Before a big exam, a sound night’s sleep will do you more good than poring over textbooks. That, at least, is the folk wisdom. And science, in the form of behavioral psychology, supports that wisdom. But such behavioral studies cannot distinguish between two competing theories of why sleep is good for memory. One says that sleep is when permanent memories form. The other says that they are actually formed during the day, but then “edited” at night, to flush away what is superfluous.To tell the difference, it is necessary to look into the brain of a sleeping person, and that is hard. But after a decade of painstaking work, a team led by Pierre Maquet at Liege University in Belgium has managed to do it. The particular stage of sleep in which the Belgian group is interested is rapid eye movement (REM) sleep, when brain and body are active, heart rate and blood pressure increase, the eyes move back and forth behind the eyelids as if watching a movie, and brainwave traces resemble those of wakefulness. It is during this period of sleep that people are most likely to relive events of the previous day in dreams.Dr. Maquet used an electronic device called PET to study the brains of people as they practiced a task during the day, and as they slept during the following night. The task required them to press a button as fast as possible, in response to a light coming on in one of six positions. As they learnt how to do this, their response times got faster. What they did not know was that the appearance of the lights sometimes followed a pattern—what is referred to as an “artificial grammar”. Yet the reductions in response time showed that they learnt faster when the pattern was present than when there was not.What is more, those with more to learn (i. e., the “grammar”, as well as the mechanical task of pushing the button) have more active brains. The “editing” theory would not predict that, since the number of irrelevant stimuli would be the same in each case. And to eliminate any doubts that the experimental subjects were learning as opposed to unlearning, their response times when they woke up were even quicker than when they went to sleep.The team, therefore, concluded that the nerve connections involved in memory are reinforced through reactivation during REM sleep, particularly if the brain detects an inherent structure in the material being learnt. So now, on the eve of that crucial test, maths students can sleep soundly in the knowledge that what they will remember the next day are the basic rules of algebra and not the incoherent talk from the radio next door.1.The phrase “poring over” in the first sentence of the passage may be best interpreted as（ ） .2.The reason why sleep is good for the memory（ ） .3.The experimenters found that their subjects（ ）.4.The Belgian group reached the conclusion that （ ）.
A.looking interestingly at B.learning without hesitation C.studying with close attention D.memorizing with a fast pace
问题2：
A.is to be clarified by behavioral psychology B.is rooted in its function of relaxing the brain C.lies in its contribution to the formation of lasting memories D.stems from its compiling memories and ridding things unwanted
问题3：
A.learned quickly how to respond to the light stimuli B.picked up the “artificial grammar” during their REM sleep C.pushed the button faster in the absence of the light pattern D.increased their response time as they learnt the u artificial grammar”
问题4：
A.the brain works more efficiently by knowing a set pattern of things B.the second theory failed to cover all the brain responses during sleep C.REM sleep reactivates connections between the nerves and the memory D.it’s beyond doubt that the subjects were learning in contrast to unlearning
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Science is an enterprise concerned with gaining information about causality, or the relationship between cause and effect. A simple example of a cause is the movement of a paddle as it strikes a ping-pong ball; the effect is the movement of the ball through the air. In psychology and other sciences, the word “cause” is often replaced by the term “independent variable”. This term implies that the experimenter is often “free” to vary the independent variable as he or she desires (for example, the experimenter can control the speed of the paddle as it strikes the ball). The term “dependent variable” replaces the word “effect”, and this term is used because the effect depends on some characteristic of the independent variable (the flight of the ball depends on the speed of the paddle). The conventions of science demand that both the independent and dependent variables be observable events, as is the case in the ping-pong example. In the case of biorhythm theory, the independent variable is the number of days that have elapsed between a person’s date of birth and some test day. The dependent variable is the person’s level of performance on some specified task on the test day. Notice that although the experimenter is not free to choose a birthday for a given individual, persons with different dates of birth can be tested on the same day, or a single subject can be tested on several different days.In order to predict the relationship between independent and dependent variables, many scientific theories make use of what are called intervening variables. Intervening variables are purely theoretical concepts that cannot be observed directly. To predict the flight of a ping-pong ball, Newtonian physics relies on a number of intervening variables; including force, mass, air resistance, and gravity. You can probably anticipate that the intervening variables of biorhythm theory are the three bodily cycles with their specified time periods. It should be emphasized that not all psychological theories include intervening variables, and some psychologists object to their use precisely because they are not directly observable.The final major component of a scientific theory is its syntax, or the rules and definitions that state how the independent and dependent variables are to be measured, and that specify the relationships among independent variables, intervening variables, and dependent variables. It is the syntax of biorhythm theory that describes how to use a person’s birthday to calculate the current status of the three cycles. The syntax also relates the cycles to the dependent variable, performance, by stating that positive cycles should cause high levels of performance whereas low or critical cycles should cause low performance levels. To summarize, the components of a scientific theory can be divided into four major categories: independent variables, dependent variables, intervening variables, and syntax.1.Based on the passage, causality may have the meaning that（ ）.2.According to biorhythm theory,（ ）.3.Many theories for predicting the relationship between cause and effect（ ）.4.The example of the ping-pong ball is used to（ ）.5.The word “syntax” used in the last paragraph refers to the（ ）.
A.cause and effect can be independent of each other B.there is hardly anything that happens without a cause C.dependent and independent variables affect each other D.cause and effect may vary respectively in most events
问题2：
A.one’s behavior can be predicted by knowing his or her birthday B.nobody can choose his or her date of birth as he or she wishes C.an individual’s performance is irrelevant to his or her birthday D.a person’s level of performance varies according to the test date
问题3：
A.testify their complete conformity with general scientific principles B.justify the identity of dependent, independent, and intervening variables C.specify the time periods of bodily cycles in terms of psychological tests D.verify their prediction by variables inconsistent with conventions of science
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