閱讀理解-1

Whatdoes a scientist do when he or she "explains something? Scientificexplanation comes in two forms: generalization and reduction. Mostpsychologists deal with generalization. They explain parlicular instances ofbehavior as example of general laws. For instance, most psychologists wouldexplain a pathologically (病態)strong fear of dogs as example of classical conditioning. Presumably, theperson was frightened earlier in life by a dog. An unpleasant stimulus waspaired with the sight of the animal (perhaps the person was knocked down by avigorous dog and the subsequent sight of dogs evokes the earlier response offear.
Most physiologists deal with reduction. Phenomena are explained in terms ofsimpler phenomena. For examjle, the movement of a muscle is explained in termsof changes in the membrane (生物膜)ofmuscle cells, entry of particular chemicals and interactions between proteinmolecules within these cells. A molecular biologist would "explain"these events in terms of forces that bind various molecules together and causevarious parts of these molecules to be attracted to one another.
The task of physiological psychology is to "explain" behavior inphysiological terms. Like other scientists, physiological psychologists believethat all natural phenomena-- including human behavior--are subject to the lawsof physics. Thus, the law of behavior can be reduced to description ofphysiological processes.
How does one study the physiology of behavior? Physiological psychologistscannot simply be reductionists. It is not to observe behaviors and correlatethem with physiological events that occur at the same time. Identicalbehaviors, under different conditions, may occur for different reasons, andthus be initiated by different physiological mechanisms. This means that wemust understand " psychologically" why a particular behavior occursbefore we can understand what physiological events made it occur.