Lecture 26: Forgetting - II

[Music] [Music] hello I welcome you all in the lecture series of memory today we are going to talk about forgetting extending our discussion we did in previous lecture in previous lecture we talked about forgetting the relevance importance of forgetting classical experiment of Herman amingos his proposal of saving method and his contribution to the memory research forgetting curve further the line we also studied about the criticism of forgetting curve today we are going to understand forgetting in little bit more detail with few examples forgetting motor skills do we forget motor skills or do we not forget motor skills why why do we forget some motor skills and why we do not forget some motor skills what we have learned from the empirical works of memory researchers that motive skills are resistant to forgetting they are more robust in nature unlike the semantic information which requires lot and lot of rehearsal and even then we may forget some information the name and detail of our colleagues friends whom we met 5 years 10 years 20 years back but we never forget how we ride bicycle even if you have ridden the bicycle 20 years back or driving a motor car or cooking is specific dish so learning to ride a bike swim es skateboard in childhood can get us engaged in those activities again without much trouble even after absence of years now the absence of year can be seen as 5 10 years 15 years 20 years or more the skill the motor skill has been classified into two types these two classification suggest and give us an hint how do we become resistant to forgetting so first classification closed Loop classification where we talk about the continuous skills each action cues the next action what are you going to do next when each action becomes a Quee then it becomes a circular in nature action one becomes Q for the action two action two becomes Q for Action three action three become Q for Action Four similarly action five action six action six become the Q for action one and formation of this circular cues a closed loop continuous loop make your memory more and more resistant make your memory undergo over learning again and again and again and again the moment you are performing action one all the other actions get activated that we are going to be called get ready the other type of a skill is the open loop skill each action is in response to different stim handwriting and typing it changes over period of time in response to different different nature of stimul present when you are typing typing of letters will be different from typing of numbers handwriting will also vary from stimuli to stimuli this is open loop but this motor skill this motor skill become also resistant to change with decade to decade also changes due to physical interference also you may your handwriting may be may become bad once you develop Parkinson's so you know how to write but your physical disability May intervene in that case so the closed loop skills are more resistant to forgetting compared to open loop skills here the rehearsal is not happening we do not practice our handwriting as we used to do in our kindergarten calligraphy but once we have learned no doubt we can use it but still we need some few Trials of practice so among the two classification which is more robust which is more resistant is the Clos Loop note some skills are complex than the others a study has been conducted where a group of people trained and given a training for CPR to save the life under life and death situation 100 people were given this training what we what we saw that when these individuals didn't practice their expertise dropped from 100% to 15% within a year what does this indicate it doesn't indicate first thing uh that it is closed loop belongs to closed loop or open loop but it indicates some motor skills are way complex than the others the motor skill which is becoming resistant to forgetting is because the skill may not be that complex as the other skill like CPR some skills some abilities are more complex than the others based on the nature of complexity and ambiguity of the task the forgetting depends upon so if the task is simpler in nature then the retain drop will not be that much so if the task is not the CPR but measuring the fever because it is very simple with the thermometer it just requires to read the mercury thermometer what is the reading such task are more simple as a result forgetting will be less forgetting event events over time now warington and Sanders use the headline from the newspaper that more than 30 years ago and then they tested their participants memory for this event so they invited a group of individual and they collected the information from the newspaper 30 years ago the time when these young middle-age individuals were in a school these individuals were being tested about the information of the event what we noticed is that forgetting is occurring moreover younger participants had better memory for both the recent and the past older events but the elderly participants they had challenge they had a challenge to remember the old information they didn't have any problem in remembering the recent event what does this mean with hm case we understood that the old information become independent of a structure so once the information is becoming independent of a structure then it doesn't depend on Hippocampus because the memory may be dependent on different parts of the brain and when the memory is become has become old and independent of its structure then this means that when these elderly individuals has to recall the information from these regions recall may be a challenge maybe their working memory capacity is not not as normal as it used to be when they were young but one thing is very clear with this warington and sandal experiment that young individuals they have better advantage over the elderly they're not only able to retrieve information from the recent past but and old events also Warrington did this test with 392 High School Al Li for their abil ability to recognize the classmates and recall their names using High School yearbook barck reported that these high school students failed to recall the name of their friends the rate to forgetting the content was relatively slow but the specificity of information that is recognizing the face or name remained at 90% for at least 15 years 15 years in past they are able to retrieve the information more years back if you go back that seems to be impaired so the ability to recognize face remained at 90% for at least 15 years and it stayed high for over 30 years it remained high but not that high as 15 years lot of practice and overlearning the process of his studying more than is necessary rehearsal overlearning is a practice every time you are do doing a rehearsal you are practicing it practice effect over memory is well established concept and idea the more you practice the more over learning you do the more rehearsal you do you're making memory resistant to forgetting as a result memory stays for long period of time memory decline is directly associated with aging rather than normal forgetting so one thing is very clear people are not able to recall or remember is not because of the normal forgetting but because of the Aging in previous lectures we have talked about the hierarchical network model in that hierarchical Network model we discussed about the networking the association the depth of Association the widening of the association in elderly this Association starts getting compromised as the time passes by barck also suggested that memory store that is resistant to change is known as PMA store PMA permanent permanent storage per my store longlasting Bar's finding made him suggest made him recommend that forgetting and Distortion should not be seen together should not be considered similar they are the separate processes now when we talk about the forgetting over lifespan how it is behaving the role of forgetting so childhood Amnesia we know the deficiency in our ability to recall the event Early Childhood event when we were 5 months old 11 months old one year old 2y old and maximum three year old as per the few studies and documentation it doesn't mean necessarily that we are not able to remember or recall or retrieve the information doesn't exist there that early memory is completely gone lost it may be there but in some different form which we are not able to remember if we will remember the nature of its is encoding and the storage then we will retrieve it boo boo c c kind of information the sound articulation production of words m m p we it may be there but we are not able to retri it childhood Amnesia is like a memory wall at around age of three which tries to inhibit block us not to reach reach to that level of information now after the age three then the autobiographical memory becomes richer over period of time some autobiographical memory we forget we do not remember but most of the information we try to keep it a steady and resistant forgetting events over period over the lifespan prospective studies in such studies researcher ask the childrens to recollect some memories and then these memories are being tested and these individuals are being tested on these memories after some period of time to understand how much information they can retrieve retrospective studies where the direct comparison between children and adult is being made who remembers the information more and better using the same identical research method what researchers have reported that in both children and adult with with with respect to retrospective Studies by the way that both children adult will report on the early childhood memory or both will generate memories in response to a qword to the shape of distribution of memories which can be grafted so they have to provide generate a memory in response to the Q word the causes of childhood Amnesia the first and the basic cause is the less linguistic ability the mental lexicon lexicon is not there mental is getting started people are trying to form the information formulate the knowledge these young individuals do not have memory in their system so they lack linguistic ability and we when we talk about the linguistic ability we have to talk about the lexical processes and non-lexical processes they may be having high non-lexical processes but the lexical processes still need to be developed in these individuals one may look into a dual root Cascade model lack of strategies for encoding the the information like using the cues at the time of learning is helpful but is is helpful cues are helpful for us priming is helpful for us even but with these young individuals the understanding about the Q and using Q as an strategy for encoding and storage is challenging bin is still under development allowing for processing and is storing personal information it has it hasn't been developed yet as a result these individual cannot form a resistive memory their memory cannot be strong enough to be used in later part of their life as a result their memory become inhibited as a result we are not able to retrieve the information Less Than 3 years another reason for childhood Amnesia is the theory of mind which means children can understand that other people have mental states that are not shared with themselves some people can have different emotional reaction to the same event or understand the event differently theory of mind so in young adults the lack of theory of mind is there as a result the childhood Amnesia arises now remnance recollection of information recollection of memories recollection bump and increase in memory between the ages of 10 and 30 between 10 and 30 we see a bump before dropping of again so all reported memories as we age after 30 it is increasing after 10 to 20 decreasing and 30 decreasing before the bump again before the rise before the rise there is a decrease for the participant over 35 years there is a period of a stronger recall above 35 years the recall C should be higher higher than this higher it is on Rise now this remnance bump which is happening above 35 years in these individual because of of his or her Consolidated experience and information till the age of 35 an individual is now utilizing that Consolidated experience and Consolidated knowledge this consolidation of information usage is giving a bum in the stronger recall poon not principle this principle suggest more recall we do for the positive events than the negative events but as I mentioned earlier in some scenario more recall is seen for the negative event than the positive event Gluk and black also found that only positive events Stand Out leaving the uh negative events inactive nonsignificant in nature sad memories tend to be recalled evenly across the lifespan it is easy to recall the sad memories over the entire lifespan so remnance bump scene between the age of 10 and 30 participants over 35 years of age has a strong recall more recall is there for positive event and then the negative event positive event seems to stand out and sad memories tend to be recalled evenly across the lifespan now let us understand why this bump is there in the recollection of information three basic Theory the first Theory self narrative hypothesis which suggest that the person develops a sense of his or her identity in a narrative or a story form and has compiled the memories to support it so when the compilation is there repository is al already formed memory bank is already being built mental lexicon is ready then collection of these memory and the bump is easy to observe so self narrative hypothesis information related to myself related to my personal story life is script hypothesis the bump is due to forming a script about our lives instead of separate narratives when we are talking about the bump due to forming a script we are talking about the gestal principle holistic approach whole is important than some of its part so life script hypothesis seems to be beneficial seems to increase our repository and this gives us the bump remance bump the idea is tied to Eric's psycholog psychosocial development theory proposing that we make memories Central about ourselves that is self-defining any information the moment you associate it with yourself the res it becomes resistant it becomes robust and becomes prone to disruption sorry uh um not prone to disruption it becomes strong enough you can can not be uh impair it it become resistant to disruption the moment you attach it to yourself the last Theory talks about uh and suggests on remin B is convis self-memory system these memories point to longterm personal con Concepts longterm personal cont Concepts we hold about ourselves and unresolved conflicts Cony is talking about the self memory system the moment you attach to yourself the moment you attach to your person personal um belief system to yourself then the personal concept makes the memory more and more robust and resistive to change so let us summarize what we studied in this lecture forgetting motor skills some skills we may forget some skills we may not forget because some skills are more complex than the other the classification of motor skills we studied about the closed skill open skills in closed skill every action becomes a cue to the following action and that is why Clos skill is more resistant towards forgetting forgetting of events or period of Time how are we forgetting the information the information which is not personal to us the information which is not self to us over a period of time we try to remove the irrelevant information the simple reason for such removal is to maintain the memory it cannot be the storhouse for all types of memories all types of information because presence of all type of information relevant and irrelevant May create confusion how the forgetting of event happening over lifespan the childhood Amnesia the nature of childhood Amnesia why this barrier is there have we lost the information about our childhood memory or is it the problem of retrieval why such inhibition is there does it have evolutionary benefit what leads towards childhood Amnesia and finally the remnance bump why is it happening what why what is the importance of remnance bump why an individual feels this bump is there is it because of the repository which has increased the Lexicon which has increased the capacity to your working memory to hold information has increased or is it because of the self because you have attached Associated the information to yourself let us stop here and in next lecture we are going to continue talking about the forgetting thank you [Music]