CC PP OOGGNNIITTIIVVEE SSYYCCHHOOLLOOGGYY AANNDD CC NN OOGGNNIITTIIVVEE EEUURROOSSCCIIEENNCCEE by Wikibooks contributors Developed on Wikibooks, the open-content textbooks collection © Copyright 2004–2006, Wikibooks contributors. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". Image licenses are listed in the section entitled "Image Credits." Main authors: Aschoeke (C) Tbittlin (C) LanguageGame (C) Itiaden (C) Pbenner (C) · Mheimann (C) Jkeyser (C) Ddeunert (C) Marplogm (C) · Pehrenbr (C) Ifranzme (C) FlyingGerman (C) Sspoede (C) · Asarwary (C) Lbartels (C) Smieskes (C) Apape (C) · Ekrueger (C) The current version of this Wikibook may be found at: http://en.wikibooks.org/wiki/Cognitive_Psychology_and_Cognitive_Neuroscience Contents C ..............................................................................................................................4 HAPTERS 01 Cognitive Psychology and the Brain................................................................................................4 02 Problem Solving from an Evolutionary Perspective........................................................................8 03 Evolutionary Perspective on Social Cognitions.............................................................................25 04 Behavioral and Neuroscience Methods..........................................................................................33 05 Motivation and Emotion.................................................................................................................47 06 Memory..........................................................................................................................................57 07 Memory and Language...................................................................................................................66 08 Imagery...........................................................................................................................................73 09 Comprehension...............................................................................................................................81 10 Neuroscience of Comprehension....................................................................................................94 11 Situation Models and Inferencing................................................................................................109 12 Knowledge....................................................................................................................................125 13 Decision Making and Reasoning..................................................................................................146 14 Present and Future of Research....................................................................................................168 A ...............................................................................................................177 BOUT THE BOOK History & Document Notes...............................................................................................................177 Authors & Image Credits..................................................................................................................178 GNU Free Documentation License...................................................................................................179 Chapter 1 1 C P B OGNITIVE SYCHOLOGY AND THE RAIN live version • discussion • edit lesson • comment • report an error Introduction I magine a young man, Knut, sitting at his desk, with his tired eyes staring at a monitor, surfing around, trying to find some worthy articles for his psychology homework. A cigarette rests between the middle and index fingers of his left hand. Without looking, he stretches out his free hand and grabs a cup of coffee located on the right of his keyboard. While sipping some of the cheap discounter blend, he suddenly asks himself: "What is happening here?" Around the beginning of the 20th century, psychologists would have said, "Take a look into yourself, Knut, analyse what you're thinking and doing," as analytical introspection was the method of that time. A few years later, J.B. Watson published his book Psychology from the Standpoint of a Behaviorist, from which began the era of behaviourism. Behaviourists claimed that it was impossible to study the inner life of people scientifically. Their approach to psychology, which they assumed to be more scientific, focussed only on the study and experimental analysis of behaviour. The right answer to Knut's question would have been: "You are sitting in front of your computer, reading and drinking coffee, because of your environment and how it influences you." Behaviorism was the primary means for American psychology for about the next 50 years. One of the primary critiques and downfalls of behaviorism was Noam Chomsky's 1959 critique of B.F. Skinner's "Verbal behaviour". Skinner, an influential behaviourist, attempted to explain language on the basis of behaviour alone. Chomsky showed that this was impossible, and by doing so, influenced enough psychologists to end the dominance of behaviorism in American psychology. As more researchers were once again concerned with processes inside the head, cognitive psychology arose on the landscape of science. Their central claim was that cognition was information processing of the brain. Cognitive psychology did not dispose the methods of behaviourism, but rather widened their horizon by adding levels between input and output. Modern technology and new methods enabled researchers to combine examinations of public actions (latencies in reaction time, number of recalls) with physiological measurements (EEG and event-related potentials, fMRI). Such methods, in addition to others, are used by cognitive science to collect evidence for certain features of mental activity. From this, references and correlations between action and cognition could be made. These correlations were inspiration and thenceforwards the main challenge for cognitive psychologists. To answer Knut's question the cognitive psychologist would probably first examining Knut’s brain in that specific situation. So let's try this! Knut has a problem, he really needs to do his homework. To solve this problem, he has to perform loads of cognition. The light is gleaming into his eyes, transducing it from his retina into nerve signals by sensory cells. The information is passed on through the optic nerve, crosses the brain at the lateral geniculate nucleus to arrive at the central visual cortex. On its journey, the signals get computed over complex nets of neurons; the contrast of the picture gets enhanced; irrelevant information gets filtered 4 | Cognitive Psychology and Neuroscience Cognitive Psychology and the Brain out; patterns are recognized; stains and lines on the screen become words; words get meaning, the meaning is put into context, analyzed on its relevance for Knut's problem, maybe stored in some part of memory. At the same time an appetite for coffee is creeping from Knut's hypothalamus, a region in the brain responsible for controlling the needs of an organism. The appetite, encoded in patterns of neural information, makes its way to the motor cortex where it is passed on to the muscles into Knut's arm. A lot more could be said about this, and Knut's question remains unanswered, but this should be enough to point out the complexity of cognition and the brain's importance. In this chapter, we are going to dig deeper into the question of what cognitive psychology is and how it became this way, and then draw connections to the brain and explain some of its most important parts. Defining Cognitive Psychology Cognitive Psychology is a psychological science which is interested in various mind and brain related subfields such as cognition, the mental processes that underlie behavior, reasoning and decision making. In the early stages of Cognitive Psychology, the high-tech measuring instruments used today were unavailable. The idea of scientifically scrutinizing what was going on in a human mind was first established during the late 19th century. Psychology Laboratories were based on measuring observable features such as reaction time. Nonetheless, there was a technique developed called analytic introspection. The latter is a method that focusses on the subject’s inner processes. Here, the subject has to give precise reports about his or her mental activity. During the first half of the 20th century and naturally parallel to behaviorism, the behavioristic approach became the main issue in psychology. The main emphasis was the examination of outer expression of inner processes, rather than the mind itself. Even though behaviorism had established itself as the mainstream, curiosity about the mind was not diminished. In the 1950s, this inquisitiveness was released in a new science named Cognitive Science. Cognitive Psychology became one of its subfields. The interdisciplinary approach of Cognitive Science enabled the use of modern technology and new methods to combine examinations of public actions (latencies in reaction time, number of recalls) with physiological measurements (EEG and event-related potentials, fMRI). Hereby, references and correlations between action and cognition could be made. Cognitive Psychology is using these methods and additional ones such as Single and Double Dissociation and brain lesioning to collect evidence for certain features of mental activity. Because of those correlations that were found, the examination of the human brain and its functions has become one of the main challenges to Cognitive Psychology. Wikibooks | 5 Chapter 1 The role of the brain Examination of brain damage has a long tradition. The Ancient Romans observed that gladiators with head injuries often lost their mental skills, whereas injuries to other parts of the body did not have such an effect. It was inferred that there was a possible link between the mind and brain. Today, the assumption that the mind is somehow implemented in the brain is taken for granted, and even the common-sense understanding presupposes a relation between mental and neuronal processes. Subsequently, research on the brain became more and more important, and the psychological methods being used shifted to systematic scientific examination of the Figure 1.1 - The resting potential is initially around -70 brain. The crucial question then became: How is this mV relative to the outside of the cell. Once the relation realized, and what properties of the brain are threshold (-55 mV) is passed, the cell depolarizes and capable of causing mental and cognitive events? the polarity reverses up to +40 mV. Subsequently the cell hyperpolarizes and the voltage becomes more negative than the resting potential for a short period. As it is not possible, in this introductory passage, to cover the entire configuration of the brain in an appropriate manner, we will just give a brief summary of the concepts behind neural signal transduction, and smoothly switch over to the anatomy of the brain. This in turn will then serve as background information in the attempt to link cognitive functions to brain structure. In principle, there are two classes of cells in the human brain: neurons and glia. Both are approximately equal in distribution, though neurons seem to play the main role in information processing. The actual signal transduction takes place in different ways. On the one hand, there is mean electrical conduction, and on the other hand, there are complicated biochemical cascades which transmit the data. Both variants can be subsumed to the concept of action potentials (Figure 1.1), which generally carry out the signal transduction from one nerve cell to another. For better conduction, the axons of the neurons are insulated by a so-called myelin sheath. The myelin in the human brain is produced by a certain class of glial cell, the oligodendrocytes. This is important because the decomposition of the myelin sheath is involved in diseases, such as as multiple sklerosis. Once the information perceived by the sensory organs is transformed into a sequence of action potentials the data is, in a way, neutral, since it has no specific qualitive properties which indicate from which sense the signal was original initiated. But how is the information encoded? In other words, how can the variety of our conscious experience be caused by simple inhibition and excitation of nerve cells embedded in an admittedly complex system? Because of the lack of better metaphors, the answer is often given by comparing the brain to a modern digital computer. Parsing the world into objects, making inferences, having associative memory and the like can be analyzed by developing computational models. The underlying paradigm is that the information is represented by the rate of action potential spikes. How this is exactly realized is the aim of research of biophysics, a subdiscipline of neurobiology. In cognitive psychology, however, the methods used differ. This is because the main interest is not devoted to the organization of single neuron circuits, but rather to the larger, functional units in the 6 | Cognitive Psychology and Neuroscience Cognitive Psychology and the Brain network. References M. S. Gazzaniga, R. B. Ivry, and G. R. Mangun, Cognitive Neuroscience, Norton & • Company, 1998, ISBN 0393972194 E. Br. Goldstein, Cognitive Psychology, Wadsworth, 2004, ISBN 0534577261 • M. W Eysenck, M. T. Keane, Cognitive Psychology, Psychology Press, 2005, ISBN • 1841693596 M. T. Banich, The Neural Bases of Mental Function, Houghton Mifflin, 1997, ISBN 0-395- • 66699-6 E. R. Kandel, J. H. Schwartz, T. M. Jessell, Principles of neural science, 2000, ISBN 0-07- • 112000-9 Links PDF file of the "ethics code" of the American Psychological Association • Cognitive Psychology miniscript by Fabian M. Suchanek • Famous papers in the history of cognition • live version • discussion • edit lesson • comment • report an error Wikibooks | 7 Chapter 2 2 P S E ROBLEM OLVING FROM AN VOLUTIONARY P ERSPECTIVE live version • discussion • edit lesson • comment • report an error Introduction G estalt psychologists approach towards problem solving was a perceptual one. That is, for them, the questions about problem solving were: how is a problem represented in a persons mind, and • how does solving this problem involve a reorganisation or restructuring of this • representation? Restructuring is basically the process of arriving at a new understanding of a problem situation - changing from one representation of a problem to a (very) different one. The following story illustrates this: Two boys of different age are playing badminton. The older one is a more skilled player, and therefore it is predictable for the outcome of usual matches who will be the winner. After some time and several defeats the younger boy finally loses interest in playing, and the older boy faces a problem. The usual suggestions, according to M. Wertheimer (1945/82), at this point of the story range from 'offering candy' and 'playing another game' to ' not playing to full ability' and 'shaming the younger boy into playing'. And this is what the older boy comes up with: He proposes that they should try to keep the bird in play as long as possible - and thus changing from a game of competition to one of cooperation. They'd start with easy shots and make them harder as their success increases, counting the number of consecutive hits. The proposal is happily accepted and the game is on again. Insight There are two very different ways of approaching a goal-oriented situation. In one an organism readily reproduces the response to the given problem from past experience. This is called reproductive thinking. The second way requires something new and different to achieve the goal, prior learning is of little help here. Such productive thinking is (sometimes) argued to involve insight. Gestalt psychologists even state that insight problems are a separate category of problems in their own right. Tasks that might involve insight usually have certain features - they require something new and nonobvious to be done and in most cases they are difficult enough to prevent that the initial solution attempt is successful. When solving this kind of problems one experiences a so called "AHA- experience" - the solution pops up all of the sudden. At one time they do not have the answer to a problem and in the next second it's solved. 8 | Cognitive Psychology and Neuroscience Problem Solving from an Evolutionary Perspective Fixation Sometimes, previous experience or familiarity can even make problem solving more difficult. In effect habitual directions can get in the way of finding new directions. This is called fixation. Mental Fixedness One approach to studying fixation was study wrong-answer verbal insight problems. To this, people tend to give rather an incorrect answer when failing to solve, than to give no answer at all. A typical example is, when people are told that, on a lake, the area covered by water lilies doubles every 24 hours and that it takes 60 days to cover the whole lake, and are asked: 'How many days does it take to cover half the lake?' the typical respond is '30 days' (whereas 59 days is correct). These wrong solutions are due to an inaccurate interpretation, hence representation, of the problem. This can happen because of 'sloppiness' (a quick shallow reading of the problem and/or weak monitoring their efforts made to come to a solution). In this case error feedback should help people to reconsider the problem features, note the inadequacy of their first answer, and find the correct solution. If, however, people are truly fixated on their incorrect representation, being told the answer is wrong doesn't help. In a study made by P.I. Dallop and R.L. Dominowski in 1992 these two possibilities were contrasted. In approximately one-third of the time error feedback led to right answers, so only approximately one-third of the wrong answers were due to inadequate monitoring. Functional Fixedness Functional fixedness concerns the solution of object-use problems. The basic idea is that, when the usual way of using an object is emphasized, it will be far more difficult for a person to use that object in a novel manner. Problem Solving - Modern Approaches Problem Solving as a Search Problem The idea of regarding to problem solving as search problems was invented by Alan Newell and Herbert Simon while trying to design computer programs which could solve certain problems. This led them to develop a program called General Problem Solver which was able to solve any well-defined problem that can be formalized like chess or the towers of hanoi, but was not able to solve any real world problem. Any given problem consists of two special states namely an initial and a desired final or goal state. To represent all possible situations between the initial and the goal state, intermediate states were introduced. Additionally there exist a set of operators to move from one state to another. A solution is a sequence of actions describing how to reach the goal state. The simplest method to solve a problem, defined in these terms, is to search for a solution by just trying one possibility after another (also called trial and error). As already mentioned, this method of problem solving is not capable of solving real world problems since it is usually not possible to formalize these problems in such a way that a search Wikibooks | 9 Chapter 2 algorithm is able to search for a solution. Means-End Analysis Another way is to try to divide a problem into smaller ones by creating sub goals. This method is called means-end analysis and can be best demonstrated with the towers of hanoi problem. The initial state is a stack of discs of different sizes on a peg. There are three pegs (A, B and C) and the discs are on the left one. A disc has to be always placed on a bigger one or on an empty peg. The goal is to move the stack of disks to the right peg, but only one disc can be moved at once. The following recursive algorithm solves this problem by using the means-end analysis: 1. move n-1 discs from A to C 2. move disc #n from A to B 3. move n-1 discs from C to B (n is the total number of discs) With each recursive loop the problem is reduced by one. This is an important everyday problem solving strategy - like, say, writing this chapter of the book. We describe one aspect after another to give you, the reader, an overview of the subject that is as comprehensible as possible. Analogies Analogies describe similar structures and interconnect them to clarify and explain certain relations. In a recent study, for example, a song that got stuck in your head is compared to an itching of the brain that can only be scratched by repeating the song over and over again. Restructuring by Using Analogies One special kind of restructuring, the way already mentioned during the discussion of the Gestalt approach, is analogical problem solving. Here, to find a solution to one problem - the so called target problem, an analogous solution to another problem - the source problem, is presented. An example for this kind of strategy is the radiation problem posed by K. Duncker in 1945: As a doctor you have to treat a patient with a malignant, inoperable tumor, buried deep inside the body. There exists a special kind of ray, which is perfectly harmless at a low intensity, but at the sufficient high intensity is able to destroy the tumor - as well as the healthy tissue on his way to it. What can be done to avoid the latter? When this question was asked to participants in an experiment, most of them couldn't come up with the appropriate answer to the problem. Then they were told a story that went something like this: A General wanted to capture his enemy's fortress. He gathered a large army to launch a full-scale 10 | Cognitive Psychology and Neuroscience