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Activating attachment representations during memory retrieval modulates intrusive traumatic memories
Consciousness and Cognition 55 (2017) 197–204
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Consciousness and Cognition journal homepage: www.elsevier.com/locate/concog
Activating attachment representations during memory retrieval modulates intrusive traumatic memories
MARK
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Richard A. Bryant , Iris Chan University of New South Wales, Australia
AR TI CLE I NF O
AB S T R A CT
Keywords: Attachment theory Memory Memory reconsolidation Intrusive memories
Although priming mental representations of attachment security reduces arousal, research has not examined the effect of attachment on the retrieval of emotionally arousing memories. This study investigated the effect of priming attachment security on the retrieval of emotional memories. Seventy-five participants viewed negative and neutral images, and two days later received either an attachment prime or a control prime immediately prior to free recall of the images. Two days later, participants reported how frequently they experienced intrusions of the negative images. The attachment group had less distress, and reported fewer subsequent intrusions than the control group. Attachment style moderated these effects such that individuals with an avoidant attachment style were not impacted by the attachment prime. These findings suggest that priming attachment security decreases distress during memory reactivation, and this may reduce subsequent intrusive memories.
1. Introduction Emotional memories, and particularly intrusive memories, are a common feature of many psychological disorders (Bryant, O'Donnell, Creamer, McFarlane, & Silove, 2011). Models of emotional memories converge on the critical role of arousal at the time of memory consolidation that contributes to subsequent distressing memories (Ehlers & Clark, 2000). Biological models propose that memory traces are strengthened by activation of glucocorticoid receptors in the basolateral nucleus of the amygdala facilitating noradrenergic signals (Roozendaal, Quirarte, & McGaugh, 2002). Supporting this proposition is much evidence that strength of emotional memories is moderated by glucocorticoid and noradrenergic activation at the time of consolidation (Roozendaal, Hahn, Nathan, de Quervain, & McGaugh, 2004). It is proposed that intrusive emotional memories are particularly strongly consolidated, and characterised by closely interconnected memory traces that result in involuntary recurrences of memories (Foa, Steketee, & Rothbaum, 1989). This is consistent with evidence that intrusive memories are predicted by glucocorticoid and noradrenergic response during the consolidation phase (Bryant, McGrath, & Felmingham, 2013; Chou, La Marca, Steptoe, & Brewin, 2014; Nicholson, Bryant, & Felmingham, 2014). There is distinct research suggesting that proximity to attachment figures alleviates stress responses (Eisenberger et al., 2011; Mikulincer, Shaver, Gillath, & Nitzberg, 2005). This evidence reflects a fundamental tenet of attachment theory that during stress we seek social support (Bowlby, 1969). This theory posits that one internalizes mental representations of attachment figures, and these representations similarly can provide a sense of security during stress. Experimentally activating attachment figures results in a range of psychological benefits, including reductions in bias to threat (Mikulincer, Shaver, & Horesh, 2006), pain-related neural activation (Eisenberger et al., 2011), noradrenergic response to threat (Bryant & Chan, 2015), and also enhancement of heart rate variability
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Corresponding author at: School of Psychology, University of New South Wales, NSW 2052, Australia. E-mail address: [email protected] (R.A. Bryant).
http://dx.doi.org/10.1016/j.concog.2017.08.010 Received 24 July 2016; Received in revised form 12 August 2017; Accepted 22 August 2017 1053-8100/ © 2017 Elsevier Inc. All rights reserved.
Consciousness and Cognition 55 (2017) 197–204
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(Bryant & Hutanamon, in press). The extent to which attachments can benefit people depends, however, on individual differences in attachment security. Attachment theories posit that prior experiences of unreliable relationships can lead to deficiencies in the capacity to benefit from attachment figures because they do not activate representations of security (Mikulincer & Shaver, 2007a, 2007b). It is proposed that prior experiences of insecure attachments lead people to evolve insecure attachment systems, which may be manifest in anxious or avoidant attachment tendencies. People with anxious attachments worry about abandonment and seek support from others, yet nonetheless perceive they are not receiving sufficient support (Campbell, Simpson, Boldry, & Kashy, 2005). Hence, they monitor attachment proximity closely, reflected in faster naming of attachment figures lexical decision tasks (Mikulincer, Gillath, & Shaver, 2002), and greater recognition of proximity-related words (Mikulincer, Birnbaum, Woddis, & Nachmias, 2000). In contrast, those with avoidant attachment tendencies distance themselves during threat processing as a means of coping; supporting this proposal is evidence that during threat avoidantly attached individuals inhibit proximity-seeking behaviour and are less likely to activate attachment representations, except when functioning under additional cognitive load (Mikulincer et al., 2000). Despite the evidence that attachments can ameliorate stress responses, no research has directly addressed the extent to which attachments may impact retrieval of emotional memories. There is indirect evidence of a link between attachment and emotional memories from literature on posttraumatic stress disorder (PTSD), which is characterised by intrusive memories of a traumatic event. Secure attachments have been shown to mitigate PTSD symptoms after trauma (Dekel, Solomon, Ginzburg, & Neria, 2004). Further, providing attachment primes to participants with PTSD results in reductions in attentional bias to threats, suggesting that attachment representations can ameliorate one of the core dysfunctions in PTSD (Mikulincer et al., 2006). To test the potential impact of attachments on emotional memories directly, the current study presented participants with traumatic and neutral images, and two days later were directed to imagine an attachment or positive non-attachment experience immediately prior to recall and recognition tasks of the images that were previously presented. A positive non-attachment prime was employed as a comparator because of strong evidence that attachment priming impacts mood (Mikulincer & Shaver, 2007a, 2007b) and that current mood impacts retrieval of memory (Bower, 1981); accordingly, the effects of an attachment prime were compared to those of a positive non-attachment prime to isolate the specific effects of activating attachment representations rather than mood. Participants were then assessed two days later to index occurrence of intrusive memories of the presented stimuli. On the basis that attachment priming can enhance mood and positive appraisals and reduce stress responses, we hypothesized that participants receiving the attachment prime would have less recall of negative material, and also fewer subsequent intrusions than those in the control condition. Moreover, we predicted these effects would be stronger for participants with low avoidant attachment tendencies relative to those who are avoidantly attached. The ambivalent nature of anxious attachment, which motivates monitoring of attachment cues and simultaneously triggers anxiety about the availability of attachments, makes specific hypotheses more difficult; however, it would be expected that anxiously attached participants would have stronger recall and intrusions of the negative material than those non-anxiously attached participants. 2. Methods and methods 2.1. Participants Seventy-five first year psychology students (56 females, 19 males) of mean age 19.25 years (SD = 3.067) were recruited from the University of New South Wales and received course credit for their participation. Following previous study demonstrating moderate effect of attachment activation studies (Mikulincer et al., 2002), we estimated a required sample size of at least 30 per cell to achieve an effect size of 0.7 between the two conditions, providing power of 80% to detect a difference between conditions at the 5% significance level. Participants were randomly assigned to the attachment or control conditions. Sixty-nine participants completed the follow-up measure of intrusions, 35 in attachment condition and 34 in the control condition. 2.2. Materials 2.2.1. Stimuli Forty images were selected from the International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2005). Twenty were negatively-valenced and high in arousal (mean valence = 2.34, mean arousal = 6.15) and depicted images of mutilated bodies, blood, and death. Twenty were neutrally-valenced and low in arousal (Mean valence = 6.31, mean arousal = 3.99) and depicted images of landscapes, plants, and household items. 2.2.2. Experiences in Close Relationships (ECR) The ECR (Brennan, Clark, & Shaver, 1998) is a 36-item self-report questionnaire that measures adult attachment along the two dimensions of attachment anxiety and avoidance. The anxious and avoidant subscales of this measure have a high level of internal consistency, with coefficient alphas of 0.91 and 0.94, respectively (Wei, Russell, Mallinckrodt, & Vogel, 2007). The ECR asks participants to rate on a 7-point Likert-scale the extent to which they agree with the statements pertaining to how they feel in emotionally intimate relationships. The statements in this version of the ECR anchored responses to “the person who I consider close to me” (Bryant & Chan, 2015). 2.2.3. Depression Anxiety Stress Scale 21 (DASS21) The DASS21 (Lovibond & Lovibond, 1995) is a 21-item self-report questionnaire that indexes levels of depression, anxiety and 198
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stress by providing a score for each subscale. It asks participants to rate on a 4-point Likert scale the extent to which the 21 statements applied to them over the past week. 2.2.4. Vividness of Visual Imagery Questionnaire (VVIQ) The VVIQ (Marks, 1973) is a self-report measure that asks participants to create four different mental images (e.g. the front of a shop you often visit). Participants are asked to rate the vividness of four aspects of each image (e.g. the details of the door) on a 5point Likert scale. This measure indexes the vividness of an individual’s visual imagery. 2.2.5. Implicit Positive and Negative Affect Test (IPANAT) The IPANAT (Quirin, Kazen, & Kuhl, 2009) is a task that indirectly measures positive and negative affect. Participants are asked to rate on a 4-point Likert scale the extent to which six non-words (e.g. SUKOV) express six different emotions (happy, helpless, energetic, tense, cheerful, inhibited). The scores for positively valenced adjectives and negatively valenced adjectives indexes implicit positive and negative affect, respectively. The IPANAT has robust internal consistency (0.81) and test-retest reliability for one week intervals (0.72 for positive affect, 0.76 for negative affect). 2.2.6. Impact of Events-Revised (IES-R) The IES-R (Weiss & Marmar, 1997) 8-item intrusions subscale indexes an individual’s experience of intrusions of emotional memories. Participants were asked on a 5-point Likert scale the extent to which intrusions were experienced with regard to the negative images they were shown. The internal consistency of the intrusions subscale has been validated (coefficient alpha = 0.86) and it has good test-retest reliability (coefficient alpha = 0.87) (Sundin & Horowitz, 2002). 2.3. Procedure The project was approved by the UNSW School of Psychology Human Research Ethics Approval Panel. Following written informed consent, participants completed the ECR and the DASS21. Participants then viewed 20 neutral images and 20 negative images on computer display monitor. Each image was presented in random order for seven seconds and was preceded by a 2 s presentation of a centered white fixation cross on a black background. After each image, participants rated how distressing they found the image (1 = not at all, 10 = extremely). Then they were completed the VVIQ. Participants returned two days later and rated how distressed they felt at that moment (1 = not at all, 10 = extremely). Participants were then administered the attachment manipulation, with participants randomly assigned to the experimental or control group. In the experimental group, participants were primed with attachment security. Participants were instructed to think about an attachment figure for three minutes. Specifically, they were instructed to think of someone “who is currently very supportive to them in their lives, who they could depend on and turn to for help, and who is someone that made they feel safe and loved”. Participants were prompted every 30 s to continue picturing this attachment figure vividly in their minds, and to focus on how this person makes them feel supported and loved. Participants in the control condition were primed with a positive non-attachment stimulus in which they were instructed to imagine for three minutes that they had a million dollars. They were instructed to “think about this wealth in terms of what it could let you do, how it could fulfil your dreams and make your life easier.” Participants were prompted every 30 s to continue picturing this wealth vividly in their minds, and to focus on how this wealth would make them feel. Immediately after priming, participants were asked to rate how vividly they imagined the experience (1 = not at all, 10 = extremely). They also rated how distressed they felt at that moment (1 = not at all, 10 = extremely). Participants then completed a surprise free recall task of the images that had been presented two days prior. Participants were allowed five minutes to write a brief but specific description of each image they could recall. For each image they recalled, participants also rated how distressing they found the image at that moment of recall (1 = not at all, 10 = extremely). Then participants completed the IPANAT. Participants were then informed that they would be emailed a follow up questionnaire two days after this session. They were informed that this questionnaire was to be completed within 24 h of receiving the email, and participants received additional course credit for their online participation. Two days after the second experimental session, participants received an email prompting them to complete the intrusions subscale of the IES-R online. 3. Results 3.1. Data analysis Two median splits were conducted according to participants’ ECR avoidance and anxiety scores to identify individuals high and low in attachment avoidance and high and low in attachment anxiety, respectively. These high and low subgroups of avoidant and attachment anxiety were used in analyses of variance (ANOVAs) of the relevant dependent variables. 3.2. Participant characteristics Participant characteristics are presented in Table 1. Planned comparisons indicated there were no significant differences between the attachment and control groups on age, gender, DASS, VVIQ, or ECR scores. Participants in the attachment and control groups 199
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Table 1 Participant characteristics.
Age DASS Depression DASS Anxiety DASS Stress VVIQ ECR Anxious ECR Avoidant Prime Vividness
Attachment Prime
Positive Prime
19.32 (2.89) 3.53 (2.84) 4.50 (3.61) 6.03 (3.39) 7.92 (1.36 70.79 (8.74) 72.65 (4.96) 7.92 (1.36)
19.19 (3.28) 3.08 (2.35) 3.70 (3.27) 6.03 (4.61) 7.05 (1.78) 69.43 (9.35) 73.40 (7.39) 7.05 (1.78)
Note. Standard deviations appear in parentheses.
differed on their rating of how vividly they imagined the prime [t(72) = 2.35, p = 0.02; η = 0.07; 95% CI: 0.13–1.60]. Therefore, the prime vividness rating was entered as a covariate on subsequent analyses. 3.3. Priming distress ratings A 2 (Prime Condition) × 2 (Time) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of distress ratings revealed a significant Time × Prime Condition interaction effect [F(1, 71) = 5.49, p = 0.02, η = 0.07] and a significant three-way Prime Condition × Time × Avoidant Attachment Style interaction [F(1, 69) = 4.9, p = 0.03, η = 0.07] (see Table 2). To disentangle the three-way interaction, separate 2 (Prime Condition) × 2 (Time) repeated measures ANCOVAs were conducted for Low Avoidant and High Avoidant conditions. In terms of Low Avoidance, there was a significant interaction effect [F(1, 33) = 7.25, p = 0.01, η = 0.18]. Posthoc comparisons indicated that the decrease in distress following the prime was greater for participants in the Attachment condition than the Control condition [t(1, 34) = −2.81, p = 0.008; 95%CI: −0.2.03 to −0.32]. In terms of High Avoidance, there were no significant main or interaction effects. Comparable analyses were conducted in terms of the High and Low Anxious attachment conditions. A 2 (Prime Condition) × 2 (Time) × 2 (Anxious Attachment Style) repeated measures ANCOVA of distress ratings revealed a significant three-way Prime Condition × Time × Anxious Attachment Style interaction [F(1, 69) = 5.89, p = 0.02, η = 0.08]. Separate 2 (Prime Condition) × 2 (Time) repeated measures ANCOVAs were conducted for Low Anxious and High Anxious conditions. In terms of Low Anxious Attachment, there were no significant main or interaction effects. In terms of High Anxious Attachment, there was a significant interaction effect [F(1, 35) = 8.13, p = 0.007, η = 0.19]. Posthoc comparisons indicated that the decrease in distress following the prime was greater for participants in the Attachment condition than the Control condition [t(1, 36) = −3.00, p = 0.005; 95%CI: −0.1.9 to −0.37]. 3.4. Implicit affective response A 2 (Prime Condition) × 2 (Valence) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of IPANAT scores indicated a significant three-way interaction [F(1, 69) = 7.31, p = 0.009, η = 0.10]. Separate follow-up 2 (Prime Condition) × 2 (Valence) repeated measures ANCOVAs were conducted for Low Avoidant and High Avoidant conditions, respectively. In terms of Low Avoidant Attachment, there was a significant interaction effect [F(1, 33) = 4.20, p = 0.05, η = 0.11]. Posthoc comparisons indicated that low avoidant attachment participants who received the attachment prime reported more positive affect to the stimuli (reflected by higher scores on positive than negative stimuli) than those who received the control prime [t(1, 34) = −2.09, p = 0.04; 95%CI: −0.0.56 to −0.01]. No significant effects were observed for High Avoidant participants. With regard to anxious attachment, a 2 (Prime Condition) × 2 (Valence) × 2 (Anxious Attachment Style) repeated measures ANCOVA indicated no significant main or interaction effects. Table 2 Mean ratings of memory distress. High
Low
Attachment
Non-Attachment
Attachment
Non-Attachment
Anxious Attachment Pre-Prime Post-Prime
2.61 (1.65) 1.78 (1.35)
2.10 (1.37) 2.40 (1.46)
1.85 (1.22) 1.60 (0.83)
1.88 (1.65) 1.65 (1.32)
Avoidant Attachment Pre-Prime Post-Prime
1.94 (1.51) 1.72 (1.32)
2.05 (1.75) 1.86 (1.39)
2.45 (1.43) 1.65 (0.93)
1.94 (1.12) 2.31 (1.49)
Note. Standard deviations appear in parentheses.
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Table 3 Mean Implicit Positive and Negative Affect Test. High
Low
Attachment
Non-Attachment
Attachment
Non-Attachment
Anxious Attachment Positive Negative
2.11 (0.43) 2.06 (0.30)
1.93 (0.43) 1.89 (0.30)
2.03 (0.39) 1.99 (0.37)
1.88 (0.33) 1.89 (0.38 s)
Avoidant Attachment Positive Negative
2.01 (0.39) 2.14 (0.31)
1.90 (0.39) 1.81 (0.32)
2.11 (0.42) 1.92 (0.33)
1.91 (0.38) 2.00 (0.33)
Note. Standard deviations appear in parentheses.
3.5. Recall The mean numbers of negative and neutral images recalled by participants are presented in Table 3. A 2 (Prime Condition) × 2 (Valence) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of recall of neutral and negative images indicated a main effect for Valence [F(1, 69) = 18.98, p = 0.000, η = 0.22], indicating that negative images were better recalled than neutral images. Similarly, a 2 (Prime Condition) × 2 (Valence) × 2 (Anxious Attachment Style) repeated measures ANCOVA of recall of neutral and negative images indicated a main effect for Valence [F(1, 69) = 20.1, p = 0.000, η = 0.23], indicating that negative images were better recalled than neutral images. 3.6. Memory-related distress ratings Mean memory-related distress ratings are presented in Table 2. A 2 (Prime Condition) × 2 (Valence) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of affective ratings when retrieving the images indicated a significant main effect for Valence [F(1, 69) = 30.46, p = 0.000, η = 0.31], a significant Prime Condition × Avoidant Attachment Style interaction [F(1, 69) = 7.56, p = 0.008, η = 0.10], a significant Prime Condition × Valence interaction [F(1, 69) = 7.35, p = 0.008, η = 0.10], and a significant three-way interaction [F(1, 69) = 5.09, p = 0.03, η = 0.07]. Separate 2 (Prime Condition) × 2 (Valence) repeated measures ANCOVAs were conducted for Low Avoidant and High Avoidant conditions, respectively. In terms of Low Avoidant Attachment, there were significant main effects for Valence [F(1, 33) = 14.95, p = 0.000, η = 0.31], Prime Condition [F(1, 33) = 10.84, p = 0.002, η = 0.25], and a significant Prime Condition × Valence interaction effect [F(1, 33) = 16.28, p = 0.000, η = 0.33]. As expected, participants reported more distress when retrieving negative than neutral images. Low Avoidant attachment participants who received the attachment prime reported less distress when retrieving negative memories than those who received the control prime (t(1, 36) = 18.64, p = 0.001; 95%CI: −0.56 to −0.01). In terms of High Avoidant Attachment, there was a significant main effect for Valence [F(1, 35) = 16.46, p = 0.000, η = 0.32]. A 2 (Prime Condition) × 2 (Valence) × 2 (Anxious Attachment Style) repeated measures ANCOVA of affective ratings when retrieving the images indicated significant main effects for Valence [F(1, 69) = 34.36, p = 0.000, η = 0.33] and Anxious Attachment Style [F(1, 69) 15.65, p = 0.000, η = 0.19], and significant interaction effects for Prime Condition × Anxious Attachment Style interaction [F(1, 69) = 7.56, p = 0.008, η = 0.10], and Valence × Anxious Attachment Style [F(1, 69) = 6.27, p = 0.02, η = 0.08]. Although the Prime Condition × Attachment Style interaction was significant, posthoc comparisons indicated only marginally reduced distressed in participants who received the attachment prime relative to those who received the control prime (p = 0.07). Participants with high anxious attachment style reported more distress when retrieving both negative (p = 0.000) and neutral (p = 0.001) than low anxious attachment style participants. 3.7. Intrusions The mean numbers of intrusions are presented in Table 4. In terms of Avoidant Attachment, a 2 (Prime Condition) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of intrusions indicated a significant Prime Condition × Avoidant Attachment Style interaction effect [F(1, 61) = 5.18, p = 0.03, η = 0.08]. Low avoidant participants who received the attachment prime reported significantly fewer intrusive memories than those who received the control prime [p = 0.02]; no such difference was observed for high avoidant participants. In terms of anxious attachment style, a 2 (Prime Condition) × 2 (Anxious Attachment Style) repeated measures ANCOVA of intrusions indicated a significant main effect for Anxious Attachment Style [F(1, 61) = 9.45, p = 0.003, η = 0.13], indicating that high anxious attachment participants reported more intrusions than low anxious attachment participants. 4. Discussion The primary findings of this study was that participants with low avoidant attachment style who received the attachment prime prior to retrieval reported less distress at the time of retrieval, recalled the images as less distressing, and reported fewer subsequent 201
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Table 4 Mean Recall and Intrusions. High
Low
Attachment
Non-Attachment
Attachment
Non-Attachment
Anxious Attachment Negative Neutral Intrusions
6.33 (1.82) 3.06 (2.13) 13.67 (7.88)
5.15 (2.18) 2.00 (1.26) 14.06 (8.28)
5.45 (2.44) 1.50 (1.15) 7.16 (5.87)
5.06 (2.75) 2.18 (1.38) 9.06 (7.13)
Avoidant Attachment Negative Neutral Intrusions
5.83 (2.48) 1.94 (1.39) 11.41 (9.30)
5.71 (2.59) 2.19 (1.40) 9.52 (7.45)
5.90 (1.94) 2.50 (2.16) 8.65 (4.97)
4.31 (1.99) 1.94 (1.40) 14.50 (8.16)
Note. Standard deviations appear in parentheses.
intrusive memories than those who received the positive non-attachment prime. Interestingly, this pattern was not apparent for participants with high avoidant attachment style. The pattern of findings regarding intrusions may be understood in the context of memory reconsolidation. There is increasing evidence that when a memory is reactivated there is a window of time when this memory is in a labile state and is susceptible to influences that can impact how the memory is reconsolidated (Nader, Schafe, & LeDoux, 2000). For example, the presence of a stressor at the time of memory reconsolidation has been shown to increase subsequent intrusive memories of distressing material (Cheung, Garber, & Bryant, 2015). Moreover, decreasing glucocorticoid levels prior to reactivation reduces emotional memory recall in a long-lasting manner (Marin, Hupbach, Maheu, Nader, & Lupien, 2011). Limiting arousal with propranolol after reactivating a distressing memory results in less subsequent physiological reactivity when they the memory is retrieved one week later relative to placebo controls (Brunet et al., 2008). It is possible that attachment activation at the time of retrieval of the memory reduced arousal, which in turn led to weaker reconsolidation of the distressing nature of the memory, and this was reflected in fewer intrusions. This interpretation accords with evidence that attachment activation reduces distress and physiological arousal (Bryant & Chan, 2015; Mikulincer et al., 2006; Selcuk, Zayas, Gunaydin, Hazan, & Kross, 2012). Although the current study did not measure physiological arousal, the affect ratings and memory-related distress ratings provide indirect evidence for this explanation. The attachment group were significantly less distressed following the prime as indexed on both explicit and implicit measures, and also when retrieving the negative emotional memories compared to the control group. Taken together, it is possible that the attachment prime reduced distress during the critical period when the negative memories could be disrupted, and therefore resulted in fewer subsequent intrusive memories. We emphasize that we did not include a condition in which the encoded memories were not reactivated, and hence we cannot necessarily infer that reconsolidation occurred in this study. Moreover, it should be noted that there is considerable debate over the nature and robustness of memory reconsolidation (Schiller & Phelps, 2011), which is supported by numerous studies that do not support the reconsolidation hypothesis (Hardwicke, Taqi, & Shanks, 2016; van Schie, van Veen, Hendriks, van den Hout, & Engelhard, 2017). In this context we note that other possible explanations exist for the findings. For example, interference of the initial memory trace may have occurred as a result of competition caused by the presentation of the prime at the time of retrieval (McGeoch, 1942). Alternately, one recent model for intrusive memories posits that these memories implicate the visuospatial memory system, and hence rely on visuospatial resources (Holmes & Mathews, 2010). Supporting this is considerable evidence that individuals who complete a visuospatial task during encoding of negative information experience fewer subsequent intrusive memories (Holmes, James, Coode-Bate, & Deeprose, 2009; Holmes, James, Kilford, & Deeprose, 2010). Moreover, drawing in visuospatial resources during reconsolidation has also been shown to reduce later intrusions (James et al., 2015). As imagining the attachment figure was reportedly more vivid than the control image, it is possible that the attachment prime involved greater visual involvement than the control prime and this interfered with reconsolidation of the distressing memory, resulting in fewer intrusions. Notably, the effect of attachment prime on intrusions was only evident in individuals with low avoidant attachment tendencies. This is consistent with the memory-related distress ratings, which demonstrated that only low avoidant individuals felt less distressed when retrieving negative images following an attachment prime. Attachment theory posits that representations of attachment availability benefit people with secure attachment systems because attachment priming activates representations based on previous experiences of secure attachments (Mikulincer & Shaver, 2007a, 2007b). It is posited that people with avoidant attachment tendencies inhibit their attachment systems during stress because of previous experiences that attachment figures are not available at times of need (Mikulincer & Shaver, 2007a, 2007b); convergent evidence indicates that avoidantly attached people distance themselves from others during stress (Mikulincer & Florian, 1995; Mikulincer et al., 2002), and are less effective at regulating self-reported distress and distressing thoughts in response to attachment priming (Bryant, & Hutanamon, in press; Mikulincer et al., 2006; Selcuk et al., 2012). It is possible that participants in the current study with elevated avoidant attachment tendencies hypocactivated their attachment system in response to the prime, and accordingly did not benefit from the attachment prime. It has been shown that avoidantly attached individuals do activate attachment themes at a preconscious level (Mikulincer et al., 2000), reinforcing evidence of a dissociation between avoidantly attached individuals’ accessibility of attachment themes on implicit and explicit measures (Dozier & Kobak, 1992; Mikulincer, Florian, & Tolmacz, 1990). It is possible that avoidantly attached individuals can suppress 202
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activation of attachment representations when under conscious control but this inhibition is not apparent at preconscious stages of processing. Although the attachment prime resulted in relatively greater reductions in explicit and implicit indices of distress relative to the positive prime, the attachment prime did not result in differential intentional retrieval. Although there is evidence that intrusive memories are related to the strength of emotional memories (Ferree & Cahill, 2009), there is other evidence suggesting that intrusive and intentional recall function differently (Cheung, Chervonsky, Felmingham, & Bryant, 2013). Models of intrusive memories posit that intrusions reflect the emotional intensity of memory rather than semantic representation (Brewin, Gregory, Lipton, & Burgess, 2010), and so it is possible that attachment priming impacted on emotional reconsolidation of the memory rather than reconsolidation of the semantic memories. We note several limitations. First, participants were able to imagine the attachment prime more vividly than the control prime. Although we controlled for imagery vividness in our analyses, the effects may be attributed to more compelling experiences of the imagined figure. Second, the prime was administered immediately before the recall task in order to determine its effects on memory retrieval. Given that retrieval reactivated the memory, the prime was administered before rather than after memory reactivation. This contrasts with paradigms that has been used in memory reconsolidation research in which a disruptive treatment is administered after memory reactivation in order to impact reconsolidation (James et al., 2015). Third, we primed attachment security by asking individuals to imagine their attachment figures. It has been suggested that priming attachment security with imagery introduces possible variability in how participants can access these representations (Selcuk et al., 2012). Future studies could prime attachment with standardized stimuli (Mikulincer et al., 2002). 5. Conclusions These findings suggest that activating attachment proximity in securely attached individuals during memory reactivation can reduce the frequency of subsequent intrusive memories. Considering that secure attachment tendencies have been shown to be protective against PTSD (Dekel et al., 2004), it is possible that activating attachment representations following trauma in securely attached people may be particularly helpful in reducing intrusive memories of trauma. This possibility deserves further research because it has potential for prevention and intervention strategies in clinical populations affected by intrusive memories. Funding This project was funded by an Australian Research Council Laureate Fellowship grant (FL0992334) awarded to RAB. References Bower, G. (1981). Mood and memory. American Psychologist, 36, 129–148. Bowlby, J. (1969). Attachment and lossAttachmentVol. 1. New York: Basic Books. Brennan, K. A., Clark, C. L., & Shaver, P. R. (1998). Self-report measurement of adult attachment. In J. A. Simpson, & W. S. Rholes (Eds.). Attachment theory and close relationships (pp. 46–76). New York: Guilford. Brewin, C. R., Gregory, J. D., Lipton, M., & Burgess, N. (2010). Intrusive images in psychological disorders: Characteristics, neural mechanisms, and treatment implications. Psychological Review, 117(1), 210–232. Brunet, A., Orr, S. P., Tremblay, J., Robertson, K., Nader, K., & Pitman, R. K. (2008). Effect of post-retrieval propranolol on psychophysiologic responding during subsequent script-driven traumatic imagery in post-traumatic stress disorder. Journal of Psychiatric Research, 42(6), 503–506. Bryant, R. A. & Hutanamon, T. (in press). Activating attachments enhances heart rate variability. PLoS One. Bryant, R. A., & Chan, L. (2015). Thinking of attachments reduces noradrenergic stress response. Psychoneuroendocrinology, 60, 39–45. Bryant, R. A., McGrath, C., & Felmingham, K. L. (2013). The role of noradrenergic and glucocorticoid interaction in the development of intrusive memories. PLoS ONE, 8, e62675. Bryant, R. A., O'Donnell, M. L., Creamer, M., McFarlane, A. C., & Silove, D. (2011). Posttraumatic intrusive symptoms across psychiatric disorders. Journal of Psychiatric Research, 45(6), 842–847. Campbell, L., Simpson, J. A., Boldry, J., & Kashy, D. A. (2005). Perceptions of conflict and support in romantic relationships: The role of attachment anxiety. Journal of Personality and Social Psychology, 88, 510–533. Cheung, J., Chervonsky, L., Felmingham, K. L., & Bryant, R. A. (2013). The role of estrogen in intrusive memories. Neurobiology of Learning and Memory, 106, 87–94. http://dx.doi.org/10.1016/j.nlm.2013.07.005. Cheung, J., Garber, B., & Bryant, R. A. (2015). The role of stress during memory reactivation on intrusive memories. Neurobiology of Learning and Memory, 123, 28–34. http://dx.doi.org/10.1016/j.nlm.2015.04.004. Chou, C. Y., La Marca, R., Steptoe, A., & Brewin, C. R. (2014). Biological responses to trauma and the development of intrusive memories: an analog study with the trauma film paradigm. Biological Psychology, 103, 135–143. Dekel, R., Solomon, Z., Ginzburg, K., & Neria, Y. (2004). Long-term adjustment among Israeli war veterans: The role of attachment style. Anxiety Stress and Coping, 17(2), 141–152. Dozier, M., & Kobak, R. R. (1992). Psychophysiology in attachment interviews: converging evidence for deactivating strategies. Child Development, 63, 1473–1480. Ehlers, A., & Clark, D. M. (2000). A cognitive model of posttraumatic stress disorder. Behaviour Research & Therapy, 38(4), 319–345. Eisenberger, N. I., Master, S. L., Inagaki, T. K., Taylor, S. E., Shirinyan, D., Lieberman, M. D., & Naliboff, B. D. (2011). Attachment figures activate a safety signalrelated neural region and reduce pain experience. Proceedings of the National Academy of Sciences, 108(28), 11721–11726. Ferree, N. K., & Cahill, L. (2009). Post-event spontaneous intrusive recollections and strength of memory for emotional events in men and women. Consciousness and Cognition, 18(1), 126–134. Foa, E. B., Steketee, G., & Rothbaum, B. O. (1989). Behavioral/cognitive conceptualizations of post-traumatic stress disorder. Behavior Therapy, 20(2), 155–176. Hardwicke, T. E., Taqi, M., & Shanks, D. R. (2016). Postretrieval new learning does not reliably induce human memory updating via reconsolidation. Proceedings of the National Academy of Sciences, 113(19), 5206–5211. Holmes, E. A., James, E. L., Coode-Bate, T., & Deeprose, C. (2009). Can playing the computer game “Tetris” reduce the build-up of flashbacks for trauma? A proposal from cognitive science. PLoS ONE, 4(1), e4153. Holmes, E. A., James, E. L., Kilford, E. J., & Deeprose, C. (2010). Key steps in developing a cognitive vaccine against traumatic flashbacks: Visuospatial Tetris versus
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verbal Pub Quiz. PLoS One, 5(11), e13706. Holmes, E. A., & Mathews, A. (2010). Mental imagery in emotion and emotional disorders. Clinical Psychology Review, 30, 349–362. James, E. L., Bonsall, M. B., Hoppitt, L., Tunbridge, E. M., Geddes, J. R., Milton, A. L., & Holmes, E. A. (2015). Computer game play reduces intrusive memories of experimental trauma via reconsolidation-update mechanisms. Psychological Science, 26(8), 1201–1215. Lang, P. J., Bradley, M. M., & Cuthbert, B. N. (2005). International affective picture system (IAPS): Affective ratings of pictures and instruction manual. Gainesville, FL.: University of Florida. Lovibond, P. F., & Lovibond, S. H. (1995). The structure of negative emotional states: comparison of the Depression Anxiety Stress Scales (DASS) with the Beck Depression and Anxiety Inventories. Behaviour Research and Therapy, 33(3), 335–343. Marin, M. F., Hupbach, A., Maheu, F. S., Nader, K., & Lupien, S. J. (2011). Metyrapone administration reduces the strength of an emotional memory trace in a longlasting manner. Journal of Clinical Endocrinology and Metabolism, 96(8), E1221–E1227. Marks, D. F. (1973). Visual imagery differences in the recall of pictures. British Journal of Psychology, 64, 17–24. McGeoch, J. A. (1942). The psychology of human learning: An introduction. New York: Longmans, Green and Company. Mikulincer, M., Birnbaum, G., Woddis, D., & Nachmias, O. (2000). Stress and accessibility of proximity-related thoughts: Exploring the normative and intraindividual components of attachment theory. Journal of Personality and Social Psychology, 78(3), 509–523. Mikulincer, M., & Florian, V. (1995). Attachment style and information processing: Individual differences in curiosity and cognitive closure. Journal of Personality and Social Psychology, 72, 1217–1230. Mikulincer, M., Florian, V., & Tolmacz, R. (1990). Attachment styles and fear of personal death: A case study. Journal of Personality and Social Psychology, 58, 273–280. Mikulincer, M., Gillath, O., & Shaver, P. R. (2002). Activation of the attachment system in adulthood: Threat-related primes increase the accessibility of mental representations of attachment figures. Journal of Personality and Social Psychology, 83(4), 881–895. Mikulincer, M., & Shaver, P. R. (2007a). Attachment patterns in adulthood: structure, dynamics, and change. New York: Guilford Press. Mikulincer, M., & Shaver, P. R. (2007b). Boosting attachment security to promote mental health, prosocial values, and inter-group tolerance. Psychological Inquiry, 18(3), 139–156. Mikulincer, M., Shaver, P. R., Gillath, O., & Nitzberg, R. A. (2005). Attachment, caregiving, and altruism: Boosting attachment security increases compassion and helping. Journal of Personality and Social Psychology, 89(5), 817–839. Mikulincer, M., Shaver, P. R., & Horesh, N. (2006). Attachment bases of emotion regulation and posttraumatic adjustment. In J. A. Simpson, D. K. Snyder, & J. N. Hughes (Eds.). Emotion regulation in families: Pathways to dysfunction and health (pp. 77–99). Washington DC: American Psychological Association. Nader, K., Schafe, G. E., & LeDoux, J. E. (2000). The labile nature of consolidation theory. Nature Reviews Neuroscience, 1(3), 216–219. Nicholson, E. L., Bryant, R. A., & Felmingham, K. L. (2014). Interaction of noradrenaline and cortisol predicts negative intrusive memories in posttraumatic stress disorder. Neurobiology of Learning and Memory, 112, 204–211. Quirin, M., Kazen, M., & Kuhl, J. (2009). When nonsense sounds happy or helpless: The Implicit Positive and Negative Affect Test (IPANAT). Journal of Personality and Social Psychology, 97(3), 500–516. Roozendaal, B., Hahn, E. L., Nathan, S. V., de Quervain, D. J., & McGaugh, J. L. (2004). Glucocorticoid effects on memory retrieval require concurrent noradrenergic activity in the hippocampus and basolateral amygdala. Journal of Neuroscience, 24(37), 8161–8169. Roozendaal, B., Quirarte, G. L., & McGaugh, J. L. (2002). Glucocorticoids interact with the basolateral amygdala beta-adrenoceptor–cAMP/cAMP/PKA system in influencing memory consolidation. European Journal of Neuroscience, 15(3), 553–560. Schiller, D., & Phelps, E. A. (2011). Does reconsolidation occur in humans? Frontiers in Behavioral Neuroscience, 5, 24. Selcuk, E., Zayas, V., Gunaydin, G., Hazan, C., & Kross, E. (2012). Mental representations of attachment figures facilitate recovery following upsetting autobiographical memory recall. Journal of Personality and Social Psychology, 103(2), 362–378. Sundin, E. C., & Horowitz, M. J. (2002). Impact of event scale: Psychometric properties. British Journal of Psychiatry, 180, 205–209. van Schie, K., van Veen, S. C., Hendriks, Y. R., van den Hout, M. A., & Engelhard, I. M. (2017). Intervention strength does not differentially affect memory reconsolidation of strong memories. Neurobiology of Learning and Memory, 144, 174–185. Wei, M., Russell, D. W., Mallinckrodt, B., & Vogel, D. L. (2007). The Experiences in Close Relationships Scale (ECR)-Short Form: reliability, validity, and factor structure. Journal of Personality Assessment, 88, 187–204. Weiss, D. S., & Marmar, C. R. (1997). The impact of event scale–revised. In J. P. Wilson, & T. M. Keane (Eds.). Assessing psychological trauma and PTSD (pp. 399–411). New York: Guilford.
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Consciousness and Cognition journal homepage: www.elsevier.com/locate/concog
Activating attachment representations during memory retrieval modulates intrusive traumatic memories
MARK
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Richard A. Bryant , Iris Chan University of New South Wales, Australia
AR TI CLE I NF O
AB S T R A CT
Keywords: Attachment theory Memory Memory reconsolidation Intrusive memories
Although priming mental representations of attachment security reduces arousal, research has not examined the effect of attachment on the retrieval of emotionally arousing memories. This study investigated the effect of priming attachment security on the retrieval of emotional memories. Seventy-five participants viewed negative and neutral images, and two days later received either an attachment prime or a control prime immediately prior to free recall of the images. Two days later, participants reported how frequently they experienced intrusions of the negative images. The attachment group had less distress, and reported fewer subsequent intrusions than the control group. Attachment style moderated these effects such that individuals with an avoidant attachment style were not impacted by the attachment prime. These findings suggest that priming attachment security decreases distress during memory reactivation, and this may reduce subsequent intrusive memories.
1. Introduction Emotional memories, and particularly intrusive memories, are a common feature of many psychological disorders (Bryant, O'Donnell, Creamer, McFarlane, & Silove, 2011). Models of emotional memories converge on the critical role of arousal at the time of memory consolidation that contributes to subsequent distressing memories (Ehlers & Clark, 2000). Biological models propose that memory traces are strengthened by activation of glucocorticoid receptors in the basolateral nucleus of the amygdala facilitating noradrenergic signals (Roozendaal, Quirarte, & McGaugh, 2002). Supporting this proposition is much evidence that strength of emotional memories is moderated by glucocorticoid and noradrenergic activation at the time of consolidation (Roozendaal, Hahn, Nathan, de Quervain, & McGaugh, 2004). It is proposed that intrusive emotional memories are particularly strongly consolidated, and characterised by closely interconnected memory traces that result in involuntary recurrences of memories (Foa, Steketee, & Rothbaum, 1989). This is consistent with evidence that intrusive memories are predicted by glucocorticoid and noradrenergic response during the consolidation phase (Bryant, McGrath, & Felmingham, 2013; Chou, La Marca, Steptoe, & Brewin, 2014; Nicholson, Bryant, & Felmingham, 2014). There is distinct research suggesting that proximity to attachment figures alleviates stress responses (Eisenberger et al., 2011; Mikulincer, Shaver, Gillath, & Nitzberg, 2005). This evidence reflects a fundamental tenet of attachment theory that during stress we seek social support (Bowlby, 1969). This theory posits that one internalizes mental representations of attachment figures, and these representations similarly can provide a sense of security during stress. Experimentally activating attachment figures results in a range of psychological benefits, including reductions in bias to threat (Mikulincer, Shaver, & Horesh, 2006), pain-related neural activation (Eisenberger et al., 2011), noradrenergic response to threat (Bryant & Chan, 2015), and also enhancement of heart rate variability
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Corresponding author at: School of Psychology, University of New South Wales, NSW 2052, Australia. E-mail address: [email protected] (R.A. Bryant).
http://dx.doi.org/10.1016/j.concog.2017.08.010 Received 24 July 2016; Received in revised form 12 August 2017; Accepted 22 August 2017 1053-8100/ © 2017 Elsevier Inc. All rights reserved.
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(Bryant & Hutanamon, in press). The extent to which attachments can benefit people depends, however, on individual differences in attachment security. Attachment theories posit that prior experiences of unreliable relationships can lead to deficiencies in the capacity to benefit from attachment figures because they do not activate representations of security (Mikulincer & Shaver, 2007a, 2007b). It is proposed that prior experiences of insecure attachments lead people to evolve insecure attachment systems, which may be manifest in anxious or avoidant attachment tendencies. People with anxious attachments worry about abandonment and seek support from others, yet nonetheless perceive they are not receiving sufficient support (Campbell, Simpson, Boldry, & Kashy, 2005). Hence, they monitor attachment proximity closely, reflected in faster naming of attachment figures lexical decision tasks (Mikulincer, Gillath, & Shaver, 2002), and greater recognition of proximity-related words (Mikulincer, Birnbaum, Woddis, & Nachmias, 2000). In contrast, those with avoidant attachment tendencies distance themselves during threat processing as a means of coping; supporting this proposal is evidence that during threat avoidantly attached individuals inhibit proximity-seeking behaviour and are less likely to activate attachment representations, except when functioning under additional cognitive load (Mikulincer et al., 2000). Despite the evidence that attachments can ameliorate stress responses, no research has directly addressed the extent to which attachments may impact retrieval of emotional memories. There is indirect evidence of a link between attachment and emotional memories from literature on posttraumatic stress disorder (PTSD), which is characterised by intrusive memories of a traumatic event. Secure attachments have been shown to mitigate PTSD symptoms after trauma (Dekel, Solomon, Ginzburg, & Neria, 2004). Further, providing attachment primes to participants with PTSD results in reductions in attentional bias to threats, suggesting that attachment representations can ameliorate one of the core dysfunctions in PTSD (Mikulincer et al., 2006). To test the potential impact of attachments on emotional memories directly, the current study presented participants with traumatic and neutral images, and two days later were directed to imagine an attachment or positive non-attachment experience immediately prior to recall and recognition tasks of the images that were previously presented. A positive non-attachment prime was employed as a comparator because of strong evidence that attachment priming impacts mood (Mikulincer & Shaver, 2007a, 2007b) and that current mood impacts retrieval of memory (Bower, 1981); accordingly, the effects of an attachment prime were compared to those of a positive non-attachment prime to isolate the specific effects of activating attachment representations rather than mood. Participants were then assessed two days later to index occurrence of intrusive memories of the presented stimuli. On the basis that attachment priming can enhance mood and positive appraisals and reduce stress responses, we hypothesized that participants receiving the attachment prime would have less recall of negative material, and also fewer subsequent intrusions than those in the control condition. Moreover, we predicted these effects would be stronger for participants with low avoidant attachment tendencies relative to those who are avoidantly attached. The ambivalent nature of anxious attachment, which motivates monitoring of attachment cues and simultaneously triggers anxiety about the availability of attachments, makes specific hypotheses more difficult; however, it would be expected that anxiously attached participants would have stronger recall and intrusions of the negative material than those non-anxiously attached participants. 2. Methods and methods 2.1. Participants Seventy-five first year psychology students (56 females, 19 males) of mean age 19.25 years (SD = 3.067) were recruited from the University of New South Wales and received course credit for their participation. Following previous study demonstrating moderate effect of attachment activation studies (Mikulincer et al., 2002), we estimated a required sample size of at least 30 per cell to achieve an effect size of 0.7 between the two conditions, providing power of 80% to detect a difference between conditions at the 5% significance level. Participants were randomly assigned to the attachment or control conditions. Sixty-nine participants completed the follow-up measure of intrusions, 35 in attachment condition and 34 in the control condition. 2.2. Materials 2.2.1. Stimuli Forty images were selected from the International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2005). Twenty were negatively-valenced and high in arousal (mean valence = 2.34, mean arousal = 6.15) and depicted images of mutilated bodies, blood, and death. Twenty were neutrally-valenced and low in arousal (Mean valence = 6.31, mean arousal = 3.99) and depicted images of landscapes, plants, and household items. 2.2.2. Experiences in Close Relationships (ECR) The ECR (Brennan, Clark, & Shaver, 1998) is a 36-item self-report questionnaire that measures adult attachment along the two dimensions of attachment anxiety and avoidance. The anxious and avoidant subscales of this measure have a high level of internal consistency, with coefficient alphas of 0.91 and 0.94, respectively (Wei, Russell, Mallinckrodt, & Vogel, 2007). The ECR asks participants to rate on a 7-point Likert-scale the extent to which they agree with the statements pertaining to how they feel in emotionally intimate relationships. The statements in this version of the ECR anchored responses to “the person who I consider close to me” (Bryant & Chan, 2015). 2.2.3. Depression Anxiety Stress Scale 21 (DASS21) The DASS21 (Lovibond & Lovibond, 1995) is a 21-item self-report questionnaire that indexes levels of depression, anxiety and 198
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stress by providing a score for each subscale. It asks participants to rate on a 4-point Likert scale the extent to which the 21 statements applied to them over the past week. 2.2.4. Vividness of Visual Imagery Questionnaire (VVIQ) The VVIQ (Marks, 1973) is a self-report measure that asks participants to create four different mental images (e.g. the front of a shop you often visit). Participants are asked to rate the vividness of four aspects of each image (e.g. the details of the door) on a 5point Likert scale. This measure indexes the vividness of an individual’s visual imagery. 2.2.5. Implicit Positive and Negative Affect Test (IPANAT) The IPANAT (Quirin, Kazen, & Kuhl, 2009) is a task that indirectly measures positive and negative affect. Participants are asked to rate on a 4-point Likert scale the extent to which six non-words (e.g. SUKOV) express six different emotions (happy, helpless, energetic, tense, cheerful, inhibited). The scores for positively valenced adjectives and negatively valenced adjectives indexes implicit positive and negative affect, respectively. The IPANAT has robust internal consistency (0.81) and test-retest reliability for one week intervals (0.72 for positive affect, 0.76 for negative affect). 2.2.6. Impact of Events-Revised (IES-R) The IES-R (Weiss & Marmar, 1997) 8-item intrusions subscale indexes an individual’s experience of intrusions of emotional memories. Participants were asked on a 5-point Likert scale the extent to which intrusions were experienced with regard to the negative images they were shown. The internal consistency of the intrusions subscale has been validated (coefficient alpha = 0.86) and it has good test-retest reliability (coefficient alpha = 0.87) (Sundin & Horowitz, 2002). 2.3. Procedure The project was approved by the UNSW School of Psychology Human Research Ethics Approval Panel. Following written informed consent, participants completed the ECR and the DASS21. Participants then viewed 20 neutral images and 20 negative images on computer display monitor. Each image was presented in random order for seven seconds and was preceded by a 2 s presentation of a centered white fixation cross on a black background. After each image, participants rated how distressing they found the image (1 = not at all, 10 = extremely). Then they were completed the VVIQ. Participants returned two days later and rated how distressed they felt at that moment (1 = not at all, 10 = extremely). Participants were then administered the attachment manipulation, with participants randomly assigned to the experimental or control group. In the experimental group, participants were primed with attachment security. Participants were instructed to think about an attachment figure for three minutes. Specifically, they were instructed to think of someone “who is currently very supportive to them in their lives, who they could depend on and turn to for help, and who is someone that made they feel safe and loved”. Participants were prompted every 30 s to continue picturing this attachment figure vividly in their minds, and to focus on how this person makes them feel supported and loved. Participants in the control condition were primed with a positive non-attachment stimulus in which they were instructed to imagine for three minutes that they had a million dollars. They were instructed to “think about this wealth in terms of what it could let you do, how it could fulfil your dreams and make your life easier.” Participants were prompted every 30 s to continue picturing this wealth vividly in their minds, and to focus on how this wealth would make them feel. Immediately after priming, participants were asked to rate how vividly they imagined the experience (1 = not at all, 10 = extremely). They also rated how distressed they felt at that moment (1 = not at all, 10 = extremely). Participants then completed a surprise free recall task of the images that had been presented two days prior. Participants were allowed five minutes to write a brief but specific description of each image they could recall. For each image they recalled, participants also rated how distressing they found the image at that moment of recall (1 = not at all, 10 = extremely). Then participants completed the IPANAT. Participants were then informed that they would be emailed a follow up questionnaire two days after this session. They were informed that this questionnaire was to be completed within 24 h of receiving the email, and participants received additional course credit for their online participation. Two days after the second experimental session, participants received an email prompting them to complete the intrusions subscale of the IES-R online. 3. Results 3.1. Data analysis Two median splits were conducted according to participants’ ECR avoidance and anxiety scores to identify individuals high and low in attachment avoidance and high and low in attachment anxiety, respectively. These high and low subgroups of avoidant and attachment anxiety were used in analyses of variance (ANOVAs) of the relevant dependent variables. 3.2. Participant characteristics Participant characteristics are presented in Table 1. Planned comparisons indicated there were no significant differences between the attachment and control groups on age, gender, DASS, VVIQ, or ECR scores. Participants in the attachment and control groups 199
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Table 1 Participant characteristics.
Age DASS Depression DASS Anxiety DASS Stress VVIQ ECR Anxious ECR Avoidant Prime Vividness
Attachment Prime
Positive Prime
19.32 (2.89) 3.53 (2.84) 4.50 (3.61) 6.03 (3.39) 7.92 (1.36 70.79 (8.74) 72.65 (4.96) 7.92 (1.36)
19.19 (3.28) 3.08 (2.35) 3.70 (3.27) 6.03 (4.61) 7.05 (1.78) 69.43 (9.35) 73.40 (7.39) 7.05 (1.78)
Note. Standard deviations appear in parentheses.
differed on their rating of how vividly they imagined the prime [t(72) = 2.35, p = 0.02; η = 0.07; 95% CI: 0.13–1.60]. Therefore, the prime vividness rating was entered as a covariate on subsequent analyses. 3.3. Priming distress ratings A 2 (Prime Condition) × 2 (Time) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of distress ratings revealed a significant Time × Prime Condition interaction effect [F(1, 71) = 5.49, p = 0.02, η = 0.07] and a significant three-way Prime Condition × Time × Avoidant Attachment Style interaction [F(1, 69) = 4.9, p = 0.03, η = 0.07] (see Table 2). To disentangle the three-way interaction, separate 2 (Prime Condition) × 2 (Time) repeated measures ANCOVAs were conducted for Low Avoidant and High Avoidant conditions. In terms of Low Avoidance, there was a significant interaction effect [F(1, 33) = 7.25, p = 0.01, η = 0.18]. Posthoc comparisons indicated that the decrease in distress following the prime was greater for participants in the Attachment condition than the Control condition [t(1, 34) = −2.81, p = 0.008; 95%CI: −0.2.03 to −0.32]. In terms of High Avoidance, there were no significant main or interaction effects. Comparable analyses were conducted in terms of the High and Low Anxious attachment conditions. A 2 (Prime Condition) × 2 (Time) × 2 (Anxious Attachment Style) repeated measures ANCOVA of distress ratings revealed a significant three-way Prime Condition × Time × Anxious Attachment Style interaction [F(1, 69) = 5.89, p = 0.02, η = 0.08]. Separate 2 (Prime Condition) × 2 (Time) repeated measures ANCOVAs were conducted for Low Anxious and High Anxious conditions. In terms of Low Anxious Attachment, there were no significant main or interaction effects. In terms of High Anxious Attachment, there was a significant interaction effect [F(1, 35) = 8.13, p = 0.007, η = 0.19]. Posthoc comparisons indicated that the decrease in distress following the prime was greater for participants in the Attachment condition than the Control condition [t(1, 36) = −3.00, p = 0.005; 95%CI: −0.1.9 to −0.37]. 3.4. Implicit affective response A 2 (Prime Condition) × 2 (Valence) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of IPANAT scores indicated a significant three-way interaction [F(1, 69) = 7.31, p = 0.009, η = 0.10]. Separate follow-up 2 (Prime Condition) × 2 (Valence) repeated measures ANCOVAs were conducted for Low Avoidant and High Avoidant conditions, respectively. In terms of Low Avoidant Attachment, there was a significant interaction effect [F(1, 33) = 4.20, p = 0.05, η = 0.11]. Posthoc comparisons indicated that low avoidant attachment participants who received the attachment prime reported more positive affect to the stimuli (reflected by higher scores on positive than negative stimuli) than those who received the control prime [t(1, 34) = −2.09, p = 0.04; 95%CI: −0.0.56 to −0.01]. No significant effects were observed for High Avoidant participants. With regard to anxious attachment, a 2 (Prime Condition) × 2 (Valence) × 2 (Anxious Attachment Style) repeated measures ANCOVA indicated no significant main or interaction effects. Table 2 Mean ratings of memory distress. High
Low
Attachment
Non-Attachment
Attachment
Non-Attachment
Anxious Attachment Pre-Prime Post-Prime
2.61 (1.65) 1.78 (1.35)
2.10 (1.37) 2.40 (1.46)
1.85 (1.22) 1.60 (0.83)
1.88 (1.65) 1.65 (1.32)
Avoidant Attachment Pre-Prime Post-Prime
1.94 (1.51) 1.72 (1.32)
2.05 (1.75) 1.86 (1.39)
2.45 (1.43) 1.65 (0.93)
1.94 (1.12) 2.31 (1.49)
Note. Standard deviations appear in parentheses.
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Table 3 Mean Implicit Positive and Negative Affect Test. High
Low
Attachment
Non-Attachment
Attachment
Non-Attachment
Anxious Attachment Positive Negative
2.11 (0.43) 2.06 (0.30)
1.93 (0.43) 1.89 (0.30)
2.03 (0.39) 1.99 (0.37)
1.88 (0.33) 1.89 (0.38 s)
Avoidant Attachment Positive Negative
2.01 (0.39) 2.14 (0.31)
1.90 (0.39) 1.81 (0.32)
2.11 (0.42) 1.92 (0.33)
1.91 (0.38) 2.00 (0.33)
Note. Standard deviations appear in parentheses.
3.5. Recall The mean numbers of negative and neutral images recalled by participants are presented in Table 3. A 2 (Prime Condition) × 2 (Valence) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of recall of neutral and negative images indicated a main effect for Valence [F(1, 69) = 18.98, p = 0.000, η = 0.22], indicating that negative images were better recalled than neutral images. Similarly, a 2 (Prime Condition) × 2 (Valence) × 2 (Anxious Attachment Style) repeated measures ANCOVA of recall of neutral and negative images indicated a main effect for Valence [F(1, 69) = 20.1, p = 0.000, η = 0.23], indicating that negative images were better recalled than neutral images. 3.6. Memory-related distress ratings Mean memory-related distress ratings are presented in Table 2. A 2 (Prime Condition) × 2 (Valence) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of affective ratings when retrieving the images indicated a significant main effect for Valence [F(1, 69) = 30.46, p = 0.000, η = 0.31], a significant Prime Condition × Avoidant Attachment Style interaction [F(1, 69) = 7.56, p = 0.008, η = 0.10], a significant Prime Condition × Valence interaction [F(1, 69) = 7.35, p = 0.008, η = 0.10], and a significant three-way interaction [F(1, 69) = 5.09, p = 0.03, η = 0.07]. Separate 2 (Prime Condition) × 2 (Valence) repeated measures ANCOVAs were conducted for Low Avoidant and High Avoidant conditions, respectively. In terms of Low Avoidant Attachment, there were significant main effects for Valence [F(1, 33) = 14.95, p = 0.000, η = 0.31], Prime Condition [F(1, 33) = 10.84, p = 0.002, η = 0.25], and a significant Prime Condition × Valence interaction effect [F(1, 33) = 16.28, p = 0.000, η = 0.33]. As expected, participants reported more distress when retrieving negative than neutral images. Low Avoidant attachment participants who received the attachment prime reported less distress when retrieving negative memories than those who received the control prime (t(1, 36) = 18.64, p = 0.001; 95%CI: −0.56 to −0.01). In terms of High Avoidant Attachment, there was a significant main effect for Valence [F(1, 35) = 16.46, p = 0.000, η = 0.32]. A 2 (Prime Condition) × 2 (Valence) × 2 (Anxious Attachment Style) repeated measures ANCOVA of affective ratings when retrieving the images indicated significant main effects for Valence [F(1, 69) = 34.36, p = 0.000, η = 0.33] and Anxious Attachment Style [F(1, 69) 15.65, p = 0.000, η = 0.19], and significant interaction effects for Prime Condition × Anxious Attachment Style interaction [F(1, 69) = 7.56, p = 0.008, η = 0.10], and Valence × Anxious Attachment Style [F(1, 69) = 6.27, p = 0.02, η = 0.08]. Although the Prime Condition × Attachment Style interaction was significant, posthoc comparisons indicated only marginally reduced distressed in participants who received the attachment prime relative to those who received the control prime (p = 0.07). Participants with high anxious attachment style reported more distress when retrieving both negative (p = 0.000) and neutral (p = 0.001) than low anxious attachment style participants. 3.7. Intrusions The mean numbers of intrusions are presented in Table 4. In terms of Avoidant Attachment, a 2 (Prime Condition) × 2 (Avoidant Attachment Style) repeated measures ANCOVA of intrusions indicated a significant Prime Condition × Avoidant Attachment Style interaction effect [F(1, 61) = 5.18, p = 0.03, η = 0.08]. Low avoidant participants who received the attachment prime reported significantly fewer intrusive memories than those who received the control prime [p = 0.02]; no such difference was observed for high avoidant participants. In terms of anxious attachment style, a 2 (Prime Condition) × 2 (Anxious Attachment Style) repeated measures ANCOVA of intrusions indicated a significant main effect for Anxious Attachment Style [F(1, 61) = 9.45, p = 0.003, η = 0.13], indicating that high anxious attachment participants reported more intrusions than low anxious attachment participants. 4. Discussion The primary findings of this study was that participants with low avoidant attachment style who received the attachment prime prior to retrieval reported less distress at the time of retrieval, recalled the images as less distressing, and reported fewer subsequent 201
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Table 4 Mean Recall and Intrusions. High
Low
Attachment
Non-Attachment
Attachment
Non-Attachment
Anxious Attachment Negative Neutral Intrusions
6.33 (1.82) 3.06 (2.13) 13.67 (7.88)
5.15 (2.18) 2.00 (1.26) 14.06 (8.28)
5.45 (2.44) 1.50 (1.15) 7.16 (5.87)
5.06 (2.75) 2.18 (1.38) 9.06 (7.13)
Avoidant Attachment Negative Neutral Intrusions
5.83 (2.48) 1.94 (1.39) 11.41 (9.30)
5.71 (2.59) 2.19 (1.40) 9.52 (7.45)
5.90 (1.94) 2.50 (2.16) 8.65 (4.97)
4.31 (1.99) 1.94 (1.40) 14.50 (8.16)
Note. Standard deviations appear in parentheses.
intrusive memories than those who received the positive non-attachment prime. Interestingly, this pattern was not apparent for participants with high avoidant attachment style. The pattern of findings regarding intrusions may be understood in the context of memory reconsolidation. There is increasing evidence that when a memory is reactivated there is a window of time when this memory is in a labile state and is susceptible to influences that can impact how the memory is reconsolidated (Nader, Schafe, & LeDoux, 2000). For example, the presence of a stressor at the time of memory reconsolidation has been shown to increase subsequent intrusive memories of distressing material (Cheung, Garber, & Bryant, 2015). Moreover, decreasing glucocorticoid levels prior to reactivation reduces emotional memory recall in a long-lasting manner (Marin, Hupbach, Maheu, Nader, & Lupien, 2011). Limiting arousal with propranolol after reactivating a distressing memory results in less subsequent physiological reactivity when they the memory is retrieved one week later relative to placebo controls (Brunet et al., 2008). It is possible that attachment activation at the time of retrieval of the memory reduced arousal, which in turn led to weaker reconsolidation of the distressing nature of the memory, and this was reflected in fewer intrusions. This interpretation accords with evidence that attachment activation reduces distress and physiological arousal (Bryant & Chan, 2015; Mikulincer et al., 2006; Selcuk, Zayas, Gunaydin, Hazan, & Kross, 2012). Although the current study did not measure physiological arousal, the affect ratings and memory-related distress ratings provide indirect evidence for this explanation. The attachment group were significantly less distressed following the prime as indexed on both explicit and implicit measures, and also when retrieving the negative emotional memories compared to the control group. Taken together, it is possible that the attachment prime reduced distress during the critical period when the negative memories could be disrupted, and therefore resulted in fewer subsequent intrusive memories. We emphasize that we did not include a condition in which the encoded memories were not reactivated, and hence we cannot necessarily infer that reconsolidation occurred in this study. Moreover, it should be noted that there is considerable debate over the nature and robustness of memory reconsolidation (Schiller & Phelps, 2011), which is supported by numerous studies that do not support the reconsolidation hypothesis (Hardwicke, Taqi, & Shanks, 2016; van Schie, van Veen, Hendriks, van den Hout, & Engelhard, 2017). In this context we note that other possible explanations exist for the findings. For example, interference of the initial memory trace may have occurred as a result of competition caused by the presentation of the prime at the time of retrieval (McGeoch, 1942). Alternately, one recent model for intrusive memories posits that these memories implicate the visuospatial memory system, and hence rely on visuospatial resources (Holmes & Mathews, 2010). Supporting this is considerable evidence that individuals who complete a visuospatial task during encoding of negative information experience fewer subsequent intrusive memories (Holmes, James, Coode-Bate, & Deeprose, 2009; Holmes, James, Kilford, & Deeprose, 2010). Moreover, drawing in visuospatial resources during reconsolidation has also been shown to reduce later intrusions (James et al., 2015). As imagining the attachment figure was reportedly more vivid than the control image, it is possible that the attachment prime involved greater visual involvement than the control prime and this interfered with reconsolidation of the distressing memory, resulting in fewer intrusions. Notably, the effect of attachment prime on intrusions was only evident in individuals with low avoidant attachment tendencies. This is consistent with the memory-related distress ratings, which demonstrated that only low avoidant individuals felt less distressed when retrieving negative images following an attachment prime. Attachment theory posits that representations of attachment availability benefit people with secure attachment systems because attachment priming activates representations based on previous experiences of secure attachments (Mikulincer & Shaver, 2007a, 2007b). It is posited that people with avoidant attachment tendencies inhibit their attachment systems during stress because of previous experiences that attachment figures are not available at times of need (Mikulincer & Shaver, 2007a, 2007b); convergent evidence indicates that avoidantly attached people distance themselves from others during stress (Mikulincer & Florian, 1995; Mikulincer et al., 2002), and are less effective at regulating self-reported distress and distressing thoughts in response to attachment priming (Bryant, & Hutanamon, in press; Mikulincer et al., 2006; Selcuk et al., 2012). It is possible that participants in the current study with elevated avoidant attachment tendencies hypocactivated their attachment system in response to the prime, and accordingly did not benefit from the attachment prime. It has been shown that avoidantly attached individuals do activate attachment themes at a preconscious level (Mikulincer et al., 2000), reinforcing evidence of a dissociation between avoidantly attached individuals’ accessibility of attachment themes on implicit and explicit measures (Dozier & Kobak, 1992; Mikulincer, Florian, & Tolmacz, 1990). It is possible that avoidantly attached individuals can suppress 202
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activation of attachment representations when under conscious control but this inhibition is not apparent at preconscious stages of processing. Although the attachment prime resulted in relatively greater reductions in explicit and implicit indices of distress relative to the positive prime, the attachment prime did not result in differential intentional retrieval. Although there is evidence that intrusive memories are related to the strength of emotional memories (Ferree & Cahill, 2009), there is other evidence suggesting that intrusive and intentional recall function differently (Cheung, Chervonsky, Felmingham, & Bryant, 2013). Models of intrusive memories posit that intrusions reflect the emotional intensity of memory rather than semantic representation (Brewin, Gregory, Lipton, & Burgess, 2010), and so it is possible that attachment priming impacted on emotional reconsolidation of the memory rather than reconsolidation of the semantic memories. We note several limitations. First, participants were able to imagine the attachment prime more vividly than the control prime. Although we controlled for imagery vividness in our analyses, the effects may be attributed to more compelling experiences of the imagined figure. Second, the prime was administered immediately before the recall task in order to determine its effects on memory retrieval. Given that retrieval reactivated the memory, the prime was administered before rather than after memory reactivation. This contrasts with paradigms that has been used in memory reconsolidation research in which a disruptive treatment is administered after memory reactivation in order to impact reconsolidation (James et al., 2015). Third, we primed attachment security by asking individuals to imagine their attachment figures. It has been suggested that priming attachment security with imagery introduces possible variability in how participants can access these representations (Selcuk et al., 2012). Future studies could prime attachment with standardized stimuli (Mikulincer et al., 2002). 5. Conclusions These findings suggest that activating attachment proximity in securely attached individuals during memory reactivation can reduce the frequency of subsequent intrusive memories. Considering that secure attachment tendencies have been shown to be protective against PTSD (Dekel et al., 2004), it is possible that activating attachment representations following trauma in securely attached people may be particularly helpful in reducing intrusive memories of trauma. This possibility deserves further research because it has potential for prevention and intervention strategies in clinical populations affected by intrusive memories. Funding This project was funded by an Australian Research Council Laureate Fellowship grant (FL0992334) awarded to RAB. References Bower, G. (1981). Mood and memory. American Psychologist, 36, 129–148. Bowlby, J. (1969). Attachment and lossAttachmentVol. 1. 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