Psychology, Sixth Edition
Cognition and Language
Cognitive psychology is the study of the mental processes people use to modify, make meaningful,
store, retrieve, use, and communicate to others the information they receive from the environment. (see introductory section)
- An information-processing system receives information, represents information through symbols, and manipulates
those symbols. (see The Circle of Thought)
REMEMBER: Psychologists consider people similar to information-processing systems
in the way they take in information, pass it through several stages, and
finally act on it.
Thinking can be described as part of an information-processing system in which mental representations are manipulated
in order to form new information. (see The Circle of Thought)
- A reactiontime is the amount of elapsed time between the presentation of a physical stimulus and an overt reaction to that stimulus. (see Mental Chronometry)
Example: Susan and several of her friends are standing in her office looking for
her keys. Suddenly, Dave calls out, "Hey!" and throws her the keys. The reaction time is the time it takes Susan to look up and get ready to catch the keys after hearing Dave
Evoked brain potentials are small temporary changes in voltage that occur in the brain in response
to stimuli. Psychologists can study information processing and can look for abnormal functioning in the brain
by examining evoked potentials. (see Evoked Brain Potentials)
REMEMBER:Evoke means to "cause" or "produce." Stimuli evoke, or produce, small changes in the brain. Psychologists have instruments that allow them to record these changes for study.
Example: About 300 milliseconds after a stimulus is presented, a large positive peak--the P300--occurs. The timing can be affected by how long sensory processing and perception
Concepts are basic units of thought or categories with common properties. Artificial
and natural concepts are examples. (see Concepts)
Formal concepts are concepts that are clearly defined by a set of rules or properties. Each member of the concept meets all the rules or
has all the defining properties, and no nonmember does. (see Concepts)
Example: A square is a formal concept. All members of the concept are shapes with
four equal sides and four right-angle corners. Nothing that is not a square shares these properties.
Natural concepts are defined by a general set of features, not all of which must be present for an object to be considered
a member of the concept. (see Concepts)
Example: The concept of vegetable is a natural concept. There are no rules or lists
of features that describe every single vegetable. Many vegetables are difficult
to recognize as such because this concept is so "fuzzy." Tomatoes are not vegetables, but most people think they are. Rhubarb is a vegetable, but most
people think it is not.
- A prototype is the best example of a natural concept. (see Concepts)
Example: Try this trick on your friends. Have them sit down with a pencil and paper. Tell them to write down all the numbers that
you will say and the answers to three questions that you will ask. Recite
about fifteen numbers of at least three digits each, and then ask your friends
to write down the name of a tool, a color, and a flower. About 60 to 80 percent of them will write down "hammer," "red," and "rose" because these are common prototypes of the concepts tool, color, and flower.
Prototypes come to mind most easily when people try to think of a concept.
Propositions are the smallest units of knowledge that can stand as separate assertions.
Propositions are relationships between concepts or between a concept and
a property of the concept. Propositions can be true or false. (see Propositions)
Example:Carla (concept) likes to buy flowers (concept) is a proposition that shows a relationship between two concepts. Dogs bark is a proposition that shows a relationship between a concept (dog) and a
property of that concept (bark).
Schemas are generalizations about categories of objects, events, and people. (see
Schemas, Scripts, and Mental Models)
Example: Dana's schema for books is that they are a bound stack of paper with stories or
other information written on each page. When her fifth-grade teacher suggests that each
student read a book on the computer, Dana is confused until she sees that
the same information could be presented on a computer screen. Dana has now
revised her schema for books to include those presented through electronic media.
Scripts are mental representations of familiar sequences, usually involving activity.
(see Schemas, Scripts, and Mental Models)
Example: As a college student, you have a script of how events should transpire in the classroom: students enter the
classroom, sit in seats facing the professor, and take out their notebooks.
The professor lectures while students take notes, until the bell rings and
they all leave.
Mental models are clusters of propositions that represent people's understanding of how things work. (see Schemas, Scripts, and Mental Models)
Example: There is a toy that is a board with different types of latches, fasteners,
and buttons on it. As children play with it, they form a mental model of how these
things work. Then, when they see a button, perhaps a doorbell, they will
have an understanding of how it works.
Images are visual pictures represented in thought. Cognitive maps are one example. (see Images and Cognitive
Cognitive maps are mental representations of familiar parts of your world. (see Images
and Cognitive Maps)
Example: Lashon's friend asks, "How do you get to the mall from here?" To answer the question, Lashon pictures the roads and crossroads between
their location and the mall and is able to describe the route for his friend
Reasoning is the process whereby people make evaluations, generate arguments, and reach conclusions.
(see Thinking Strategies)
Formal reasoning (also called logical reasoning) is the collection of mental procedures that
yield valid conclusions. An example is the use of an algorithm. (see Thinking Strategies)
Algorithms are systematic procedures that always produce solutions to problems. In
an algorithm, a specific sequence of thought or set of rules is followed to solve the problem. Algorithms can be very time-consuming. (see
Example: To solve the math problem 3,999,999 1,111,111 using an algorithm, you would multiply the numbers out:
This computation takes a long time. You could, however, use a heuristic to
solve the problem: round the numbers to 4,000,000 1,000,000, multiply 4 1, and add the appropriate number of zeros (000,000,000,000). Although simpler
and faster, this heuristic approach yields a less accurate solution than
that produced by the algorithmic approach.
Rules of logic are sets of statements that provide a formula for drawing valid conclusions
about the world. (see Thinking Strategies)
Syllogisms, components of the reasoning process, are arguments made up of two propositions, called premises, and conclusions based on those premises.
Syllogisms may be correct or incorrect. (see Thinking Strategies)
Example: Here is an incorrect syllogism: All cats are mammals (premise), and all
people are mammals (premise). Therefore, all cats are people (conclusion).
Informal reasoning is used to assess the credibility of a conclusion based on the evidence available
to support it. There are no foolproof methods in informal reasoning. (see Informal Reasoning)
Heuristics are mental shortcuts or rules of thumb used to solve problems. (see Informal
Example: You are trying to think of a four-letter word for "labor" to fill in a crossword puzzle. Instead of thinking of all possible four-letter combinations (an algorithmic
approach), you think first of synonyms for labor--job, work, chore--and choose the one with four letters.
- The anchoring heuristic is a biased method of estimating an event's probability by adjusting a preliminary estimate in light of new information
rather than by starting again from scratch. Thus, the preliminary value biases
the final estimate. (see Informal Reasoning)
Example: Jean is getting ready to move to the city. Her parents lived there ten years
ago and were familiar with the area that she wants to move into now. Ten
years ago it was an exceedingly dangerous neighborhood. Since that time,
however, many changes have taken place, and the area now has one of the lowest crime rates in the
city. Jean's parents think that the crime rate may have improved a little, but, despite
the lower crime rate, they just cannot believe that the area is all that safe.
- The representativeness heuristic involves judging that an example belongs to a certain class of items by
first focusing on the similarities between the example and the class and
then determining whether the particular example has essential features of the class. However, many times people do not consider the
frequency of occurrence of the class (the base-rate frequency), focusing
instead on what is representative or typical of the available evidence. (see
Example: After examining a patient, Dr. White recognizes symptoms characteristic of
a disease that has a base-rate frequency of 1 in 22 million people. Instead
of looking for a more frequently occurring explanation of the symptoms, the
doctor decides that the patient has this very rare disease. She makes this decision based on the similarity
of this set of symptoms (example) to those of the rare disease (a larger
class of events or items).
- The availability heuristic involves judging the probability of an event by how easily examples of the event come to
mind. This leads to biased judgments when the probability of the mentally
available events does not equal the actual probability of their occurrence.
(see Informal Reasoning)
Example: A friend of yours has just moved to New York City. You cannot understand
why he has moved there since the crime rate is so high. You hear from a mutual
acquaintance that your friend is in the hospital. You assume that he was
probably mugged because this is the most available information in your mind about New York City.
Mental sets occur when knowing the solution to an old problem interferes with recognizing
a solution to a new problem. (see Obstacles to Problem Solving)
Example: The last time his CD player door wouldn't open, Del tapped the front of it and it popped open. This time when it won't open, Del does the same thing--not noticing that the power isn't even on!
Functional fixedness occurs when a person fails to use a familiar object in a novel way in order
to solve a problem. (see Obstacles to Problem Solving)
Example: Lisa is very creative in her use of the objects in her environment. One
day she dropped a fork down the drain of the kitchen sink. She took a small refrigerator magnet and tied it to a chopstick.
She then put the chopstick down the drain, let the fork attach itself to
the magnet, and carefully pulled the fork out of the drain. If Lisa had viewed the magnet as being capable only of holding material against the refrigerator, and the chopstick
as being useful only for eating Chinese food, she would have experienced
Confirmation bias is a form of the anchoring heuristic. It involves a reluctance to abandon an initial hypothesis and a tendency
to ignore information inconsistent with that hypothesis. (see Obstacles to
Artificial intelligence (AI) is the study of how to make computers "think" like humans, including how to program a computer to use heuristics in problem
solving. (see Problem Solving by Computer)
Example: Lydia plays chess against a computer that has been programmed with rules,
strategies, and outcome probabilities.
- The utility of an attribute is its subjective, personal value. (see Evaluating Options)
Example: Juan prefers large classes because he likes the stimulation of hearing many
opposing viewpoints. In choosing courses, Juan decides whether the positive utility of the preferred class
size is greater than the negative utility of the inconvenient meeting time.
Expected value is the likely benefit a person will gain if he or she makes a particular decision several times. (see Evaluating Options)
Example: Sima doesn't have enough money for this month's rent. She knows that going on a shopping spree would be a wonderful stress-reliever
in the short run, but the increase in her amount of debt would outweigh the
enjoyment in the long run.
Language is composed of two elements: symbols, such as words, and a grammar. (see
The Elements of Language)
Example: The German and English languages use the same symbols (Roman characters),
but each has a different set of rules for combining those symbols. The Russian language has different symbols (Cyrillic
characters) as well as different rules of grammar.
Grammar is the set of rules for combining symbols, or words, into sentences in a
language. (see The Elements of Language)
Phonemes are the smallest units of sound that affect the meaning of speech. (see
From Sounds to Sentences)
Example: Phonemes are sounds that make a difference in the meaning of a word. By changing the beginning phoneme, the meanings of the following words are changed:
bin, thin, win.
REMEMBER:Phono means "sound." Phonemes are sounds that change the meaning of a word.
Morphemes are the smallest units of language that have meaning. (see From Sounds to Sentences)
Example: Any prefix or suffix has meaning. The suffix s means "plural," as in the words bats or flowers. The prefix un means "not," as in unhappy or unrest. S and un are morphemes for the words bat, flower, happy, and rest.
Words are made up of one or more morphemes. (see From Sounds to Sentences)
Example: The word unwise is made up of two morphemes: un and wise.
Syntax is the set of rules that dictates how words are combined to make phrases and sentences.
(see From Sounds to Sentences)
REMEMBER:Syn means "together" (as in synchronized). Syntax is the set of rules that determines the order
of words when they are put together.
Semantics is the set of rules that governs the meaning of words and sentences. (see
From Sounds to Sentences)
Example: The sentence, "Wild lamps fiddle with precision" has syntax, but incorrect semantics.
Surface structures of sentences are the order in which the words are arranged. (see Surface
Structure and Deep Structure)
- The deep structure of a sentence is an abstract representation of the relationships expressed in a sentence, or, in other words, its various meanings. (see
Surface Structure and Deep Structure)
Example:The eating of the animal was grotesque. The surface structure of this sentence is the order of the words. The deep
structure contains at least two meanings: The way the animal is eating could be grotesque,
and the way people are eating an animal could be grotesque.
Babblings are the first sounds infants make that resemble speech. Babbling begins at about four months of age. (see The Development of Language)
Example: While Patrick plays, he says, "ba-ba-ba."
- The one-word stage of speech is that period when children use one word to cover a number of
objects and frequently make up new words. This stage lasts about six months. (see The Development
Example: Laura says "ba" to stand for bottle, ball, or anything else that starts with a b. Amy always asks for milk, even if she wants something else to drink, such as water or juice.