In the context of dissociative identity disorder (DID), which was previously known as multiple personality disorder, the term "alter" refers to an alternate personality state that exists within the same individual. When an alter is in control of the body, it is often referred to as "switching" or experiencing an "alter switch."
During an alter switch, the host personality (the original or core identity) may experience amnesia or memory gaps for the time when an alter is in control. In other words, the host may not be aware of what the alters are doing during those periods of dissociation. This lack of awareness is a common feature of DID and is known as "dissociative amnesia."
While an alter is in control, they may have their own thoughts, feelings, behaviors, and perceptions, separate from the host and other alters. The degree of separation and amnesia can vary from person to person and from one alter to another within the same individual.
It is important to note that DID is a complex and controversial psychiatric condition, and not everyone in the mental health field agrees on its nature and origin. However, for those who experience it, dissociative amnesia and the phenomenon of losing time during alter switches are common aspects of their subjective experiences. Therapy and support are essential for those living with DID to cope with its challenges and enhance their overall well-being.