by Robert Novella

The New England Journal of Skepticism Vol. 1 Issue 3 (Summer '98)
 

     Human memory routinely performs amazing events with effortless ease. Experiences decades old can be vividly recalled with the subtlest of triggers.  But our brains are not like a computer hard drive inside our heads where details are laid down and recalled with absolute fidelity. Memory is a creative process like visual perception. Memories are malleable, they can be changed, fused, created, altered, and lost. They are susceptible to other people’s suggestions and leading questions. Memory researcher Daniel Schacter writes: “memories for individual events resemble jigsaw puzzles that are assembled from many pieces,” it is normal for people to “knit together the relevant fragments and feelings into a coherent narrative or story.”  (Schacter, 1996)

          Psychologists divide memory into two sections, explicit and implicit (also known respectively as declarative and procedural memory). Implicit memories exist without our awareness. They are skill based; what we remember without thinking, like riding a bike or playing the piano. Explicit memory is divided into short term and long term. Short term or working memory is the RAM (random access memory) of our minds. Unless reinforced, it typically retains bits of information for fifteen or twenty seconds and is limited to seven (plus or minus two) at one time. If a new object is added to short term memory than one of the current objects drops out and is forgotten. Long term memory is composed of semantic elements and episodic elements. Semantic memory is knowledge of the world and abstract information like words, definitions, procedures, historical dates etc. Episodic memory includes personal experiences and life’s events like our childhood and what happened at work yesterday.  These one-time memories are much more fragile than over-learned ones like semantic or implicit memories. Therefore it is these memories that are most unreliable and capricious.

         Gradually we have moved from a video camera conception of memory to a reconstructionist view. Memory does not passively record facts and file them away; rather the process is a creative amalgamation of fact and fantasy. It is an interpretive construction that cannot be absolutely verified without external corroborating evidence.  Memory moves from short term to long term storage in a process called consolidation. If consolidation does not take place then the experience will be forgotten when it leaves short term memory. But even if memories reach long term storage with little distortion there is no guarantee that it will remain that way. Memories naturally decay over time. The more time that has passed since an experience has been recalled the more likely that distortion or forgetting has occurred. This might be a major cause of childhood amnesia; children rarely remember anything before the age of three probably because they cannot rehearse or discuss memories which causes them to decay and disappear. Even with frequent recall and retelling,  however, there are no guarantees.  As we recall a memory we focus on some aspects and ignore others; over time this can change the memory because the disregarded aspects are weakened or lost. Gradual repetition and rehearsal of slightly different versions of the memory alter it without our awareness, creating distorted memories. No recall is like the previous recall.  Experimental psychologist Frederic Bartlett first made this point in his landmark 1932 text, Remembering: A Study in Experimental and Social Psychology. “Some widely held views have to be completely discarded,” he wrote, “and none more completely than that which treats recall as the re-excitement in some way of fixed and changeless ‘traces.’” To the contrary, he believed that remembering is “an imaginative reconstruction, or construction, built out of the relation of our attitude toward a whole active mass of organized past reactions or experience.” (Bartlett, 1932)

        Memories are often contaminated or distorted  by information acquired after an event. This so called post-event-information can come from suggestions or facts that are unconsciously integrated into the original memories. Once this is done the memories form a cohesive story that is impossible to separate into its true and false components. Dr. Elizabeth Loftus describes in her book The Myth of Repressed Memory experiments in which subjects were exposed to a film of a bank robbery followed by a television account of the event that contained erroneous details. Many of the subjects incorporated the incorrect details into their memory of the robbery and steadfastly refused to believe that they could be wrong. Loftus has performed hundreds of similar experiments with thousands of people and claims that post event information has been clearly shown to have an influence on memories (Loftus, 1996). As a practical application of this information, police officers should never show a single suspect’s photo to the victim of a crime. If this individual is then picked out of a line up, it would be difficult to determine if the victim is remembering the assailant or the person in the photograph.

        Emotions can have an effect in creating and recalling memories. Emotions felt as we recall an event can reshape memories, imbuing them with our current emotional state even though the original memory had no trace of the emotion. This is the opposite of attempting to lift your mood by remembering pleasant past experiences. Intense emotional reactions to memories do not necessarily mean that they are accurate, it just means that there is a greater likelihood that we will perceive them to be true. (Ofshe, Watters, 1994)
It is generally assumed that memories created with intense emotion like a personal tragedy or national tragedy like the Challenger shuttle explosion are exceptionally infallible. The vividness of these “Flashbulb” memories increases our subjective confidence in the accuracy of these memories. They are not necessarily more accurate than other memories, however, for these too have been shown to contain incongruities (Neisser & Harsch, 1992; McCloskey, Wible & Cohen, 1988). The day after the Challenger shuttle explosion, psychologist Ulric Neisser asked his students to fill out a questionnaire about the incident, like where they were when they heard the news, who told them etc. Three years later he asked them the same questions again and at least 25% of them were wrong about every major detail. Only 10% matched their responses to the ones from three years earlier. Furthermore, confidence in the memories had no correlation with their accuracy. Students who had inaccurate recall were just as likely to be confident in their memories as students whose memories were unchanged.

         Not only can memories be distorted and changed but completely fabricated into what are called false memories. The following is a recognition memory test  Think of and try to memorize the following words: butter - food - eat - sandwich - rye - jam - milk - flour - jelly - douggh - crust - slice - wine - loaf -  toast. When asked if “bread” was in the list many people erroneously believe it was. This is a false memory caused by ‘source memory confusion’ and has been shown to occur in 40 to 60% of test subjects (Roediger, McDermott 1995). The effect can be striking. People on whom I have performed similar tests report vivid memories of the false word, some could even see the word in the list. One person so vividly remembered it that she said  it was in the first row third from the top. This probably occurs because memory relies on meaning. Experimental psychologist Frederic Bartlett saw memory as a tool that people use to construct meaning (Bartlett, 1932). All details are not recorded but the gist remains. Because of this we incorrectly believe that “bread” was in the list due to its relation to the other words. Generally this mechanism serves us very well but sometimes it can lead to false memories.

         People often unwittingly aid us in constructing false memories. Mere questions and suggestions about a memory can significantly influence it, changing it in ways of which we are unaware. Memory researcher Elizabeth Loftus performed experiments in which she showed students slides of staged car accidents. One showed a car making a right turn at a stop sign and bumping into a pedestrian. Weeks after viewing the slides students were asked about the accident making a passing reference not about a stop sign but a yield sign that did not exist. Another questionnaire was then filled out revealing a strong bias for remembering the nonexistent yield sign. This occurred in 70% of subjects even though 87% had originally correctly identified the stop sign just after viewing the slides. (Loftus, Miller, Burns, 1978)  Another experiment showed a tape of cars hitting each other. Those who were asked the speed of the cars when they “hit” each other produced lower estimates than those that were asked the speed when they “crashed” into each other. In this case, simply changing the word “hit” with “crashed” appeared to have an impact on recall. These experiments clearly show that suggestions and even leading questions can create false memories that are just as compelling and believable as true memories but just as false as the erroneous information that produced them.

Common Memory Errors

        Subjective Validation is a psychological phenomenon in which people tend to remember significant or coincidental events and forget others. This is especially true of one sided events like temporally unspecified predictions. If they come true you remember, if they don’t you don’t. Subjective Validation skews our memories of the past preventing us from putting events into perspective. For example, if during the course of a reading a psychic makes thirty predictions and three come true it is not unusual to focus on and remember the three correct predictions and forget incorrect ones. Upon looking back on the reading our distorted memory leads us to believe that the psychic’s hit rate was much more impressive than it really was. By acknowledging the selective nature of memory we can put our memories in a better context and forestall the creation of erroneous belief systems based on subjective validation.

        Confabulation is the filling in of gaps in memory to make a coherent story. Fact and fantasy become inextricably intermingled. This is a natural and unconscious process that occurs because our brain wants stories that flow and make sense.  The end result can be a memory with a few confabulated elements or it can be entirely fabricated with nothing in common with the original event.
 
 
Repressed Memories

        Repressed memories have torn families apart and irrevocably damaged the lives of uncounted people throughout America. That is quite a feat for a phenomenon that probably does not exist. Repressed Memories are said to be memories, generally of abuse, that resurface after years in hiding when properly triggered. People all over the country are suddenly confronting their parents with lawsuits due to recovered memories that reveal years of sexual or ritualized satanic abuse. The enitre theory of repression, however, is based on a misconception that has no experimental backing.

    The concept presupposes that memories are indelibly and unerringly stored in the warehouse of our minds where they can then be retrieved in pristine condition. The main purpose of this article has been to dispute that anachronistic yet pervasive claim. A further presupposition is that terrible memories are commonly hidden from conscious access unless triggered by the appropriate cues. In many cases it is therapists who provide the cues through hypnotic regression, sodium amytal (truth serum) and visualizations. All of these methods produce a highly suggestive state, fertile ground for the creation of false memories. (called false memory syndrome)

        It might seem reasonable that terrible memories can be concealed from us for decades but modern memory researchers disagree. Children exposed to traumatic events rarely bury these memories, rather they exhibit unmistakable symptoms such as intrusive memories, fear of reoccurrence, and lack of interest in ordinary activities. (Loftus, 1996) The American Psychological Association echoed these views stating: “The reality is that most people who are victims of childhood sexual abuse remember all or part of what happened to them.”  (Office of Communication, August, 10, 1995).

        Memories are not the infallible recordings of past experiences but reconstructions of the past that are filtered, interpreted and expounded upon. Few specifics are actually recorded; details are added based on what had to be so. Most of the time they serve us extremely well but they are far more malleable than we would like to believe. Not only do they decay over time but false memories can be constructed, suggestions and leading questions can alter them unbeknownst to us. More often than not, memory does not create stories but stories create memories.
 

References:

1) Roediger, H.L. & McDermott, K.B. (1995). Creating false memories: Remembering words that were not presented in lists. Journal of Experimental Psychology: Learning, Memory and Cognition, 21, 803-814.
2) Schacter, Daniel L. Searching for Memory. New York, NY: Basic Books (A Division of HarperCollins Publishers), 1996.
3) Richard Ofshe, Ethan Watters: Making Monsters: False Memory, Psychotherapy and Sexual Hysteria, 1994, p. 109.
4) Loftus, E., Ketcham K.,The Myth of Repressed Memory: False Memories and Allegations of Sexual Abuse. New York, NY: St. Martins Press, 1996, p. 62
5) Loftus, E. F., Miller, D.G., & Burns H.J. (1978)  Semantic integration of verbal information into a visual memory.  Journal of Experimental Psychology: Human Learning, 4, 19-31.
6) Bartlett  F.,  Remembering: A Study in Experimental and Social Psychology. Cambridge Univ Press, 1995 (Originally published in 1932)
7) Neisser, U., & Harsch, N. (1992). Phantom flashbulbs: False recollections of hearing the news about Challenger. In E. Winograd & U. Neisser (Eds.), Affect andaccuracy in recall: Studies of "flashbulb memories" New York: Cambridge University Press.