Memory

Imagery.—Just as knowledge of the present physical environ ment and response to its demands involves the mental events named "sensations," so knowledge of the past or use of knowl edge acquired in the past is bound up with events termed "im ages." For every variety of sensation, sight, sound, etc., there is a corresponding variety of imagery. When to-day we recall the sight of the fishing boats returning to harbour, we have visual imagery of what we saw last evening; similarly we may recall the cry of the gulls by auditory imagery. We may recall in verbal imagery the comments made when the scene was presented. The difference between sensation and imagery is not one which can be well expressed in words. Everyone knows it from his own expe rience. We call images "dead" as compared with actual sense data. They not only lack "liveliness" but seem fragmentary and fluctuating; now this is present. now that, and as we attempt to fixate them they are apt to die out. Imagery, again, does not stand in as close relation to movement as sense experience. A sensation produces a motor response. There is adjustment of sense organ and impulsive action. With imagery there may be some adjustment of sense organ as in the fixed look when trying to see a visual image clearly, but there is no attempt to stretch out a hand to take the imaged object nor to step aside to avoid it. Imagery is not normally accompanied by the wealth of or ganic sensations which form a background to sense experience of the special senses.

Conditions of Memory and Obliviscence.

Accepting re tentiveness as the fundamental vital fact lying behind all mem ory, we may ask what are the special conditions which determine memory. They are : depth of impression and strength of associa tion. The rationale of all memory training is based on these two conditions. To be recalled the original incident or acquirement must have made a sufficiently deep impression upon us. Physical circumstances may secure this; strength of stimulation or repeated stimulation. Important also is the physical fitness of the organism to receive impressions. Depth of impression also depends upon the individual's interest in the situation, its appeal to his emo tions, its connection with some purpose he has in view. To be remembered or recalled the past experience must be suggested by the present. Suggestion depends upon continuity between the past

and the present, a continuity of interest, direct or indirect. There is an association between the suggesting present and the suggested past experience or acquirement. The conditions of suggestion are known as the "laws of association" (see ASSOCIATION OF IDEAS). If depth of impression and strength of association ensure mem ory, feebleness of impression and failure of association entail obliviscence or forgetting. If association links fail there can be no suggestion, and where there is no suggestion there can be no recall of past experience by the present. The breaking down of association links gives rise to a condition known as "dissociation." This may occur for a given group of ideas or for incidents con nected with a given period in a man's life (see AMNESIA). Some psychologists attribute all failure of association to "repression." They assert that all experiences which are painful or in conflict with accepted standards of life are repressed into the uncon scious and thereby cut off from the associations of conscious memory. They regard repression as the explanation of all for getting. But this view is unwarrantably narrow. It not only overlooks natural decay which is the complement of growth in all living processes, but it confuses conditions which ought to be distinguished: the repression of an associated idea by reason of its pain value and the temporary inhibition of one line of associa tion through interest in another. It is, surely, perverted pedantry to seek some painful association in a forgotten engagement when such obliviscence is due to the inhibition of all ideas unconnected with an absorbing occupation.

Characteristics of a Good Memory.

These may be sum marized as readiness in forming deep impressions and strong asso ciations, the durability of these and the ease of recall, their faith fulness to the originals of experience. The characteristic that renders memory serviceable in practical life is relevancy. In relevant recall only those associations are followed which have bearing on the purpose in hand. A rambling memory may be full and faithful but in the service of thought a controlled selective recall of important points is more fruitful.