|
|
Teatro della MemoriaThis image of a fractal vortex with superimposed a small family picture is a symbol of the mystery of human memory:so big to seem infinite and yet so difficult to access and bound to perish with our physical body. |
|
Topics
Giulio Camillo and his memory's theatre What are doing those virgins in Ravenna's memory palaces?Perfect recall and perfect oblivion are impossible Memories become temporarily labile on retrieval How to remember the first 22,000 digits of pi Entering in a painting to remember it Remembering pleasurable experiences can boost your immune system The more you know the less you see! Now they are there, now they are gone Keeping your memory in good health To hear a C you need time and a lot of memory Using inner dialog to improve memory and learning In which conditions you remember best Effects of Maltreatment on Brain and Memory What autistic people can teach us about memory Genes,proteins and long term memory 5000 years ago the biggest experiment in neuroplasticity has started Please put a door between them Online resources |
[This is a more or less random sequence of thoughts about memory ordered putting the most
recent first;a rational index is on the left]Please put a door between them[Added November 2011] The method of loci so well described by the book Moonwalking with Einstein by Joshua Foer is based on remembering hundreds of loci . There are rules on how to create them in such a way that they can be easily remembered. These include the fact that they should have all about the same size, be well illuminated , well separated, ... These rules are obvious since they make more easy the recollection. New research by Radvansky and others make more clear what means "well separated" and how it works. I couldn't get the original paper but a previous paper on the same subject: Walking through doorways causes forgetting:Situation models and experienced space describes very well the experimental protocol. The experiments are done using computers and virtual reality techniques: you are requested to walk a space containing many desks with objects on them. You carry an empty box and you should pick an object and put it in the box. Than you carry it to another desk. This will go on for some time and different objects. From time to time you are asked what you have in the box. It is as simple as this. You have to remember only what is the last object that you picked. Here the interesting result is the following : if you use the same space and the same desks layout but put one or more walls and doors between them, the number of times you forget the object's name increases. In the last paper Radvansky has demonstrated that there is real forgetting because the person doing the experiment will return after passing a few doors in the place where he picked the object and there is no recovery of memory:i.e. the fact of passing a doorway will produce a permanent forgetting. Radvansky explains this "the act of passing through a doorway serves as a way the mind files away memories".From this research it is also apparent another striking feature of our brain: it works in the same way in real world, in virtual reality, reading about a scene, looking at the scene in a movie and of course imagining the scene as they do in the method of loci. This may seem surprising but it isn't if you just replace our brain with a computer trying to move in real world. Of course the computer doesn't interact with real objects but only with a stream of 2D images and other data. Using these it must create a 3D model of the unknown real world. It is exactly what the brain does but it does it so effortlessly that we may think that we are interacting with real objects. This instantaneous simulation of reality is also done by our brain when it reads a text , sees a movie or imagines a walk in a memory palace. Now coming back to the method of loci. The essence of the method is that you store all the information you want to remember in the loci of the memory palace. Then you get this information back walking from locus to locus. As you do this, it is important also, that, after you extract the information from a locus (something like picking an object from a desk), this information shouldn't bother you any more (since you have already used it) and so, to forget it, you just imagine that you pass a doorway and you arrive at the next locus ready to pick a new object. Instead in real life you may want exactly the opposite when you have forgotten what you needed from the refrigerator. Before passing the doorway use for example some hand gesture to remember and reverse the door's effect on memory. Or just kept repeating the name of the thing you need... What are doing those virgins in Ravenna's memory palaces?[Added November 2011] The fast answer is : exactly what are doing the "virgins" during bunga-bunga parties in Berlusconi's (real) palaces. For the long answer please read the book Moonwalking with Einstein by Joshua Foer. I try to summarize (of course mistakes are mine). This book is all about method of loci. This method has been invented around 3000 years ago and is based on two important principles that allow the fast and permanent remembering of almost everything.The first principle is the use of "loci" (places in latin) and is based on the fact that our brain is very good at remembering places. JF describes this very well: if you are left alone in a house never seen before for a short time (for example an hour), that hour of exploration is enough to memorise hundreds of details of the house forever. Now, if you only could read a book about a complex subject or a deck of cards in the same way as you "read" the house , you have discovered a way to memorize instantly everything. This is what the second principle of the method addresses: "images agentes" vivid images of "something" happening in the places that you already know very well (i.e. the loci). Now, what are the things happening around you that you best remember: mostly things where other people is involved and having emotional content. For example, if we are in a situation which is dangerous for us , we store instantly everything happening around us and we automatically replay the scene day and night (in our dreams) for many days until that scene becomes a permanent part of our brain. This is what means "vivid images": imagine a scene happening in one of the loci in which someone that you know well is doing something nasty, fearsome or simply funny or bizarre. Then this scene will stick effortlessly to your brain and , if it encodes a concept in a book or a card in a deck, this information would also be stored forever. Before you rush using the method , be warned : you need a year of training to set up enough memory palaces (i.e. empty houses) and then to create effortlessly new images... Now coming back to the virgins... Sexual images are of course among the more memorable so Peter of Ravenna, a 15th-century writer on the topic advised "If you wish to remember quickly, dispose the images of the most beautiful virgins into memory places". Is Daniel Tammet a liar?[Added November 2011] In his wondeful book Moonwalking with Einstein Joshua Foer speaks also about Daniel Tammet. This is the famous autistic savant that has written a book explaining ,among other things, how he was able to learn the first 22,514 digits of pi. Joshua Foer attempts to convince the reader that Daniel Tammet is a liar. Of course there is no doubt that Tammet has Asperger and that he was able to memorise all these digits (or to perform other extraordinary feats involving memory). What he criticises is the explanation given by Tammet on how he managed doing it. The reason is very simple: as he very well explains in his book, there are methods that can enable anyone to do this and these methods don't require extraordinary powers like synaesthesia. According to someone this is a "misstep" in Foer's book : see for example this review. But my opinion is that in this case, it is better to use the Occam razor until we have more evidence: why should we believe that this accomplishment was possible by extraordinary powers when normal methods suffice?5000 years ago the biggest experiment in neuroplasticity has started[Added November 2011] I have to catch-up after more than 3 years. This is an age for neuroscience research. I have read a lot of new books and I will report here about four that I have found amazing for the subject of this page. Let's start with the wonderful Moonwalking with Einstein by Joshua Foer who has become by now the reference for anyone interested in memory and isn't an expert in the field. The best book written on the Art of Memory after the classic by Frances Yates. Or perhaps better because Joshua Foer has spent a year putting the method of loci to work. Enough on Joshua although I could continue for many pages, being his book so well written and documented.I will report then three books together:
Repeat to remember[Added October 2008] John Medina book :Brain rules explains what we know about the brain after the Neuroscience discoveries in these last years trying to distill this knowledge in a list of possible ways to improve our learning in school or our intellectual work. Medina concentrates only on well proven facts and has the gift to present these results in a way that emphasize all their importance to improve our learning and working experience. For example when considering memory, he explains what we know about the mechanism behind short term (working) memory and long term memory. Then he distills the single rule : repeat to remember. He clearly explains the importance of this rule reporting the well known case of patient HM without hippocampus and without the possibility to form new long term memories. This case shows some astonishing facts about memory:
Memory as kludge[Added June 2008] Gary Marcus book :Kluge The Haphazard Construction of the Human Mind has a captivating description of human memory as a kludge produced by random evolution. This explains why our memory has so many faults. It explains less why it is so good. If computer memory is the goal of a perfect evolution then why autistic people that have almost computerlike memory are so unfit to social life?But this doesn't mean that memory isn't a kludge , it is a wonderful kludge but we know still very little about it. If we knew better we would try to exploit this kludginess to our benefit. The most deceiving part of Marcus Gary's book is the list of advices to help us cope with our mind kludge. I am a programmer and I live of kludges. Most of the programs to which I contribute are full of kludges. And I know that the best way to profit from a kludge is with a cleverer kludge. These are missing in Gary Marcus book probably because right now we don't know enough well the divine hack (this is how we programmer call the ultimate kludge) that is behind our mind. How to remember the first 22,000 digits of pi[Added April 2008] I have read the book Born in a blue day by # Daniel Tammet. Daniel Tammet has a mild form of autism called Asperger's syndrome and reports in this extraordinary book how he was able to memorize in a few weeks the first 22,000 digits of pi and then recall them in around 5 hours before a jury that checked the correcteness of each digit. As with Luria's mnemonist the secret seems to be synaesthesia. Daniel sees each digit as a distinct pattern : for example the 9 is blue and tall. To him a string of 10 random digits is like a landscape. In the book he makes some sample drawing of this peculiar landscape that he sees in the mind. What he has done is to build little by little a huge landscape in his mind representing all the 22,000 digits of pi. In the day of the recall he had only to concentrate himself on the features of this extraordinary mental painting extracting one by one all the pi digits.Mirror neurons or : Why compute when you can search about actions?[Added October 2006] This article about mirror neurons has prompted in my mind the following ideas. In Computer Programming (I am a programmer) we use the following trick when we write programs: when some complex computation produces only a small set of results, we replace the computation with a search in the table of possible outcomes.It seems that the brain has done the same thing with mirror neurons.Mirror neurons are a set of neurons (the equivalent of the search table) that fire when we look another person doing something. So we have the neuron that fires when we see another person moving the hand forward to shake it with someone else. Another neuron will fire if a person is moving the hand striking a nail head with a hammer, etc ..., These neurons are extremely important to simplify the image processing otherwise necessary to understand other people's intents. This can be understood seeing this task from a computer program point of view. You have the images of an alien built in some strange ways, doing something. You have to infer from this stream of images what a person is doing. A very complex problem indeed. But wait a moment!For us the "alien" isn't an alien really: he/she is someone built like us and the possible outcomes of a move are really very few. So you see why the brain prefers to hardcode these possible outcomes of our action in a "table" of a few mirror neurons. So ,when the brain looks at someone doing something, it has only to search and choose which is the correct mirror neuron to fire. Something it can do so quickly that we effortlessly understand what other people are doing .Another trick used by the brain is that the mirror neurons for the action "drink from a cup of coffee" are near the neurons that fire when we drink from a cup i.e. near the place where are the neurons that start the same action in our body.In fact they are a subset of these neurons:i.e. the mirror neurons fire both when we drink a cup or see another drinking a cup. Mirror neurons were in fact discovered by chance by Giacomo Rizzolatti and his colleagues at the University of Parma monitoring the motor neurons of monkeys. What is interesting in this mirror neurons system is that we have it in part hardcoded from the birth: this explains why newborn babies can imitate adults. If you stick your tongue out of the mouth in front of a newborn baby , he does the same! But the system develops and changes during all life as we learn to do new things. The hand movements of an expert piano player fire completely different set of mirror neurons in an observer who is an expert player himself or someone who doesn't know how to play piano! People with autism seem to have a deficit in this system. To understand other peoples intentions they have to make a lot of effort : reason about the images and try ,by comparing these with other images they have in memory, to decide what's happening. Just imagine how scaring this is: this person coming toward you with raised hands is going to greet you , to hit you or what else... They have no clue. This information overload explains why autistic people fear other people's eye contact. It is something similar to our ability to recognize people's faces. Normally this is effortless and you can assume that we must have in our brain a "table" of neurons each one connected to a well known person that fires when we see this person. But when we lose this capacity ( Prosopagnosia) then to recognize a person you must make an effort and try to use other cues . An experience that is both scaring and difficult. Sleep and memory[Added September 2006] The last scientific result about memory and sleep :A daytime nap containing solely non-REM sleep enhances declarative but not procedural memory leads to the following reasoning. Why humans (and animals) sleep? The obvious answer : to help our body recover is not an answer. In fact it is enough to stay quiet withouth sleeping in order to recover from stress. The evidence is mounting that the only purpose of sleep is to enhance our memory. This explains also why childs sleep more (they have to learn a lot).Expert's memory[Added September 2006] Advertising about memory training courses often promises that you will get instant success after following them. Of course this isn't true. No memory training will transform you in a genius. But let's go the other way around : let's see what is the role of memory in a genius. Since geniuses are difficult to find and study, we can try to study experts in some well known field. This is what scientists are doing since many years with chess masters. Chess experts are given a number (a kind of vote) that reliably measures the degree of expertise in playing chess. The results are very interesting and seem to point to a very important role of memory. What makes the difference between the amateur and the master is that the expert is able to recognize "patterns" where a novice doesn't see anything. This kind of high level memory is acquired in many years (at least 10) of effortful practice. This contrasts with the idea that a genius is born i.e. Mozart that effortlessly composes music. In fact Mozart too has done his ten years of practice guided in his effortful practice by his father who was a musician. It seems that only practice in an environment that provides challenges (thus effortful) can provide this superior memory. So experts and also geniuses are made not born and need proper motivation and environment. The process of being able to recognize these high level patterns is similar to the well known process of information chunking .Memory and Obsessive-Compulsive Disorder[Added June 2006] Obsessive-Compulsive Disorder (OCD) episodes are experimented by almost anyone and consist in irrational worries that let you perform rituals to neutralize them. For example you have to return many times to check that the home door or a faucet is closed. In this case you don't remember that you have closed the door. So the author of this How to Remember Amazing Amounts of Information says that it was enough for him to imagine , everytime he closed a door, some weird thing happening to the door and the key, This would make the action memorable and cure the ocd symptom.The way of the actor[Added January 2006] How do actors memorize all these lines?Trying to answer this question, Helga and Tony Noice have found a surprising way to master cognitive abilities that can be of great help to non-actors and to aged people. The answer to their question is that actors don't use rote memorization. Instead they learn their lines by ... acting. An actor would concentrate not on the words, but on their meaning and divide the script lines in chunks called "beats" or "intentions".During each beat the actor has the same motivations of the character. So the actor will rehearse his lines by going from a "beat" to the next and trying to use any clue (physical, emotional) to remember the lines involved.What is interesting is that this strategy can be used by non-actors :for example students, to improve learning. An example on how a student can use this strategy, is by imagining to explain what is learning to other people. (This is a technique that I use frequently myself: the best way to learn something , is to teach a course about what you are learning!) Yet more surprising is the fact that engaging aged people in a four-weeks course on acting, improved word-recall and problem solving abilities. Unconscious memory[Added August 2005] It is by now a well known phenomenon that the same information inaccessible to explicit (conscious) memory, may be accessible to implicit (unconscious) memory. You can literally see something without knowing that you are seeing it. This has some fascinating consequences. For example, I use a list of images connected to the numbers 1,2,3,... to remember things. So, for each number I remember an image. But remembering (becoming conscient of ) the image usually requires some time (from a few seconds to a few minutes). It is very well possible that during this interval of time my implicit memory has already recollected the image. By using some adequate strategy, I can try to use this implicit knowledge to improve my conscious recollection. This tacit knowledge is connected to the amygdala and to the fast system that helps us react quickly to dangerous situations. It perceives words and numbers as global patterns and its main purpose is to decide if they are dangerous or neutral.Sing songs for lasting memory[Added August 2005] Some time ago after hearing a rap song about the history of jazz, I was thinking about how this may be a good way to learn anything. Just transform the information you want to learn in a rap rhyme. Someone else had the same idea judging from this site that sells cd with rap tracks to learn things.The little voice in the head[Added June 2005] The voice in the head ,when we read silently, is indeed a voice! Experiments have shown that we really hear the sound of a voice reading the text (i.e. it is as if the brain runs an experiment simulating ourselves that read the words in the text aloud and then understands the meaning of the written text).The visual pattern of words plays no role in understanding. The Chinese people also, when read silently , understand the written text because of the sound heard and not because of the pattern of ideograms. For the same reason deaf people have problems learning to read. From the same fact comes a suggestion to improve learning of new languages: when you read a text , always imagine hearing the sound of the words also if you don't know exactly the correct sound. The more you know the less you see![Added June 2005] When an adult sees a cat, in fact he doesn't see it:he just thinks "big deal, it's only a cat, why I should pay attention?". But what was the color of the eyes, the color of the fur, etc...If you ask him later, he doesn't remember because he has not paid attention in the first place. Childs instead remember every detail of the cat.But also the adult can remember a cat like a child . He has only to increase the attention level with some trick. For example giving the cat names of other animals or objects. "What a lovely onion with wiskers!" All this has been confirmed by an experiment. 11 steps to a better memory![Added May 2005] An interesting article from New Scientist on 11 steps for a better brain is in fact mostly focused on ways to control the effects of aging on memory .
Sleep to remember![Added January 2005] Normal sleep consists typically of periods lasting around 90 minutes that repeat 4 or 5 times each night.Each period starts with a non-REM phase where we go through 4 stages of sleep until we reach the stage of deep sleep with low frequency electrical brain waves. Then the REM sleep starts with a lot of brain activity and rapid eye movements. This ends when we get awake for usually a very short time and then a new cycle of sleep starts: light sleep, deep sleep, REM sleep. Early experiments have shown that rem sleep doesn't have any influence on remembering lists of words or facts(i.e. declarative memory). Instead rem sleep influences procedural memory (like the ability to recognize patterns in a computer screen).Motor skills which depend on procedural memory, are affected also by non-rem deep sleep. Skills that require visual abilities are improved by both rem and non-rem deep sleep.Sometimes also an hour with shut-eyes makes a big difference. It seems that different kinds of memory need different kinds of sleep.This may explain why sleeping on a problem can produce sometimes the result of getting awake the next morning with a solution. Studies in animals have shown that during the sleep the same neurons activated during the day by doing some task like traversing a maze, are activated again. It seems as if during the night we are re-enacting (simulating) the same experiences that we had during the day. This seems to produce two results:
Genes,proteins and long term memory[Added January 2005] This fascinating article by Douglas Field on Making Memories Stick describes the mechanism how a short term memory becomes a long term memory at the level of the single neuron. For this to happen, a gene in the nucleus must be activated. This gene will produce "memory proteins" that are sent to all neuron's synapses but will strengthen only the particular synapse that has started the gene. In this way a temporary activation of the synapse may become permanent.The same mechanism is also responsible , during recall, of memory reconsolidation. If protein synthesis is inhibited for some reason, you can erase long term memories .Your body remembers for you![Added January 2005] In the film "Paris,Texas" by Wim Wenders, the main character is trying to get his memories back walking around. When someone asks him how he knows where to go, he answers : My body remembers for me. This sentence has always made a great impression on me. It may mean many things. That when we reach some place, we remember easily the way we got there. Another meaning is that this knowledge is based on procedural memory so is unconscious and difficult to erase. In Alzeimer's disease the procedural memory is the last to go.Amnesics including the famous patient HM (with hippocampus removal) can still learn implicit knowledge of procedures.It is possible to say from this that by including some procedural knowledge (especially if you are old) you can improve your learning and memory? For example , with the use of the Web, there is a big procedural component in our knowledge because we can learn something by remembering how to get to that information. Another strategy that I have found useful is the following: this is applied to learning a list of let's say 10 "concepts". I give a number to each concept and write down the 10 numbers on a sheet of paper in a ordered way: 1 2 3 4 5 6 7 8 9 10As I write the numbers I try to recollect the "concepts" connected. I will repeat the exercise many times each time starting with a new blank sheet. The idea is to base the recollection of the 10 concepts on the recollection of the procedure of writing down the ten numbers. I have reinvented the method of loci! Remembering dreams[Added September 2004] Since we dream so much, why the dreams we remember are so few? The answer is astonishing:it is true that we dream a lot of time but most of this time the brain circuitry needed to register those dreams is off. Only in the very few moments that we get awake during the night, we are able to register a few dream images , That's all.It seems that every night, also if we think that we slept all night, there are a few moments where ,for few seconds, we get awake and can register the end of the last dream. This explains why,with some training, everyone can remember many dreams every night.What autistic people can teach us about memory[Added February 2004] A small percentage of people with autism have some remarkable abilities: it is the so called Savant Syndrome.They show mostly artistic abilities (play music or paint).The reason fo these abilities may be a normal right brain hemisphere that compensates for a damaged left hemisphere . But what about the extraordinary memory that such people show(this phenomenon was depicted in the film Rain man)?The almost limitless memory of savant people seems to be of the kind called procedural.This is the kind of implicit memory that we use when we learn to do something like riding a bicycle. This memory is the last to be lost by people with Alzheimer. Again, it seems that the damage that produces the autism has destroyed the explicit semantic memory, leaving intact this "low-level" memory. Although the autistic people don't know the meanings of what they learn, they are able to remember a lot of things almost without effort. Some autistic savants become able to describe how they do it. Their account is fascinating and may be of great help in understanding how the brain works. For example see the case of Daniel Tammet and Temple Grandin.Memories become temporarily labile on retrieval[Added January 2004] Memory reconsolidation is the process by which consolidated long term memories become temporarily labile after retrieval. Apparently something happening during or shortly after the retrieval can change and in some cases completely destroy the memory. This has been shown experimentally with rats and other animals.Now they are there, now they are gone[Added October 2003] I am a steady moviegoer and,as such, I like to speak with friends and relatives about movies. In these talks it is of course important to remember movie titles,actors and director names. As the number of films seen increases , remembering all these names becomes more and more difficult.Of course this is understandable, you can't remember thousands of names. But what is really amazing is the following phenomenon: there are names that switch on and off almost endlessly in your memory. You can remember them easily for a few days , then they go away to come back after ,etc,etc. Also amazing is that some names instead, you never forget.This is sometime understandable:for example, if you have seen some actor or actress in person, you won't forget the name so easily.But perhaps this is not so difficult to understand.The problem is that we think about memories recall as a computer that retrieves information from storage. If the information is there we must find it. Is it really like this? Let's think about it from the point of view of our mammal cousin: for example a cat.There is no doubt that a cat has a memory. But what about recall: can a cat like a computer recall anything anytime? No, he recalls something only if there is some stimulus connected in some way with the object to be remembered. This means that our ability to "remember at will" like a computer is unique for us humans and has probably been acquired with language. But as such it is not perfect and difficult to maintain.On the other hand , "remembering like a cat" is more low level and is less damaged by aging. Alzheimer and memory[Added January 2003] First a news: Blog to Cope With Alzheimer's Fog .Seniors in the early stages of Alzheimer's disease, with mild to moderate memory loss, are writing Web logs to help them make sense of their daily lives. And the activity, they say, is slowing the onset of their symptoms.Human memory is very difficult to study because of its complexity and the impossibility to carry out experiments with living subject. But Alzheimer's disease is nothing else that a memory experiment carried out by nature. A terrible experiment:what happens to memory if you destroy little by little neurons almost everywhere in the brain in around ten years? Which memory subsistem will go down first, which will last up to the end. The result of this terrible experiment is that episodic memory will go first. What lasts more is procedural memory. In fact the memory impairment in Alzheimer's patients is the same that experiment aged people but instead of proceeding slowly it is very fast. For this reason some scientist says that AD is not a proper disease but only the simptoms of a very fast aging. Let your left hand recall[Added April 2002] With people that have no connection between the left and right brain hemisphere, it is possible to do some startling experiment. You can show an object only to the right hemisphere and see that the person is unable to name the object. What does all this mean especially regarding memory? That we have in fact two brains and each brain processes information in its way and has its special way to store this information. So, an object , for the left hemisphere is a word and for the right hemisphere is a shape. If they cannot comunicate, the left hemisphere will be unable to give a name to some object that we know very well. It is possible that also in normal persons, a reduced communication between the hemispheres can be the origin of memory failings? We know for certain, that in most people the left hemispere is connected to language and normally acts as the boss: i.e. if there are contrasts between the two hemispheres, the left wins. This is understandable, otherwise we will be all like Dr. Jeckyl and Mister Hide. But it is possible in some cases when, we have problems with memory, to improve recall trying to use explicitily the right hemisphere memory store? I am not an expert, so this experiment that I have tried, has no scientific basis, but anyhow... So, taking in account that my left hand is controlled by the right hemisphere , when I have a problem recalling something, I will ask my left hand to describe it. What happens is that my left hand will make some sign in space or against my body and I will try to use this sign to recall what I have forgotten. Does it work? Yes, but I am not sure how it works. Perhaps, it only works because it breaks some thought patterns that were taking me nowhere. Perhaps some scientist should do some serious research in this field.Effects of Maltreatment on Brain and Memory[Added March 2002] This is a report on the effect of child abuse on their brain development: it gives some glimpses on how the memory works in normal people. For example : our memories have ,for survival purposes , all an emotional content. This is regulated by the limbic system. For example, the amygdala (part of this system) is responsible to filter and interpret incoming sensory information in emotional terms (it is a snake or a stick?) to help initiate the appropriate response early enough(the "rational" processing of the same information comes too late for survival).Persistent stress produces a smaller amygdala and this is connected to depression, hostility and irritability. Hippocampus (also part of limbic system) is important in determining what information will be stored in long term memory: it seems that the left part of this organ has smaller size as result of overexcitation of the limbic system. This points to the possibility that there is a reduced communication right-left hemisphere. In fact the organ responsible for this communication, the corpus callosum, has a reduced size. The left hemisphere is specialized in language whereas the right hemisphere is specialized in spatial information and emotions.Is this reduced communication and increased importance of right-hemisphere connected to the fact that disturbing memories are stored in the right hemisphere? Can this be the cause of depression? Seven sins of memory[Added June 2001] I am reading a book by Daniel L. Schacter on memory(Searching for Memory: The Brain, the Mind, and the Past) and by searching online about his work I have discovered that his last book is about the "Seven sins of memory". By the way,the book I am reading is really a magnificent book written by a researcher in the field. So I am looking forward to read this new book. From an online search the seven sins summarize the failings of our memory:We don't remember something because
False memories 2[Added April 2001] The presidential optical illusion will demonstrate other features of our brain that lead to false memories. When we look at the world around us we try immediately to understand what we see by putting it in a well known category and then we forget about it. So in this case almost always we "understand" that we are looking at Clinton and Gore and we don't check the face of Gore. So in future we will remember that we have seen without any doubt Clinton and Gore! In fact we haven't checked that Gore was really Gore and not Clinton in disguise. How many times we disregard small important details in what we see considering them unimportant? How many times we are fooled by this into seeing and remembering something false? How many things around us are never seen and so lost for our memory because of this peculiar way of our brain of processing things? For example, when we look at some image, a check of the eye movements shows that instead of scanning the entire image, we fix our attention and scan again and again always the same points of the image. In this way we can look at the same image hundreths of times and never see some interesting detail.Memory and smell[Added March 2000] Does the sense of smell improve learning?The other day I had the following experience. From time to time I do "experiments" on memory by learning a list of ten items. If I start in the evening , it will take usually a few rehearsals and for the following morning the list is perfectly memorized. This time, when I was starting the exercise, going through the list for the first time, something happended. An electrical appliance misbehavior produced a smoke with a pungent scent of melting plastic. The problem was quickly fixed but the smell was still present after many hours. I discovered also that my learning of the list was a lot faster and I could use, the following morning, the smell to recall it!Initial detection of odors occurs in the nose in the olfactory epithelium. The epithelium contains millions of odor molecule specific neurons that make direct physical contact between the external world and the brain. When a certain odor is detected it causes certain neurons to fire in the olfactory bulb . The olfactory bulb then sends a signal to the olfactory cortex and then on to the Limbic system for further processing and memory recall. The information goes to the thalamus (part of the Limbic system) but also ,in case of smell and taste, to the amygdala and hippocampus(also part of the Limbic system). This gives smell (and taste) poweful memory stimulating properties that can explain what I experienced.The Limbic system is referred as the "seat of emotion" and is basically an information storing and processing system.The hippocampus ,for example, serves to recall simple, short-term memories stimulated by sensory input.These memories are spatial. The amygdala can ,instead, evoke memories connected to emotion.In fact, removal of hyppocampus will produce short term memory failures. Removal of amygdala will produce emotionless aggressive behaviour in monkeys.So,it seems,that by using some smell during learning, we are in fact storing our memories using still another track. This will improve both the process of learning and recall. Here is an interesting document on the subject. Memory and depression 2[Added February 2000] There are some interesting news about this subject.Memory loss in senior citizens seems to be correlated with depression. This means that if you cure depression, you cure also the memory problems.But I would consider here also the other possibility:a cure of the memory problems, can cure the depression. Let's say it in another way:all of us have recollections of wonderful moments in our life. Normally we have access to these memories,but depressed people, seem to have lost the capacity to access them.When we are depressed, we tend to see only the bad things about ourselves and the world. We may condemn ourselves unfairly for relatively unimportant human failings. We tend to withdraw into ourselves and may not notice what is going on around us. So, we may not remember things because we didn’t notice them in the first place. People who are depressed may also become agitated and this will make it hard to concentrate.Now, new discoveries shows that the brain continually reorganizes itself. It's called "neuroplasticity." And it means that you create your brain from the input you get .So it's possible that through special brain exsercises, you can cure depression.What kind of exercises? These exercises should produce a rewiring of the brain, so they must be like the exercise you do when you learn playing a new musical instrument, a constant training. So, I suppose, that the computer should be essential to administer these exercises. Keeping memory in good health[Added February 1999] This document from the Exploratorium, gives some sound advice on how to keep your memory in good health.
Remembering pleasurable experiences can boost your immune system[Added January 1999] It was well known that pleasurable experiences will increase our immune response. But new experiments show that it is enough to remember pleasurable experiences to boost our immune system.So from now on, the doctor may give as a cure :remember ten good things happened to you.In which conditions you remember best[Added December 1998] I try to recall from time to time long lists of items learned with the method of loci. I have got some experience on the best conditions to remember things.
Move your hands to remember![Added December 1998] Why do we gesture when we speak? To this question Robert Krauss has,after a long research, the following surprising answer. The main purpose of hand gestures is not to communicate but to facilitate access to the mental lexicon.Krauss tells a story about this: two friends walk together in a icy cold day. One of the two speaks and speaks moving the hands;the other remains silent with his hands kept in the pockets. "Why are you so silent today?" asks him the always talking friend."I forgot to take the gloves with me", answers the silent one.Using inner dialog to improve memory and learning[Added September 1998] It is obvious that ,if you speak about a subject you are learning with someone , this will improve the learning and memory about the subject. But, not always is another person available to help us. Fortunately there is another kind of dialog that goes on almost all the time in our mind. This is the inner dialog. When we are worried about something,for example, we'll go through the problem again and again speaking in our head with a lot of imaginary persons. We can improve our learning and memory by using consciously this inner dialog to rehearse. For example, we can imagine speaking with the author of the material if this is on a book. Or we can imagine giving a conference about a subject. Or sending a mail.In my experience, I have found that when I am preparing a seminar (I teach Web related technologies), I learn a lot of things just by rehearsing the seminar again and again. This learning comes almost without effort because I am worried about the seminar and so I will think again and again about it. In fact,the problem is now quite the contrary, I would sometime like to forget about it to relax.Memory and hypertext 2[Added November 1997] Someone says that hypertext on Internet will make human memory obsolete. In future we will go around carrying a device connected to Internet where we will be able to find all the information we need. The human memory ,no more needed, will atrophy.Well ,my opinion is different. Web hypertext will make human memory more used and more strong. I have a personal experience about this. I am a steady moviegoer and ,having seen thousands of films (I am 50 years old), I know by heart hundreds of actors,directors and other people connected to cinema. Since some year my memory is showing the usual effect of aging:the names of many of these people were lost. I could still recollect the face, the movie scene but the name was gone. I have so decided to relearn them again using the Web. When I find some new lost name I will start searching the Web for it and surf sometime . After that I notice that I am able for many hours afterward to remember the name (I suppose because of the short memory mechanism). Than thinking about it I will invent some links that will help the long term recollection of the name. Just to make an example: let's consider the director Ridley Scott. After surfing the Web I have no problems in the following hours to remember his name. Then I note that he has the same name as the actor George C. Scott (which I remember very well because of the film Patton):so this is the first link. Considering now Ridley I note that it is similar to Riddle and Ridley Scott loves riddles in his films:so this is the second link used for long term memory. Note that the Web surfing was essential in establishing these links. In this way,I am relearning again all the names. The learning is further improved by writing a web page about movies. This is used to help my surfing but also my learning. Having written,for example, in this page that Rowan Atkinson is one of my preferred comedians it is a lot more difficult that I will forget the name of Ms. Bean impersonator. Another example of this use of the Web is this Diary of found again words(in Italian). Through a link to a table of search engines I can help my memory surfing the net material about the lost and found again word. Entering in a painting to remember it[Added July 1997] In the movie Dreams by Kurosawa there is this delightful episode where the hero enters literally in a Van Gogh painting. Of course, if we could enter a painting or a image with the mind's eye, the experience would be unforgettable and we would remember all the details of the image. In fact something like this happens when we visit a place that we saw before only in a photograph.The experience will change completely our perception of the image and we now for the first time notice in it details that were completely missed before our real life visit. The problem is that we usually look at an image just the time to "classify" it and then we remember only this approximate classification.It was a church, a woman, etc But all the details are lost in the process. Did the church have a clocktower, what kind of cloth was the woman wearing? There is a way that can be sometime used to avoid this kind of blindness to images resulting from our predominant verbal knowledge:by looking with a magnifying lens at the image and exploring it piece by piece we can have a more vivid experience of the same image and in this way increase the chance of remembering single details.Dream to remember[Updated June 1997] According to recent studies,dreams may reflect a fundamental aspect of mammalian memory processing(only mammals dream).The long term memory of crucial information acquired during the waking state seems to require the reprocessing of this information during the REM phase of sleep when we dream. To avoid interference with sleep of the re-enacted experience the motory neurons that command our muscles are inhibited, except for those that command our eye movement. Everything seems to start with activation of hippocampus a part of the brain involved with memory processing. The kind of memory which is more influenced by sleep and dreams is the implicit procedural memory. This should be "obvious" from the fact that also animals dream and animals have only this kind of memory. Memory and hypertext[Updated May 1997] The advice to a student on tricks to improve learning of school material, is the occasion to speak on the fact that hypertext writing will help the recollection since you are now using also spatial memory(hypertext is like a building with hyperlinks acting as doors to new pages).There is a fascinating history concerning the links between memory and the Web(i.e. internet hypertext). This is reported from Time in an interview to Tim Berners Lee, the inventor of the Web, in the May 19,1997 issue. Tim has problems remembering people's names or faces, so he wrote a computer program based on hypertext to help him remember. Later he extended his system to Internet inventing the Web. So we may say that the Web has been created to serve as a memory substitute for people having problems remembering! Also Ted Nelson, who is considered the inventor of hypertext, started to think about this new concept, out of the personal problem of keeping track of his huge stream of ideas. This was in the early 1960 and he has worked since then on hypertext with his famous Xanadu project.Only Tim Berners Lee by connecting the hypertext with Internet would make Nelson dream true. You can read about the wonderful story of Nelson in this chapter of a book by Howard Rheingold. False memories[Added May 1997]Of course, we all know how imperfect human memory is. You check your recollection of a family episode with a relative discovering that it is very different from what you remembered. But it is possible to remember something that has never happened? Yes and it is very easy to demonstrate it! This wonderful article from May 97 Scientific American shows how to create false memories.You ask to someone to remember a list of words like bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn, drowsy . These words are all connected with a hidden word "sleep". Then, when you check the memory of the subject, there is a very high probability that he remembers the word "sleep" as one of the words to memorize! It seems like a trick, but it shows how our brain can be easily fooled. Most of the subjects are absolutely convinced that the word "sleep" was present in the original list.Perfect recall and perfect oblivion are impossible[Added May 1997]I have "experimented" for many years with learning and recollecting long lists of words (around 1000 items). What you discover with this exercise,that apart from the initial effort to learn the list,once you know it by heart,you have to rehearse it regularly to keep it in memory. In my case I found that I had to rehearse every month, otherwise the list would start to lose its pieces. The "damage" was proportional to the time passed without recollection:after for example, one year, re-learning the list was a big job, although not like the first time. Until now, I have found no way to ensure a perfect recall of a list without periodic recollections. On the other end ,it is also true that a list never goes really away. For example,around 20 years ago, I learned by heart a list of 1000 movies titles but I didn't rehearse it any more, after the initial learning. Now , when I see the title of a movie, I can easily remember that it was in the list.Sometime it would be nice to have something like perfect oblivion. Think about all those sad memories haunting you from the past. Unfortunately this proves impossible because of the way our memory system works. Not only are our memories scattered everywhere in the brain, but part of them are outside the control of our consciousness. In fact our brain seems to have two systems that work in parallel,each one with its memory:the unconscious one is based on the inner brain and ensures a quick reaction to dangerous situations. The other one is under our consciousness and will examine later the situation. So if we see something looking like a snake on our way, we first jump to avoid it and then we look more carefully to discover that it is only a stick. It is possible that the memories used by the inner brain are impossible to erase. Where are our memories stored[Added May 1997]Where in the brain are our memories stored? There is a neuron or group of neurons for each memory? You destroy the neuron and that specific memory goes away? No. A specific memory is almost everywhere in the brain, to destroy it you have to destroy almost all of the brain. How we know? by experimenting with animals. But also by looking at the parts of the brain activated during learning and recollecting through imaging techniques.Many parts of the brain are involved and what is amazing the parts involved are different for the same memory during learning and retrieval.So where are our memories in the brain? Most likely the storage takes place as pattern of connections among neurons.In fact, almost every memory is made of many different patterns of neuronal connections, some for sounds, some for sights, some for smells or textures--tens of thousands of neurons firing off minute electric impulses simultaneously. The changing role of memory[Added April 1997]This interesting document by Larry Wendt:Narrative as genealogy offers an interesting glimpse on the changing role of memory in our culture.The first culture is oral: in this culture the storyteller and the poet are of great importance, since they are the memory of this tribal society.Big efforts are done to preserve this memory with long and rigorous apprenticeship.Then we have the text culture (where the text is first a manuscript, then a printed book and more recently TV).Here the culture is saved using writing so we have the sacred books. The storyteller becomes a rhetorician that uses the so called "Art of Memory" to write the main points of his speech in the "loci" in his brain. Until the paper becomes so cheap that there is no more need for this art:in fact now we use transparencies. Anyhow we think always in terms of linear printed text. The latest culture is the hypertext culture:here the hypertext itself is a memory strategy to keep track of all the associations between our own thoughts but also our thoughts and those of the rest of the world. Seen from the outside the Web can be seen as a one million channels TV mostly full of trash.But in this new culture we are not only spectators or surfers, we also contribute creating the hypertext. This is something new and no one knows where this will get us. To hear a C you need time and a lot of memory[Added September 1996] The processing of sounds by the brain consists in taking a temporal sequence of single values coming from the ear and trying to give to these some meaning (for now forget that we have two ears to make things simple). But only to hear a single note your brain must sample the sound for some time and has to store the information somewhere.A lot more you have to store just to follow a tune. This storage is called working memory and should be present also for the eye.Aging of memory[Added September 1996] As people become old, they start experiencing problems with memory especially recalling names and recognizing faces.Research shows these minor episodes of forgetting are common after 20.Age seem not to affect some types of memory,so you can easily remember the same things using different strategies to store them.Additional information: Aging and Memory Memory training for aged people Giulio Camillo and his memory's theatre[Added July 1996] Giulio Camillo in XVI century thought that he could build a physical place, a majestic building full of allegorical sculptures and paintings where he would capture all human knowledge. This was the theatre of memory. The owner could have access to the whole knowledge by simply visiting this place. It was like a museum but it was also a kind of magic place:a machine to acquire instant wisdom. Camillo was well known in its times:he got also some financing from the king of France for his idea. At least one painting is known from Titian as being prepared for this theatre. Camillo's idea was to use the ancient method of loci in a new way:instead of building through mental visualization an imaginary palace where to store knowledge, he made plans for a real building with the only purpose to serve as support of knowledge.To understand how he got this idea you have to consider that he lived before the birth of modern science but after the printing revolution was making the knowledge of the ancients available to everyone. The basic idea of Camillo and other contemporary people was that a memory system by reflecting the macrocosm in the human microcosm had magic effects.The whole story can be read in a wonderful book by Yates called The art of memory .The Mind of a Mnemonist[Added July 1996] One of the most fascinating stories about memory can be found in this book written by Luria about the case of "S".Luria explains in the introduction how 'S' was sent to him because of his amazing ability to recall things from the past. 'S' himself wasn't aware of any peculiarities in himself and couldn't conceive of the idea that his memory differed in some way from other peoples.Luria gave him words,letters and numbers to remember,sometimes as many as 70,this was no problem for 'S' to recall.He could even recall the lists in reverse order.When asked to recall the lists 16 years later there was still no hesitation from 'S'. Luria studied this subject for many years and found that he had problems forgetting the material, not remembering it as happens for almost anyone. Memory and depression[Added July 1996] By using brain imaging techniques,memory shows up as the capability of firing groups of neurons in different parts of the brain.The same techniques show on the other hand, that the depressed has a marked incapacity to fire neurons in some parts of the brain. Can depression be cured by mnemonic tricks? Types of memory[Added July 1996] Immediate memory allows the mind to hold and let go of a sensory impression within a very short time. If you look at an image and close your eyes, you'll remember it for only about a second unless you 'decide' to store it.This temporary sensory is necessary to allow the brain to process for example the speech heard.Short-term memory lasts about a minute. We use it, for instance, to retain a phone number between reading it in the phone book and dialing. Short-term memory can hold about seven items. Long-term memory can last many decades. It is estimated that the human brain could hold more then 1,000 times the information contained in a large 20-volume encyclopedia. Then we have episodic memory , semantic memory and procedural memory. You remember a ride with a horse, the meaning of the word "horse", how to ride a horse. This classification can be useful to develop memorization strategies.For example it is easy to remember something you have done only once(episodic memory); so why not memorizing some difficult semantic information (for example meaning of foreign words) by learning them when you visit a place never seen before, or do in general something new. Concerning long term memory, a more detailed discussion distinguishes between declarative memory (that includes what we called semantic and episodic memory) as things that we recall by speaking and non declarative memory or things that we recall by doing. Declarative memory is based on hippocanpus and is also called explicit. Non declarative memory is based on parts of the brain different from hippocampus. Non declarative memory includes implicit i.e. memory at work when we remember how to do things. It includes also procedural memory : this is at work in priming, conditioning, etc... Mnemonics tricks[Added July 1996] I am fascinated from memory and also from tricks people use to improve it. These tricks in the past formed the "Art of Memory" and were to be known by any instructed people,since there were no other means readily available to register knowledge. One simple trick can be found here .The memory for stories:myths[Added July 1996] There are many kinds of memory and a single remembering is stored in our brain in many different places.This is like the recording of movies with a soundtrack separated from images:but in the brain you have recording about a lot of things in parallel. For example:images,sounds,smell,etc Among these different ways to store the material,one of the most powerful, concerns our capability to connect material in a story.This is the base of the mythic(sp) knowledge.For example myths(stories) have been built about Science.Memory and emotion[Added July 1996] There is a deep connection between memory and emotion.We never forget facts connected to deep emotions.This is exploited in mnemonics in the method of loci used since antiquity. You had to use a well known building where you use some well known places as loci.The items to be remembered would be attached by means of striking images to these loci.More striking are the images,more chance you have to remember the items.It is here that the emotion plays its role.The brain stores emotional memories very differently from unemotional ones. Negative emotional memories are stored with more details than positive memories.Traumatic memories appear to be captured by two separate parts of the brain: the hippocampus, the normal seat of memory, and the amygdala, one of the brain's emotional centers. The hippocampus is responsible for normal conscious long term memory, the amygdala for subconscious memories. So it may happen that a situation that has caused you some harm in the past can make you uncomfortable although you don't understand why. |
