The comparative effectiveness of heart rate biofeedback, speech skills training, and a combination...

Biofeedback and Self-Regulation, Vol. 7, No. 1, 1982

The Comparative Effectiveness of Heart Rate Biofeedback, Speech Skills Training, and a Combination of Both in Treating Public- Speaking Anxiety 1

Mark E. McKinney 2 University of Nebraska Medical Center

Robert J. Gatchel Uniformed Services University of the Health Sciences, Bethesda

Forty-two speech-anxious undergraduate students (21 female, 21 male) were administered either heart rate biofeedback training, speech skills training, or a combination of both to aid in the alleviation of speech anxiety. Physio- logical (heart rate, tonic skin conductance level, systolic blood pressure, and diastolic blood pressure), overt motor, and self-report measures of anxiety were assessed during a pretreatment speech and two posttreatment speeches. Results indicated that all treatments were effective in lowering overt motor and self-report components of anxiety. However, only the biofeedback and combined group subjects demonstrated significantly less heart rate increase while speaking before an audience during the posttreatment assessment. Two individual difference variables examined in this study-cognitive~autonomic focus of anxiety and subjective confidence in treatment- were not found to significantly influence treatment effectiveness. Finally, factor analyses of

1This article is based on a dissertation submitted by the first author to the Department of Psychology of the University of Texas at Arlington in partial fulfillment of the requirements for the Ph.D. degree. The research was supported in part by a grant to the second author from the National Heart, Lung, and Blood Institute (Grant No. NIH 1 R01 HL 21426). Special thanks go to Gina Bellamy, Mark King, Lila Menteer, and Kirsi Niemela for their help in conducting the research and data analyses. Also, special thanks to Lois Lippert for her help in preparing the manuscript.

2Address all correspondence to Mark E. McKinney, Cardiovascular Center, The University of Nebraska Medical Center, 42nd and Dewey Avenue, Omaha, Nebraska 68105.

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0363-3586/82/0300-0071503.00/0 © 1982 Plenum publishing Corporation

72 McKinney and Gatchel

the physiological data suggested that heart rate changes play a large role in the physiological component of anxiety.

A series of earlier studies have examined the efficacy of heart rate deceleration biofeedback as a treatment of speech anxiety (Gatchel & Proctor, 1976; Gatchel, Hatch, Watson, Smith, & Gaas, 1977; Gatchel, Hatch, Maynard, Turns, & Tauton-Balckwood, 1979). In the first of these studies, Gatchel and Proctor (1976) found that heart rate biofeedback significantly reduced self-report, overt motor, and physiological (heart rate and skin conductance) components of anxiety, relative to a control group that was administered a psychomotor task rather than the biofeedback task. This study also suggested the importance of therapeutic-expectancy factors on the fear-reduction process. In order to more systematically examine such therapeutic expectancy/placebo factors, as well as evaluate the effectiveness of biofeedback in comparison to other treatment techniques, Gatchel et al. (1977) assessed the relative therapeutic impact of four different procedures: (1) heart rate biofeedback, (2) an active muscle relaxation training method developed by Goldfried and Trier (1974), (3) a combination of both, and (4) a false-biofeedback placebo method in which subjects who had been informed previously of the possible benefits of heart rate reduction were led to believe that they were successfully decelerating heart rate. Results of this study indicated that all four procedures were equally effective in decreasing the self-report component of speech anxiety. However, the first three treatment methods were associated with less physiological arousal relative to the false biofeedback group. Moreover, among the first three treatment groups, the combined procedure group evidenced the greatest reduction in physiological arousal.

In the most recent study of this series, Gatchel, Hatch, Maynard, Turns, and Tauton-Blackwood (1979) examined the comparative short-term and long-term effectiveness of combined muscle relaxation/heart rate biofeedback, systematic desensitization, and the false-biofeedback placebo procedure in the treatment of speech anxiety. During both short-term evaluation and long-term assessment (a 1-month follow-up conducted in a different room with a larger audience), 3 the false-biofeedback group again demonstrated as much reduction in self-reported anxiety as the other two

3The change in audience size might have confounded the reported results. However, recent research in our laboratory has indicated that audiences of two or six persons (the sizes used by Gatchel and his colleagues) do not elicit different levels of reported anxiety in speech-anxious subjects required to give a speech with no pretraining (Gatchel, McKinney, & Paulus, 1979).

Treatment of Public-Speaking Anxiety 73

groups. Thus, the powerful impact of this placebo condition on the self- report component of speech anxiety does not appear to be illusory or short- lived. Again, though, this procedure, as well as systematic desensitization, did not produce as much reduction in physiological arousal as the veridical biofeedback condition.

The treatment methods employed in the above studies specifically dealt with the physiological component of speech anxiety. Another type of nonphysiological-based training-speech skills t ra ining-may be equally effective in alleviating speech anxiety. It is an extremely popular method, consisting of giving the subject information on how to prepare for a speech, how to cognitively deal with the anxiety experienced while speaking, and how to effectively deliver a speech. While this is a popular and widely used method, there are surprisingly no controlled studies in the scientific literature evaluating just how effective this type of training actually is, relative to other methods, in alleviating speech anxiety. The present study compared the clinical effectiveness of this type of training to our biofeedback procedure. In addition a third treatment, consisting of a combination of biofeedback and speech skills training, was evaluated. This group was included to assess whether a combination of treatments is more effective than the individually administered treatments. It was hypothesized that this combined procedure would prove to be the most effective treatment since it si- multaneously deals with both the physiological and cognitive components of anxiety.

Two individual difference variables were also examined in this investi- gation in order to assess their impact on treatment effectiveness. The first-degree of expected therapeutic effectiveness-has been found by Borkovec and Nau (1972) to affect the fear-reduction treatment process. The second-relative degree of cognitive/autonomic focus of awareness during anxiety-was hypothesized to possibly differentiate between individuals most responsive to the biofeedback procedure and those most responsive to the more cognitive speech-skills training procedure. Multivariate analysis techniques were used to analyze the data in order to assess any differential patterns of responding.

Finally, it should be noted that no placebo control group was included in the present study. Our past research has amply demonstrated that self- reported anxiety changes are very much affected by nonspecific placebo factors, while the physiological changes appear to be more treatment- specific. By not including such a control group, all potential participants could be recruited under the auspices of a treatment program and provided with treatment in the most expedient manner.


METHOD

Subjects

Subjects were 21 male and 21 female undergraduate volunteers, recruited from the University of Texas at Arlington and Tarrant County Junior College, who scored 15 or above on the Paul Self-Report of Con- fidence as a Speaker questionnaire (Paul, 1966). Any individual who had past cardiovascular disease or prior biofeedback training, who was taking medication that might adversely affect heart rate control, or who was an ex- cessive caffeine, nicotine, or alcohol consumer was not used in the study. The 42 subjects were randomly assigned to groups, and these groups were counterbalanced for sex of subject.

Apparatus

Heart rate (HR), tonic skin conductance level (SCL), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were recorded throughout all sessions on a Narco Bio-systems physiograph. Beckman silver/silver chloride electrodes were attached to the skin over the subject's anterolateral lower ribs to measure heart rate. A Narco Bio-systems GSR coupler (Type 7175) maintained a constant-current density of 10 uA/cm 2 through two silver/silver chloride electrodes (with the diameter of the circular surface area being approximately 1 cm). These electrodes were placed on the palmar mound and ventral side of the subject's left hand and wrist. Johnson and Johnson K-Y jelly was used as the electrolyte. SPB and DBP were measured using a Narco Bio-systems electrosphygmomanometer (Model No. PE-300) for all but eight subjects.

Binary heart rate feedback was presented via a light that flashed with every heartbeat. In addition, the experimenter would periodically sample HR during 30-second intervals and, if this average heart rate was below a preestablished baseline, a separate "average" feedback light was presented to inform the subject. A Lexington Instruments constant-cuff blood pressure/heart rate feedback device was used for binary feedback presentation (for a detailed description, see Tursky, Shapiro, & Schwartz, 1972). This device was also used to measure BP for the first eight subjects, but a mal- function in the air compressor necessitated changing to the electrosphygmomanometer (BP recordings using the two devices did not differ significantly).

All speeches were recorded using a Sony videotape monitor, recorder, and remote camera. All auditory stimuli were presented via a portable Sony


cassette player/recorder with remote control. An intercom system was always in use to ensure any required subject-experimenter communication.

Procedure

Pretreatment Assessment . Each subject was contacted by the experimenter via telephone and given a topic on which to prepare an initial speech. Upon arrival for the first session, the subject was requested to read and sign an informed consent form, and then to complete a cognitive/autonomic focus questionnaire based on the Paul (1966) questionnaire? Following this, all physiological sensing devices were attached, and instructions were read to the subject. A 15-minute baseline was then taken, during which BP was sampled at 5, 10, and 14 minutes. Following this, the subject was asked to stand, the subject room door was opened, and a video camera was positioned to record the subject. The subject then delivered a 3-minute speech, while the experimenter sampled BP at 1 minute into speaking. At the end of 3 minutes, the experimenter instructed the subject to have a seat and to relax. The door was then closed, and the subject listened to taped instructions for muscle relaxation training (Budzynski & Stoyva, 1969) for the next 10 minutes. BP was sampled 5 and 10 minutes into relaxation, When this was completed, the experimenter returned, removed all devices, and asked the subject to complete a nervousness questionnaire (Gatchel et al., 1977). The subject was then instructed to practice relaxation at home for 30 minutes each night and was given a log sheet on which to record practice time.

The second session consisted of 20 minutes of relaxation following a 5- minute baseline. BP was sampled at 4 minutes into baseline, and 5, 10, 15, and 20 minutes into relaxation. This session was provided primarily as a habituation session, and to gather information on physiological patterns during relaxation. Again, each subject was encouraged to practice muscle relaxation for 30 minutes each night and to record this on the log sheet.

Sessions 3-6 were the actual training sessions. Here, the subjects diverged into different procedures, depending on group assignment. All subjects completed a treatment rationale questionnaire (Borkovec & Nau, 1972) at the beginning of Session 3 and at the end of Session 6. Also, the State-Trait Anxiety Questionnaire, State Form A (Spielberger, Gorsuch, & Lushene, 1970) was completed by all subjects immediately before and after sessions 3-6.

4For details on the construction of this questionnaire, contact the first author.


Heart Rate Biofeedback Training. Following a 10-minute baseline, with BP sampled at 5 and 8 minutes, instructions to lower heart rate using the feedback display were presented. The feedback then remained on for 3 minutes. An average 30-second HR sample was also taken at .5 and 1.5 minutes into feedback. If the feedback samples were lower than the base sample, the "average" feedback light was flashed to additionally inform the subject of successful deceleration. Following the feedback interval, instructions were presented to the subject to lower HR without feedback. This no- feedback trial was 1 minute in duration. The "average" feedback light was flashed, if the average heart rate during the first 30 seconds of this interval was lower than baseline. Following this 1-minute period, a 1-minute rest period was instituted. This cycle of feedback, no-feedback transfer, and rest was repeated five times during each session. BP was sampled during the last minute of each feedback period, and during the first 20 seconds of each rest period. Following each session, the experimenter asked the subject to practice decelerating heart rate at home for 30 minutes each night and taught the subject how to measure HR via the radial pulse so as to allow assessment of success. In addition, the experimenter reminded the subject of the number of "average" feedback flashes achieved each session, and kept a chart of each subject's performance throughout training.

Speech Skills Training. This training format was similar to the biofeedback group in terms of the time course. Again, a 10-minute baseline preceded training, and training consisted of five cycles of a 3-minute interval, a 1-minute interval, and a 1-minute rest period. BP was sampled just as it was during biofeedback. The differences involved the training procedures themselves. In this procedure, each session dealt with a different topic: Session l - p r a c t i c e and rehearsal; Session 2-se l f -conf idence; Session 3 - a u d i e n c e effects; Session 4 - s p e a k i n g style. These topics were presented via cassette tape. The tape initially instructed the subject to listen to a series of statements s dealing with one facet of that day's topic, and to try to remember as many as possible. For the next 3 minutes, the subject heard five to seven statements, with each being repeated once. The tape then instructed the subject to imagine an arousing speaking episode (specific to that day's topic) and then to "talk down" the anxiety by repeating the statements just heard. This allowed some desensitization to occur and also provided the subject with an opportunity to rehearse under mild arousal conditions. The experimenter recorded the number of successful recalls during this 1-minute period and, if the number exceeded the number recalled

5These statements were taken from a manual prepared by Dr. Ernest Buckley to whom we are indebted, and from the general statements used by Meichenbaum and his colleagues (Meichenbaum, 1974). Lists of the actual statements are available from the first author upon request.


for the previous cycle, flashed a feedback light as a signal of success. This was followed by the l-minute rest period. The cycle was repeated five times. Following the session, subjects were asked to spend 30 minutes before the next session writing down as many of the statements just heard as could be recalled. In addition, the experimenter kept a chart of each subject's best performance throughout training.

Combined Heart Rate Biofeedback~Speech Skills Training. This combined group received treatment identical to the biofeedback group for Sessions 3 and 4, and treatment identical to the speech skills training group for Sessions 5 and 6. However, in order to keep the time length of sessions equal across groups, the tapes heard by subjects in this group had a more abbreviated presentation of the four topics.

Posttreatment Assessment. Session 7 was a posttraining speech session identical to Session 1 (all subjects were given a topic on which to prepare a speech after Session 6). At the conclusion of this session, the subject was given a topic on which to prepare a speech for Session 8, the generalization test session. During this session, the subject was seated behind a portable podium, facing an array of four chairs and a large two-way mirror. The physiograph and videotape equipment were housed in the adjoining laboratory, and the subject was filmed through the mirror (with informed consent). The experimenter attached the HR and SCL electrodes, but no BP cuff was employed. The rest of the session proceeded exactly as Session 7, with the exception of having a four-person audience (two male, two female) enter just prior to the speech's beginning, and having them exit immediately after speech completion. The audience members were instructed to act inter- ested but not to ask questions or unduly disrupt the subject's speech. Fol- lowing a 4-minute recovery period, the experimenter returned, removed the electrodes, and had the subject complete the self-report of nervousness scale (Gatchet et al., 1977).

Data Reduction and Analysis

Heart Rate. Baseline HR was determined by calculating the number of beats in the 14th minute of baseline during speech sessions, the number of beats in the 4th minute of baseline during muscle relaxation, and the number of beats in the 8th minute of baseline during training sessions. Speaking HR was the average HR in beats per minute (bpm) for the total 3 minutes of each speech. Training HR was the HR in bpm during the median 3-minute interval of each training session (HR was calculated for each 3-minute interval, rank-ordered, and the median value defined the median interval). Muscle relaxation HR was computed by calculating the beats during the 15th minute of relaxation in Session 2.


Skin Conductance. SCL was measured in Kohms of resistance and was converted to micromhos of conductance for analysis. The baseline values used correspond to the final value of each session's baseline. All other values were determined by taking the value at the end of the minute or interval used to define HR.

Blood Pressures. Both SBP and DBP were measured in m m Hg. The samples used were the ones corresponding to the minutes or intervals defined by HR.

Overt Motor Behavior. The Paul Behavioral Checklist, modified form (Gatchel & Proctor, 1976) was used to assess overt motor anxiety. Three raters viewed the videotapes and recorded all instances of the targeted behaviors. The average of the total number of target behaviors observed served as the overt nervousness score.

RESULTS

Manipulation Checks

Subjects' initial Paul Self-Report of Confidence as a Speaker scores (Paul, 1966) were compared in a one-way analysis of variance (ANOVA), with treatment group the only factor. The differences were not significant. The group means (biofeedback = 23.43, speech skills training = 22.57, combined = 22.50) were much higher than Paul 's (1966) original normative sample (x = 11.6, a = 5.9), indicating relatively higher initial speech anxiety among the subjects in our sample.

Ratings of overt motor nervousness reported by the three raters were subjected to correlational analysis in order to ascertain the degree of agree- ment during speech-anxiety assessment in Sessions 1, 7, and 8. Table I reports these correlations. As can be seen, all correlations were highly significant, p < .001.

Table I. In te rcor re la t ions o f Over t M o t o r Ra t ings Sessions 1 ,7 , and 8

Session 1 Session 7 Session 8

Ra te r 1 Ra te r 2 Ra te r 1 Ra te r 2 Ra te r 1 Ra te r 2

Ra te r 2 .743 .733 .832 p < .0001 p < .0001 p < .0001

Ra te r 3 .688 .489 .585 .572 .831 .801 p < .0001 p < .001 p < .0001 p < .0001 p < .0001 p < .0001

Treatment of Public-Speaking Anxiety

Biofeedback Training and Heart Rate Decrease

79

Table II presents the median heart rate during baseline and feedback periods for each session for the biofeedback training group. A one-between (sex of subject) . and two-within (period: baseline or training; session) analysis of variance of these data yielded a significant period effect, F(1, 12) = 13.78, p < .01. This confirms the ability of subjects to decelerate their heart rate during feedback training trials. There was also a near-significant Session X Period effect, F(1, 12) = 4.41, p < .06.

This study also provided an opportunity to examine the effects of length of training on heart rate decrease performance. One group (the biofeedback group) was administered four training sessions, while a second group (the combined group) received only two biofeedback training sessions. A one-way analysis of variance (with group being the only factor) of the median heart rate levels during the feedback periods of the last training session of both groups yielded no significant group effect. Thus, length of training (two sessions versus four sessions) did not have a significant effect on the magnitude of heart rate deceleration performance.

Speech Anxiety Assessment Sessions

Table III presents the changes in physiological, overt motor, and self- report measures for each group during speech preparation and presentation in Sessions 1, 7, and 8. As can be seen, there is a greater reduction in the various dependent measures during posttreatment assessment, relative to the pretreatment assessment phase. Analyses of variance indicated that self- reported nervousness decreased significantly from Session 1 levels during both Session 7, F(1, 36) = 54.18, p < .0001, and during Session 8, F(1, 36) = 40.21, p < .0001. Similarly, all groups showed decreased overt motor

Table II. Median Heart Rate During Baseline and Feedback Periods of Each Session for the

Biofeedback Training Group

Baseline Feedback

First training session (session 3) 78.4 75.8

Second training session (Session 4) 78.5 75.5

Third training session (Session 5) 78.1 76.5

Fourth training session (Session 6) 79.3 76.4

80 McKinney and Gatchei

Table Ill. Changes in Self-Report, Overt Motor, and Physi- ological Measures for Each Group During Baseline and Speech

Presentation in Sessions 1, 7, and 8

Speech skills Biofeedback Combination

Session 1

Self-report 25.4 26.1 25.8 Overt motor 27.1 30.1 28.2 HR 29.0 18.2 14.9 SCL 1.058 1.906 1.346 SBP 20.8 16.6 21.4 DBP 9.6 21.8 14.9

Session 7

Self-report 16.4 19.9 18.5 Over motor 14.0 21.5 16.0 HR 28.0 29.1 21.5 SCL 1.395 1.469 1.280 SBP 24.0 20.2 19.9 DBP 13.8 16.4 14.2

Session 8

Self-report 20.2 16.2 18.5 Overt motor 15.3 16.0 17.2 HR 37.4 25.0 27.1 SCL .320 .888 .592

nervousness levels during Session 7, F ( I , 36) = 46.18, p < .0001, and Session 8, F(1, 36) -- 58.13, p < .0001. There were no other significant main or interaction effects.

To conduct independent tests of the many physiological dependent measures with separate ANOVAs is not statistically sound, since any shared variance among the measures might be retested with each analysis of a par- ticular measure that shares in the common variance. Indeed, in the present data, intercorrelation of the dependent measures does occur (there are several correlations greater than .30). In such cases, multivariate statistical procedures are most appropriate. Therefore, linear discriminant analyses (Cooley and Lohnes, 1971) were performed on these physiological, overt motor , and self-report data, for each session, in order to assess whether a linear function could be constructed that would significantly discriminate among the treatment groups. The differences beween baseline and speaking levels of the four physiological variables, as well as self-reported nervousness scores and the average overt motor nervousness rating, were used in the analyses. All were standardized prior to use.

The Session 1 data were entered in a simultaneous fashion to con- servatively test the importance of the physiological variables. The analyses indicated that a discriminating function could not be created (Wilk's A -- .69, which, when converted to X 2, equaled 13.74 and was not significant). For the Session 7 data, which were also entered in a simultaneous fashion, again no discriminating function could be constructed (X2(12) = 8.27, p >


Table IV. Standardized Canonical Dis- criminant Function Coefficients Session

8

Variable Coefficient

Heart rate .921 Skin conductance - . 190 Overt motor rating - .628 Self-reported nervousness .390

.05). For the Session 8 data, the same analysis was performed, but without BP data (which was not recorded in this session). Prior to removing a function, it was found that Wilk's k = .60 (X2(8) = 18.9, p < .05), indicating that a discriminant function could be constructed. 6 This function had an eigenvalue of .59, accounted for 93.95% of the variance, and had a canonical correlation of .61 with the independent variable. Examination of the standardized canonical discriminant function coefficients (see Table IV) revealed high loadings for HR and overt motor nervousness rating, in the opposite directions. Examination of the mean HR changes seen in each group, for Session 8 only (see Table III), showed a clear superiority for the two groups having a biofeedback component. Scheff6 post hoc contrasts of group means confirmed these observations with both the biofeedback and combined groups being significantly different from the speech skills group, p < .05.

Examination of the average overt motor mean ratings showed a reversal in the rank-order of group improvement (biofeedback subjects showed the least improvement and speech skills training subjects the most), but a post hoc contrast of means revealed no significant differences.

Individual Difference Variables

Initial subjective confidence in the treatment (assessed during Session 3) and cognit ive/autonomic focus of fear 7 were postulated to influence treatment performance. Therefore, these variables were entered with the dependent variables previously used in the above discriminant analyses in

6It should be noted that the Session 8 data did not include SBP or DBP. It could be argued that this may have accounted for the significant function, either by providing large variance accounted for by HR, or by decreasing the degrees of freedom. Therefore, the Session 1 and Session 7 data were reanalyzed, excluding both SBP and DBP. However, again no significant funct ions could be derived.

7The cogni t ive /autonomic score was measured on an integer scale but was dichotomized for these analyses. A high score indicated greater au tonomic focus. Therefore, the seven highest scorers in the biofeedback group, the autonomic treatment , and the seven lowest scores in the speech skills t reatment , the cognitive t reatment , plus seven subjects chosen at r andom from the combined group, were assigned a score of 1 on this variable (nominally, they were the subjects receiving "tailored" treatment). The rest were assigned a score of 0.


Table V. Classification Differences When Cog- nitive/Autonomic Focus and Subjective Treat-

ment Confidence ARe Included

Percent correctly classified

Without inclusion Withinclusion

Session i 57.14 54.76 Session 7 57.14 61.90 Session 8 64.29 69.05

order to test their importance. In no case did the variables significantly improve discrimination. However, they did improve the percentage of cases classified in Session 7 and 8, but not in Session 1, suggesting some small amount of influence (see Table V).

Physiological Con comitan ts o f Speech Anxiety, Relaxation, and Biofeedback Performance

In order to isolate the physiological response patterns associated with speech anxiety, relaxation, and biofeedback performance, the raw physiological data acquired during the initial speech, during the 15th minute of muscle relaxation training in Session 2, and during the middle feedback period of the first heart rate biofeedback training session (N = 28) were entered into three separate factor analyses, employing a principal factoring

Table VI. Factor Score Coefficients for the Ex- treme Anxiety, Heart Rate Biofeedback, and

Extreme Relaxation Situations

Variable Factor 1 Factor 2

Extreme anxiety situation

Heart rate .34 Skin conductance - . 10 Systolic blood pressure .50 Diastolic blood pressure .18

Heart rate biofeedback situation

Heart rate .21 - .33 Skin conductance .10 -- .09 Systolic blood pressure .70 - . 3 6 Diastolic blood pressure .23 .84

Extreme relaxation situation

Heart rate .00 - .33 Skin conductance .14 - .09 Systolic blood pressure .58 --.36 Diastolic blood pressure .32 .84


method with iterations to improve commonality estimates (Gorsuch, 1974). Table VI shows the factor coefficient loadings of all factors having an eigenvalue greater than 1 for each situation. As can be seen in this table, in all of the initial factors, SBP has a relatively high loading, indicating that it may be especially important in defining the relaxation-anxiety continuum. More importantly, it can be seen that heart rate has a high loading in only two of the conditions-the speech anxiety condition and the biofeedback training condition; it does not load highly for the relaxation training condition. This indicates that a dominant response associated with speech anxiety (heart rate) is also directly affected by the biofeedback training procedure. Thus, the biofeedback procedure appears to be well suited for dealing with an important physiological response associated with speech anxiety.

DISCUSSION

This study clearly demonstrated that all three treatment procedures were associated with significant decreases in the self-report and overt motor components of speech anxiety during posttreatment assessment. There were no differences among the groups on these measures. However, the groups did differ significantly in their ability to reduce the physiological component during the last generalization assessment session (Session 8). The two treatment procedures having a biofeedback component were associated with the least amount of heart rate increase.

These two biofeedback treatment procedures were effective in blocking the physiological component of speech anxiety during the generalization test session only when subjects spoke before a live audience, and not when they spoke before a videotape camera in Session 7. These findings were somewhat surprising since they contradicted the prediction that performance before a live audience would show relatively less treatment effect due to the greater anxiety provoked by such a situation (Knowles, Kreuser, Hass, Hyde, & Schuchardt, 1976; Latane & Harkins, 1976). Two explanations of the present results are immediately apparent. First, one could argue that they simply reflect a practice effect, with the presentation of the second posttreatment assessment speech becoming easier than the first. Second, subjects may have viewed Session 8 as the target of goal session and tried much harder to utilize the treatment techniques in that session because of the "live" audience. The presence of an audience, rather than distracting or disrupting performance, may have actually enhanced it (Cottrell, Wack, Sekerak, & Rittle, 1968; Henchy & Glass, 1968; Paulus & Murdoch, 1971). Anecdotally, several subjects reported that they prepared more for Session 8 than for Session 7 because of the live audience factor.


Another important finding of the present study was yielded by the factor analyses of the physiological measures used in the assessment of speech anxiety. These analyses indicated that heart rate and blood pressure responses play an important role in defining speech anxiety, whereas skin conductance level does not. Therefore, a treatment geared toward the control of these cardiovascular variables would be a logical approach. The pattern of physiological changes during heart rate biofeedback training co- incided with this pattern of cardiovascular responses. Muscle relaxation training, however, affected only the blood pressure response and not heart rate. Thus, although Silver and Blanchard (1978) have suggested that biofeedback and muscle relaxation treatment have similar efficiency and efficacy levels, the present results suggest that the two do not have identical effects on all the physiological components of speech anxiety. In passing, it should also be noted that rather than skin conductance level, spontaneous electrodermal activity may be a more sensitive index of anxiety. Future research will need to evaluate this component of electrodermal responding rather than the level measure.

The amount of heart rate deceleration produced by the biofeedback procedure, although significant, was relatively small (only approximately 2 bpm). Blanchard and Young (1973) have pointed out the fallacy of equating statistical significance and clinical significance. The inclusion of procedures designed to increase the magnitude of deceleration, such as those recently developed by McKinney, Geller, Gatchel, Barber, Bothner, and Phelps (1980), may be necessary to obtain more therapeutically beneficial effects of biofeedback training. The fact that improvement was produced in the present study, though, even with this limited amount of performance magnitude, testifies to the potential power of this treatment technique.

As in previous studies from this laboratory (Gatchel et al., 1977; Gatchel, Hatch, Maynard, Turns, & Tauton-Blackwood, 1979; Gatchel & Proctor, 1976), both the overt motor ratings and the self-report measures of anxiety showed large decreases after such treatment. In the studies that included a false biofeedback procedure, similar decreases in these variables were found to be produced by the placebo treatment. However, in the Gatchel and Proctor (1976) study, the control group, which was not constructed or advertised as an analogue biofeedback treatment, did not show these decreases in the overt motor and self-report anxiety measures. This suggests that these effects are due to placebo factors (Peek, 1977; Shapiro & Morris, 1978) and do not simply reflect a regression to the mean phenomenon. As Shapiro and Morris (1978) have pointed out, placebo treatments are often just as effective as active treatments when correctly administered. Certainly, each of the treatment groups in this study appears to have the components necessary to achieve these desired fear-reduction effects.


The lack of significant effects for the two individual difference variables assessed in this study-cognitive/autonomic focus and subjective confidence in t rea tment- was somewhat surprising in the light of previously reported results (Borkovec & Nau, 1972; Sirota, Schwartz, & Shapiro, 1974). However, both variables in this study were severely restricted in range, with almost all subjects reporting high subjective confidence levels and high autonomic focus levels. This restriction in range reduces correlation (Nunnally, 1978) and makes it difficult to examine the true relationship between variables. In passing, it should be noted that the combined treatment group was the only one that received a higher average confidence score after its administration. This may have implications for choice of treatment with particularly skeptical subjects.

In summary, the three treatment methods assessed in the present study were equally effective in alleviating the self-report and overt motor components of speech anxiety. However, the two treatment groups that included a biofeedback component were associated with the greatest modulation of physiological responding. This suggests that, for those individuals in which physiological reactivity is a dominant and distracting component of their anxiety response, biofeedback may be useful as an ad- junctive treatment to be used with other methods (Gatchel, 1979). Of course, biofeedback procedures designed to increase the magnitude of heart rate deceleration, such as those recently developed by McKinney, Geller, Gatchel, Barber, Bothner, and Phelps (1980), will have to be employed in order to possibly produce more therapeutically efficacious results.

The speech skills training package used in the present study will also have to be expanded in order to provide a more adequate assessment of its effectiveness. In retrospect, only one session of cognitive behavior modification may not have been enough. Moreover, in future studies, the statements used to elicit imagery rehearsal should contain both stimulus and response propositional elements since Lang, Kozak, Miller, Lerin, and McLean (1980) have demonstrated the importance of using response propositions in eliciting maximum physiological reactivity while imaging. This is particularly important in light of the fact that speech-anxious individuals do not respond as strongly to images of speaking as they do to real-life speech situations (Weerts & Lang, 1978).

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(Revision received July 17,1981)

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