Memory deficits can take many forms and have different causes. One memory deficit is known as dissociative amnesia. This issue is characterized by an inability (or arguably, unwillingness) to recall autobiographical experiences that are stressful or traumatic in nature. This deficit goes beyond ordinary memory loss and can cause distress in normal areas of functioning. To be considered dissociative amnesia, the memory deficit must not be able to be explained by other memory or cognitive disorders or the result of a brain injury/lesion. Dissociative amnesia is often described as a symptom of PTSD and is most common in trauma or violence victims or forensic patients who have committed violent crimes. There is much controversy surrounding this memory deficit because is it mostly evident by self-reporting and is often seen as a “way out” or voluntary memory suppression. There are three forms of dissociative amnesia. Localized refers to memory loss surround a specific event of life-time period. Selective refers to an ability to retrieve some aspects of an event but not the entire circumstance. These two forms can co-occur. Generalized is the rarest form and refers to the loss of a patient’s entire autobiographical memory and sometimes their identity (Mangiulli et al., 2021).
Because there is no injury or physiological event that leads to or causes dissociative amnesia, the brain mechanisms that cause the deficit have long been debated. However, the most commonly agreed upon neurological explanation is increased activity of the bilateral dorsolateral pFC. Also attributed to this deficit is decrease hippocampus activity and suppression caused by pathways from the right inferior frontal gyrus and the right middle frontal gyrus. These explanations are consistent with the presumption that dissociative amnesia is a reversable memory deficit marked by inability (or unwillingness) to retrieve due to unconscious (or voluntary) memory repression (Kikuchi et al., 2010).
Class, why do you think dissociative amnesia is so controversial? Is there a way for a clinician or investigator to determine whether an individual is truly experiencing this memory deficit? Why is this so common among those who have committed violent crimes?