Provided is an apparatus, system, and method for targeted memory enhancement. A computer processing circuit receives a plurality of electroencephalography (EEG) signals from a plurality of spatially separated EEG sensors located on the head of a subject that is asleep. A first process of the computer processing system determines a sleep state of the subject and upon determining that the subject is in sleep stage 2 or 3 based on a specific EEG signal, the processing system triggers a second process of the computer processing system that determines a transition event in the specific EEG signal, and upon detecting the transition event delivers an intervention to the subject designed to evoke a specific neurophysiological change to the subject.