Experiment has attacked most of the major problems of memory within the last fifteen years. Three general methods have been used: (1) re production: the observer 'reproduces,' a line of poetry or a tone that he has heard previously; (2) recognition: e.g. a color is shown twice in succession, and the observer reports whether he recognizes it the second time as the same color or whether it looks 'lighter' or 'greener' or 'paler': (31 comparison: emphasis is laid on the \Illicit is eon pared with a similar perception. The first important work was done by II. Ehhinghans in 1883 under the first method. Series of 'nonsense-syllables' (e.g. Iml, rum, MI) were read over and over, and then an attempt was made to write them from memory. The investi gator found that as the interval between learning and Veprodueing was gradually lengthened, the amount remembered fell off at first rapidly and then more and more slowly. The influence of length of series, order. repetition, rhythm. etc., wa, also studied• Ebbinghaus's method ha, been repeated with many ether subjects related to memory which have been investigated are the elvaracter of the stimulus, combination of sense modalities, association and arrangement, the of disease, of age, race, and individual differences. The present tendency is away from quantitative determinations of capacity and to ward a qualitative analysis of the memorial con sciousness. The part played by feeling and mood, and the charact,a•isties of the image, are. e.g. attracting more attention than the answer to the question numb c•an one remember of an event after an interval of an hour or a day?" Knelt sense-department has its own memory. There are. i.e. auditory. visual, tactual, gustatory 'memories.' and not one single 'memory! The manner in whirl these memories are combined in a single mind is 1:nm.vn as the individual's `mem ory type' or 'ideational t‘. pp.' There are four chief memory types; visual (predominance of 'pietnre-ideas'). auditory (predominance of
mud ideas'). tactual or motor lo.4.41otninance of 1.41411' and ideas'), and a mixed type in which the various sense 1114.11101'1i, are more or evenly balanced. \\lien 'object-images' pass into 'word three suldvres are formed: serbaki-nal. verbal-auditort. and verbal-tac tual i.e. words ate seen. heard. or felt in the throat. In most minds there are several mem ories, with one the visual) appearing in exec.-4.f the !."1.1. I M w i N.111oN.
The attempt to improve the effi ciency of memory is known the art of nip. • 11101lies. which is said 0) have 011.611111Pd wit) t he Creel: poet :\ o,t I inemonie include the formation of artificial associations as an all to recollection. eommon device for remembering 4...r., is the association of the digits with letters. Then the letters correspond ing to the figures in a date are brought together in a word which is associated, in turn, with the event, whose is to be retained.
Alcmory is subject to many disturbances or 'diseases,' most of which fall under the head of amnesia, or loss of memory.' Amnesia may be either general or partial. In general amnesia. a greater part of memory disappears. (1) tempo rarily. as in epilepsy, or (2) periodically, as in altered personality, or (3) progressively (e.g. proper names are forgotten before adjectives and verbs). Partial amnesia covers loss of memory for colors, sounds, number,. proper Haines. etc. APHASIA). A less frequent disorder of inetnory is or exaltation of memory. A person's general memory, or his memory for a language 4U' for some event of his childhood, is remarkably elaritied. loinally come illusions of mentors, or paramnesias, in which the subject be lieves that a new experience has been passed through before (illusion of familiarity). or as signs to a recent date experiences which have oc curred at a reunite time.