The Seven Sins of Memory

Schacter asserts that "memory's malfunctions can be divided into seven fundamental transgressions or 'sins'."[1] These are transience, absent-mindedness, blocking, misattribution, suggestibility, bias, and persistence. The first three are described as sins of omission, since the result is a failure to recall an idea, fact, or event. The other four sins (misattribution, suggestibility, bias, and persistence) are sins of commission, meaning that there is a form of memory present, but it is not of the desired fidelity or the desired fact, event, or ideas.

Transience
Transience refers to the general deterioration of a specific memory over time. Much more can be remembered of recent events than those further in one's past. This is especially true with episodic memory, because every time an episodic memory is recalled, it is re-encoded within the hippocampus, altering the memory each time one recalls it. Transience is caused because of interference. There are two types of interference: proactive interference (old information inhibits the ability to remember new information), and retroactive interference (new information inhibits the ability to remember old information).

Absent-mindedness
This form of memory breakdown involves problems at the point where attention and memory interface. Common errors of this type include misplacing keys or eyeglasses, or forgetting appointments, because at the time of encoding sufficient attention was not paid to what would later need to be recalled.

Blocking
Blocking is when the brain tries to retrieve or encode information, but another memory interferes with it. Blocking is a primary cause of Tip of the tongue phenomenon (a temporary inaccessibility of stored information).

Misattribution
Misattribution. It entails correct recollection of information with incorrect recollection of the source of that information. For example, a person who witnesses a murder after watching a television program may incorrectly blame the murder on someone he or she saw on the television program. This error has profound consequences in legal systems because of its unacknowledged prevalence and the confidence which is often placed in the person's ability to impart correctly information critical to suspect identification.

Suggestibility
Suggestibility is somewhat similar to misattribution, but with the inclusion of overt suggestion. It is the acceptance of a false suggestion made by others. Memories of the past are often influenced by the manner in which they are recalled, and when subtle emphasis is placed on certain aspects which might seem likely to a specific type of memory, those emphasized aspects are sometimes incorporated into the recollection, whether or not they occurred. For example, a person sees a crime being committed by a redheaded man. Subsequently, after reading in the newspaper that the crime was committed by a brown-haired man, the witness "remembers" a brown-haired man instead of a redheaded man.

Bias
The sin of bias is similar to the sin of suggestibility in that one's current feelings and worldview distort remembrance of past events. This can pertain to specific incidences and the general conception one has of a certain period in one's life. Memories encoded with a certain amount of stimulation and emotion are more easily recalled. Thus, a contented adult might look back with fondness on his or her childhood, induced to do so by positive memories from that time, which might not be representative of his/her average mood during his/her childhood.

Persistence
This failure of the memory system involves the unwanted recall of information that is disturbing. The remembrance can range from a blunder on the job to a truly traumatic experience, and the persistent recall can lead to formation of phobias, post-traumatic stress disorder, and even suicide in particularly disturbing or intrusive instances.