Hello and welcome to Chapter8, where we're going to talk about cognition and language.
In the first part of this lecture, we're going to explore mental representations, thinking strategies, and biological aspects of cognition. For lecture part 2, we're going to be looking more into problem solving and decision making; and lastly, in lecture part 3, we'll be looking a little bit into language.
So let's kick off with lecture part 1, where we're going to explore mental representations, thinking strategies, and biological aspects of cognition.
So many things that we talk about in the first part of this chapter relate to the field of cognition and cognitive psychology, where we want to know more about mental processes, by which we're going to receive information from the environment, make it meaningful in some way, retrieve it when it's necessary, and also to share that when communicating with others. Well, with mental representations, what we're really going to look at here are what are some of those ingredients of thought, what are the ways in which thinking occurs in the brain? How can we conceptualize that and better understand the ways in which cognition takes place? Well, as you can see, we're going to be looking at different representations—schemas, scripts, mental models, couple different kinds of concepts, propositions, and then images and cognitive maps. Some of these we're going to talk about in this lecture; others will be concepts that you'll cover on your own.
Let's first talk about schemas. You'll very likely remember schemas from Chapter 12-Human Development. Remember, schemas provide general structure, allow us to hold information together to an overall organization. There are concepts and a way for various things in the world around us; and if you remember from Chapter 7-Memory, the act of remembering sometimes requires an active process of construction or building things back together from our memory; and as we do that, as we're recalling information, we're using those schemas to bring everything back together. So if I was to ask you about your schema of a family, immediately you would start to construct those details of what a family is to you. Likewise if I asked you about the basic structure of telling a story or how a game of baseball works, you would no doubt be able to relay that information because of the schemas you've developed about those things. Well let's take a look at another example.
In this activity, what I'd like you to do is to draw a penny; and I'd like you to do this from memory. So don't look at a penny before you attempt this, but go ahead and stop the presentation for a few minutes. Draw either the front or the back of a US penny, and we'll take a look at one on the next slide and see how closely yours is to the actual penny. Grammatically, this should be "close"--not "closely."
And here you see a visualization of the 2010 US penny. Now, these were redesigned in 2010; so it's possible that, if you drew the front or back of it, it might be more representative of the previous version of the US penny. But take a few minutes again and pause the presentation if you have to; see how many of the details that you included, which ones were missing, maybe which details were perhaps placed in a different location; and then we'll talk a little bit more on the next slide.
So how easy was it for you to remember a lot of those details? Many people really struggle with this. We have a schema for what a penny is, certainly. We probably use them relatively frequently throughout our day, but the details tend to drop out. And remember, this is consistent with what we know about long-term memory. The schemas—that information—are really in long-term memory in kind of a generalized way. Unless we have a strong reason to know the details, often we just have a very broad concept or generalization of what the penny might be, or lots of other information, for that matter.
Well, let's take a look at even another schema example. I want you to read the following story, and we're going to answer a couple of questions about the story: where is Rocky and what is he doing?
"Rocky slowly got up from the mat, planning his escape. He hesitated a moment and thought things were not going well. What bothered him most was being held, especially since the charge against him had been weak. He considered his present situation. The lock that held him was strong, but he thought he could break it. He knew, however, that his timing would have to be perfect."
"Rocky was aware that it was because of his early roughness that he had been penalized so severely, much too severely from his point of view. The situation was becoming frustrating. The pressure had been grinding on him for too long. He was being ridden unmercifully. Rocky was getting angry now. He felt he was ready to make his move. He knew that his success or failure would depend on what he did in the next few seconds." So again, take a few moments, pause the presentation if you have to, and answer those two questions: where is Rocky and what is he doing?
So as you were listening to that story, you no doubt developed a schema about his situation based on the details that you were reading. Two common schemas that really come up in the story is that Rocky's either in prison or that he's involved in a wrestling match, and what you can do is go back in the presentation and reread the story, this time using a different schema than the one that you first used, and see if those details look different to you, sound different evoke different sort of imagery; and also take note of how we do fill in information based on our schemas.
As a last example of schemas, we're going to read about Amy. So I want you to read this paragraph and answer the following questions. "Amy heard the bell outside. She ran to get her piggy bank and then outside to get a Popsicle."
So how old is Amy? What season is it? Why did she get her piggy bank, and where did she get the Popsicle? Take a few moments to think through the answers to these questions, and then we'll talk more about it on the next slide.
Many people, when they hear this story, think that Amy is a little girl, that it's probably summer, and she went to get her piggy bank so she could get money to pay for a Popsicle from an ice cream truck. Well, if you had this, if you had this kind of concept or schema, or even a different one, how did you know the information about Amy? How did you fill in those blanks? Maybe it's from your own experiences when you were a child, but how would somebody think about that if they don't know what an ice cream truck is or if their neighborhood never had ice cream trucks in it? Might you can see this story a little bit differently, or fill in the information around Amy a little differently? So it's important to know that schemas are also culturally specific. If someone grew up in a rural America, would they have that same information about Amy? Or what if it was someone from a different country? So again, this is sort of showing the power of schemas and how they have an influence on how we understand and process the things around us.
In addition to schemas, we also utilize scripts a lot in daily life. A script is really a schema with a time line. So if I was to ask you, "Talk me through going to a movie theatre; what would that be like?" you might talk about going in the front door, you pay for the ticket, then you go to the concession stand and make your purchases of popcorn and soda. You go to the ticket agent; they're going to tear the ticket in half and point you to the theatre. Once you get into the theatre, you're going to walk, find your seat. Hopefully at this point, you, at least for the people around you, you silence your phone. Maybe you say it's okay to talk during previews, but it's generally you don't talk when the movie starts. You could go through a lot of different details, and of course it might vary. But again, there's a sort of timeline involved; and any of this kinds of activities that we go through throughout the day—whether it's your wakeup routine in the morning, attending class, or going to a restaurant—these scripts help us to get through and know what are the things to do and what's that process kind of looks like? So this is another important ingredient of thought that really influences our cognition.
Also, in our daily lives, we're presented and sort of approached by concepts. Concepts are those categories of objects, events, ideas that have some sort of common property; and there are two types we talk about in the book. One is formal concepts. These would be clearly defined by a very strict set of rules or properties. Any number of that formal concept has all of the defining properties, and nonmembers do not. So examples of formal concepts might be a square, what constitutes a prime number, or what constitutes an inert gas. These are things where you either meet the requirements and you are a member, or you don't and you're not. So this certainly exists in our lives, but more often than not we're dealing with and presented with natural concepts. So, as you might imagine, these have no fixed set of defining features; but there might be typical or characteristic features. A member of a natural concept that might possess all or most of those characteristic features is called a prototype. So perhaps a natural concept would be a chair. A prototypical chair, we might think of as kind of L-shaped, with four legs, possibly with arms on either side. If you were to think of a chair, maybe that's the image that came up into your mind; but we can also start thinking about a lot of different types of chairs—those with wheels, those that have sort of strange designs, perhaps artistic designs. Perhaps it's amorphous, sort of like a bean bag, or a nice plush couch that you sit on. Or it could be a straight-backed, hard chair. On and on the list could go. Again, these are examples of natural concepts; and the closer something is to the prototype the more likely it is to sort of evoke that concept in your mind; or you're going to associate it with that thing. But we can also think of natural concepts in terms of games or family, again, to revisit that idea. Depending on your experience with, say, family, or games, that might very heavily influence what that natural concept is to you, what those properties might be.
Well, as we move on from those mental representations, those ingredients of thought, we now want to think, "If that's sort of the raw information that we're receiving and that we're processing, well, how might we put those things together? How might we transform or elaborate those representations into ways that allow us to reason, to problem solve, to make decisions?" And that's really where these thinking strategies come in into play. We're going to talk about formal reasoning a little bit, and then focus a bit more on informal reasoning.
In formal reasoning we're talking about things like algorithms, systematic methods that allow you to produce a correct solution to a problem, assuming that a solution even exists. As the example in the book states, that astronomers' estimates of the sun's core temperature were based on formal reasoning—this logical reasoning, which has rigorous procedures to reach those valid conclusions; some of those procedures included applications of mathematical formulas. Those formulas are examples of algorithms. Algorithms are sometimes expressed as flowcharts , something you might be fairly familiar with. And a formal reasoning would also include rules of logic, and syllogisms, syllogisms being those logical arguments where you're given two premises with a conclusion and you have to see, "Are the premises and conclusion valid? Does the conclusion logically follow from the premises?" And of course, you know, with any logical reasoning puzzle, we may have certain biases that lead us astray and perhaps cause us to make illogical conclusions or logical fallacies. And these are certainly things you would talk more about if you took a course in logic and reasoning; so for the purposes of this course, we're going to kind of leave it to some of those classes if you want to explore that further. What we really want to focus a bit more on is informal reasoning.
Often when we're presented with information, whether you're reading it on a website or in a book, something's communicated from a friend, what's going to happen is that we're going to think through or process that with the use of heuristics. These are mental short cuts, they're rules of thumb. Whereas an algorithm is going to present a correct solution if it exists, with a heuristic it's something that's probably but not necessarily correct or true. So they can at times lead us astray because they also bias our thinking and lead to some of those errors, and we want to talk about three common but problematic heuristics that we use all the of the time, and that would be the anchoring heuristic, the representativeness heuristic and availability heuristic.
Let's say that you're going to put a house up for sale on the market, or perhaps your parents are, and the belief is that you feel your house is going to sell in a week, feel pretty confident, you think the price is set well, it's going to be a week. Then you meet with a realtor, and the realtor says that, on average, houses are on the market two months before they sell, that's kind of the current state of the housing market. Are you likely to then say, "Ok, my house is going to sell in two months"? Probably not. Often in a case like this, you might say, "Well, maybe it's going to be two weeks." Well, why would you not go all the way over to what the realtor said, based on that information, certainly by somebody who's an expert and knows a lot about the housing market? Well, what's happening here is the anchoring heuristic. You're going to estimate the probability of an event not by starting from scratch but by adjusting from an earlier estimate. So you already had that week time-line in mind, so you're going to make adjustments from that, not going from zero. The same is true in sort of your belief of being a victim of a crime. Say, if you're visiting a big city and you feel that you're 50% likely to be mugged while you're in that city, then perhaps you read a news story or you look into some crime data and see that well really the estimation, the likelihood is probably about 5% in reality. Chances are you're not then going to think, "Well, there's only a 5% likelihood." You're probably going to stay anchored to that original estimation and say, "Well, maybe I'm actually 40% likely to be mugged"; and you can probably, I'm sure, think about examples where you had a pretty firm idea in your mind about probability or the estimation of something, and then you were presented with information. Did you immediately go to that information, which is probably based in reality; or were you more likely to sort of, maybe gradually, get there by making those small moves? That's really the anchoring heuristic at play.
Now, let's look at a different scenario. And in this scenario, a panel of psychologists interviewed a sample of 70 engineers and 30 lawyers, summarizing their impressions and thumbnail descriptions of each individual. Now, the following description has been drawn at random from that sample of 70 engineers and 30 lawyers; and this is what it says: "John is a 39-year-old man. He is married and has two children. He is active in local politics. The hobby that he most enjoys is rare book collecting. He is competitive, argumentative, and articulate." So what's the probability that John is a lawyer?
Often in this situation, people estimate pretty highly that John is indeed a lawyer; but in reality, there's a 30% likelihood. Why? Because from that particular study, there were 70 engineers and 30 lawyers; but because we know that information about John—that he's into rare book collecting, that he's articulate and argumentative—those details tend to make us think, "Well he's definitely a lawyer." And therefore, we might estimate higher probability that indeed that's who he is. This is a representativeness heuristic at play. So we're going to decide if an example belongs to a certain class or group on the basis of how similar it is to other items in that class or group. A few other examples that you might think of is a rich car buyer or a student who belongs to a fraternity or sorority. Immediately you're going to think about what sort of, again, that prototype or concept, that natural concept is; and then if you were to see somebody, you would sort of apply that to that person and say, "Ok, how much is this person likely to belong to this group? How likely is this person that fits my schema of someone in a fraternity or sorority?" And etc. So this is an example of representativeness heuristics.
Our third heuristic is the availability heuristic. We use this when we judge the likelihood of an event or the correctness of a hypothesis based on how easily that hypothesis or event comes to mind. So, what's the likelihood that I'm going to be attacked by a shark if I go swimming in the ocean? Well, what we see is that with publicity around pretty rare events, people tend to overestimate the likelihood that things will happen to them. Why? Because the availability of those things might be saturated in the media; and you could think back to a litany of public health scares everywhere from anthrax, West Nile, the H1N1 influenza, avian flu, SARS, shark attacks—the list kind of really goes on and on. But in these situations, when they happen, people will overestimate the likelihood that they might be a victim of one of those health scares, for instance. And we overestimate these things because they are pretty memorable (even though they may be rare events) often because they are sensationalized or that they are very extreme or that there are pretty strong consequences if you became a victim, say, of a shark attack. So again, this is really sort of the availability heuristic at play and how it operates.
So certainly, those heuristics give us some insight into how we might make automatic judgments about the world around us. Let's also talk a little bit about some of the biological aspects of cognition, what's going on behind the scenes in the brain; and what we find is that the brain's better at performing simple tasks using one hemisphere rather than two. That's because when a task is easy, the translation between the hemispheres just takes too much time. So for instance, if you're in an experiment and you have to press a button when a visual stimulus is presented on a screen, this might be an example of one of those easy tasks in which one of the hemispheres allows for better performance than rather relying on both hemispheres to make that response. We also see that if you were presented with a picture, your right hemisphere is going to process the overall configuration; it's going to look sort of at the big picture, if you will, while your left hemisphere is going to process a lot of those details. So the hemispheres are kind of working on different aspects of that recognition and cognition.
Also, in the book, we talk about evoked potentials. Evoked potentials, or EPs, are small, temporary changes in the EEG recordings following a discreet event in the environment. So again, if we go back to that example of being presented a visual stimulus on the screen, cognitive psychologists might be looking at these evoked potentials when those stimuli are presented. And they're interested in two different kinds of EPs, one is the N100; this is a negative voltage direction. It occurs at about 100 milliseconds after the stimulus is presented. This is when the brain's primary sensory cortex receives and processes sensory characteristics of an environmental stimulus, in other words, sensation. So we can understand, kind of, when sensation is taking place by looking at these evoked potentials.
The other important evoked potential is the P300; and this is in the positive voltage direction, which occurs at about 300 to 500 milliseconds after the stimulus is presented. And this is roughly analogous to perception of the stimulus and when attention is given to the stimulus; and of course, in the second half of this course, we do look more closely at sensation and perception and how those work. So this is sort of a flavor of things to come, but what we find within this evoked potential is that the size of the P300 is usually larger when presented with a surprising stimulus or if someone calls your name. If a surprising stimulus does not evoke a large P300, this could be indicative of brain damage; so this is a way that neuroscientists, cognitive psychologists, might also be able to understand not only brain function but brain dysfunction.
And here we see sort of a visual representation on an EEG readout of an evoked potential, noting both the N100 in the negative voltage direction and the P300 in the positive voltage direction. Again, roughly equating to the process of sensation in the sensory cortex and of perception. This does bring a close to lecture part 1. Join me for lecture part 2 where we're going to talk more about problem solving and decision making.