Harvard Psychological Studies, Volume 1 / Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. - Unknown

Phase.	I	II	III	IV	V	VI	VII	VIII	IX	X
Accented.	1.000	1.103	1.069	1.172	1.241	1.139	1.206	1.310	1.241	1.310
Unacc.,	1.000	1.083	1.128	1.169	1.159	1.208	1.169	1.250	1.169	1.169

The cause of the apparent retardation lies, as before, in a change occurring primarily in the accented elements of the rhythm, and this progressive differentiation, it is inferable from the results cited above, affects adjacent unaccented elements as well, the whole constituting a process more naturally interpretable as a functional accompaniment of progressive definition in the rhythmical treatment of the material than as a mark of primary temporal retardation.

The contribution of the several intervals according to position in the series and irrespective of accentual stress is given in the table following.

TABLE XLVII.

Interval	I	II	III	IV	V	VI	VII	VIII	IX	X
First,	1.000	1.136	1.136	1.182	1.227	1.227	1.227	1.273	1.318	1.318
Second,	1.000	1.042	1.042	1.125	1.166	1.042	1.042	1.083	1.083	1.166
Third,	1.000	1.150	1.250	1.250	1.250	1.250	1.400	1.400	1.450	1.450
Fourth,	1.000	1.059	1.059	1.147	1.179	1.147	1.179	1.294	1.206	1.179

A rhythmical alternation is here presented, the contributions of the first and third elements being far in advance of those of the second and fourth. The values of the minor pair are almost equal; of the major the third exceeds the first. Under the assumption already made this would indicate the existence at these points of nodes of natural accentuation, of which the second marks the maximum reached in the present series.

The determination of relative time-values for accented and unaccented intervals was next sought by indirect experimentation, in which the affective aspect of the experience was eliminated from consideration, and account was taken only of the perception of quantitative variations in the duration of the successive intervals. Proceeding from the well-known observation that if every alternate element of a temporally uniform auditory series receive increased stress, the whole series will coalesce into successive groups of two elements in which the louder sound precedes and the weaker follows, while the interval which succeeds the unaccented sound, and which therefore separates adjacent groups, will appear of greater duration than that which follows the accented element, the investigation sought by employing the method of right and wrong cases with a series of changing time-values for the two intervals to determine the quantitative proportion of the two durations necessary to produce the impression of temporal uniformity in the series.

Two rhythm forms only were tested, the trochaic and dactylic, since without an actual prolongation of considerable value in the interval following the louder sound, at the outset, no apprehension of the series as iambic or anapæstic could be brought about. The stimuli were given by mechanism number 4, the distance of fall being 2/8 and 7/8 inch respectively for unaccented and accented sounds. The series of changes included extreme proportional values of 0.714 and 1.769 in duration of the two intervals. Six persons took part in the investigation. In the following table is given the percentage of cases in which the interval following the unaccented element was judged respectively greater than, equal to, or less than that which followed the accented element, for each of the series of ratios presented by the time-values of the intervals in trochaic rhythm.

TABLE XLIX.

Ration of Unaccented to Accented Interval.	Unaccented Interval Judged to be
Ration of Unaccented to Accented Interval.	+		=		-
1.000 : 1.769	0.0	per cent.	100.0	per cent	0.0	per cent.
1.000 : 1.571	12.5	"	50.0	"	37.5	"
1.000 : 1.400	22.0	"	56.0	"	22.0	"
1.000 : 1.222	16.0	"	84.0	"
1.000 : 1.118	26.0	"	74.0	"
1.000 : 1.000	61.6	"	38.4	"
1.000 : 0.895	100.0	"
1.000 : 0.800	88.8	"	11.2	"
1.000 : 0.714	100.0	"