Imagine the following situation: A young man, let’s call him Perry, was sitting at his desk, reading some papers required to complete a psychology assignment. In his right hand he held a cup of coffee. With his left one he reached for a bag of chips without removing the focus of his eyes from the paper. He reads the letters on the page and understands their meaning. Suddenly, he glanced up to the ceiling of his room and asked himself, “What is happening here?” Probably everybody has had experiences like the one described above. Even though, at first glance, there is nothing exciting happening in this everyday situation, a lot of what Perry just did or thought is highly interesting particularly for researchers and students in the field of Cognitive Psychology.
Module 2: Introduction to Psychology Research Methods Cognitive Psychology, like other psychology disciplines, relies heavily on the scientific method - the process of using careful observation of the world to develop and test hypotheses. Cognitive psychologists typically use experiments to develop theories and test hypotheses. In an experiment, researchers manipulate, or cause changes, in the independent variable, and observe or measure any impact of those changes in the dependent variable. The independent variable (or variables) is a variable under the experimenter’s control, or the variable that is intentionally altered between groups. In the case of a memory experiment, an independent variable might be the amount of time a participant has to study a list of 30 words they later need to recall. For this example, let's say one group of participants can study the list for 1 minutes, and another can study it for 5 minutes. The dependent variable is the variable that is not manipulated at all, or the one where the effect happens. One way to help remember this is that the dependent variable “depends” on what happens to the independent variable. Continuing with the memory example, the proportion of words a participant might recall (the dependent variable) depends on how long the participant could study the list (the independent variable). Thus, any observed changes or group differences in recall can be attributed to the time spent studying.
Module 3: Cognitive Psychology Research Methods Behavior Methods One of the important assumptions of cognitive psychology experiments is that the more cognitive processes or stress on cognitive processes a task requires, the longer it will take to complete that task or more errors will be committed while completing the task. Let's return to Perry for a moment. If the reading assignment for Perry's class is to read a chapter from a textbook, which is written to summarize a body of research for an undergraduate to understand, he might have no problem reading at a steady pace while also munching on his snacks. Contrast that to if Perry were assigned to read an original peer-reviewed research article from an academic journal, where the audience is other professionals in the field. In this case, Perry will likely have to dedicate more mental effort to understand what is written in the article and to understand the authors' conclusions based on the results of their study. If you were to compare his behavior of the two readings, you might expect that (after accounting for length of the reading) it would take Perry longer to complete the article compared to the textbook chapter. You might also expect that if Perry were to take a quiz over the two different readings, Perry might make more wrong answer on the article quiz than the textbook quiz.
Module 4: Biological Components of Cognition While working on his homework, Perry reaches for a hot cup of hot coca without breaking eye-contact with is reading. Ouch! Perry had missed the handle of the mug and touched the hot cup. "Why does that have to hurt so bad?" Perry wonders. He knows from what he had learned in school that the body and brain are able to communicate, but how does that happen? And how does it happen so quickly? The brain is the most complex part of the human body. It is the center of consciousness and also controls all voluntary and involuntary movement and bodily functions. It communicates with each part of the body through the nervous system, a network of channels that carry electrochemical signals.
Module 5: Cognitive Neuroscience Methods Neuroscientific methods are used to gain insight into how the brain influences the way individuals think, feel, and act. There is an array of methods, which can be used to analyze the brain and its relationship to behavior. Well-known techniques include EEG (electroencephalography) which records the brain’s electrical activity and fMRI (functional magnetic resonance imaging) which produces detailed images of brain structure and activity. Other methods, such as the lesion method and case studies, are lesser known, but still influential in today's neuroscience research. Methods can be organized into the following categories: anatomical, physiological, and functional. Other techniques include modulating brain activity, analyzing behavior or computational modeling. When evaluating the various cognitive neuroscience methods used in experiments, it is important to consider the temporal resolution and spatial resolution of the method. Temporal resolution refers to the degree to which the measure is sensitive to events in time. The higher the temporal resolution, the better the measure is at quickly detecting changes in neural activity. Spatial resolution refers to how precise the measure is at localizing neural activity. At its best, the ideal spatial resolution would be at the level of individual neurons, but this is rarely the case. The higher the spatial resolution, the more accurate the method is at identifying what specific areas are stimulated during a cognitive process.
Module 6: Sensation Versus Perception Perry's finger is still feeling a bit sensitive from touching his hot cup of cocoa. He feels a small jolt of pain each time he presses a computer key. Why does my finger feel like that? he wonders. He knows that nerves in his peripheral nervous system are sending signals to his central nervous system, but why does he feel the pain in his finger? He looks away from his bright computer monitor to ponder this question, and he notices his room appears dimmer than it should. After a few moments of looking around the room, he begins to see more details of the objects in his room. The lighting hasn't changed, but what Perry can see has changed. The topics of sensation and perception are among the oldest and most important in all of psychology. People are equipped with senses such as sight, hearing and taste that help us to take in the world around us. Amazingly, our senses have the ability to convert real-world information into electrical information that can be processed by the brain. The way we interpret this information—our perceptions—is what leads to our experiences of the world.
Module 7: Top-Down Processing and Visual Perception Gestalt Principles of Perception In the early part of the 20th century, Max Wertheimer (1912) published a paper demonstrating that individuals perceived motion in rapidly flickering static images—an insight that came to him as he used a child’s toy tachistoscope. Wertheimer, and his assistants Wolfgang Köhler and Kurt Koffka, who later became his partners, believed that perception involved more than simply combining sensory stimuli (i.e., bottom-up processing). This belief led to a new movement within the field of psychology known as Gestalt psychology. The word gestalt literally means form or pattern, but its use reflects the idea that the whole is different from the sum of its parts. In other words, the brain creates a perception that is more than simply the sum of available sensory inputs, and it does so in predictable ways. Gestalt psychologists translated these predictable ways into principles by which we organize sensory information. In other words, there are predicable top-down processing effects for how we interpret ambiguous stimuli. As a result, Gestalt psychology has been extremely influential in the area of sensation and perception (Rock & Palmer, 1990).
Module 8: Theories of Attention Exams are just around the corner, and Perry is buckling down to get some last-minute studying. He opens his laptop while on the couch. It's quiet. I'll probably focus better with a little background noise; he thinks to himself. He turns on the show he is currently binging, then returns to his laptop, plugs a headphone from his computer into his left ear, and pulls up a lecture video. He begins watching the lecture, but after a few minutes he hears something exciting happening in the TV show. He looks up at the TV and watches the action unfold. He then realizes he has no idea what was just said in the lecture video. He tracks back to the last place he remembers listening. He watches the lecture for a few more minutes, but his eyes keep shifting back to the TV show. Wait, what did my professor just say? Then, Perry hears a tone from his cellphone alerting him he has an unread text message. It's from his friend Terry. He reads the message and, once again, realizes he doesn't know what was said in the lecture or what just happened in the show. After 20 minutes of 'studying' Perry realizes he's really only made it five minutes into the lecture video. Why can't Perry pay attention to all of these things at the same time? We use the term “attention” all the time, but what processes or abilities does that concept really refer to? This chapter will focus on how attention allows us to select certain parts of our environment and ignore other parts, and what happens to the ignored information. A key concept is the idea that we are limited in how much we can do at any one time. So, we will also consider what happens when someone tries to do several things at once, such as driving while using electronic devices.
Module 9: Attention and Errors Failures of Awareness: The Case of Inattentional Blindness In a groundbreaking series of studies in the 1970s and early 1980s, Neisser and his colleagues devised a visual analogue of the dichotic listening task (Neisser & Becklen, 1975). Their subjects viewed a video of two distinct, but partially transparent and overlapping, events. For example, one event might involve two people playing a hand-clapping game and the other might show people passing a ball. Because the two events were partially transparent and overlapping, both produced sensory signals on the retina regardless of which event received the participant’s attention. When participants were asked to monitor one of the events by counting the number of times the actors performed an action (e.g., hand clapping or completed passes), they often failed to notice unexpected events in the ignored video stream (e.g., the hand-clapping players stopping their game and shaking hands). As with dichotic listening, the participants were unaware of events happening outside the focus of their attention, even when looking right at them. They could tell that other “stuff” was happening on the screen, but many were unaware of the meaning or substance of that stuff.
Module 10: Memory and Information Processing Theory Perry woke up for the morning feeling relaxed and refreshed until he looked at the clock. His first class of the day was going to start in 15 minutes! He had forgotten to set his alarm the night before. He jumped out of bed, quickly threw some cloths on, grabbed his backpack, and ran out the door. Fortunately, he arrived to class only a few minutes late. He sat down, pulled out his notebook, and stated feeling around for pencil. Nothing. Perry could have sworn he had put a bunch of pencils in his backpack earlier. What good was his notebook without something to write? Then, he saw one of his classmates pull a pen from the small front pocket of their backpack. Instantly, Perry could vividly remember grabbing a handful of pencils and putting them in the side pocket of his backpack the other day. He unzipped the pocket to find the writing utensils at last. Why did I forget so much this morning? Perry wondered. Why do I remember something one minute, and forget it the next? “Memory” is a single term that reflects a number of different abilities: holding information briefly while working with it (working memory), remembering episodes of one’s life (episodic memory), and our general knowledge of facts of the world (semantic memory), among other types. Remembering episodes involves three processes: encoding information (learning it, by perceiving it and relating it to past knowledge), storing it (maintaining it over time), and then retrieving it (accessing the information when needed). Failures can occur at any stage, leading to forgetting or to having false memories. The key to improving one’s memory is to improve processes of encoding and to use techniques that guarantee effective retrieval. Good encoding techniques include relating new information to what one already knows, forming mental images, and creating associations among information that needs to be remembered. The key to good retrieval is developing effective cues that will lead the rememberer back to the encoded information. Classic mnemonic systems, known since the time of the ancient Greeks and still used by some today, can greatly improve one’s memory abilities. In this module, we reveal what psychologists and others have learned about memory, and we also explain the general principles by which you can improve your own memory for factual material. You will learn more about the different memory storage systems in more depth in the following chapters.
Module 11: The Three Stages of the Memory Process Psychologists distinguish between three necessary stages in the learning and memory process: encoding, storage, and retrieval (Melton, 1963). Encoding is defined as the initial learning of information; storage refers to maintaining information over time; retrieval is the ability to access information when you need it. If you meet someone for the first time at a party, you need to encode her name (Lyn Goff) while you associate her name with her face. Then you need to maintain the information over time. If you see her a week later, you need to recognize her face and have it work as a cue to retrieve her name. Any successful act of remembering requires that all three stages be intact. However, two types of errors can also occur. Forgetting is one type: you see the person you met at the party, and you cannot recall her name. The other error is misremembering (false recall or false recognition): you see someone who looks like Lyn Goff and call the person by that name (false recognition of the face). Or, you might see the real Lyn Goff, recognize her face, but then call her by the name of another woman you met at the party (misrecall of her name).
Module 12: Sensory, Short-Term, and Working Memory After class, Perry overheard some of his classmates discussing creating a study group for the upcoming exam. Perry joined the conversation and said he was interested. After figuring out when and where to study, Perry swapped phone numbers with one of the other students. He repeated the seven digits in his mind until he typed them into his phone. Now he just needed to enter the name for the new contact. Crap, what was her name? Perry whispered to himself. He looked up from his phone, but the group had already dispersed. Perry shrugged and entered "Study Buddy." In this chapter, we'll look at what James called primary memory, information stored temporarily and make up our conscious experiences. We will specifically discuss three storage systems that are often included in information processing theories of cognition: sensory memory, short-term memory, and working memory. We will then review findings that demonstrate why short-term memory stores are separable from long-term memory stores.
Module 13: Improving Short-Term Memory It should be clear that short-term memory has limits, but those limits are flexible. This has been demonstrated in the studies described earlier in the chapter, but there are also more concrete examples of how the boundaries of memory can be pushed. In 2013, Simon Reinhard sat in front of 60 people in a room at Washington University, where he memorized an increasingly long series of digits. On the first round, a computer generated 10 random digits—6 1 9 4 8 5 6 3 7 1—on a screen for 10 seconds. After the series disappeared, Simon typed them into his computer. His recollection was perfect. In the next phase, 20 digits appeared on the screen for 20 seconds. Again, Simon got them all correct. No one in the audience (mostly professors, graduate students, and undergraduate students) could recall the 20 digits perfectly. Then came 30 digits, studied for 30 seconds; once again, Simon didn’t misplace even a single digit. For a final trial, 50 digits appeared on the screen for 50 seconds, and again, Simon got them all right. In fact, Simon would have been happy to keep going. His record in this task—called “forward digit span”—is 240 digits! When most of us witness a performance like that of Simon Reinhard, we think one of two things: First, maybe he’s cheating somehow (he is not, by the way). Second, Simon must have abilities more advanced than the rest of humankind. After all, psychologists established many years ago that the normal memory span for adults is about 7 digits, with some of us able to recall a few more and others a few less (Miller, 1956). That is why the first phone numbers were limited to 7 digits—psychologists determined that many errors occurred (costing the phone company money) when the number was increased to even 8 digits. But in normal testing, no one gets 50 digits correct in a row, much less 240. So, does Simon Reinhard simply have a photographic memory? He does not. Instead, Simon has taught himself simple strategies for remembering that have greatly increased his capacity for remembering virtually any type of material—digits, words, faces and names, poetry, historical dates, and so on. Twelve years earlier, before he started training his memory abilities, he had a digit span of 7, just like most of us. Simon has been training his abilities for about 10 years as of this writing and has risen to be in the top two of “memory athletes.” In 2012, he came in second place in the World Memory Championships (composed of 11 tasks), held in London. He currently ranks second in the world, behind another German competitor, Johannes Mallow.
Module 14: Long-Term Memory Perry was preparing for his first meeting with his study and his study group, when he got a text message from “Study Buddy”. It read, “Garry, Jerry, Mary, and Larry will be joining us too. It should be a good group, since Larry said he knows you from another class.” Who the heck is Larry? Perry thought to himself. He swung his backpack over his shoulder and headed to the library. Perry arrived at the designated meeting spot, and other member of the group started to arrive. Last, was a person Perry immediately recognized and could not believe he had forgotten in the first place. “Hi Larry,” said Kerry (that’s Study Buddy). Perry immediately started to remember working with Larry on a class presentation two semesters ago. He remembered the topic of the presentation, the other members of their group, that they regularly met at the campus coffee shop to work, and so on. How is it that Perry forgot the name of someone he worked closely with but then remembered all of these details once Perry recognized Larry’s face? In this chapter, we’ll discuss the factors of long-term memory that contribute to our ability to remember information for years, as well as why we forget information, even when it is very important. If information makes it past short-term memory, it may enter long-term memory, memory storage that can hold information for days, months, and years. The capacity of long-term memory is large, and there is no known limit to what we can remember. Although we may forget at least some information after we learn it, other things will stay with us forever. Long-term memory is the continuous storage of information. Unlike short-term memory, the storage capacity of long-term memory has no (known) capacity limits. It encompasses all the things you can remember that happened more than just a few minutes ago to all of the things that you can remember that happened days, weeks, and years ago. If you think of memory like how computers work, the information in your long-term memory would be like the information you have saved on the hard drive. Information might not be on your mind (your short-term memory), but you can pull up this information when you want it, at least most of the time. Not all long-term memories are strong memories. Some memories can only be recalled through prompts. For example, you might easily recall a fact, “What is the capital of the United States?” or a procedure, “How do you ride a bike?” but you might struggle to recall the name of the restaurant you had dinner when you were on vacation last year. A prompt, such as that the restaurant was named after its owner, who spoke to you about your shared interest in soccer, may help you recall the name of the restaurant.
Module 15: Memory Errors – More than Just Forgetting Amnesia We will now consider a profound form of forgetting called amnesia that is distinct from more ordinary forms of forgetting. Most of us have had exposure to the concept of amnesia through popular movies and television. Typically, in these fictionalized portrayals of amnesia, a character suffers some type of blow to the head and suddenly has no idea who they are and can no longer recognize their family or remember any events from their past. After some period of time (or another blow to the head), their memories come flooding back to them. Unfortunately, this portrayal of amnesia is not very accurate. What does amnesia typically look like?
Module 16: Theories of Categories and Concepts The study group decided to mix things up, and Mary hosted a study session with snacks at her apartment. She boiled a kettle for tea, and Perry went over to the kitchen to pour himself a cup. Thinking about how his kitchen is organized, he opened the cabinet above the stove—a close, convenient location. No mugs—instead Perry found spices and other cooking ingredients. “Where are your mugs?” Perry asked. “Over in the corner by the glasses,” Marry replied. Perry opened the cabinet and found a shelf of glasses, a shelf of cups and travel mugs, and a shelf of coffee mugs. Makes sense, Perry thought. Perry then overheard the study group discussing which topics to cover. “Let’s review memory processes, then short-term memory, then working memory, since that’s the chapter order,” Garry suggested. “How about doing the sections on sensory memory, then attention, then short-term memory, then long-term memory, since that’s kind of similar to information processing approaches?” Kerry countered. This conversation got Perry thinking about knowledge. They had learned a lot over the course of the semester, and all that knowledge had to be somewhere. Is knowledge organized like Mary’s kitchen with information filed into organized spaces? Or, is it more like Perry’s preference of having the most used items readily available? Most human cognitive abilities rely on or interact with what we call knowledge. How do people navigate through the world? How do they solve problems, how do they comprehend their surroundings and on which basis do people make decisions and draw inferences? For all these questions, knowledge, the mental representation of the world is part of the answer. What is knowledge? Knowledge is a structured collection of information, that can be acquired through learning, perception, or reasoning. This chapter deals with the structures both in human brains and in computational models that represent knowledge about the world. First, the idea of concepts and categories as a model for storing and sorting information is introduced. Then the concept of semantic networks and how such models can be used to explain the way humans store and handle information. Apart from the biological aspect, we are also going to talk about knowledge representation in artificial systems which can be helpful tools to store and access knowledge and to draw quick inferences. This chapter will also examine the human brain with regard to hemispheric specialization. This topic is not only connected to knowledge representation, since the two hemispheres differ in which type of knowledge is stored in each of them, but also to many other topics in this course. Where, for example, is memory located, and which parts of the brain are relevant for emotions and motivation? In this chapter we focus on the general differences between the right and the left hemisphere. We consider the question whether they differ in what and how they process information and give an overview about experiments that contributed to the scientific progress in this field.
Module 17: Hemispheric Distribution We now turn to the question of how the brain is specialized to store knowledge. In particular, what kind of knowledge is present in each hemisphere. These questions can be subsumed under the topic of hemispheric specialization (or lateralization of processing), which looks at the differences in processing between the two hemispheres of the human brain. Differences between the hemispheres can be traced back to as long as 3.5 million years ago (Corballis, 1989). Evidence for this are fossils of australopithecines (which is an ancient ancestor of homo sapiens). Because differences have been present for so long and survived the natural selection, they must be useful in some way for our cognitive processes.
Module 18: Imagery Perry was on his way to visit his friend Garry who lives in a large apartment complex. Perry knew Garry's apartment number was 64, meaning the fourth unit of building 6. The buildings, however, were not arranged in a way that the numbering made sense. Perry had been to the complex before, so he knew he could rely on his long-term memory to find Garry's apartment without guessing which way to go. To do this, Perry closed his eyes and imagined the last time he visited Garry. In his mind, he could see himself turning right after entering the complex, then walking on the path between buildings 2 and 5. The path is lined with short bushes and there is a large crack in the sidewalk near the other side. Building 6 is across a section of grass. After imagining the last time Perry made this trip, he wondered how he was able to so clearly experience the visual aspects of the complex. Perry used mental imagery to do this. Mental imagery is the cognitive ability to intentionally experience sensory information that is not physically available. In Perry's example, he is using visual imagery from memory to navigate a familiar place. Mental imagery can also be used to "experience" perceptions you have not directly had (i.e., imagination). You've probably never been to the Moon, but given images, videos, and description you've encountered in the past, you might be able to reasonable imagine what it would be like. Mental imagery was already discussed by the early Greek philosophers. Socrates sketched a relationship between perception and imagery by assuming that visual sensory experience creates images in the human's mind, which are representations of the real world. Later on, Aristoteles stated that "thought is impossible without an image". At the beginning of the 18th century, Bishop Berkeley proposed another role of mental images—similar to the ideas of Socrates—in his theory of idealism. He assumed that our whole perception of the external world consists only of mental images. At the end of the 19th century, Wilhelm Wundt—the generally acknowledged founder of experimental psychology and cognitive psychology—called imagery, sensations, and feelings the basic elements of consciousness. Furthermore, he had the idea that the study of imagery supports the study of cognition, because thinking is often accompanied by images. This remark was taken up by some psychologists and gave rise to the imageless-thought debate, which discussed the same question Aristoteles already had asked: Is thought possible without imagery? In the early 20th century, when Behaviorism became the mainstream of psychology, Watson argued that there is no visible evidence of images in human brains and therefore, the study of imagery is worthless. This general attitude towards the value of research on imagery did not change until the birth of cognitive psychology in the 1950s and 60s. More recently, imagery has often been believed to play a very large, even pivotal, role in both memory (Yates, 1966; Paivio, 1986) and motivation (McMahon, 1973). It is also commonly believed to be centrally involved in visuo-spatial reasoning and inventive or creative thought.
Module 19: Language and Psychology Perry has to prepare a presentation with his study group. They text each other and decide to meet at one of their apartments. Perry arrives right on time and enters his living-room, without closing the door. They begin working when one of the group members says: "It's gotten kind of cold in here." Perry then stands back up and closes the door. Why did Perry do that? His group member did not ask him to close the door, yet Perry knew what they meant. This banal series of events highlights the utility of language. The group members used digital visual symbols to communicate about a future meeting at a location most of them had not been to before. The group was meeting to collectively create a presentation that uses language to share specialized information. Finally, Perry was able to infer that his teammate wanted the door closed without them using the words door or close. Language is a central part of everyday life and communication a natural human necessity. For those reasons there has been a high interest in their properties. However, describing the processes of language turns out to be quite hard. We can broadly define language as a system of symbolic communication through which we code and express our feelings, thoughts, ideas, and experiences.
Module 20: Using Language Conversations are dynamic interactions between two or more people (Garrod & Pickering, 2004; Pickering & Garrod, 2004). The important thing to mention is that conversation is more than the act of speaking. Each person brings their own knowledge, and conversations are much easier to process if participants bring in shared knowledge. In this way, participants are responsible of how they bring in new knowledge. Grice (1975) proposed a basic principle of conversation and four "conversational maxims." His cooperative principle states that the speaker and listener agree that the person speaking should strive to make statements that further the agreed goals of conversation. The four maxims state the way of how to achieve this principle. 1. Quantity: The speaker should try to be informative, no over-/underinformation. 2. Quality: Do not say things which you believe to be false or lack evidence of. 3. Manner: Avoiding being obscure or ambiguous. 4. Relevance: Stay on topic of the exchange. An example of a rule of conversation incorporating three of those maxims is the given-new-contract. It states that the speaker should construct sentences so that they include given and new information. Consequences of not following this rule were demonstrated by Haviland and Clark (1974) by presenting pairs of sentences (either following or ignoring the given-new-contract) and measuring the time participants needed until they fully understood the sentence. They found that participants needed longer in pairs of the type: "We checked the picnic supplies. The beer was warm." Rather than: "We got some beer out of the trunk. The beer was warm." The reason that it took longer to comprehend the second sentence of the first pair is that inferencing has to be done (beer has not been mentioned as being part of the picnic supplies).