1nternationnl Journal of P.sychop&siofogyogy 2 (1984) 33-37

Elserie! 33

P§P ooo42

SELF-RI3FPORT AND HEART RATE RESPONSES TO A STRESSFUL TAIIK

DEBRA LEWIS ‘, WILLIAM J. RAY 2+*, MICHAEL 0. WILKINSON I, L.4UXEN DOYLE ’ and ROBERT RICKETTS 3

’ Sports Psychology Program, ’ Department of Psyckologv and 3 Depart*me)tt qf Recreation, The Penq&x~a State Lhziver.Gt,: Un rsity

Park, Pk 16802 (U.S.A.)

(Accepted April l&h, 1554)

Key words: stress - cardiovascular processes - sex differences - sport psycho%gq

Data were obtained from a risk task, the zipwire, in order to examine self-report and heart rate responses of males atd females. Using this task, heart rate data demonstrated similar patternc to those found dn @ier parachuting studies. ANOVAs demonstrated significant differences between sexes in self-report measures, but no signific,ant differences in heart rate. In addjtion, examination of the reletions!aps between heart rate and self-report showed a positive correlation for the women, while there was a negative correlation for the. men.

INTROmJCTION

Increasing interest in risk activities such as hang gliding, sky diving, scuba and adventure programs (e.g., Outward Bound or NOLS School) has pro- vided a means for researchers to study the mecha- nisms involved in the control of stress responses through coping strategies and physiological adap- tation. Most of the previous in:lestigations into this area have been conducted using parachutists (Fenz and Epstein, 19157; Shane and Slinde, 1968; Reid et al., 1971).

The results of a number of s&dies using heart rate (HR) reveal a common respor,se p?,:iern for both no&e and experienced parachutists. Fenz and Epstein (1967) examined the heart rate of sport parachutists at various time periods prior to the jump until the moment of egress. The overall pattern for novice jllmpers resembled an inverted ‘V’ shaped curve with heart rate being greatest at the point of final altitude. Shane and Slinde (19683

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01678760/84/$33.130 ,?3 1584 Elsevier Science Publishers B.V.

continuously monitored HR during free fall parachuting, from just pl”lor to exiting the aircraft unti.l 5 min after landing. They a1s.o found an inverted ‘V’ pattern even though it represeated a later time period in the jumping event. Reid et al. (1971) combined the time measures used in the previous two investigations when examining the HR responses of military parachutists” They moni- tored heart rate one hour prior to the jump, during aircraft assent, just prior to egress, during free fall, durin., canopy deployment, while under canopy, upon landing aiaU -J at a post-landing time period. The results confirmed a hypothesized ‘double in- verted v’ pattern when cardiac activity was moni- tored tPsotTgho=t the entire task.

The resl:?s of the renz ar?d Gpstcir; study also show low.-:r heart rate for the experienced parachutist as compared with the novice during the period !eading up to the jump, From heart rate alone it might be assumed that through experience the anxiety associated with the task was reduced. However, Fenz and Epstein demonstrated that experienced parachutists report greatest stress upon arrival at the airport; while the inexperienced group

reported greatest stress just prior to the jump. They interpret th.is to mean that stressor responses are not extinguished through experience, but are controlled or inhibited so that maximal response occurs a: a time when execution of the desired task will not be adversely effected.

Recently we have begun to use a task that has a number of advantages over parachuting as a means of s-:adying responses to a stressful situation. The task we used was the ‘zipwire’ in which an individ- ual slides down a 60 ft. wire via a pulley from a 35 foot height. Compared with parachuting, the zipwire task allowed us to take heart rate and self-report measures concomitantly rather than on alternatii:e days as in the previous studies. Because of the short duration of the task we were aiso able to record a number of trials from the same person on a given day thus allowing us to follow the progression of a given individual as he or she gains more experience on the task. In addition, data were obtained from females. This had not been done in the earlier parachuting studies. Females’ data were particularly important since previous research related to achievement (Frankenhaeuser et al., 1’978; Rauste-von Wright et al., 1981), elec- tric shock (Kopacz and Smith, 1971; Liberson and Liberson, 1975), and self-regulation of emotion (Davidson and Schwartz. 1976) report sex dif- ferences iii both physiological and cognitive re- spcnses. In this report we present data using the zip-wire techGlue as it relates to 3 issues: (I) the concomitant measurement of cognitive and phyai- ological responses to stress; (2) the resultant physi- ological and cognitive changes as one gains more experience on the task; and (3) sexual differences in cognitive and physiological responding to the task.

METHOD

Subjects Twenty volunteers (10 males and 10 females)

were recrtiited from undergraduate physical educa- tion classes. All potential subjects were screened to insure that they had no prior risk recreation expe- rience. ’

The nature of the experimental situation re- quired a multi-scale, short from questionnaire, which would assess subjects’ anxiety in several modes and could be completed quickly and easily. Thus, tine Imminent Threat Inventory (ITI), a 16= item questionnaire, was developed by the investi- gators in order to assess state anxiety levels prior to the performance of a stressful task. The inven- tory was comprised of 4 subscales: cognitive, somatic, autonomic and behavioral, each contain- ing four items. The item:: were drawn from previ- ously validated scales frequently used in the anxiety literature. A 10 point (O-9) Likert-type scale was used to assess subjects’ responses to individual items.

A Hewlett-Packard Telemetry System was used to measure heart rate. Three surface eiectrodes were attaehed to: (I) the area of the manubritum; and (2) on either side of the sternum in the inter- costal space between the fifth and sixth ribs. Aver- age HR in beats per minute (RPM) was de- tertined from a 10 s sample from the strip re- corder.

Procedures When subjects arrived at the test site Hl? elec-

trodes were put in place and a pre- or baseline HR was determined. In addition, they filled out the self-report measure (ITI) to assess pre-anxiety levels. Path subject completed eight trials. During the first, second, fourth, sixth and eighth trials both physiological and self-report measures were obtained. The subjects climbed up the ladder to the platform, where they sat quietly for 2 min and completed the questionnaire. Sitting quietly al- lowed the HR response to rid itself of increases as a result of the work involved in climbing the ladder. At the end of 2 min the subject stood up. An assistant helped them put their hands through the two loops and they slid down the wire.

HR was recorded at 7 different points: (1) just prior to climbing the ladder (TR); (2) sitting on the platform (PLAT (2); (3) standing on the platform (PLAT); (4) takeoff (TARS); (5) riding down the zipwire (ZIP); (6) immediately upon reaching the

ground (DOWN); and (7) 1 min after reaching the ground (1 MIN).

Treatment of the data The two dependent variables , the self-report

scale and the physiological variable, HR, were analyzed separately. Th¢ ITI was submitted to an analysis of variance for repeated measures (ANOVA) in a 2 × 7 (sex × trials) design with trials bei~lg the repeated measure. The ITI's 16 items were totaled for each of the 7 trials (5 task trials and pre- and post-measures) and these scores were submitted as single data points.

An average H R in BPM was determiined for each of the 8 stages. These H R data points were examined through an analysis of variance for re- peated measures (ANOVA) in a 2 x 5 x 7 (sez x triais X stages) design.

The relationship between heart rate and self-re- port measures was examined by the use of a Pearson product-moment correlation.

35

150 ,o,

...- %

!40 ,o" ~.

130

120

110

100 ,,,,,,,,,,, TRIAL I

TRIAL 6

C ~ " = ~ ' - - " ~ i m il • TB PLATG PLAT TAKE ZIP DOWN l~',lIN

STAGES

Fig, L Mean difference between males and females for ITI scores.i

RESULTS AND DISCUSSION

Heart-rate Statistical analysis (ANOVA) of the heart rate

data revealed significant differences between trials F4,72=,~.471, P < 0.04) between stages (F7,126 = 86.681, P < 0.001) and the trials by stages interac- tion (F2s,so4 = 5.403, P < 0.03)~ There were no sig- nificant sex differences in heart rate. In the com- parison of trial 1 to trial 6 seen in Fig. 1, we can see that mean H R did respond in a manner similar to that found in previous parachute studies. Trial 1 shows a heart rate increase through all stages and peaking with the ride down the wire. Trial 6 shows an increase up through the subject standing on the platform, ready to takeoff. Then there is a i~.?:~ drop at the goal act, the takeoff, followed by an increase in HR, peaking at the trip down. The rise in heart rate on the first trial of the present study parallels the similar rise for novice parachuters reported by Fenz and Epstein (1967). Iikewise the initial leveling off on trial 6 also parallels the leveling off demonstra ted by experienced parachuters in this same study. It is possible to speculate from these data that a given individual

may be able to ~:ove from a novice to a more advanced stage in the zipwire task witbA_n_ the 6 trials presented. Observational data also strongly confirm tiffs suggestion since by the 8th trial some subjects began to experiment with the procedure and traveled down the wire kicking their feet or putting them above their head. For this reason this last trial was removed from discussion.

Self-report Females, overall, reported more anxiety than

males (Fla s = 8.393, P < 0.0!). A s~gnl.fie~rxt trials effect (;~a08 = 34.576, P < 0.001) as well as a sig- nificant sex by trials interaction (F6,10 s = 9.22, P < 0.007) was obtained. Neuman-Keuls follow-up analyses showed significant self-report changes be- tween the initial trials for females but not for males. After the first trial, female self-reported anxiety dropped significantly from the first to the second trial and from the second to the fourth trials (P < 0.05). While scores continued to drop on successive trials, the changes were not statisti- cally significant. Males, on the other hand, showed no significant differences between trials, although the pattern was similar to that of the females;

36

\v[vei? ~l~e:t~'e~acea, b e t w e e r t , s e x e s o v e r trials w e r e

analyzed~ results revealed that males were signifi- cantly lower than females in self-reported anxiety h~. the pre-level, tria! 1, t::ial 2, trial 4 and trial 6 ( F < 0.05). Fig. 2 presents t!;ese results° Although previous research (e.g., Kopacz and Smith. 1971; Liberson and Liberson, 1975) often attributes lower anxiety self-reports by males to a need to be a 'strong sitent type', other research has offered an explanation based on experiential differences of males and females to adrenaline output. ]'his ex-- ptanatio~ suggests that high adrenaline excretion during stress is experienced by females as discom- fort and by males as feelings of success, effort, and alertness. We are able to add behavioral support for this general speculation.

Corm'elations Over the 6 trials the correlation between self-re-

port and heart rate was positive for the females but negative for the males (see Table I). Thus, in general the females reported higher anxiety the higher the heart rate was whereas the males re- ported less anxiety with a higher heart rate. When the specific stage at which heart rate is taken is considered an even more interesting picture

° ! 6o / \

5° /

4 C

o U to

E ao \ . \ % ,,,, 2C "'.-,

!01 ~ MALES V ' " ~ ' ~ ........... FEMALES

a ! I I I~ i ! PRE 1 2 4 13 B POST

TRIALS

Fig. 2. Hear t rate m e a n s for all stages of trial 1 and trial 6. All means based on 20 subjects.

T A B L E I

Co:-~w&Eo;~s be~.weet~ heart rate taken at the base #f the tree (E~zs~,~ a~ld on the yla(form (PtaO and se~f -report measures take~ on ~he p/atjbrt~z Jbr males and females over .'.ria&

7}i,7/I 7?ial 2 7'rim 4 Trial 6 Trial 8

Males Base 0.12 - 0 . 3 0 0.38 - 0 . 4 3 - 0 . 2 0 Plate - 0 . 0 2 3 - 0 . 8 6 " * - 0 . 6 6 " - - 0 5 2 -0063 *

Females Base 0,55 0.66 * 0.73 * 0.59 0.73 * Plat 0.34 0 , i8 0.35 0.42 0.24

* P < 0 . 0 5 ; * * ? < 0 . 0 I .

emerges. For males the highest correlations be- tween heart rate and self-report occurred at the stage in which they are filling out the question- naire on the platform before comb,g down. The higher their heart rate at this stage the less anxiety they report. The females, on the other hand, showed the highest correlations between self-re- port taken on the platform and the heart rate taken at the base of the tree before the trial actually began. It is as if a female's self-report rating was a reflection of her heart rate at the beginning of the trial whereas the male's rating reflected in a negative association of his heart rate while he completed the questionnaire.

CONCLUSIONS

In the present data, it is possible that the sig- nificantly higher questionnaire scores for the females were not so much the singular result of a socialization to male/female sex roles, but a combination of both cognitive and basic physio- logical differences of when and what they react to, including the socialization processes. These pre- liminary data raise interesting questions concern° ing how self-report and heart rate measures might be related differently in males and females.

A concluding note should point out the poten- tial of the zipwire technique for answering a num- ber of questions such as the interrelationship be- tween different physiological variables, the manner in which self-report may be mediated by auto-

nomic perception, and the possibility of differen- tial self-report by males and females being media- ted differently may a!ao be assessed using tim zipwire technique. More theoretical i~mplications such as the opponent process model could also be tested with this procedure (Solomon, 1980). At present, we are examining the manner in which both cognitive and somatic coping skills may mediate the response to the task in an effort to gain a better understanding of cognitive/ physiological reactions to stress.

REFERENCES

Davidson, R.J. and Schwartz, G.E. (1976) Patterns of cerebral lateralization during cardiac biofeedback versus self-regula- tion of enmtion: sex differences. Psychophysiology, 13: 62--68.

Fenz, W.D. and Epstein, S. (1967) Gradients of physiological arousal in parachutists as a function of an approaching .iump. Psychosom. ];ted., 29: 33-51.

37

Frankenhaeuser, M., Rauste-von Wright, M., Collins, A,~ yon W~ight, J., Sedval, G, and Swahn, C.G. (1978) Sex dif- fere~ce~ in psychoneuroen&~rine reactions to examination stress. PsTchosem. Mcd, 40: 334-343.

Kopacz, F.M. and Smith, B.D. (t97~) Sex differences i~ ski~ conductance measures as a function of sht~k threat, i\9:- chophysiologv, 8: ,~93-~03.

Liberson, C.W. and Liberson, W.T, (1975) Sex differences in autonomic responses to eleclric shock. Psychophysiologv, 12: 182-186.

O r ' . . I o . ~ Rauste-vcn W~ght, M, v~n Wright, J. and Frankm,~user , M, (1981) Relationships between sex-related psychological characteristics during adolescence and catecholamine excre- tion during achievement stress. Psychopt~ysiology, 18: 362-370.

Reid, D.H., Doerr, J.E., Doshier, H.D. and Ellertson D.G, (1971) Heart rate response to parachuting: physiological studies oI mdlitary parachutists via F M / F M telemetry-ll. Aerospace Med., Nov,: 1200-1207.

Shane, W.P. and Slinde, K.E. (1968) Continuous . . . . . . . . . . . . . ing during free fall parachuting. Aerospace Med., June: 597-603.

Solomon, R.L. (1980) The opponent-process theory of acquired motivation. Amer. Psychol., 35: 691-712.