MEMORY (OF. mcmoric, memo/T, ?armoire, Fr. memoirs, from Lat. memoria, from mentor, mindful; connected with Gk. pippepoe, larrmeros, anxious, Skt. solar, to remember). The scious representation of past experience. To say that a man has 'a good memory' means that he is able to recall past events fully and accurately. The term is also used, more broadly and loosely, to include the capacity of retention. Thus mem ory is figuratively called a storehouse. This im plies that 'within memory' are preserved bits of experience which may reappear in consciousness from time to time in the form of recollections. It is well to keep distinct the terms retention, which properly considered is a physiological fact, a matter of cerebral mechanics, and conscious representation, or recollection—memory in the strictly psychological sense.
Recollection involves no new or peculiar men tal processes. The core of a recollection or `a memory,' as it may he called, is the 'memory idea.' This may appear either as an image— visual, auditory, tactual, etc. (see 1 ALWINATION ) —or as a word or a series of words. The thing that brands the image or word as a memory-idea is its reference. One may have the visual image of a castle. which is no particular castle; or of a pin, which is no particular pin; this is merely a mental image without a setting: or one may have a visual image of a recent event which conies to mind as 'a-part-of-yesterday' or `a-thing-that-oe eurreddast-spring! The latter images refer to the past as `sty own past.' They hear the marks of private ownership. The only way in which the memory-idea is unique is, then, in its flute (ion, its office in joining items of experience which have different temporal localization. In termediate steps between the perception and the memory-idea are furnished by ( 1 ) the after image (q.v.) ; (2) the memory after-image (i.e. the event that persists in `standing before the mind' after the external stimulus has ceased to act, as Lady -Macbeth's horror of the King's blood) ; and (3) the feeling that 'I have known this thing before;' finally comes (4) the free immory-idea. The 'reference' in the memory image is given, first, by the setting, i.e. by the associations which cluster around the idea; sec ondly, by the degree of clearness and stability of the various parts of the image; and, thirdly, by the 'at home' mood or the mood of familiarity (see FAAIILIABITY) which attaches to whatever 'tits in' with one's own list of experiences. The
verbal memory-image or idea came in, of course, after the acquisition of language; and it is probable that the inure direct 'intuitional' images of sense also appeared quite late in the life series. The complete disjunction of 'present' and `past' demands an advanced stage of mental de velopment.
is intimately related to recognition (q.v.). Indeed, one often says to an acquaint ance "I remember you;" meaning that the ac quaintance is recognized, that his face is famil iar. •llut recognition need not imply a reference to a definite past at all; it may rest simply on the feeling of familiarity that is aroused by the meeting. Recognition starts front a present per ception; memory or recollection front an image or idea.
Recollection is either active or passive. The effort to 'call up' a name or a situation in which a known event occurred is an instance of active recollection; whereas, in passive recollection, memories 'come of themselves.' as in the case of a reverie or in the successive appearance of the words and music of a remembered song. The former demands active attention, the latter pas sive. Almost any phase of consciousness may initiate recollection: the perception of a color may do it, or that of a sound, or a shiver of cold, a feeling, a 'bracing effort,' etc. See AssoetA TION OF IDEAS for the incentives to recollection.
Retention rests upon some modification of the cortex during excitation. The most acceptable theory of retention is the theory of 'functional dispositions' (Wundt). Excitation so disposes nerve elements (probably in their molecular ar rangement) that their functions are more or less permanently altered. In this manner, a reexcita tion 'renews' a function which has already been impressed upon the nervous substance. The con cept of physical memory tins been extended to cover all changes in organic matter which outlast the operation of their causes. It is thus made synonymous with physiological habit. See HABIT.