Chapter 8
Cognition and Language
• Cognition refers to thinking, gaining knowledge, and dealing with knowledge.
• Language is intimately related to the activities of cognition. It is a system of arbitrary symbols that can be combined to create an infinite number of meaningful statements.
Module 8.1
Cognitive Psychology
• Cognitive psychologists study how people think and acquire knowledge, know what they know, how they imagine and how they solve problems. • Cognitive psychology uses a variety of methods
to measure mental processes and test theories about what we know and how we know it.
Attention
• Attention is the tendency to respond selectively to stimuli – It is generally true that a feature or object that is
unusual or different will get your attention quickly, while one that is surrounded by similar objects will require a long and patient search.
• Finding an unusual feature or figure relies on a
preattentive process, a procedure for extracting information automatically or simultaneously across a large portion of the visual field.
• Finding a typical feature or figure requires an
attentive process, a procedure that considers only one part of the visual field at a time.
Attention
• Preattentive and attentive processes
– The Stroop effect is another example of the difference between preattentive and attentive processes.
– Although it is difficult to explain, it seems that reading for most of us is an automatic and
preattentive process.
– Being asked to refrain from reading and name the colors instead makes substantive
Figure 8.5
Attention Limits over Space and Time
• Change blindness
– Recall the concept of the sensory store
– People believe they remember everything in a scene they have recently scanned
– But they frequently fail to detect changes in parts of a scene upon viewing it again
– This common failure is referred to as change blindness
Video:
Change Blindness
PLAY VIDEO
Attention
• Shifting attention
– Many routine tasks that we perform require little attention.
• When we intentionally shift our attention to a
particular stimulus, it is difficult to attend to other things.
• This is a kind of “negative priming” that occurs when we attend to one thing and deliberately ignore another. We may briefly find it hard to identify the previously ignored stimulus.
Attention
• Shifting attention
– A related effect is the attentional blink. – During a brief time after perceiving one
stimulus, it is difficult to attend to something else.
– Effects such as these are of crucial
importance in both the trivial activity of playing a video game, and potentially life-and-death situations such as flying an airplane or
Figure 8.4
Figure 8.4 Each gauge represents a measurement of a different variable in a machine. For the top row, the operator must check gauges one at a time. In the bottom row all the safe ranges are now in the safe ranges. The operator detects an unsafe reading preattentively.
Attention Deficit Hyperactivity Disorder
• ADD is characterized by easy distraction, impulsiveness, moodiness and “inability” to follow through on plans.
• When the symptoms include noticeable fidgetiness, the condition is referred to as Attention Deficit Hyperactivity Disorder (ADHD).
• These disorders are estimated to occur in 3 to 10% of all children and about 70% of those afflicted are boys.
• There are ongoing disputes about the true nature of the disorder.
Categorization
• The formation of categories or concepts is one of the primary ways that we organize information about our world.
• In general we categorize people, objects or events together when they have important qualities in common.
Categorization
• Ways of describing a category: Prototypes
– A prototype is a familiar or typical example of a category.
– We decide whether or not an object belongs in a category by determining how well it
resembles the prototypical members of the category
Categorization
• Prototypes
– We use ROSE as the prototypical flower.
– Daisy and tulip resemble it closely enough that you would quickly agree that they belong in the same category.
– What about the “corpse flower” – which has a
blossom that is not colorful and a terrible fragrance? Although you would also classify it as a flower, you would pause because it doesn’t resemble the
Categorization
• Prototypes
– The prototype approach suggests that membership is a category may be a matter of degrees, not a yes-or-no question.
– Prototypes are harder to apply to compound categories.
– We can discuss a category without having an existing example of its members.
• Try to think of a prototypical “rare insect.”
• Do we require a prototype to discuss or think about “extinct amphibians?”
Categorization
• Conceptual networks and priming
– Thinking about something usually means relating it to a network of related concepts.
• It’s difficult to think about something “by itself.” • We have a hierarchy in mind of categories and
subcategories.
• The upper levels of the hierarchy are the more common, broadly shared characteristics.
• The lower levels are the more distinctive or special characteristics.
CONCEPT CHECK:
Which question takes longer to answer:
Do astronauts travel in spaceships?
Do astronauts sometimes get traffic tickets?
The first one is a more distinct feature and should be easier to answer (although both are true).
Categorization
• Conceptual networks and priming
– When you hear about one concept, the other concepts that you associate with it are also primed or activated.
• This process is called spreading activation.
• If you hear the word “car” you think of
“drive” or “road.” What do you think of when you hear the word “school”?
Figure 8.10
Figure 8.10 According to one explanation, the word Armstrong and the ideas astronaut, first person on the moon, and famous sayings all activate the linked saying “One small step for a man . . .”
Mental Processes
• Many of these findings we have described are based on research involving self-report of subjects concerning their mental processes. • Remember that conclusions based on such findings are tentative. • We strengthen them by performing many studies, using different
Module 8.2
Problem Solving
• The 4 phases of problem solving
– Understanding and simplifying the problem – Generating hypotheses
– Testing the hypotheses – Checking the result
Figure 8.11
Problem Solving
• Algorithms
– When a problem is well defined, we can apply an algorithm to solve it.
– An algorithm is a mechanical, repetitive, step-by-step procedure for arriving at the solution to a problem.
– Mathematics is a field of knowledge made up primarily of algorithmic problem solving.
– The steps for programming your VCR also comprise an algorithm. Do you know it?
Problem Solving
• Heuristics
– Many problems that we face are too ill defined for the use of any algorithm.
– An example of such a problem would be “What career would be best for me?”
– For less well defined problems we apply
heuristics. Heuristics are strategies for simplifying a problem or guiding an
Problem Solving
• Insight
– Using insight to solve a problem differs from using algorithms.
• Most people can look at a mathematical problem and accurately gauge whether or not they would be able to solve it.
• Insight strategies are used in cases where we have no idea whether or not we would be able to solve the problem.
• Insight solutions often seem to be arrived at suddenly.
Problem Solving
• Sudden or gradual insight?
– It is probably the case that we work on insight problems without realizing that we are doing so.
– We are making use of the information that we have already stored related to the problem.
– Even when subjects in insight problem-solving studies claim to have “no confidence” in their abilities to arrive at the solution, they do so a majority of the time.
Figure 8.15
Figure 8.15 (a) Draw the trajectory of water as it flows out of a coiled garden hose. (b) Draw the trajectory of a bullet as it leaves a coiled gun barrel.
Figure 8.16
Problem Solving
• Reasoning by heuristics
– Critical thinking involves using our
considerable ability to evaluate our own thinking (called metacognition) to carefully evaluate for and against any conclusion.
– All thinkers make these errors, and monitoring our cognition can be a demanding activity, but the clarity and knowledge that we can achieve by doing so makes the effort well worth it.
Problem Solving • Reasoning by heuristics
– The representativeness heuristic is the tendency to assume that if an item is similar to members of a
particular category, it is also a member of the category.
– “If it looks like a duck….”
– It is better to make these judgments in light of the available base-rate information—that is, the data about the frequency or probability of a given item or event.
– People tend to use only the representativeness heuristic and fail to consider the frequency data.
Problem Solving • Reasoning by heuristics
– The availability heuristic is the strategy of assuming that how easily one can remember examples of an
event is an indicator of how common that event actually is.
– For example, it is easier to think of examples of people dying from car crashes than from stomach
cancer, so you assume that you are more likely to die in a car crash.
– You are somewhat more likely to die from stomach
cancer. The actual base rate of digestive cancer is the higher one.
Table 8.1
Problem Solving
• Common errors of human cognition
– Overconfidence is our belief that our
answers are more accurate than they actually are.
– We tend to be overconfident about our answers to difficult questions.
– We are under-confident about our answers to easy questions, because statistically it is hard to be overconfident about answers that are
Problem Solving
• Other common errors of human cognition
– Besides the inappropriate use of heuristics, there are many other erroneous tendencies in human thought.
– Studying and preventing such errors is one of the goals of critical thinking
– Critical thinking is the careful evaluation of evidence for and against any claim or
Problem Solving
• Common errors of human cognition
– People are also overconfident about their accomplishments.
– Before the fact, we will overestimate the quality of our predicted performance.
– After the fact, we will overestimate the quality of our past performance.
– Research studies of ordinary people and experts are consistent in supporting these tendencies.
Problem Solving • Common errors of human cognition
– Sometimes we commit to an explanation or hypothesis before we have all the available information on the problem.
– Premature commitment to a hypothesis can lead us to fail to consider other plausible possibilities and fail to arrive at the correct answer.
– Functional fixedness is one special case of premature commitment.
– It is the tendency to adhere to a single approach to a problem or a single way to use an item.
Figure 8.18
Figure 8.18 Given only these materials, what is the best way to attach the candle to a wall so it can be lit?
Problem Solving
• Attractiveness of valuable but very unlikely outcomes
– We appear to have an affinity for picking a slim chance of a big gain over a sure but small profit.
– The low probability of winning may be part of the appeal.
– People report more pleasure from a surprising gain than from one that was expected.
Problem Solving
• Attractiveness of valuable but very unlikely outcomes
– These tendencies help to explain the universal popularity of gambling.
– Gambling has been a common behavior in all world cultures throughout history.
– There are identifiable patterns of thought that promote this behavior.
Problem Solving
• Common errors of human cognition
– The way a question is framed or presented can also influence the way in which we
answer it.
– The tendency to answer a question differently when it is phrased differently is called the
framing effect.
– This effect is important to keep in mind for those who need to persuade others to do things.
Figure 8.19
Figure 8.19 Most people chose A over B, and D over C although A produces the same result as C and B produces the same result as D. Amos Tversky and Daniel Kahneman, (1981) proposed that most people play it safe to gain something but accept a risk to avoid a loss.
Concept Check
“50% of all military personnel prefer to watch TV talk shows, but only 10% of all middle-aged people do. So more watchers of TV talk shows are military personnel.”
What information would you need to assess the accuracy of this statement?
The base rates:
How many military personnel are there? How many middle-aged people?
Concept Check
• My friend gives me a crystal and says if I wear it everyday I will remain healthy. I wear it and
remain healthy. So I conclude that the crystal is causing me to remain healthy.
• What do you think?
Premature commitment to the hypothesis
Problem Solving • Common errors of human cognition
– If you spend $70.00 on tickets to an event, but
you feel sick and miserable on the evening of that event, would you go anyway?
– If you were given tickets to the same event, but you felt sick and miserable on the evening of the event, would you go anyway?
• People are more likely to go if they have spent their own money. This is the sunk cost effect. • The sunk cost effect is our tendency to do
something that we’d otherwise choose not to do, just because we spent the money to do it.
Decision-Making
• There are unconscious influences on decision-making processes.
– A short period of distraction after presenting
evidence for two differing choices is more likely to produce a decision in favor of the choice with more positive features.
– Conscious decisions made after a brief period
tended to focus on one aspect that could easily be explained,
– Unconscious processing produced a choice with
more advantages and with which the person making the decision felt more satisfied later.
Decision-Making
• Maximizing and satisfying
– To thoroughly consider every possibility in order to find the best one is to maximize in making a choice. Maximizing depends on algorithms.
– To stop at the choice that is good enough is
to satisfy. This process usually depends on
Expertise
• People vary in their performance on problem-solving and decision-making tasks.
• We refer to those whose abilities are particularly advanced we as experts. Expert performance goes a step beyond what is typically expected in completion of a task.
Expertise
• Practice effects
– Our first inclination is to attribute expert abilities to special, inborn talents.
• Studies show that expert abilities are most often the result of practice.
• Those who show advanced abilities in an activity usually begin learning it at a younger age and spend more time in concentrated practice.
• The rule-of-thumb is that developing expertise takes about 10 years of concentrated practice.
Expertise
• Expert pattern recognition
– Experts are especially good at looking at patterns and recognizing important features quickly.
– This talent is most evident when we consider a demanding visuospatial game such as chess.
– It is true however that in many other activities, from bird watching to reading PET scans, that pattern recognition is a key skill possessed by experts.
Successful and Unsuccessful Problem Solving
• We have examined some of our strengths (creativity and expertise) and weaknesses
(poorly constructed heuristics and gambling) in problem solving.
• Learning about the strengths and weaknesses of our decision-making is a big step towards
improving the quality of our problem solving processes.
Module 8.3
Language
• As far as we can tell, although many species can communicate by exchanging signals, only
human languages can truly be called productive. • Humans can express new ideas through
Language
• Animal languages are comprised of prepackaged messages.
• Human languages communicate a deep structure, the intended meaning of the words.
• Almost any human language provides enough vocabulary and
grammatical variation that the deep structures can be converted into many differently arranged statements that still represent the same idea.
• Linguist Noam Chomsky called this quality of language
Figure 8.22
Figure 8.22 According to transformational grammar, we can transform a sentence with a given surface structure into any of several other sentences with different surface structures.
Language
• This flexibility and creativity that our language provides can also get us in trouble.
– While picnicking in the meadow we saw hawks with our binoculars.
• Hawks have excellent eyesight and don’t need binoculars.
• Seriously though, if we are not careful about our use of
transformational grammar, our intended meaning may be unclear or as in this case, ambiguous.
Animal Language
• One of the first examples of an animal using human language was Washoe the chimp, raised by psychologists.
• Through conditioning by researchers Washoe developed an impressive vocabulary of 100 signs.
• But Washoe used these signs almost exclusively to make requests. • She rarely used them to describe things or make new, original
Animal Language
• Bonobo chimpanzees show more facility with human sign language. • They can refer to objects that they are not requesting, they can
describe past events, and respond well to spoken requests. • It is not entirely clear whether bonobos are a particularly bright
species of great ape, or whether the training was somewhat better than that which Washoe received.
• The bonobos were exposed to human language very early in life, and received a great deal of observational exposure to humans using the signs.
Human Specializations for Learning Language • Language and general intelligence
– Psychologists are trying to determine whether our intelligence has caused our development of
language.
• Some highly intelligent species of animal do not develop a flexible language.
• People with Williams syndrome have general cognitive abilities classified in the IQ range
associated with mental retardation, but have excellent facility with language.
• It appears that language ability is not synonymous with intelligence.
Human Specializations for Learning Language • Language learning as a specialized capacity
– Psychologists divide into two broad camps regarding human language learning.
• Nativists, such as Chomsky and Steven
Pinker, believe that humans are born with a built-in, brain based mechanism for learning language.
• They refer to this as a language acquisition device or a “language instinct.”
Human Specializations for Learning Language • Language learning as a specialized capacity
– The basis for the nativist view of language learning is the poverty of stimulus argument.
– This argument states that children do not encounter enough information in the environment to learn or infer grammar, so they must be born with the
knowledge.
– Several research studies with infants younger than 1 year of age have produced evidence of tendencies to detect regularities, patterns and meaning in sounds.
Human Specializations for Learning Language • Language learning as a specialized capacity
– The information that children get may not be so sparse though; in almost all world cultures parents make special concessions to infant understanding in speech by using parentese, a slow and high-pitched method of communication that may enhance early language learning.
– But even very young infants do start picking up
language rules very early, extracting a great deal of information from what they hear.
Human Specializations for Learning Language
• Language and the human brain
– Studies of the brain using persons with brain damage and modern imaging techniques
have allowed us to identify two areas vital for the processing and production of language.
Figure 8.26
Figure 8.26 Brain damage that produces major deficits in language usually includes the left-hemisphere areas shown here. However, the deficits are severe only if the damage is more extensive, including these areas but extending to others as well.
Human Specializations for Learning Language • Language and the human brain
– Broca’s area is vital for using and understanding grammatical devices – prepositions, conjunctions, prefixes, suffixes, and the like.
– Wernicke’s area appears to be important for naming objects and comprehending language.
– People with damage to these areas develop
aphasias – a term for various inabilities to process or use language.
– Language production and processing activates very widespread areas of the brain.
Human Specializations for Learning Language
• Stages of language development
– There is impressive evidence of the
universality of stages of language learning, including identical stages of productive and receptive language in young children of all world cultures, young hearing impaired
children, and hearing children of deaf parents who are learning both sign and spoken
Human Specializations for Learning Language
• Stages of language development – productive – Random vocalizations; “cooing” – 3 months – More distinct babbling – 6 months
– Jargon (babbling with speech inflections); language comprehension far better than production – 1 year
– Says some words (mostly nouns), a few phrases – 1 1/2 years
Human Specializations for Learning Language
• Stages of language development – productive – Speaks in two-word phrases – 2 years
– Simple, if grammatically uneven, sentences – 2 1/2 years
– Large (1000 word) vocabulary and better sentences – 3 years
Table 8.2
Human Specializations for Learning Language
• Children exposed to no language
– Children who do not receive much early exposure to language do not develop a language of their own nor do they learn
human language well after starting regular exposure.
– The early lives of such children are unknown so it is hard to know with any certainty if lack of exposure is the only culprit.
Human Specializations for Learning Language
• Children exposed to no language
– Some deaf children who do not receive
exposure to sign language invent their own sign languages, which increase in complexity as they mature.
– The unique sign languages of these children have some interesting similarities (subject – object specifications for example).
Human Specializations for Learning Language
• Children exposed to two languages
– Some children grow up in a bilingual
environment, receiving roughly equal exposure to two different languages.
– These children learn both languages equally well.
– If exposure to the second language begins
early in life, the representation and storage of the languages in the brain is identical.
Human Specializations for Learning Language • Children exposed to two languages
– Although exposure to two or more languages can slow down the overall process of acquisition, it
bestows some long-term cognitive benefits as well. – Adults who were raised in bilingual environments
show an enhanced degree of cognitive flexibility in understanding that there are many ways to say the same thing.
– There are many practical advantages in being able to communicate with speakers of other languages.
Human Specializations for Learning Language • Understanding language
– Language production and comprehension can be a very complex task.
• A good reader reads simple sentences quickly and complex or ambiguous
sentences slowly.
• Even a simple word is broken down into a sequence of sounds that change depending on the arrangement of those sounds.
Human Specializations for Learning Language • Understanding language
– Readers and speakers of all languages must be aware of the assumptions that underlie the use of language. The same word may have more than one meaning, for example, and context must be considered in order to correctly use and
comprehend that word.
– The use of negatives in a language adds further complexity and possibility of erroneous production by the speaker/writer or erroneous reception by the listener/reader.
Figure 8.29
Figure 8.29 Most students preferred Kool-Aid made with sugar labeled “sugar” instead of sugar labeled “not cyanide,” even though they had placed the labels themselves.
Evidently, people do not fully believe or don’t always trust the word “not.” (Based on results of Rozin, Markwith, & Ross, 1990)
Human Specializations for Learning Language
• Reading
– Context is almost always important in interpreting the parts of language.
• The word-superiority effect refers to the fact that people are generally better at
recognizing individual letters when they are a part of a word rather than when they are standing alone or with a nonsense cluster.
Figure 8.30
Figure 8.30 Either a word or a single letter flashed on a screen and then an interfering pattern. The observers were asked, “Which was presented: C or J?” More of them identified the letter correctly when it was part of a word.
Figure 8.31
Figure 8.31 Students identified an indicated letter better when they focused on an entire word (a) than on a single letter in a designated spot (b).
Figure 8.32
Figure 8.32 According to one model, a visual stimulus activates certain letter units, some more strongly than others. Those letter units then activate a word unit, which in turn strengthens the letter units that compose it. For this reason we recognize a whole word more easily than a single letter.
Human Specializations for Learning Language
• The motion of our eyes across a page or
surface, as we scan words and parts of words, influences reading.
– Phonemes are units of sound – single letters or combinations of letters.
– Morphemes are units of meaning – usually syllables or words.
Figure 8.34
Figure 8.34 The word shamelessness has nine phonemes (units of sound) and three morphemes (units of meaning).
CONCEPT CHECK:
How many phonemes comprise the word “doggedly”? How many morphemes?
It has seven phonemes: d-o-gg-e-d-l-y. It has three morphemes: dog-ged-ly.
Human Specializations for Learning Language
• Reading
– Human eyes move steadily when we are following a moving object, but our eyes alternate between brief stationary
periods and periods of quick movement when we are
reading, which makes the eye movements of reading rather “jerky”.
• Fixations are the periods when your eyes are stationary.
• Saccades are the quick eye movements that
take your gaze from one fixation point to another. You are virtually blind during the saccades.
Human Specializations for Learning Language
• Reading – Why?
• The parietal cortex may signal the primary visual cortex to shut down activity briefly during the saccades.
• Your brain may automatically direct you to attend to the distinct stimulus at the end of each saccade and ignore the blur that you sense during each saccade.
Human Specializations for Learning Language
• Reading
– We are seeing during the fixations and not during the saccades.
– This is all happening very, very quickly. Most readers have four fixations per second, in
between which saccades occur lasting 25-50 milliseconds.
Human Specializations for Learning Language • “Speedreaders”
– Speedreaders have briefer fixations and backtrack less frequently than do average adult readers.
• With practice some people can double or triple their reading speed with normal comprehension.
• Some of the more extraordinary claims of speedreaders remain untestable – for example, the claim that some can read between 5000 and 10,000 words per minute.
• It is likely that these readers are fixating on some words and guessing at the rest.
• Speedreaders who know that they are going to be tested on the details of what they have read are observed to slow
Language
• It is still unclear why other species have not
evolved this incredibly useful skill of flexible and productive language.
• It is a large-scale adaptation of humankind that has given us tremendous power in the natural world.