The four stages in meditation correspond to something that's happening in the brain anyway so this is the first stage dharana or focus again. There are different circuits in the brain which are different neural pathways which light up in fMRI imaging and meditator can reports yes at that time my mind wandered  and they see different parts of nearby parts of the brain lighting up. This is actually the fifth of the eight limbs of yoga yama and niyama one and two the moral practices asana number three sitting posture then prana yama that is breathing a control of the breath that is number four fifth is patthya.