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

Summary

The video script explores the brain's complex process of information processing, comparing it to a computer. It delves into sensory memory, including iconic and echoic memory, and the limited capacity of working memory, which is about seven items. The script explains the components of working memory, such as the visuo-spatial sketchpad and phonological loop, and the central executive's role in coordinating them. It also distinguishes between explicit (declarative) and implicit (non-declarative) memories, highlighting the unlimited capacity of long-term memory and its various types, including semantic, episodic, procedural, and priming.

Takeaways

• 🧠 The brain processes information similarly to a computer, using an information-processing model with input, processing, and output stages.
• 👀 Sensory memory is the first stage of processing, including iconic memory for visual information and echoic memory for auditory information, each lasting different durations.
• 🕒 Visual information in sensory memory is vivid but fleeting, lasting less than half a second, while auditory information lasts around three to four seconds.
• 🤔 Working memory, also known as short-term memory, holds about seven plus or minus two pieces of information at a time, influenced by complexity and age.
• 📞 The concept of working memory capacity is why phone numbers were traditionally seven digits long, as it's the optimal amount of information for people to remember without confusion.
• 🎨 The visuo-spatial sketchpad processes visual and spatial information, while the phonological loop handles verbal information, including words and numbers.
• 🔄 The central executive in working memory coordinates the efforts of the visuo-spatial sketchpad and the phonological loop, creating an integrated representation.
• 🔗 The episodic buffer acts as a connector to long-term memory, storing integrated representations that combine different types of information.
• 💾 Long-term memory is the final stage, capable of storing a vast amount of information with different components for explicit (declarative) and implicit (non-declarative) memories.
• 📚 Explicit memories include semantic memory for facts and episodic memory for events, while implicit memories involve procedural memories like riding a bike and priming which influences interpretation of events.
• 🌀 Long-term memory's capacity is believed to be unlimited, unlike the limitations of processing information at any given moment.

Q & A

What is the information-processing model of the brain?

The information-processing model is a conceptual framework that likens the brain to a computer. It suggests that the brain receives input from the environment, processes this information, and then outputs decisions based on that processing.

What is sensory memory and what are its two main components?

Sensory memory is a temporary register of all the information the senses are taking in. Its two main components are iconic memory, which is memory for what you see, and echoic memory, which is memory for what you hear.

How long does visual information last in sensory memory?

Visual information in sensory memory is incredibly vivid but only lasts for less than half a second.

Compare the duration of auditory information to visual information in sensory memory.

Auditory information in sensory memory lasts longer than visual information, approximately three to four seconds, compared to less than half a second for visual information.

What is working memory and how is its capacity typically described?

Working memory, also known as short-term memory, is what you're thinking about at any given moment. Its capacity is typically described by the 'magic number seven', meaning it can hold about five to nine pieces of information at a time.

Why were phone numbers initially seven digits long?

Phone numbers were initially seven digits long because that was determined to be the optimal number of pieces of information a person could hold in mind without getting them confused or mixed up, based on the capacity of working memory.

What are the two main components of working memory and their respective functions?

The two main components of working memory are the visuo-spatial sketchpad, which processes visual and spatial information, and the phonological loop, which processes verbal information such as words and numbers.

What role does the central executive play in working memory?

The central executive in working memory acts like a traffic cop, coordinating the efforts of the visuo-spatial sketchpad and the phonological loop, helping to create an integrated representation for storage in the episodic buffer.

How does the episodic buffer function in the information processing model?

The episodic buffer acts as a connector to long-term memory, storing integrated representations that combine information from both the visuo-spatial sketchpad and the phonological loop.

What are the two main categories of long-term memory and their characteristics?

The two main categories of long-term memory are explicit memory, which includes facts and events that can be clearly described (semantic and episodic memory), and implicit memory, which involves unconscious memories such as procedural memories and priming.

What is the difference between semantic memory and episodic memory?

Semantic memory is a type of explicit memory that deals with the general knowledge of facts, such as the meaning of words. Episodic memory, also explicit, is memory for specific events or episodes, like remembering your last birthday party.

How does priming work as a type of implicit memory?

Priming is a type of implicit memory where previous experiences influence the current interpretation of an event. For example, if you were recently exposed to a picture of a bunny, you might be more likely to think of 'hair' as 'H-A-R-E' when prompted, due to the priming effect of the bunny image.

Is there a limit to the capacity of long-term memory?

As far as we know, the capacity of long-term memory is unlimited, meaning the brain can store an extensive amount of information without becoming 'too full'.

Outlines

00:00

🧠 Understanding the Brain's Information Processing

This paragraph delves into the brain's complex process of taking in and recalling information, introducing the information-processing model. It likens the brain to a computer, emphasizing the input, processing, and output stages. Sensory memory, including iconic and echoic memory for visual and auditory information respectively, is highlighted, with the former lasting less than half a second and the latter around three to four seconds. The paragraph also touches on working memory, which can hold about seven items at a time, and its components like the visuo-spatial sketchpad and the phonological loop. The central executive's role in coordinating these components and the episodic buffer's function as a connector to long-term memory are also discussed.

05:02

📚 Types of Memory: Explicit and Implicit

The second paragraph explores the types of long-term memory, distinguishing between explicit (declarative) and implicit (non-declarative) memories. Explicit memory is further divided into semantic memory, which deals with general knowledge, and episodic memory, which stores personal experiences. Implicit memory encompasses procedural memories, like riding a bike, and priming, which influences current interpretations based on past experiences. The paragraph also addresses the misconception that the brain can become 'full,' clarifying that, unlike a computer, the capacity of long-term memory is believed to be limitless.

Keywords

💡Information-processing model

The information-processing model is a conceptual framework that likens the human brain to a computer, suggesting that it receives input, processes it, and outputs decisions. This model is central to the video's theme as it provides a foundation for understanding how we take in and make sense of information from our environment. The script uses this model to explain the stages of memory, from sensory input to long-term storage.

💡Sensory memory

Sensory memory, also referred to as the sensory register, is the initial stage where all sensory input is temporarily registered. It is crucial for the video's narrative as it sets the stage for how we first interact with information from our surroundings. The script mentions iconic and echoic memory as components of sensory memory, highlighting their distinct durations and roles in retaining visual and auditory information.

💡Iconic memory

Iconic memory is a specific type of sensory memory that deals with visual information. Defined as the memory for what we see, it is vivid but lasts for less than half a second. The video uses iconic memory to illustrate the brief yet impactful nature of our initial visual perception, emphasizing its role in the information processing sequence.

💡Echoic memory

Echoic memory is the component of sensory memory responsible for auditory information. It lasts longer than iconic memory, approximately three to four seconds, allowing us to retain what we hear for a short period. The script uses echoic memory to explain how we can recall the last thing someone said to us, even if we momentarily tune out of a conversation.

💡Working memory

Working memory, also known as short-term memory, is where we process the information we decide to pay attention to. The video emphasizes its importance by describing it as the current focus of our thoughts and highlighting its capacity to hold about seven items of information at a time. The script provides the example of phone numbers, which were historically seven digits long to match this capacity.

💡Visuo-spatial sketchpad

The visuo-spatial sketchpad is a component of working memory that processes visual and spatial information. The video explains its role in handling images and maps, illustrating how it contributes to our ability to process and remember visual data. The script uses it to show how we can mentally manipulate visual information.

💡Phonological loop

The phonological loop is another component of working memory that processes verbal information, such as words and numbers. The video script uses the example of repeating a phone number to oneself to demonstrate how the phonological loop helps in temporarily retaining and manipulating verbal information.

💡Central executive

The central executive is a concept within working memory that coordinates the activities of the visuo-spatial sketchpad and the phonological loop. The video likens it to a traffic cop, emphasizing its role in integrating different types of information. The script uses the central executive to explain the coordination of visual and verbal processing in complex tasks like reading a map.

💡Episodic buffer

The episodic buffer is presented in the video as a connector to long-term memory, responsible for creating an integrated representation of information. It is crucial for the video's message as it explains how information from working memory is consolidated and prepared for long-term storage. The script highlights its role in linking short-term processing with long-term retention.

💡Long-term memory

Long-term memory is the final stage in the information processing model, where information is stored for extended periods. The video script discusses its capacity, suggesting it is unlimited, and differentiates it into explicit and implicit memory types, providing a comprehensive view of how we retain information over time.

💡Explicit memory

Explicit memory, also known as declarative memory, refers to facts or events that can be consciously recalled and described. The video script explains its two subtypes: semantic memory for general knowledge and episodic memory for personal experiences. It uses explicit memory to illustrate how we remember and articulate information.

💡Implicit memory

Implicit memory, or non-declarative memory, includes memories that we may not be able to articulate, such as procedural memories for skills like riding a bike. The video script uses implicit memory to show how our past experiences influence our actions and interpretations without conscious effort.

💡Priming

Priming is a concept within implicit memory that describes how previous experiences can influence current interpretations. The video script provides the example of the word 'hair' being influenced by recent exposure to a bunny picture, demonstrating how priming affects our cognitive processes.

Highlights

The brain processes information similarly to a computer, with an input, processing, and output system.

Sensory memory is the first stage of information processing, registering all sensory inputs.

Iconic and echoic memory are specific to visual and auditory information, lasting less than half a second and about three to four seconds, respectively.

Working memory, also known as short-term memory, holds about five to nine pieces of information at a time.

The capacity of working memory is defined by quantity rather than time.

Phone numbers were historically seven digits long to match the capacity of working memory.

Working memory processes different types of information through the visuo-spatial sketchpad and phonological loop.

The central executive coordinates the visuo-spatial sketchpad and phonological loop for integrated processing.

The episodic buffer acts as a connector between working memory and long-term memory.

Long-term memory is like hitting the Save button, capable of storing vast amounts of information.

Explicit memory includes semantic and episodic memory, dealing with facts and events.

Implicit memory encompasses procedural memories and priming, influencing actions and interpretations without explicit awareness.

Procedural memory allows us to perform tasks like riding a bike without needing to consciously remember how.

Priming shows how past experiences can influence current interpretations of events or words.

Long-term memory's capacity is believed to be unlimited, contrasting with the processing limitations of working memory.

The information-processing model is conceptual and does not describe the physical locations in the brain.

The model highlights the importance of attention in selecting what information moves from sensory to working memory.

Different components of memory specialize in processing distinct types of information.

Transcripts

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.