and psychology, yet the precise specification of the relation remains a point of controversy. Specialized memory Studies have shown there is a memory advantage for information encoded with reference to the self. Somatic markers, that is memories connected to an emotional charge, can be helpful or dysfunctional - there is a correlation but not causation, and therefore cannot be relied on. Patients with Alzheimer's who have difficulty recognizing their own family have not shown evidence of self-knowledge. The division of memory Self-theories have traditionally failed to distinguish between different source that inform self-knowledge, these are episodic memory and semantic memory. Both episodic and semantic memory are facets of declarative memory, which contains memory of facts. Declarative memory is the explicit counterpart to procedural memory, which is implicit in that it applies to skills we have learnt; they are not facts that can be stated. Episodic memory Episodic memory is the autobiographical memory that individuals possess which contains events, emotions, and knowledge associated with a given context. Semantic memory Semantic memory does not refer to concept-based knowledge stored about a specific experience like episodic memory. Instead it includes the memory of meanings, understandings, general knowledge about the world, and factual information etc. This makes semantic knowledge independent of context and personal information. Semantic memory enables an individual to know information, including information about their selves, without having to consciously recall the experiences that taught them such knowledge. Semantic self as the source People are able to maintain a sense of self that is supported by semantic knowledge of personal facts in the absence of direct access to the memories that describe the episodes on which the knowledge is based. Individuals have been shown to maintain a sense of self despite catastrophic impairments in episodic recollection. For example, subject W.J., who suffered dense retrograde amnesia leaving her unable to recall any events that occurred prior to the development of amnesia. However, her memory for general facts about her life during the period of amnesia remained intact. This suggests that a separate type of knowledge contributes to the self-concept, as W.J.'s knowledge could not have come from her episodic memory. A similar dissociation occurred in K.C. who suffered a total loss of episodic memory, but still knew a variety of facts about himself. Evidence also exists that shows how patients with severe amnesia can have accurate and detailed semantic knowledge of what they