اثر حواس پرتی و ارزیابی مجدد تهدید هدایت شونده بر کاهش ترس در طول درمان بر اساس مواجهه ترس های خاص

Abstract To test predictions derived from the emotional processing theory of fear reduction, claustrophobics (N=58) were randomized to one of four exposure conditions: (a) exposure with guided threat reappraisal, (b) exposure with a cognitive load distracter task, (c) exposure with both guided threat reappraisal and cognitive load distracter task and (d) exposure without guided threat reappraisal or cognitive load distracter task. We hypothesized that self-guided in vivo exposure would lead to less fear reduction if performed simultaneously with a cognitive load distracter task that severely taxes information processing resources. In contrast, we hypothesized that focusing on core threats during exposure would enhance fear reduction. The main findings were largely consistent with predictions. The cognitive load task (regardless of focus of available attention) had a detrimental effect on fear reduction, while guided threat reappraisal (regardless of cognitive load) had a facilitative effect. The greatest level of fear reduction and the lowest level of return of fear were observed in the exposure condition involving guided threat reappraisal without cognitive load. Clinical implications and directions for future research are discussed.

Results 2.1. Treatment group equivalence There were no significant differences between the treatment groups on pretreatment fear-related indices. These findings indicate that the four exposure conditions were equivalent at baseline. 2.2. Manipulation check Participants rated their degree of attentional focus using a 0 (not at all) to 100 (completely) Likert scale. A composite index was obtained by averaging across the six treatment trials. The resulting indices of attentional focus were: (a) GTR (M=90.8, S.D.=7.4), (b) CLDT (M=81.2, S.D.=12.5), (c) GTR+CLDT (for distraction task: M=84.4, S.D.=8.6), (for threat focus: M=21.3, S.D.=16.0), (d) CTRL (self-guided distraction: M=74.2, S.D.=26.8; self-guided threat focus: M=37.5, S.D.=27.7). In addition, error percentages for the distraction task were calculated for the CLDT and GTR+CLDT conditions. CLDT participants missed 15.7% of all presented cues and participants in the GTR+CLDT condition missed 9%. 2.3. Treatment outcome 2.3.1. Within-group changes from pre to posttreatment Highly significant reductions in subjective fear from pre- to posttreatment were observed for each of the four exposure conditions across BAT 1 and BAT 2 (all p's<0.001). None of the four groups showed significant reductions in HR reactivity from pre to posttreatment. 2.3.2. Effects of treatment condition on fear reduction Means and standard deviations of subjective fear indices and heart-rate reactivity at pre, post and follow-up for the four treatment conditions are presented in Table 1. Fig. 1illustrates the pre, post and follow-up levels of subjective peak fear across the treatment conditions for BAT 1. Table 1. Means and standard deviations of maximum fear and heart-rate reactivity during two behavioral approach tests at pre, post and follow-upa Measure Exposure condition GTR CLDT GTR+CLDT CTRL M SD M SD M SD M SD BAT 1 max fear Pre 71.3 16.0 72.1 15.8 70.0 14.6 75.7 12.8 Post 1.3 3.52 25.7 18.3 15.3 18.1 15.0 22.5 Follow-up 16.15 17.1 35.4 21.5 35.0 29.6 28.6 31.1 BAT 2 max fear Pre 64.7 23.6 75.7 19.9 70.7 16.9 69.3 13.9 Post 25.3 25.6 37.1 26.7 38.0 31.7 28.6 28.8 Follow-up 24.6 20.3 45.4 22.2 38.6 28.8 30.0 30.4 BAT 1 HR reactivity Pre 1.0 7.5 −0.6 7.9 −0.6 11.8 0.1 10.0 Post −2.1 8.7 3.3 9.3 −2.3 9.6 1.0 12.3 Follow-up 1.3 11.7 3.3 8.7 −4.7 11.5 .4 13.5 BAT 2 HR reactivity Pre 1.5 5.4 −0.1 6.1 1.6 6.7 −3.0 6.7 Post −1.4 9.0 4.7 8.7 −2.0 9.6 −1.0 15.0 Follow-up 2.2 13.2 3.4 9.6 −4.6 10.1 −0.6 15.5 a GTR: guided threat reappraisal; CLDT: cognitive load distraction task; GTR+CLDT: guided threat reappraisal plus cognitive load distraction task; CTRL: exposure control. Table options Peak fear at pre, post and follow-up assessments during two behavioral approach ... Fig. 1. Peak fear at pre, post and follow-up assessments during two behavioral approach tests across the four exposure conditions. Figure options Results of the MANCOVA revealed significantly greater fear reduction among those receiving guided threat reappraisal relative to those who did not (F(3, 48)=5.13, p<0.01). Conversely, those receiving the cognitive load distraction task showed significantly less fear reduction than those who did not (F(3, 48)=6.08, p<0.01). The interaction effect was close to significant and follow-up simple main effects showed that GTR resulted in less post fear than CTRL and GTR+CLDT (p<0.01) and CLDT resulting in more post fear than CTRL and GTR+CLDT (p<0.10). None of the planned comparisons were significant for the effects on heart-rate reactivity. Fig. 2 depicts the number of participants attaining high end-state functioning in the BAT 1 chamber for each treatment condition at posttreatment and follow-up. High end-state functioning (HEF) for two behavioral approach tests across the ... Fig. 2. High end-state functioning (HEF) for two behavioral approach tests across the four exposure conditions. Figure options 2.3.3. Generalization of fear reduction For the generalization probe (BAT 2), the pattern of mean fear responses was consistent with expectation, with GTR obtaining most — and CLDT obtaining the least fear reduction on all subjective fear indices. However, none of the between-condition differences in BAT 2 were statistically significant (see Table 1 and Fig. 1). Comparisons of HEF across the four treatment groups revealed a similar pattern of scores as observed for the BAT 1 chamber. However, these differences were not significant (see Fig. 2). 2.3.4. Maintenance of fear reduction and return of fear (ROF) within treatment effects From pre to follow-up, all four conditions displayed significant reductions in peak fear on both BAT 1 (all p's<0.001) and BAT 2 (al p's<0.01). All four groups showed some return of fear from posttreatment to follow-up for BAT 1, which was significant for the CTRL (t=−2.79, p<0.01), GTR (t=−3.33, p<0.01) and GTR+CLDT (t=−2.64, p<0.05) groups. None of the four groups showed significant return of fear for BAT 2. 2.3.5. Effects of treatment condition on fear reduction at follow-up As can be seen from Table 1 and Fig. 1, the pattern of mean fear responses was consistent with expectation. On peak fear, participants receiving distraction (i.e. CLDT and GTR+CLDT) scored higher than those not receiving distraction (F(1,48)=3.51; p<0.10). There were no significant treatment effects for HR reactivity. For BAT 2, the interaction effect was significant, with CLDT showing more fear than either CTRL (F(3,44)=4.11; p<0.05) or GTR+CLDT (F(3,44)=4.45; p<0.01). The percentage of participants displaying ROF by condition is presented in Fig. 3. There was a nonsignificant trend (χ2(1)=2.02, p<0.10; one-tailed) for those in the two cognitive load groups to show higher ROF. In contrast, those in the GTR group (without CLDT) had lower ROF than the three other groups combined (χ2(1)=2.88, p<0.05; one-tailed). Return of fear (ROF) for two behavioral approach tests across the four exposure ... Fig. 3. Return of fear (ROF) for two behavioral approach tests across the four exposure conditions. Figure options 2.4. Treatment process Means and standard deviations of subjective fear indices at each of the six treatment trials for four groups are presented in Table 2. Table 2. Means, standard deviations and growth curve parameters of maximum fear, starting fear and fear change parameters for the four exposure conditions during treatment Exposure condition Exposure trials Fear change parameters 1 (M (S.D.)) 2 (M (S.D.)) 3 (M (S.D.)) 4 (M (S.D.)) 5 (M (S.D.)) 6 (M (S.D.)) Initial estimate Change estimate Max fear GTR 54.3 (21.6) 46.0 (25.9) 25.3 (20.0) 13.0 (11.9) 6.0 (8.28) 4.29 (6.46) 56.2 (5.7) −12.0 (1.3) CLDT 56.7 (17.2) 47.0 (23.1) 34.3 (22.3) 25.3 (20.0) 20.3 (19.6) 14.5 (17.1) 54.6 (5.7) −9.3 (1.3) GTR+CLDT 60.4 (21.3) 42.1 (25.8) 27.9 (20.5) 19.3 (16.4) 15.0 (14.5) 10.7 (13.3) 53.7 (5.5) −9.2 (1.3) CTRL 60.7 (18.7) 51.4 (22.8) 42.9 (28.1) 32.1 (28.8) 25.0 (27.7) 22.1 (26.4) 59.3 (5.7) −8.1 (1.3) Start fear GTR 45.3 (20.7) 38.0 (22.1) 23.9 (18.4) 11.7 (11.0) 5.3 (8.3) 3.6 (6.3) 47.0 (4.7) −9.9 (1.0) CLDT 32.7 (11.6) 28.0 (20.7) 23.0 (22.3) 14.0 (14.0) 10.9 (14.6) 9.9 (14.6) 30.7 (4.7) −5.3 (1.0) GTR+CLDT 50.4 (18.5) 37.1 (20.2) 25.7 (19.9) 16.4 (13.9) 11.4 (12.9) 10.0 (13.6) 46.3 (4.5) −7.8 (1.0) CTRL 46.8 (23.7) 40.7 (22.7) 32.9 (26.4) 27.1 (26.4) 22.9 (25.3) 20.7 (27.3) 48.9 (4.9) −5.8 (1.1) Within trial fear change GTR 14.7 (13.0) 11.7 (10.3) 10.3 (12.6) 5.7 (9.8) 1.33 (3.52) .71 (2.67) 16.1 (2.7) −3.3 (.7) CLDT 8.3 (12.5) 6.7 (9.0) 10.0 (13.2) 5.3 (6.1) 3.9 (4.7) 2.9 (4.7) 8.7 (2.7) −1.0 (.7) GTR+CLDT 17.7 (16.4) 15.0 (12.9) 8.6 (9.5) 4.3 (6.5) 3.6 (5.0) 1.4 (3.6) 16.9 (2.6) −3.4 (.6) CTRL 8.6 (12.9) 10.0 (8.8) 4.3 (6.5) 3.6 (6.3) 2.1 (4.3) 4.3 (8.5) 8.7 (2.7) −1.3 (.7) Table options 2.4.1. Within-trial habituation The three groups showed equivalent levels of within-trial fear reduction across the six 5 min treatment trials. 2.4.2. Fear activation A significant main effect of cognitive load was observed on initial fear activation (F(1,55)=4.04, p<0.05). Participants receiving the CLDT task either alone or in combination with GTR displayed lower initial fear activation during the first 5-min of treatment relative to those who did not receive CLDT. However, the main effects of CLDT on fear activation were qualified by a significant CLDT by GTR interaction. Multiple comparisons revealed that the CLDT group showed significantly lower initial fear than both the CTRL (F(1,55)=7.24, p<0.01) or GTR+CLDT (F(1,55)=5.74, p<0.05) groups. However, arguing against a fear activation effect, were the positive (albeit insignificant) correlations obtained between initial fear level and posttreatment fear. 2.4.3. Between-trial habituation Fig. 4 presents the fear decay slopes for each of the four conditions. The GTR and CLDT+GTR conditions showed greater between-trial fear change than the CLDT and CTRL conditions (F(1,55)=9.8, p<0.01; one-tailed). The interaction effect was not significant, but follow-up simple main effects showed higher between-trial habitation for GTR as compared to CTRL (F(1,55)=7.21, p<0.01) and, in turn, higher between-trial fear reduction for GTR+CLDT than for CLDT alone (F(1,55)=2.98, p<0.05). In addition, a post hoc comparison revealed that the GTR condition led to significantly faster between-trial fear reduction than the CLDT group (F(1,55)=9.61, p<0.01). Between-trial habituation during six 5-min treatment trials across the four ... Fig. 4. Between-trial habituation during six 5-min treatment trials across the four exposure conditions.