2008-01-09
Zimbardo video on memory.
Psychologists think that there are more than type of memory, known as the stereoposition effect. If I am going to profit from what I learn today, I am going to have to remember it, the smells and textures and some neurons help you translate this information into codes that the brain can get and retrieve when it needs it. If I am to survive I have to remember what things are dangerous and what things are edibile. Images, ideas, language, and even physical actions have to be represented in memory and retrieved when needed. To many psychologists and neuroscientists, memory is the royal pathway to studying the pathway of the mind and the structures of the brain. Experts estimate that the average brain can store 100 trillion bits of information, and yet we are capable of seemingly forgetting simple things. When our memory system fails us, we can forget or become uncertain of what we have learned, known or even seen with our own eyes for a wide variety of reasons.
Research on forgetting makes us aware that memory is a complex, dynamic psychological process. Your memory can be affected by how much you concentrate and rehearse. And it can also be effected by the context in which you learn something. And the context in which you recall it. And it can be affected by your motivation, you can be motivated to forget or remember, which can be blended in with your wishes, fears and fantasies. The state of your memory can be traced to your physical state and biological condition. And also: to interference from other events and experiences. Modern research into memory began a little over 100 years ago.
The German Psychologist, Erban Hebbinghouse, studied the memorization of syllables, and he hoped to attain a pure, quantified measurement of memory, uncontaminated by other learning. He learned a list of syllables, and tried to retain the list in memory by learning other lists, and he tested himself how many times he had to reread the list until he learned it perfectly. It was a logarthmic scale. Ebbinghouse's memories showed a rapid loss, then gradual decline. Why did Ebbinghouse's memories fade so quickly, even with so much training? He had handicapped himself by trying to get rid of the influence of meaning: no hooks to already stored information, no context to help him organize the unfamiliar with the familiar, in turn of getting rid of meaning, he stripped himself of the most powerful strategy of the human mind - the meaning, order, and organization of information.
Many basic principles of memory were discovered, using subjects that tried to recover nonsense symbols at precisely controlled intervals. Other researchers studied animals making decisions and traveling mazes. This line of research changed in the 1960s. For the first time, the psychologists could create a working model of the mechanisms of memory. Kind of like the computer. The information could be any knowledge or data received and processed by the individual. The complexity of memory could be dissected. Input must be encoded, put into codes that the brain can register. It must be stored. Finally, it must be retrieved on demand.
There are two kinds of memory: long-term memory, and short-term memory. To understand the process of retrieval, consider LTM as your own private library, but instead of stored in books, it's stored in associative networks, where each concept is linked to another that has common properties, so the activation process spreads automatically and across other networks that link in any way meaning to the individual. To become conscious, to identify and understand what's going on around me, something more than long-term memory. LTM is a passive storehouse and not an active information processor.
We need a STM, short term memory. STM is the transient working-memory that holds all of the knowledge currently in use, all of the new information and those things that we are paying attention to right now, and the information that we retrieve from our LTM must pass through the STM for inspection. STM has two major limitations: only a small amount of information can be held there, and the information can only be held for a short amount of time, and it fades as soon as we shift our attention elsewhere, the new always pushes out the old. Our ST(w)M is an important part of our psychological presence, and it links stories and episodes together as we work, read, play, and just take in the world. STM does all of this, and yet it does not hold anything for more than half a minute, and it can only store 5 to 9 items with an average of 7.
Our memories can be held longer with rehearsle without distraction, or with grouping and chunking. A chunk can be a word, a meaningful phrase, or a number sequence. 7 chunks is better than 7 items. 1 7 7 6 1 8 1 2 1 8 6 1 1 9 1 4 1 9 4 1. Or read it as dates. We learn new material by associating it with old behavior. Specialist in techniques that enhance memory, known as mnemonic techniques. Every memory problem can be broken down. The first problem is originally learning material, and the other stage is retrieving it and asked to recall. There are several techniques to improve memory. There's the PEG word mnemonic, where there are pegs and clues that help you associate things that you are remember.
The storage procedure, learning procedure and retrieval plan are all different and you have to connect them. Sigmund Freud was the first to recognize that what we choose to remember and forget maintains integrity and self-esteem, and repression is where the ego fights off bad ideas and puts them into the subconscious, and that sometimes these ideas show up again as Freudian slips. There's also the constructive process of remembering, where new information is made to fit better by making up new details, reinterpreting others, we are able to construct new themes and stories even for information that is inconsistent and incoherent. How and what you remember is determined by who you are and what you already know.
Schemas - our preconceptions about people, objects and situations. These are our constructions and distortions of memory arise as we try to fit new information into old schemas. How much would you be able to recall about what is in this office? Subjects spent a few minutes in this room. Later, they were questioned about its comments. The subjects were strongly influenced by their preconceived notions. Ongoing research about memory is leading psychologists to many discoveries. Beyond theories about how memory does not work and does work is the physical reality of the process.
There is a corresponding physical change in the brain itself. See LTP. Memory changes the brain. Every bit of information that you acquire is encoded in the neurons of your brain. These memory engrams form the foundation of everything you know how to do. The procedural knowledge behind every skilled action. There's also a semantic/declarative knowledge from the world of concepts, ideas and things. And yet, another batch of engrams works in the service of your episodic memory, your diary of your experiences each tagged with time and place and where it happend. Together, these engrams establish your perspective on your life. What is the anatomy of memory, where is the engram?
Karl Lashly started the search for memory. He trained them to learn mazes, then removed portions of their cerebral cortex. He found that memory suffered no matter what part of the brain he removed. He thought that memory was stored everywhere. Peutsch is an example of this. Richard Thompson of the U of S C. He used rabbits. He traced the circuitry involved in conditioning. The first goal of research has been to localize where the memory is stored. Classical conditioning. We mapped through the brain, recording the electrical activity of nerve cells, looking for the generation of potentials that relate to the actual learning behavior. There's this giant chamber where they wire up the rabbit to a computer, the whole apparatus. It's rather restraining. It's a conditioning experiment. They make a lesion of the brain and try to figure out if the rabbit still remembers the response. These memory traces seem to be in the little structure in the inner positive nucleas. The learned eyelid response is just over here, a small cubic millimeter of tissue, and any learned discrete movement is done via a tiny lesion in the interpositive nuclease.
We can go after the physical and chemical parts of the brain that store memory. We will be able to develop new techniques and tools to deal with memory disorders.
The best known type of memory loss is functional amnesia. It is found in people with anxiety and hysteria, where they have escaped an extremely unpleasant life. Hypnosis and psychotherapy can heal amnesia. There is also the destruction of brain tissue that causes memory loss, known as "organic amnesia" - alcohol, poisoning, senility, Alzheimer's, etc., brain tissue atrophy. As more of the cortex is loss, so are the memories, the personalities. Life without memory is life without a past, and without a future. Thinking, reasoning and judging, problem solving, and all of these are in the domain of cognitive psychology.
1 9 1 2 <-- serial position effect
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