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Current time:0:00Total duration:4:33

Video transcript

we all know that our memories aren't perfect as frustrating as it can be we forget people's names birthdays and other things we'd like to remember one reason for getting happens is the very normal process of decay when we don't include something well or when we don't retrieve it for a long time we become unable to retrieve it later one theory about why this happens is that the pathway to and from the memory meaning the neural connections between the cues and the memory become weaker over a period of disuse so it becomes harder to stimulate those neurons this is sort of the classic use it or lose it problem if you learn something once and don't ever revisit the memory it's likely to decay over time one interesting pattern of decay is that it seems pretty consistent even for different types of materials your initial rate of forgetting is very high but it levels off after a period of time back in the late 1800s the German philosopher and psychologist named Ibanez was the first person to really look at the decay in human memory he made himself learned a bunch of three-letter nonsense syllables and then he tested himself to see how much he remembered at different time intervals from zero to 30 days he found that his rate of forgetting was very rapid at first if he remembered those words after a few days however then he generally remembered them for all 30 days later on people replicated this pattern with different materials and over different time intervals and they found that the more integrated the initial learning is the more stretched out the rate of forgetting is but it still follows the same pattern for example if you study a language for a few years then it'll take you more than a few days to forget it similar to Ebbinghaus is original for getting curves though most of your forgetting will occur within the first few years of disuse after that point you're forgetting will pretty much level off the interesting thing about decay and forgetting is that just because you can't retrieve something doesn't mean it's completely gone from your long-term memory other than outright retrieval one way we can tell if people have learned something before is by how quickly they relearn that information or skill so remember ABing house in addition to forgetting he studied relearning with those same three-letter nonsense syllables he found that even if he couldn't produce all the syllables from his list it took him less time to learn the list the second time around than the first time indicating that some foundation of the memory still existed even though he couldn't produce it at the time this foundation is called savings because it's what saved in your memory whether you realize it or not relearning works with procedural skills too for example imagine that you learned how to play a particular song on the piano a few months ago but you can't play any of it today now I give you the music to that song and ask you to learn it again if the inability to retrieve something meant that it was completely gone from your long-term memory then it would take you the same amount of time to learn the song the second time around however it probably would take you less time to relearn it than it did for you to learn it originally in this faster rate of relearning tells us that you still have some information about that song stored in your long-term memory sometimes decay isn't the problem though it's that something else seems to be blocking our ability to get to the information we want this experience is called interference and there are two main types retroactive and proactive retroactive interference is interference that goes backwards that is some new piece of learning seems to reach back and impair your ability to retrieve something you used to know for example when you move to a new place you get used to writing your new address on all the different forms and documents and stuff and after a while of using this new address you may find it difficult to recall your old one in this case your new address would be running some retroactive interference on your old address proactive interference on the other hand is interference acting forward something you learned in the past gets in the way of your ability to learn and retrieve something correctly in the future so I'll give you an example of something to happen to me a few months ago it used one password for my email for a really long time but then I had to change it sometimes when I log in it's still hard for me to remember what my new password is because all I can come up with is the old one in this case is the prior learning of my old password is impeding my ability to remember the new one