It appears that sets of bilateral stimulation (BLS) have the potential to invite unfinished traumatic experience into awareness. This can be a problem for clients who are dissociative, or who are on the verge of being overwhelmed by a traumatic memory. The memory can feel more real than the real situation the patient is in, and the experience can be one of nontherapeutic retraumatization. For clients who are potentially dissociative, the degree of orientation to the present situation can be assessed through the use of the back of the head scale (BHS). This procedure allows both therapist and client to be able to closely monitor and maintain the dual attention aspect of successful trauma processing; the simultaneous co-consciousness of the safe present and the traumatic past. The use of the BHS throughout a therapy session can be very useful in insuring that client is staying present while reprocessing disturbing memories.