Semantic Networks and Spreading Networks – Memory (PSY)

00:01 So let’s take a look at another really interesting thing which is networks and what they play in terms of memory recall and memory storage.

00:09 So information stored in a long-term memory is done in an organized network and this is really cool.

00:14 And what we’re saying is that things aren’t just arbitrarily thrown in your brain, in long-term memory, and the analogy I like to use is a computer again or you can go to a library, is that books are stored long-term in areas that are quite organized and that makes sense.

00:32 So there’s a network, right? So you have sort of all the periodicals in a certain spot and you have all the reference books and the maps analysis and it’s organized and so that there’s some consistency, but they’re all linked, right? So you can have different types of maps, you can have atlases.

00:46 They’re all in that area of maps, but there’s a network.

00:49 If you think of a computer, you’re going to have things organized in certain folders and subfolders and subfolders of the subfolders, and that organization allows you to improve and understand your access.

01:00 So, individual ideas or hubs are called nodes.

01:03 And so as you can see from this diagram, we have the first node, which is animal. Okay? So you also have a bird and so, how are those two connected? Well, a bird is an animal.

01:13 And then you have another term or a thing that you can have in your memory, which is plumage or a canary and Tweety, and you could see how they’re all linked.

01:20 So Tweety is an instance of a canary, and the canary is a type of bird, and a bird has plumage or feathers, and then you might have another one that says “Seeds".

01:28 Birds eat seeds,” so there’s a linkage.

01:30 Okay, that’s the point that I want you to understand, is there’s a linkage or a network.

01:34 Now, nodes are connected by associations.

01:38 That’s what we’re going to call -- that’s what we call the lines in between each of these nodes, is association.

01:43 The strength of the association is related to how frequently and deeply the connection is made.

01:48 So, you know, for us, bird and say seeds or canary, that -- that connection is going to be fairly relevant.

01:58 It’s going to be commonly used because -- you know, or bird, feather, and flight.

02:02 Those are three words that are highly connected and when you think of bird, a lot of times you do think of flying or you think of feathers.

02:08 So there’s a deep connection, as opposed to bird and maybe flu.

02:14 Like, well, how does bird and flu connect? There is a connection, but you got to work through that.

02:20 Well, years ago we had an epidemic of avian flu, and avian means bird, it was bird-derived, and that’s a type of bird.

02:28 So bird and flu, there’s a connection, but it’s fairly weak and it’s not as deep and so therefore, it’s going to be harder to recall.

02:36 Now, why do we even care about this and what impact does this have? Well, it’s going to lead to -- increased connections leads to increased recall and the more you recall something, the stronger it is in your memory.

02:49 So like I was saying to you before, you might have things in your memory that you don’t access very often.

02:53 The less you access something, the less it’s activated, the easier it is for you to lose it.

02:59 Okay? So let’s take a look at some examples here.

03:03 So nodes are only activated once they reach a certain threshold.

03:05 So if I say to you right now, banana.

03:11 The word “banana” kicks in, you hear what I say, that gets processed and you’re activating parts of your memory and you’re going to say, “Banana.” And now you’ve actually activated that network.

03:22 There are words associated with banana that I have just activated in private.

03:27 But have I activated every word associated with banana? The answer is no, because I need to achieve a certain threshold or limit of activation.

03:34 Now, the words that are really tight with banana like maybe yellow, monkey, bread.

03:42 Who knows? It’s kind of individual.

03:43 But all the words that are really tightly associated with banana get activated and there’s other words that are -- can be linked to banana, but really, I didn’t reach the threshold, I didn’t activate them, and so, they’re really not brought to the forefront.

03:56 Now, response threshold is reached by the summation of input signals from multiple nodes.

04:01 So the more connections a word has and the more that word gets activated via those networks, the more likely that you will remember those words.

04:10 So there are words that we say all the time.

04:12 It recalls us of stories, times.

04:14 It makes it very easy to remember those words.

04:16 And there are words that we barely ever use or concepts that don’t come up very often.

04:21 So activation of a node leads to stimulation of neighboring connected nodes.

04:24 So I say bird, and that by me saying bird, I have activated plumage, canary, Tweety, and animal, and I have to have achieved a certain response threshold for me to actually activate that.

04:36 Now, bird might also be connected to something else which, I don’t know, is connected to the word “farm” and it’s also connected to the word “zoo.” So if I’m saying zoo a lot and farm a lot, those are also activating bird.

04:50 So collectively, you add all that up, and the word “bird” in my mind gets activated a whole lot, and therefore, memory of that word is quite high.

04:57 So there’s another example of that spreading network.

05:00 So the activation of a few nodes can lead to a pattern of activation within the network that spreads onward activation known as spreading activation.

05:08 So in this example I have the word “beer,” one of my favorite words.

05:12 You say the word “beer” and all of a sudden what happens? Different words start getting activated -- good times, party, friends, success, sex, women.

05:21 If you’re a woman saying it, could be -- it could be men, and these are all words that are somehow related to beer and, again, this can be very individual.

05:30 For some people beer might mean, you know, like I hate it, vomiting, sick, you know, jail, or it can mean a whole bunch of things, divorce.

05:38 So the words themselves and the connectivity is quite individual, but the process that I’m talking about of spreading activation is a consistent theme.

05:47 So it also explains contextual cues, priming, and associations.

05:51 So if I say -- if I say the word “beer” and all of a sudden I’m asking you, what is one of your favorite beverages? I said the word “beer” and I’ve activated the system so I’ve kind of primed you.

06:07 And you might say, “Well, geez. You just said beer, I’ve been thinking about beer, so, yeah, I love beer. I also love milk and I love juice.” Okay.

06:16 Well, a lot of times they’ll have this phenomenon where they’ll flash a word and this is -- this is still for debate, but they have this subconscious word where they’ll prime you with a flash of a word and I had done this in another lecture.

06:30 If I were to say red and I keep talking about something else, and you heard the word “red,” we discuss something else, and then I now ask you, “Okay, can you name your favorite fruit?” Now, I said fruit but I had primed you with the word “red.” Red activated all the things that you know that are red -- red lips, red liquorice, red food which is strawberries, cherries, and so on, and so on.

06:55 And so now when I’m asking you a completely unrelated question or you’ve had another interaction and somebody’s saying, “What is your favorite fruit?” You might not say banana because a banana is yellow.

07:03 Because I primed you with the word “red,” I’ve activated the words “strawberry,” “cherry,” “apple,” which are red, and so your recall might be -- actually, if I’m naming a fruit that I love, strawberries. I love strawberries.

07:15 That priming or a contextual cue can pre-activate the system for you or it can lower the threshold required to fire a certain word because of that spreading activation.