The fact that experiences influence subsequent behavior is evidence

of an obvious but nevertheless remarkable activity called remembering.

Learning could not occur without the function popularly named

memory. Constant practice has such an effect on memory as to lead to

skillful performance on piano, to recitation of a poem, and even to 【M1】__________

reading and understanding these words. So-called intelligent behavior

demands memory, remembering being a primary requirement for

reasoning. The ability to solve any problem or even to recognize that a

problem exists and depends on memory. Typically, the decision to cross 【M2】__________

a street is based on remembering many early experiences. 【M3】__________

Practice (or review) tends to build and maintain memory for a task

or for any learned material. Over a period of no practice that has been 【M4】__________

learned tends to be forgotten; and the adaptive consequences may not

seem obvious. Yet, dramatic instances of sudden forgetting can be seen to

be adaptive. In this sense, the ability to forget can be interpreted to

have survived through a process of natural selection of animals. Indeed, 【M5】__________

when one’s memory of an emotional painful experience leads to serious 【M6】__________

anxiety, forgetting may produce relief. Nevertheless, an evolutionary

interpretation might make it difficult to understand how the commonly

gradual process of forgetting survived natural selection.

In thinking about the evolution of memory together with all their 【M7】__________

possible aspects, it is helpful to consider what would happen if

memories failed to fade. Forgetting clearly aids orientation in time,

since old memories weaken and the new tends to stand out, 【M8】__________

provide clues for inferring duration. Without forgetting, adaptive ability 【M9】__________

would suffer, for example, learned behavior that should have been 【M10】_________

correct a decade ago may no longer be.

【M4】