The Study of Human Memory and its Disorders.

                   The case study of H.M., Miller, 1966                      

At the age of 9, Mr.Molaison banged his head hard after being hit by a bicycle rider in his neighborhood near Hartford. This boy then developed severe seizures, but at the time, scientists had no way of looking inside his brain. They could not tell if the blow from the accident had anything to do with the seizures, or had they have any high understanding of how complex functions like memory or learning functioned biologically. After eighteen years, his condition got severe as he was blacking out frequently, had devastating convulsions and could no longer earn a living. He arrived at the office of Doctor Scoville, who after exhausting other treatments, decided to surgically remove two finger-shaped slivers of tissue from Mr. Molaison’s brain. These two slivers are now known to be a portion of temporal lobes- the hippocampus, an area deep in the brain, about level with the ears. The seizures disappeared, but the procedure left the patient radically changed. His short term memory worked without much of a notable change, however it became obvious that he could no longer transfer new information into long term memory. He could recall events from earlier in life, as he had long term memory from before the operation, but he could not make new memory. This incident, however, has become one of the great milestones in the history of modern neuroscience. In order to study his memory, doctors gave him tests and tasks.. Every time Molaison performed a task, it struck him as an entirely new experience. He had no memory of doing it before, however with practice he became proficient.

The implications of these studies were enormous. Although his condition was tragic, it helped us now know that that the temporal lobe is important for forming and storing memory, as well as that the hippocampus, which they removed, plays a key role in forming new memories Scientists could now determine that there were at least two systems in the brain for creating new memories, which was a big step from the old theory, that both short-term and long-term memory were wired together in the brain. One of these systems is known as declarative memory, and we now know that it records names, faces and new experiences and stores them until they are consciously retrieved. This system depends on the function of medial temporal areas, particularly in the hippocampus, which is what Molaison lacked. The other system, commonly known as motor learning, is subconscious and depends on different brain systems. “This explains why people can jump on a bike after years away from one and take the thing for a ride, or why they can pick up a guitar that they have not played in years and still remember how to strum it.” 

Soon after information from this study was revealed, scientists wanted an amnesic study and researches began to map out other dimensions of memory. Since they saw that Molaison’s short-term memory was fine, and he could hold on to it for about 20 seconds, they inferred that it was holding on to them without a hippocampus was impossible. This came opened a way to study the explicit and implicit systems of the brain, and provided a basis for all research that came after.

Studies on Limitations of Memory

In the 1930's,  Frederic Bartlett, a British psychologist from Cambridge University, performed several studies which helped pinpoint a theory of how we use past information to help us process new information. The idea of this theory is that new encounters with the world are rarely new to us. Rather, the way we process information or the way we act in specific settings, is determined by relevant previous knowledge stored in our memory and organized in the form of schemas. The schema theory therefore explains the influence of stored knowledge on our behavior, current information, and the way we process it. Schema theory both helps, but also hinders our accurate recall of memory. If you take into account, when you are told a story, you listen for the most important facts and conflicts presented. You use schema to remember it, insisting that it follows the patter of stories that you learned about before. The next time you tell the story, you use the details you remembered, as well as schemas to fill in the missing blanks. The study done by Bartlett in 1932, was a similar one to my example. In his study, he had his participants read The war of Ghosts, a Native American folk tale. This test showed how schema can be useful, although it helps lower the accuracy of our memory. Schemas are used for simple information- processing, and function to help us understand (although we might interpret our own meaning.)

In a French & Richards experiment of 1993, the effect of schema was studied on memory retrieval. In this study the participants were shown a simple picture of a clock. In one group, were told to draw the clock, after examining it, based on their memory. The clock on the picture had, instead of the conventional roman numeral IV, the representation of IIII. They found out that majority of participants that had to draw the clock from memory drew instead of the original IIII on the picture, the conventional IV of roman numerals. French and Richard explained this result in terms of schema knowledge of roman numerals to effect the participant's memory retrieval.

Another experiment, conducted by Loftus and Palmer in 1974, showed the bias of schema theory. They showed a group of students a video of a car accident. Each had a varied verb (smashed, bumped, collided, contracted), when asked the question: How fast were the cars going when they hit each other? These different verbs painted a different picture in our brain, and when weeks later, the participants were asked if they seen any broken glass, the ones that had a stronger verb (such as smashed or hit), showed a greater percentage of answering yes to the question. Our schema, is as well, affected by the memories we have, and when we are given the impression that cars are going fast and they have a accident, we think - there must have been broken glass! - that is what we have stored in our schema under car crashes with uncontrollable speed of cars. Because our schema is a knowledge stored, based upon stereotypical and logical facts that our brain automatically tries to fit pieces of puzzles together to make sense of what is happening. In eyewitness testimonies, or our own memories, schema also plays little tricks on us. When something happens and we are forced to remember it later, we fill the gaps with the most logical answers - things that we seen happen in situations like these before. In the case of Ronald Cotton, this could have been one of the reasons why he got blamed for a crime he did not do, and why the witness' faulty memory was taken into account as hard core evidence.

In conclusion, schemas can be both beneficial and misleading. It is like a human instinct that helps us use our knowledge in an order that it would make the most sense, yet it is easy to hold influenced over us. Schema is beneficial for understanding and organizing our ideas better. It helps us to get the main picture more quickly and clearly, but it can be easily affected by our past experience and false knowledge. This could lead to misjudgements and it may mess us up on details of our memory, as shown in the experiment of French & Richards. Either way, depending on many different factors that influence our schemas, schema itself has ups and downs, positive and negative effects but is a basic part of our lives and memories, and without it we would have a hard time to make sense of the action around us.

False Memory

Have you ever wondered if your memory can change? People have, for many years, thought that memory is set in stone, and nothing can influence it. Over the last 40 years, however, scientists and psychologists have changed their point of view. As people noticed that memory can be malleable, we started to question the reliability of eyewitnesses in court.This leads to questions about the validity of criminal convictions that are based largely on the testimony of victims or witnesses.An important psychologist that links with this topic is Elisabeth Loftus, a leading expert in eyewitness testimony. The idea that eyewitnesses do not usually testify what they witnesses but, rather, remake their memories on the basis of relevant schematic information, was the basis of much of the pioneering work on eyewitness testimony by Loftus and her colleagues. In 1984 a man name Ronald Cotton got accused of rape, and sentenced to jail. In the end, this was the case that broke the national headlines, and pointed out that memory can be manipulable.

Composite Sketch

The Ronald Cotton case became known and set as an example of false memory. The night when Jennifer Thompson was raped, she swore to herself that she would bring her rapist behind bars. She studied his face, trying her best to capture most detail to help the police find the criminal. However, even after all her efforts to make sure the right guy was sentenced, someone made a mistake. She created a composite sketch, which brought up various suspects. These suspects were showed to Jennifer in a photo line-up, followed later by a physical line up.

When the culprit is not there in a line up, and the witness thinks that he might be there, the mind finds the "best fit." In both lineups, Jennifer hesitated, but picked Ronald Cotton.  This acted for her as a reinforcement, and her mind made the switch of the real rapist's face and Cotton's face permanent. When you are a witness, and you are not sure about your decision right away, if you cannot say "Yes, that is him!" in the first 10 seconds, there is a big chance that it is not him. This is because you take time to take old information and new information, to form a brand new memory.

The pictures of the accused, and the real rapist.

The way lineup is done is wrong. Suspects should be shown one at a time so the witness does not compare the suspects, but the picture in their mind of the criminal to each suspects. This is a better way to do line ups, because this way we can try to prevent your mind from choosing "the best fit." Ronald Cotton was not the rapist Jennifer saw, but because he was the closest thing to the image in her mind, her mind framed him. Cotton knew he was innocent, and he had suspicions that Bobby Poole was the real rapist. He had another trial in which Jennifer Thompson was presented with the accused (Cotton), and the actual rapist (Poole). She was looking at the actual rapist, but in her mind, the real criminal was Ronald Cotton. Jennifer exclaimed that Poole was "not him", and she was angry at the fact that people would doubt that she knew who her real rapist was. Jennifer Thompson did not feel anything when standing in front of Bobby Poole, because in her mind, Ronald Cotton was sealed as the real criminal. In the end, DNA tests revealed that the real rapist was, after all, Poole. 

From this we can see how easily even the littlest details can alter our memory. Eye witness testimony has two characteristics, it is unreliable, and most convincing for the jury. As a person, you cannot overcome what your brain wants to do, and that is in this case, to find the suspect. Memory is altered, every time new information is added. Any comment or reinforcement, can seal an idea, and form in into a memory. Eye witness testimonies should still continue to be used, or else criminals would be too confident that people would not be protected, but because of its low accuracy, it should not be used as solid evidence in trials which sentence people to jail.