperity.[clarification needed]