Different experiential, psychophysiological, and neurobiological responses to traumatic symptom provocation in post-traumatic stress disorder (PTSD) have been reported in the literature. The term bottom-up processing is used in sensorimotor psychotherapy, a somatic approach to facilitate processing of unassimilated sensorimotor reactions to trauma. Lanius found this approach useful in dealing with dissociative symptoms and adapted it to be used in conjunction with bilateral stimulation (BLS), as part of a comprehensive treatment approach for individuals with complex post-traumatic stress disorder (C-PTSD) and dissociative symptoms. When we use the Standard eye movement desensitization and reprocessing (EMDR) Protocol, we work with sensorimotor, emotional, and cognitive aspects of information. Bottom-up processing is a way to work with issues of dissociation. Traumatic memories appear to be timeless, predominantly nonverbal, and imagery-based. Somatic memory is an essential element of traumatic memory; trauma memories, at least in part, are encoded at an implicit level.