Information processing model: Sensory, working, and long term memory | MCAT | Khan Academy


Take a second to think about
everything you’ve done today. You’ve taken in way more
information than you could possibly remember
in detail– things you’ve seen, heard, smelled,
touched, and tasted. But somehow, some
information gets stored in a way that
lets you access it later. So what makes this process work? Our brains are
really complicated, so scientists have
come up with models to represent how our brain
takes in and makes sense of information in
our environment. One of the most
influential models is the
information-processing model, which proposes that our brains
are similar to computers– we get input from the
environment, process it, and output decisions. It’s important to note that
this model doesn’t really describe where things
happen in the brain. It’s more conceptual. The first stage, then,
is getting the input, which occurs in sensory memory. This is sometimes also
called the sensory register, so if you hear that
term, just know it’s the same thing
as sensory memory. And this is where
you first interact with the information
in your environment. It’s a temporary register
of all the information your senses are taking in. Even though you
have five senses, the two most studied in terms
of memory are sight and sound. So within sensory
memory, you have iconic memory, which is
memory for what you see, and echoic memory, which is
memory for what you hear. One of the really interesting
things about sensory memory is that it lasts a
different amount of time depending on the modality of
the information coming in. So visual information
is incredibly vivid, but it only lasts for
less than half a second. Auditory information. on the other hand, lasts
a little bit longer. It lasts for about
three or four seconds. So if you’ve ever tuned
out of a conversation and your friend gets mad that
you’re not listening to them, you can thank echoic
memory for helping you remember the last
thing they actually said. So we have a ton of information
coming into our sensory memory, but we can’t possibly
process all of it. We decide what to
pay attention to, and that gets passed along into
working memory to be processed. Working memory is
just whatever you’re thinking about right
at this moment. And it’s also called
short-term memory, but we’re going to stick
with working memory because that’s what
psychologists call it. Working memory capacity works
a little bit differently. It’s not defined by time
so much as quantity. Just remember the
magic number seven. Your working memory can hold
about seven plus or minus two pieces of information at
a time, so about five to nine. This does vary a
little bit based on how complicated those
pieces of information are, how old you are,
that kind of thing. But generally, it’s
right around seven. And an interesting fact
is that this is actually why phone numbers started
out as seven digits long. It was determined that that’s
as many pieces of information as a person could hold in
mind without getting numbers confused or mixing them up. And just like sensory memory
has different components for different types of
input, working memory has different
components to process those distinct types of input. Visual and spatial information,
like pictures and maps, are processed in the aptly-named
visuo-spatial sketchpad, while verbal information,
meaning words and numbers, are processed in the
phonological loop. Again, think of
repeating a phone number to yourself just long
enough to type it in. That’s using your
phonological loop. Be careful here, though. “Verbal information” means
any words and numbers, so words and numbers you heard that
came from the echoic memory, and words and numbers you saw
that came from iconic memory. So we’ve got a little bit
of mix-and-match here. Now, you might be thinking
that sometimes you need to process
input place that has verbal and visual
information together, such as a map with street
names and landmarks. In that case, you need
someone to coordinate the efforts of the
visuo-spatial sketchpad and the phonological loop. So something called the central
executive fills that role. You can think of him kind
of like a traffic cop who directs the other components
of working memory. Once the central executive tells
the visuo-spatial sketchpad and the phonological
loop to coordinate, then they create an
integrated representation that gets stored in the
episodic buffer, which acts as a connector
to long-term memory. Long-term memory
is the final stage in the information
processing model. When stuff gets in here, it’s
like hitting the Save button on your computer. Unfortunately, our memories
aren’t quite as foolproof as that. It doesn’t work perfectly. But we can store a
lot of information in long-term memory. Once again, there are
different components that specialize in
different types of memories. We have two main categories–
explicit, also called declarative, and implicit,
also called non-declarative. As you can see,
psychologists like to give these things
multiple names, but fortunately,
they can generally be broken down
into something that makes sense, so don’t
get intimidated. Explicit memories, for
example, are facts or events that you can clearly
or explicitly describe. So any time you take a
vocabulary test or remember the state capitals, you’re
using a specific type of explicit memory
called semantic memory. And “semantic” just means
“having to do with words,” so you can think
about it as being able to remember simple facts
like the meaning of words. A second type of
explicit memory is called episodic memory,
which is memory for events, like your last birthday party. Just like a TV episode
is a sequence of events, your episodic memory stores
event-related memories. While explicit memories
are easy to define, implicit memories are
a little bit fuzzier. They involve things you may
not be able to articulate, such as how to ride a bicycle. You probably can’t
say clearly how much pressure to put on the
pedals or exactly how to turn the handlebars. But provided that you ever
learned in the first place, if you get on a
bike and just do it, you probably won’t fall over. Memories for procedures
like riding a bike are conveniently called
“procedural memories.” The last type of
implicit memory is called priming, which means that
previous experience influences your current
interpretation of an event. For example, if I say the word
“hair,” what do you think of? If you paid attention at
the beginning of this video, then you might have thought
of “hair” as “H-A-R-E,” meaning “rabbit,” because you
were primed with the bunny picture at the beginning. Your recent experience of seeing
a bunny stayed in your memory and influenced your
interpretation of the word that I said. If you weren’t paying attention,
or if you’ve maybe had to push your hair out of your face
in the last few minutes, then you might have thought
of “hair” as “H-A-I-R,” because it’s generally
a more common word. With all these
components of memory, you might be wondering how
much it can actually hold. I think we’ve all had the
feeling that we can’t possibly take in any more information,
and while it might be true but you can’t process any more
information at the moment, unlike like the computer in
front of you, as far as we know, long-term memory
capacity is unlimited. So your brain
never actually gets too full for more information.

53 Replies to “Information processing model: Sensory, working, and long term memory | MCAT | Khan Academy”

  1. Very good video, but in my AS psychology course we call the model proposed by Baddeley as Working Model of Memory

  2. sad that LTM has just as much to do with intellilgence as all the Short Term/Working memory, but most tests of intelligence do not measure LTM efficiency.

  3. Do hallucinations in schizophrenia disrupt working memory and thus effect short term memory or long term memory?

  4. your videos are very educational and goes directly to the long term memory . thank you very much I m in your debt

  5. Where is the 3 types of Memory
    Majority types of Memory
    STM-Short Term Memory
    LTM-Long Term Memory
    EM-Episodic Memory
    SM-Sensory Memory

  6. there are two more types of implicit memory-
    Associative/classical conditioning and non associative.
    Great lecture.Ty!

  7. You finished that on the best note! Unlimited sounds awesome to me. 😁

  8. It might be worth including the 6th and 7th senses in this as well (vestibular and proprioception).

    "The vestibular system explains the perception of our body in relation to gravity, movement and balance.

    Proprioception is the sense of the relative position of neighboring parts of the body and strength of effort being employed in movement."

    This would mostly explain the implicit/procedural memories, such as riding a bike, etc.

  9. great Video, the explaniations are simple and easy to take, futhermore its include all the informations it has to. thanks !

  10. i love your wonderful voice, also the way you deliver the information is easy to understand, grasp and remember, cute !!!

  11. I had a process come to me out of nowhere. I called it source processing kinda like the computer concept but if you really understand the whole process of the brain than u can manipulate the system by creating a super self processing software that organize and prepair specific sources to be stored in specific memory for optimal processing which unlike all other theories I heard instead of only long term memory you break through to Subconscious memory which is SELF PROCESSING and pretty much creates knowledge on its own useing thousands of sources by cross referenceing sources and altimally rearranging irrelevant sources. Warning if you don't have a foundation to receive this knowledge i personally think once you fall into subconscious you can loose it because you don't control your subconscious I'm not a neurologist, scientists, etc. I just thought about it tried it and the shit work. I can hear a subject and come up with an equation for processing it effectively.

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