1. BASIC FUNCTIONS OF THOUGHT
   Cognitive psychology is the study of mental processes by which the information humans receive from their environment is modified, made meaningful, stored, retrieved, used, and communicated to others.
   1. The Circle of Thought
      The five core functions of human thinking--describe, elaborate, decide, plan, and guide action--form a circle of thought. An information-processing system receives information, represents the information with symbols, and then manipulates those representations. Thinking is the manipulation of mental representations in order to form new representations.
   2. Measuring Information-Processing
      Researchers study the time it takes to go through the stages of information processing, or mental chronometry. Reaction time is the time elapsed between the presentation of a stimulus or information and a response. Several factors influence reaction time in quick decisions: complexity, stimulus-response compatibility, expectancy, and speed-accuracy tradeoff.
      Evoked brain potentials are used to analyze mental events and their timing. Evoked potentials are changes in voltage on an electroencephalogram (EEG) that are reactions to stimuli.
2. MENTAL REPRESENTATION: THE INGREDIENTS OF THOUGHT
   1. Concepts
      Concepts are categories of objects, events, or ideas with common properties, such as the way they look or the subjects they contain. Artificial concepts can be defined by a set of characteristics that all members have and no nonmembers have. Natural concepts are concepts whose members must have at least some of the characteristics that define the concept. Prototypes are objects or events that best represent a natural concept.
   2. Propositions
      The smallest units of knowledge that can stand as separate assertions are called propositions. Propositions can be either true or false.
   3. Schemas, Scripts, and Mental Models
      Schemas are our general knowledge about categories of objects, events, and people. Scripts are mental representations of sequences of activity. Large clusters of propositions in long-term memory that represent people's understanding of how things work are called mental models.
   4. Images and Cognitive Maps
      Thinking is sometimes based on visual image manipulation, such as rotation of a mental image of an object. Cognitive maps are images of familiar locations. Although useful, cognitive maps are often distorted by the rectangular bias.
3. THINKING STRATEGIES
   Reasoning is the process by which we generate arguments, evaluate them, and reach conclusions.
   1. Formal Reasoning
      The mental procedures that yield a valid conclusion are known as formal or logical reasoning. Algorithms are systematic methods that always reach a correct result. At the core of the study of logic is using the rules of logic in the evaluation of syllogisms. Logic errors include bias about conclusions and limits on working memory.
   2. Informal Reasoning
      People tend to use heuristics, or mental shortcuts, rather than algorithms, which always yield a correct solution. Several commonly used heuristics are the anchoring, representativeness, and availability heuristics.
4. PROBLEM SOLVING
   1. Strategies for Problem Solving
      Strategies for problem solving are decomposition, working backward, analogies, means-end analysis, and incubation.
   2. Focus on Research Methods: Locating Analogical Thinking
      To study the relationship between brain activity and analogical mapping, researchers used PET scans and asked participants to perform two tasks in succession. The tasks made similar demands on the brain with the exception that one of the tasks required analogical thinking while the other did not. Psychologists then "subtracted" the brain activity recorded for the task without analogical demands from the activity recorded for the task requiring participants to make analogies. Areas that remained "active" after the subtraction--mainly the left frontal and parietal lobes--were taken as evidence of the source of analogical thinking. Future research is necessary to determine if these areas are activated in all analogical thinking, or in certain types of analogical thinking.
   3. Obstacles to Problem Solving
      1. Multiple Hypotheses. Testing the incorrect hypothesis first when more than one hypothesis exists can delay problem solving.
      2. Mental Sets. Viewing a new problem from the perspective used for old problems can prevent the discovery of simpler solutions. Functional fixedness, the inability to use objects in new ways, can also impede problem solving.
      3. The Confirmation Bias. Once we choose a hypothesis, we tend to interpret available information as confirming it.
      4. Ignoring Negative Evidence. We do not use the lack of evidence as often as we should when testing a hypothesis.
   4. Building Problem-Solving Skills
      Experts efficiently use old information to organize new material into smaller, more meaningful units and use their experience as a guide. However, experts need to beware of mental sets, functional fixedness, and confirmation biases.
   5. Problem Solving by Computer
      Artificial-intelligence (AI) scientists develop computer systems that imitate the products of human perception and thought.
      1. Symbolic Reasoning and Computer Logic. Expert systems are computer programs that solve very specific problems. These systems require an extensive knowledge base and an inference engine. Unfortunately, the computer's expertise in one area cannot be easily transferred to a different domain or area.
      2. Neural Network Models. Many AI specialists have begun to use a connectionist or neural-network approach because much of intelligent diagnostics and problem solving depends on recognition and classification of conditions and patterns.
      3. Computer-Assisted Problem Solving. Computer-human combinations are increasingly being used to solve problems more efficiently than either could do alone.
5. DECISION MAKING
   Risky decisions are decisions made when the result is uncertain.
   1. Evaluating Options
      Multiattribute decision making involves choosing between options that have both positive and negative features, or attributes.
      1. Comparing Attributes. Multiattribute decisions can be difficult because comparisons of many attributes must be made despite the limited storage capacity of working memory. Utility is the subjective, personal value of each attribute. The positive and negative utilities of each attribute must be weighed in a decision.
      2. Estimating Probabilities. Good decisions maximize expected value. People must take into account the probabilities of certain outcomes and the outcome value in decision making.
   2. Biases and Flaws in Decision Making
      People do not always maximize expected values for several reasons.
      1. Gains, Losses, and Probabilities. Positive utilities are not mirror images of negative utilities; people feel worse about losing a certain amount than they feel good about gaining the same amount. Most people see large losses as disproportionately more serious than small losses. People assess the probability of a decision incorrectly because they tend to estimate incorrectly the probability of rare or frequent events, are operating from gambler's fallacy, or have too much confidence in their own predictions.
      2. How Biased Are We? Psychologists are not sure how to answer this question. Do people make too many decision-making mistakes because they are attempting to satisfy criteria other than expected value?
   3. Naturalistic Decision Making
      Naturalistic decision making involves the use of prior experience to develop mental representations of how organizational systems really work and then to use this "situation awareness" to solve current problems.
   4. Linkages: Group Processes in Problem Solving and Decision Making
      Group interaction shapes decision-making processes. Group discussions follow a consistent pattern. Various options are proposed and debated until a minimally acceptable solution is agreed upon. This option is staunchly defended against all newer options and is likely to become the group's decision. The outcomes of group decisions may be more extreme than individual decisions--a phenomenon called group polarization.
      When a correct solution can be easily demonstrated to all members, groups usually outperform individuals. On less clear-cut problems, though, the best group member may outperform the group. The critical element in successful group problem solving is the sharing of individual members' unique information and expertise.
6. LANGUAGE
   1. The Elements of Language
      A language has two basic elements: symbols and grammar.
      1. From Sounds to Sentences. Phonemes are the smallest unit of sound with meaning. Morphemes are the smallest unit of language with meaning. Words are made of morphemes, which in turn consist of phonemes. Rules of syntax determine the ways in which words are combined to form sentences. Semantics are rules that govern the meanings of words and sentences.
      2. Surface Structure and Deep Structure. The surface structure of a sentence (the string of words) may have more than one meaning, or deep structure.
   2. Understanding Speech
      1. Perceiving Words and Sentences. The gaps we hear between spoken words are not real but are perceived because of top-down processing. Syntax, memories, and knowledge of the world help us comprehend and remember verbal and written communication.
      2. Using Context and Scripts. An understanding of language depends on constructing information based partly on the context in which the information is encoded. Context may be created by the situation and by personal factors such as education and culture.
      3. Conventions and Nonverbal Cues. Conventions, built up over years of experience, often govern the meaning of conversations. Nonverbal cues also play a role in the understanding of conversations.
   3. The Development of Language
      1. The First Year. At about four months of age, babies begin repeating simple syllables, called babblings. At about nine months, babies stop uttering sounds that aren't part of the language to which they are exposed. At twelve to eighteen months, babies utter their first real words, which usually are proper names and object words. In the one-word stage, children tend to use one word at a time and overextend its use to mean more than one object.
      2. The Second Year. These appear at about eighteen to twenty-four months of age as two-word pairs. These first sentences are telegraphic: brief and to the point. Next are three-word sentences that use subject-verb-object sequences. Word endings begin to appear, but at first are used incorrectly. Finally, adjectives and auxiliary verbs are added. By age five, children have acquired most of the syntax of their native language.
      3. The Third Year. At about age three, children begin to use auxiliary verbs, question words, and clauses.
   4. How Is Language Acquired?
      1. Conditioning, Imitation, and Rules. Conditioning, imitation, and rules do not fully explain the development of language in children. However, when adults provide correct revisions of a child's conversation, the learning process is enhanced.
      2. Innate Sources of Language Acquisition. Noam Chomsky suggests that children possess an innate language acquisition device that helps them learn the complexities of language. There appears to be a critical period for language development.
      3. Bilingualism. Children in a bilingual environment prior to the end of the critical period show enhanced language performance. Those children with similar mastery of two languages, or balanced bilinguals, may have more cognitive flexibility and creativity.
   5. Thinking Critically: Can Nonhumans Use Language?
      What am I being asked to believe or accept?
      Some researchers believe that nonhumans can use language.
      What evidence is available to support the assertion?
      Research with chimpanzees suggests that animals can learn to use words and adopt a crude grammar.
      Are there alternative ways of interpreting the evidence?
      Other researchers argue that chimps' very short sentence structure and lack of spontaneous and creative use of language mean that they are incapable of language. In addition, experimenter bias may explain some of the "language learning" results seen in chimpanzees.
      What additional evidence would help to evaluate the alternatives?
      Studies in the area are few in number. More studies using more subjects need to be done. In addition, researchers need to examine the limiting capacity of nonhuman working memory and its effects on animals' use of language.
      What conclusions are most reasonable?
      Psychologists are still not in full agreement on this issue. The communication displayed by animals is much more limited than human children's language. And the level of language produced by chimps so far falls short of matching their very high levels of intelligence. But the evidence does suggest that under the right conditions, animals can learn language-like skills.
   6. Culture, Language and Thought
      Research across cultures and within North American culture suggests that language does not determine what we can think about, but it does influence how we think, solve problems, and make decisions.