Perceptual and Motor Skills, 1979,49, 940-942. @ Perceptual and Motor Skills 1979
VARIATIONS IN PERCEPTION OF SHORT TIME INTERVALS DURING MENSTRUAL CYCLE1 JILL DRAPKIN MONTGOMERY California School of Professional Psychology, Berkeley Summary.-The hypothesis that women experience heightened sensitivity and responsivity premenstrually was tested by asking 10 women to produce short time intervals at four phases of the menst!ual cycle. 10 men were assigned to "pseudo-cycles" and tested as a control. The test was based on the assumption that a greater sensitivity to stimuli is reflected in a "slowing down" of subjective time. The women produced the shortest time intervals three to four days before menses, confirming the hyporhesis.
As a first step in a project designed to refine and test a hypothesis about psychological alterations during the menstrual cycle, 10 women were asked to produce short time intervals during a 4-phase cycle: on the 3rd day of menses, mid-way through the cycle, 3 or 4 days before menses, and 24 hours before menses. The hypothesis, in its first formulation, was drawn from Cath and Mayer,' who describe the premenstrual period as one in which there is "a change in reactivity to internal and external stimuli, altering the way in which stimulation is perceived, modulated, and responded to, . . . [which] is generally experienced as a heightened sensitivity and responsivity" (p. 5). A measure of variations in the perception of time intervals rather than in the acuity of one of the senses was chosen as a test because time estimation seemed to be a more general reflection of the cognitive state. This judgment was in line with Ornstein's information-processing-storage theory of time ( 1969), according to which the experience of duration is formed out of the totality of immediate experience. Ornstein states that an increase in the number or complexity of stimuli experienced within a given interval lengthens the experienced duration of that interval. Thus, on the assumption that such an increase would reflect a generally "heightened sensitivity and responsivity," it seemed that the test would confirm the hypothesis if women produced shorter intervals, i.e., experienced lengthened duration, during the premenstrual period. Ten nulliparous women, with regular cycles, not using oral contraceptives, were tested during two menstrual cycles. Subjects' chronological ages were from 24 to 35 yr. Cycle lengths varied between subjects from 28 to 31 days. Ten men were tested during nvo "pseudo-cycles" as a control. The women began the test at the point in their natural cycles at which they had arrived when the experi'The author gratefully acknowledges the assistance of Elizabeth Mayer and Phylis Cath. 'P. Cath, Pr E. L. Mayer, A psychological investigation of the premenstruum preliminary report. (Unpublished paper, Mt. Zion Hospital, San Francisco, California, 1977)
941
PERCEPTION AND MENSTRUAL CYCLE
ment began. The male cycles were correspondingly staggered. Male subjects were randomly assigned to begin on the jrd, 14th, 26th, or 28th day of a "pseudocycle." In an initial interview subjects were instructed to arrange to be alone and prepared to be seated by their telephone in a quiet, clockless room with reading material at hand. The subjects were telephoned on the specified days in their cycles and at the same time each day; they were asked to produce two 30-sec. intervals and two 15-sec. intervals, and to read a piece of written material for what they estimated to be 30 s e c . V h e i r productions were timed with a stopwatch. The women were called back on what should have been the first day of menses to check the regularity of the cycle. If the cycle was delayed, the test would be repeated at that time and the subject would be called back the following day. The women produced the shortest intervals on the third or fourth day before menses on all five tests, as anticipated (Table 1 ) . In a repeated-measures analysis of variance of the women's tests a planned comparison of the intervals produced on the 3rd and 14th days with those produced three days before menses showed a significant variation ( p = 0.05) for all the tests except the reading. The Fl,ls ratios for tests 30 sec. 1, 15 sec. 1, TABLE 1
MEANSA N D
STANDARD FOR
Day 3 after beginning menses M SD
30 sec., No. 1 Women Men 15 sec., No. 1 Women Men 30 sec., No. 2 Women Men 15 sec., No. 2 Women hlen Read 30 sec. Women Men
DEVIATIONS OF 15- AND 30-SEC. INTERVALS 10 WOMENAND 10 MEN Mid-cycle SD
M
3-4 days premenses M SD
24 hours premenses M SD
20.20 29.85
11.28 8.36
20.75 29.10
10.03 5.50
15.45 26.60
6.71 9.26
19.60 30.65
15.19 13.32
13.75 16.70
7.30 4.44
12.40 15.90
5.74 3.90
10.20 15.20
4.93 5.43
12.35 15.95
8.77 6.80
22.10 32.15
12.27 10.97
20.80 32.50
11.63 9.19
17.50 31.65
8.84 11.60
19.40 33.80
12.61 17.28
14.05 17.30
6.67 5.40
13.55 16.35
6.83 4.48
10.75 16.15
4.98 5.85
13.40 17.55
7.79 9.82
34.30 37.50
21.66 11.66
32.55 39.20
20.67 14.28
27.50 37.15
14.76 13.49
32.55 36.35
2 3 18 15 28
"The use of the telephone was our attempt to test subjects' perception of time in a quasicontrolled setting without removing them from the context of their daily lives. Although it might have been more valid to use a lnboratorv, -~rocedure.the results were convincine and flelt to be worth reporting.
-
942
J. D. MONTGOMERY
30 sec. 2, 15 sec. 2, and read 30 sec., respectively, were 5.49, 8.06, 6.25, 17.04 ( p 4 .04), and 3.09. The reading material of some of the subjects differed markedly in complexity and interest from session to session; this may account for the relative nonsignificance of the variation shown on the reading test. The men showed no significant variation as a function of cycle phase on any test. (Interestingly, the data for women is inexplicably roughly paralleled by those for men over time.) The women consistently produced shorter intervals than the men; a two-way repeated-measures analysis of variance showed that this difference was significant for the two 30-sec. tests (Fl,ls= 5.80, p = .03, and Fljls = 6.28, p = .02). There were no interactions of sex by phase on any of the tests perhaps because the sample was very small. Since the sense of time is the outcome of a complex process probably involving both central and peripheral cognicive and sensory systems (Goldstone & Lhamon, 1974), the fact that the women consistently produced shorter intervals than the men might be explained as reflecting differences at any point in the process. It might suggest, for example, a greater over-all sensitivity to stimuli, or higher level of arousal in women or merely be an artifact of the design. It should be noted that these findings are not consistent with those of Koppel, Lunde, Clayton, and Moos ( 1969). Although they reported a significant variation in the production of 30- and 15-sec. intervals over the menstrual cycle, their 8 subjects showed the tendency to produce longer rather than shorter intervals in the premenstrual period. REFERENCES GOLDSTONE, S., & LHAMON, W. T. Studies of auditory-visual differences in human time
judgment: 1. Sounds are judged longer than lights. Perceptual and Motor Skills, 1974, 39, 63-82.
KOPPEL,B. S., LUNDE, S., CLAYTON, R. B., & MOOS, R. I-I. Variations in some measures
of arousal during the menstrual cycle. Journal o f Nervous and Mental Disease, 1969, 148, 180-187.
ORNS'TEIN. R. E. O n the experience o f time. New York: Penguin, Accepted October 2, 1979.
1969.
VARIATIONS IN PERCEPTION OF SHORT TIME INTERVALS DURING MENSTRUAL CYCLE1 JILL DRAPKIN MONTGOMERY California School of Professional Psychology, Berkeley Summary.-The hypothesis that women experience heightened sensitivity and responsivity premenstrually was tested by asking 10 women to produce short time intervals at four phases of the menst!ual cycle. 10 men were assigned to "pseudo-cycles" and tested as a control. The test was based on the assumption that a greater sensitivity to stimuli is reflected in a "slowing down" of subjective time. The women produced the shortest time intervals three to four days before menses, confirming the hyporhesis.
As a first step in a project designed to refine and test a hypothesis about psychological alterations during the menstrual cycle, 10 women were asked to produce short time intervals during a 4-phase cycle: on the 3rd day of menses, mid-way through the cycle, 3 or 4 days before menses, and 24 hours before menses. The hypothesis, in its first formulation, was drawn from Cath and Mayer,' who describe the premenstrual period as one in which there is "a change in reactivity to internal and external stimuli, altering the way in which stimulation is perceived, modulated, and responded to, . . . [which] is generally experienced as a heightened sensitivity and responsivity" (p. 5). A measure of variations in the perception of time intervals rather than in the acuity of one of the senses was chosen as a test because time estimation seemed to be a more general reflection of the cognitive state. This judgment was in line with Ornstein's information-processing-storage theory of time ( 1969), according to which the experience of duration is formed out of the totality of immediate experience. Ornstein states that an increase in the number or complexity of stimuli experienced within a given interval lengthens the experienced duration of that interval. Thus, on the assumption that such an increase would reflect a generally "heightened sensitivity and responsivity," it seemed that the test would confirm the hypothesis if women produced shorter intervals, i.e., experienced lengthened duration, during the premenstrual period. Ten nulliparous women, with regular cycles, not using oral contraceptives, were tested during two menstrual cycles. Subjects' chronological ages were from 24 to 35 yr. Cycle lengths varied between subjects from 28 to 31 days. Ten men were tested during nvo "pseudo-cycles" as a control. The women began the test at the point in their natural cycles at which they had arrived when the experi'The author gratefully acknowledges the assistance of Elizabeth Mayer and Phylis Cath. 'P. Cath, Pr E. L. Mayer, A psychological investigation of the premenstruum preliminary report. (Unpublished paper, Mt. Zion Hospital, San Francisco, California, 1977)
941
PERCEPTION AND MENSTRUAL CYCLE
ment began. The male cycles were correspondingly staggered. Male subjects were randomly assigned to begin on the jrd, 14th, 26th, or 28th day of a "pseudocycle." In an initial interview subjects were instructed to arrange to be alone and prepared to be seated by their telephone in a quiet, clockless room with reading material at hand. The subjects were telephoned on the specified days in their cycles and at the same time each day; they were asked to produce two 30-sec. intervals and two 15-sec. intervals, and to read a piece of written material for what they estimated to be 30 s e c . V h e i r productions were timed with a stopwatch. The women were called back on what should have been the first day of menses to check the regularity of the cycle. If the cycle was delayed, the test would be repeated at that time and the subject would be called back the following day. The women produced the shortest intervals on the third or fourth day before menses on all five tests, as anticipated (Table 1 ) . In a repeated-measures analysis of variance of the women's tests a planned comparison of the intervals produced on the 3rd and 14th days with those produced three days before menses showed a significant variation ( p = 0.05) for all the tests except the reading. The Fl,ls ratios for tests 30 sec. 1, 15 sec. 1, TABLE 1
MEANSA N D
STANDARD FOR
Day 3 after beginning menses M SD
30 sec., No. 1 Women Men 15 sec., No. 1 Women Men 30 sec., No. 2 Women Men 15 sec., No. 2 Women hlen Read 30 sec. Women Men
DEVIATIONS OF 15- AND 30-SEC. INTERVALS 10 WOMENAND 10 MEN Mid-cycle SD
M
3-4 days premenses M SD
24 hours premenses M SD
20.20 29.85
11.28 8.36
20.75 29.10
10.03 5.50
15.45 26.60
6.71 9.26
19.60 30.65
15.19 13.32
13.75 16.70
7.30 4.44
12.40 15.90
5.74 3.90
10.20 15.20
4.93 5.43
12.35 15.95
8.77 6.80
22.10 32.15
12.27 10.97
20.80 32.50
11.63 9.19
17.50 31.65
8.84 11.60
19.40 33.80
12.61 17.28
14.05 17.30
6.67 5.40
13.55 16.35
6.83 4.48
10.75 16.15
4.98 5.85
13.40 17.55
7.79 9.82
34.30 37.50
21.66 11.66
32.55 39.20
20.67 14.28
27.50 37.15
14.76 13.49
32.55 36.35
2 3 18 15 28
"The use of the telephone was our attempt to test subjects' perception of time in a quasicontrolled setting without removing them from the context of their daily lives. Although it might have been more valid to use a lnboratorv, -~rocedure.the results were convincine and flelt to be worth reporting.
-
942
J. D. MONTGOMERY
30 sec. 2, 15 sec. 2, and read 30 sec., respectively, were 5.49, 8.06, 6.25, 17.04 ( p 4 .04), and 3.09. The reading material of some of the subjects differed markedly in complexity and interest from session to session; this may account for the relative nonsignificance of the variation shown on the reading test. The men showed no significant variation as a function of cycle phase on any test. (Interestingly, the data for women is inexplicably roughly paralleled by those for men over time.) The women consistently produced shorter intervals than the men; a two-way repeated-measures analysis of variance showed that this difference was significant for the two 30-sec. tests (Fl,ls= 5.80, p = .03, and Fljls = 6.28, p = .02). There were no interactions of sex by phase on any of the tests perhaps because the sample was very small. Since the sense of time is the outcome of a complex process probably involving both central and peripheral cognicive and sensory systems (Goldstone & Lhamon, 1974), the fact that the women consistently produced shorter intervals than the men might be explained as reflecting differences at any point in the process. It might suggest, for example, a greater over-all sensitivity to stimuli, or higher level of arousal in women or merely be an artifact of the design. It should be noted that these findings are not consistent with those of Koppel, Lunde, Clayton, and Moos ( 1969). Although they reported a significant variation in the production of 30- and 15-sec. intervals over the menstrual cycle, their 8 subjects showed the tendency to produce longer rather than shorter intervals in the premenstrual period. REFERENCES GOLDSTONE, S., & LHAMON, W. T. Studies of auditory-visual differences in human time
judgment: 1. Sounds are judged longer than lights. Perceptual and Motor Skills, 1974, 39, 63-82.
KOPPEL,B. S., LUNDE, S., CLAYTON, R. B., & MOOS, R. I-I. Variations in some measures
of arousal during the menstrual cycle. Journal o f Nervous and Mental Disease, 1969, 148, 180-187.
ORNS'TEIN. R. E. O n the experience o f time. New York: Penguin, Accepted October 2, 1979.
1969.
