Sixteen Experimental Investigations from the Harvard Psychological Laboratory - Hugo Münsterberg (best life changing books txt) 📗

since they affected all series of the C

set.

 

The third change in the conditions was the substitution in the

movement series of movements employing objects for movements of the

body alone, and the consequent placing of objects on the table in the

movement and in the object series of which the subject obtained a

single mental image. All of the subjects were of the opinion that this

single mental image was an aid in recall. Each of the objects

contributing to form it was individualized by its spatial order among

the objects on the table. The objects shown through the aperture were

connected merely by temporal contiguity. On this account the object

and the movement series of the C set are not altogether comparable

with those of the A and the B sets. We should expect a priori

that the object and the movement series in the C set would be much

better recalled than those of the A and the B sets.

 

The fourth change was from imaged or made movements of the body alone

to imaged or made movements employing objects. If, as the A and the

B sets have already demonstrated, the presence of objects at all is

an aid to recall, the movement series of the C set should show a

greater gain over their corresponding verb series than the simple

movements of the body in the A and the B sets showed over their

corresponding verb series. For, employing objects in movements is

adding the aid of objects to whatever aid there is in making the

movements.

 

Turning to the results, we consider the C set by itself with

reference to the effect of the use of objects vs. images in general.

The summary from Table IV. shows that under the conditions given,

after intervals of from slightly less than one day to two days, five

of the six subjects recall object couplets better than noun couplets.

One subject, M recalls noun couplets better. It also shows that

under the conditions and after the intervals mentioned all six

subjects recall movement couplets better than verb couplets. In view

of the small difference here and of his whole record, however, M is

probably to be classed as indifferent in both substantive and action

series.

 

RECALL AFTER NINE AND SIXTEEN DAYS.

 

Thus far recall after these longer intervals has not been discussed.

The experiment was originally devised to test recall after two days

only, but it was found that with two of the subjects, M and Mo,

recall for greater intervals could be obtained with slight additional

trouble. This was accordingly done in the B and C sets. The

results of the four other subjects in the B set are not so

satisfactory on this point, because not enough was recalled.

 

The most interesting fact which developed was an apparently slower

rate of forgetting, in many cases, of the nouns and verbs than of the

objects and movements. In the noun-object group of the B set it is

noticeable in three out of the four possible subjects, viz., B, Ho,

and Mo. M alone does not show it. The two other subjects, S and

B, did not recall enough for a comparison. In the verb-movement

group of the B set it is also marked in three out of the four

possible subjects, viz., M, Ho, and Mo. B alone does not show

it. It is also seen in the C set in the results of M and Mo, in

both the noun-object and the verb-movement groups. With the four other

subjects in the C set it could not be noticed, since the series ran

their course in a day. In M (verb-movement group, C set) and Mo

(noun-object group, C set) the originally higher object or movement

curves actually fall below their corresponding noun or verb curves.

 

The results of the tests for recall after nine and sixteen days are

summarized in the following tables. They should be compared with the

recall of these same series after two days given in Tables II. and

IV., nor should it be forgotten that all four types started with

perfect immediate recall. The figures give per cents, correct after

eliminating indirect-association couplets.

 

TABLE V.

 

SHOWING RECALL AFTER NINE AND SIXTEEN DAYS.—SUMMARY FROM B SET.

 

Days. Nine. Sixteen Nine. Sixteen.

N. O. N. O. V. M. V. M.

M. 36 38 29 31 56 19 50 31

S. 0 6 0 6 0 7 0 0

Hu. 0 7 0 20 0 25 0 6

B. 13 21 13 13 7 20 7 13

Ho. 25 23 17 0 25 33 0 8

Mo. 57 63 57 56 20 79 20 69

Av. 22 26 19 21 18 31 13 21

 

TABLE VI.

 

SAME FOR M AND Mo.—SUMMARY FROM C SET.

 

Days. Nine. Sixteen. Nine. Sixteen.

N. O. N. O. V. M. V. M.

M. 81 60 75 33 50 56 38 31

Mo. 31 20 25 20 40 53 20 40

 

THE D SET.

 

A few series of nouns, objects, verbs, and movements dissociated from

foreign symbols were obtained. The material was of the same kind as

the words used in the couplet series, being mostly monosyllabic and

seldom dissyllabic words. They had not been previously used with these

subjects. Each series contained ten words or ten objects. The same

kind of precautions were taken as in the couplet sets to avoid

phonetic aids and the juxtaposition of words which suggest each other.

The apparatus employed in the couplet sets was used. The objects in

the object series were shown through the aperture. Visual images were

required in the noun and in the verb series. The noun and the object

series were exposed at the rate of one word every 2 secs. (or 20 secs.

for the series) for M, S, and Hu, and one every 3 secs. (or 30

secs. for the series) for B, Ho, and Mo. Only one exposure of

the series was given. At its completion the subject at once wrote as

many of the words or objects as he could recall. Two days later at the

same hour he was asked to write without further stimulus as many words

of each series as he could recall, classifying them according to their

type of series.

 

The verbs were similar to the verbs of the couplet series. There was a

tendency in the verb series among most of the subjects to make a more

or less connected story of the verbs and thus some subjects could

retain all ten words for two days. This was an element not present in

the couplet verb series, according to the subjects, nor in any other

series, and the subjects were, therefore, directed to eliminate it by

imaging each action in a different place and connected with different

persons. The effort was nearly successful, some of the subjects

connecting two or three verbs, and others none. The movements employed

ten objects which were uncovered and covered by the subject as in the

C set. The exposure for the verbs and movements was 5 secs. for each

word, or 50 secs. for the series. The tests were the same as in the

series of ten nouns and ten objects, but in a number of cases (to be

specified in the table) it seemed best to shorten the interval for

deferred recall to one day.

 

The series were always given in pairs—a noun and an object series, or

a verb and a movement series forming a pair. Only one pair was given

per day and no other series of any kind were given on that day.

Usually several days intervened between the II. test of one pair and

the learning of the next, but in a little less than half of the cases

a new pair was learned on the same day shortly after the II. test of

the preceding pair.

 

The noun-object pairs and the verb-movement pairs were not given in

any definite order with reference to each other.

 

The figures in the following table indicate the number of words out of

ten which the subject correctly recalled and placed in their proper

columns. Immediate recall is also given.

 

TABLE VII.

 

Series. Im. Rec. Two Days. Im. Rec. Two Days.

N. O. N. O. V. M. V. M.

 

M.

D^{1-4} 8 9 7 7 7 10 4 5

D^{5-8} 9 7 6 6 8 8 6 6

D^{9-12} 7 7 5 6 8 10 7 7

Av. 24 23 18 19 23 28 17 17

 

Mo.

D^{1-4} 6 6 2 1 8 10 0¹ 7¹

D^{5-8} 6 5 0¹ 3¹ 8 9 2 4

D^{9-12} 5 7 1¹ 6¹ 10 10 2 7

Av. 17 18 3 10 26 29 4 18

 

S.

D^{1-4} 8 9 2 3 9 10 6¹ 9¹

D^{5-8} 8 10 2 4 9 10 4¹ 9¹

D^{9-12} 8 10 2 5 8 10 3¹ 7¹

Av. 24 29 6 12 26 30 13 25

 

Hu.

D^{1-4} 6 8 3 7 9 10 4 9

D^{5-8} 7 9 0 2 9 10 2 7

D^{9-12} 7 9 4 6 8 10 1 8

Av. 20 26 7 15 26 30 7 24

 

Ho.

D^{1-4} 9 9 3 3 10 9 5 7

D^{5-8} 9 8 1 6 9 9 6¹ 8¹

D^{9-12} 8 8 5 5 10 10 6¹ 7¹

Av. 26 25 9 14 29 28 17 22

 

¹ One day.

 

The results of the D set strongly confirm the results of the A,

B, and C sets. Table VII. shows that after from one to two days’

interval four subjects recall objects better than nouns and movements

better than verbs. One subject, M., shows no preference.

 

CONCLUSIONS.

 

We are now in a position to answer specifically the problem of this

investigation. The results show: (1) that those five subjects who

recall objects better than nouns (involving images) _when each occurs

alone_, also recall objects better than nouns when each is recalled by

means of an unfamiliar verbal symbol with which it has been coupled;

(2) that the same is true of verbs and movements; (3) that these facts

also receive confirmation on the negative side, viz.: the one subject

who does not recall objects and movements better than nouns and verbs

(involving images) when they are used alone, also does not recall

them better when they are recalled by means of foreign symbols with

which they have been coupled.

 

MINOR QUESTIONS.

 

The problem proposed at the outset of the investigation having been

answered, two minor questions remain: (1) as to images, (2) indirect

associations.

 

1. All the subjects were good visualizers. The images became clear

usually during the first of the three presentations, i.e., in 1-3

secs., and persisted until the next couplet appeared. In the second

and third presentations the same images recurred, rarely a new one

appeared.

 

An interesting side light is thrown on M.‘s memory by his work in

another experiment in which he was a subject. This experiment required

that the subject look at an object for 10 secs. and then after the

disappearance of its after-image manipulate the memory image. M.

showed unusually persistent after-images. The memory images which

followed were unusually clear in details and also persistent. They

were moreover retained for weeks, as was shown by his surprising

ability to recall the