[00:03.92]1995 Passage5

[00:07.66]That experiences influence subsequent behaviour

[00:10.78]is evidence of an obvious but nevertheless

[00:13.90]remarkable activity called remembering.

[00:17.68]Learning could not occur without

[00:19.70]the function popularly named memory.

[00:22.62]Constant practice has such as effect on memory

[00:25.95]as to lead to skilful performance on the piano,

[00:29.40]to recitation of a poem,

[00:31.51]and even to reading and understanding these words.

[00:36.22]So-called intelligent behaviour demands memory,

[00:40.05]remembering being a primary requirement for reasoning.

[00:44.38]The ability to solve any problem or even to recognize

[00:48.52]that a problem exists depends on memory.

[00:52.66]Typically, the decision to cross a street is based on

[00:56.16]remembering many earlier experiences.

[01:00.34]Practice (or review) tends to build and maintain memory

[01:05.18]for a task or for any learned material.

[01:09.11]Over a period of no practice

[01:11.52]what has been learned tends to be forgotten;

[01:14.65]and the adaptive consequences may not seem obvious.

[01:18.78]Yet, dramatic instances of sudden forgetting

[01:22.11]can be seen to be adaptive.

[01:24.93]In this sense, the ability to forget

[01:28.05]can be interpreted to have survived

[01:30.47]through a process of natural selection in animals.

[01:34.91]Indeed, when one's memory of

[01:36.83]an emotionally painful experience lead to serious anxiety,

[01:41.17]forgetting may produce relief.

[01:44.19]Nevertheless, an evolutionary interpretation

[01:47.83]might make it difficult to understand

[01:50.24]how the commonly gradual process of

[01:52.86]forgetting survived natural selection.

[01:56.79]In thinking about the evolution of memory

[01:59.86]together with all its possible aspects,

[02:02.69]it is helpful to consider what would happen

[02:05.21]if memories failed to fade.

[02:08.13]Forgetting clearly aids orientation in time,

[02:11.84]since old memories weaken and the new tend to stand out,

[02:16.47]providing clues for inferring duration.

[02:20.11]Without forgetting, adaptive ability would suffer,

[02:24.35]for example, learned behaviour that

[02:27.38]might have been correct a decade ago may no longer be.

[02:31.91]Cases are recorded of people who

[02:34.54](by ordinary standards) forgot so little

[02:37.66]that their everyday activities were full of confusion.

[02:42.01]This forgetting seems to serve that survival of

[02:44.93]the individual and the species.

[02:48.97]Another line of thought assumes a memory storage system

[02:52.69]of limited capacity that provides adaptive flexibility

[02:57.34]specifically through forgetting.

[02:59.96]In this view, continual adjustments are made

[03:03.18]between learning or memory storage (input)

[03:06.91]and forgetting (output).

[03:09.82]Indeed, there is evidence that the rate at

[03:12.90]which individuals forget is directly related to

[03:16.43]how much they have learned.

[03:19.12]Such data offers gross support of

[03:21.81]contemporary models of memory

[03:23.81]that assume an input-output balance.