Why Do We Forget?
How Much Do We Forget?
Hermann Ebbinghaus (1885) was the first person to conduct scientific research on forgetting. He made up and memorized a list of thirteen nonsense syllables (e.g., zeq, xid, lek, vut, riy), which are meaningless combinations of letters that are unlikely to have been learned already. He found that just after an hour, he recalled just a few from the list. He then concluded that most forgetting takes place soon after we learn something. Although his research was unique and compelling, contemporary results show that forgetting, especially of meaningful information, is not too rapid and not as extensive as Ebbinghaus found. Today, memory researchers agree that forgetting may be either due to encoding or retrieval failure.
Forgetting Due to Encoding Failure
The process of memory retrieval is like searching a book from the library. Forgetting due to encoding failure means that the book you are searching for is not available in the library. In short, you did not successfully transfer and store the information in long-term memory. For example, your professor is discussing about the different types of information stored in long-term memory. Because you're thinking about what you're going to do in the upcoming activities of your school organization, you're distracted, encoding only a few tidbits of information your professor wrote in the blackboard, but even those were a blur. Surprisingly, your professor gave your class a pop quiz. No matter how hard you tried to remember the details, they escape you. That's because you failed to encode and store those information in long-term memory.
Sometimes, we encode just enough information to help us get by every day. For instance, how many US citizens studied US bills and coins in detail? Nickerson and Adams (1979) introduced 15 versions of the US penny to their research participants and asked them which of the pennies the true US penny is. Most failed in the task because they encoded just enough information to distinguish the penny from the other coins. For example, they only know that pennies are copper-colored, while dimes and nickels are silver-colored; and that pennies fall between the size of dimes and quarters.
Forgetting due to encoding failure is therefore not a case of "not remembering" or simply "forgetting"; it's a case of "not knowing" and "not storing" information to long-term memory.
Forgetting Due to Retrieval Failure
Following the library model for memory retrieval, forgetting due to retrieval failure means that you can't find the book even if it's there. This happens for four reasons - the book is sandwiched between a lot of other interesting books, both on the left and right sides (interference); the title of the book is the same with the other books (generic cues); the book is located in a section of the library you rarely visit (transience); you hid the book in some place in the library where you yourself can't find, or simply, that you hid the book from yourself (repression); or that the area in the library where the book is located is in very bad condition, or in an extreme mess (brain's condition).
Interference. According to the interference theory, the information we encoded along with the needed information gets in the way of learning, and consequently, remembering. Proactive interference means that earlier learned materials interfere with memory retrieval, while retroactive interference means that materials learned later interfere with memory retrieval. The interference theory explains well the serial position effect, in which we remember information located in the first (primacy effect) and last (recency effect) parts of a list better than the middle.
Generic Cues. Using similar cues for different information makes retrieval difficult and forgetting a lot easier. For example, in a multiple-choice test, an item asks which of the two positive movements in psychology (humanistic movement and positive psychology movement) is concerned about changing the negative trends in psychological research. If your cue for both options is the word "negative", it will be difficult for you to pick the right answer because one of the options, the humanistic movement, is also concerned about changing something negative, specifically the perspective of psychologists on the capacity of the human person.
Transience. According to Daniel Schacter's (2001) decay theory, transience is the disintegration of the neurochemical memory trace as time goes by. This happens when simultaneous activation of associated neurons is rarely followed.
Repression. Repression is a kind of motivated forgetting where anxiety-provoking information is pushed in some inaccessible part of the conscious mind. Repression is often blamed why post-traumatic stress disorder occurs in some people years after the traumatic event happened.
Brain's Condition. Amnesia, a kind of extensive forgetting, is mostly caused by some neurological problems. Brain surgery often results to anterograde amnesia, while electrical shock and/or physical blow to the brain often lead to retrograde amnesia. Retrograde amnesia is more common than anterograde amnesia. Patsy Cannon, an Alabama businesswoman, developed retrograde amnesia after a car crash in 1986. She virtually needed to relearn everything. She even can't recognize her own daughter. Cannon is now an advocate for individuals with brain injury. In less extreme situations, it is difficult to remember when you lack sleep or is intoxicated with alcohol.