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Cognition and Emotion Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/pcem20
Attentional bias towards emotional facial expressions in survivors of dating violence a
Jeong-Ha Lee & Jang-Han Lee
a
a
Department of Psychology, Chung-Ang University, Seoul, Korea Published online: 17 Dec 2013.
Click for updates To cite this article: Jeong-Ha Lee & Jang-Han Lee (2014) Attentional bias towards emotional facial expressions in survivors of dating violence, Cognition and Emotion, 28:6, 1127-1136, DOI: 10.1080/02699931.2013.867834 To link to this article: http://dx.doi.org/10.1080/02699931.2013.867834
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COGNITION AND EMOTION, 2014 Vol. 28, No. 6, 1127–1136, http://dx.doi.org/10.1080/02699931.2013.867834
BRIEF REPORT Attentional bias towards emotional facial expressions in survivors of dating violence Downloaded by [Eindhoven Technical University] at 15:40 21 November 2014
Jeong-Ha Lee and Jang-Han Lee Department of Psychology, Chung-Ang University, Seoul, Korea
This study identified components of attentional bias (e.g. attentional vigilance, attentional avoidance and difficulty with disengagement) that are critical characteristics of survivors of dating violence (DV). Eye movements were recorded to obtain accurate and continuous information regarding attention. DV survivors with high post-traumatic stress symptoms (DV-High PTSS group; n = 20) and low post-traumatic stress symptoms (DV-Low PTSS group; n = 22) and participants who had never experienced DV (NDV group; n = 21) were shown screens displaying emotional (angry, fearful and happy) faces paired with neutral faces and negative (angry and fearful) faces paired with happy faces for 10 s. The results indicate that the DV-High PTSS group spent longer dwelling on angry faces over time compared with the DV-Low PTSS and NDV groups. This result implies that the DV-High PTSS group focused on specific trauma-related stimuli but does not provide evidence of an attentional bias towards threatening stimuli in general. Keywords: Dating violence survivors; Attentional bias; Emotional faces; Eye-tracking.
Dating violence (DV) refers to physical, psychological and/or sexual aggression in a dating relationship and is a serious social problem in terms of its negative sequela and high prevalence (Straus, 2004). Several studies have suggested that DV victims are likely to suffer from depression, anxiety and posttraumatic stress disorder (PTSD; Campbell, 2002). In addition, cognitive models postulate that an
attentional bias towards negative stimuli is a crucial feature that may maintain and even induce PTSD symptoms, such as flashbacks, concentration deficits and avoidance behaviours (see Ehlers & Clark, 2000). Early studies that adopted the emotional Stroop test to investigate attentional bias demonstrated that individuals with PTSD are more likely to exhibit delayed response times to
Correspondence should be addressed to: Jang-Han Lee, Department of Psychology, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Korea. Email: [email protected] This work was supported by the National Research Foundation of Korea funded by the Korea government (MEST) [grant number 2011-0003012]. © 2013 Taylor & Francis
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threatening stimuli than those without PTSD (Beck, Freeman, Shipherd, Hamblen, & Lackner, 2001; Bryant & Harvey, 1995). Recent studies have suggested that attentional bias comprises distinguishable components such as immediate attentional vigilance (or facilitated attention), difficulty with disengagement (or attentional interference) and attentional avoidance (Cisler & Olatunji, 2010). Many studies have investigated threat-related attentional bias in different subtypes of anxiety disorders. However, there are disagreements regarding the components of attentional bias underlying anxiety disorders (Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, & van IJzendoorn, 2007). For more detailed and precise information regarding the cognitive mechanisms underlying PTSD and thus for more appropriate treatment, it is important to distinguish between these components of attentional bias. From this perspective, two studies have identified components of attentional bias towards threatening stimuli that are present in PTSD patients (Pineles, Shipherd, Mostoufi, Abramovitz, & Yovel, 2009). These studies consistently indicate that the only issue encountered by individuals with clear PTSD symptoms is disengaging from such stimuli. However, these findings may be inconclusive because they were based on reaction time tasks such as a visual search task, which are unduly influenced by extraneous factors such as mood and motor speed. Eye-tracking experiments have been considered direct and appropriate methods for measuring attentional processing. However, few eye-tracking studies have considered PTSD. Bryant and Harvey (1995) focused on the initial direction of the participant’s gaze (first fixation) as an index of immediate attentional vigilance and observed that the participants with PTSD were more likely to be vigilant about threatening stimuli than those without a history of trauma. Kimble Fleming, Bandy, Kim, and Zambetti (2010) assessed the focus time (dwell time) as well as the first fixation and suggested that individuals with clear PTSD symptoms are likely to maintain their attention on threatening stimuli. Kimble et al. (2010) also observed a trend showing individuals with PTSD symptoms to be more vigilant about threatening
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stimuli. However, because these studies did not include positive stimuli, it remains unclear whether individuals with PTSD exhibit only trauma-related attentional biases or whether they are sensitive to all emotional stimuli. Thus, for a better understanding of the mechanisms inducing attentional bias in individuals with PTSD, it is necessary to examine whether attentional bias is induced exclusively by reminders of traumatic events or whether it is also induced by general emotional stimuli. Further, because previous studies separately examined the effects of PTSD and those of mere traumatic exposure, both trauma victims with/without PTSD and non-traumatised individuals must be simultaneously considered (Bryant & Harvey, 1995; Kimble et al., 2010). To address these issues, our previous study (Lee & Lee, 2012) assessed the location of the first fixation and the dwell time for DV survivors with high post-traumatic symptoms (DV-PTSD), DV survivors with low post-traumatic symptoms (Trauma Control: TC) and non-DV (NDV) controls by simultaneously presenting violent, dysphoric, happy and neutral images. On the basis of previous eye-tracking studies, we presented visual stimuli for a relatively long time period to examine the time course of attentional bias (Kimble et al., 2010). We divided 10-s trials into five 2-s intervals to determine whether group differences would be maintained; we observed that the DV-PTSD group was more likely to spend more time on violent stimuli compared with the TC or NDV group throughout the 10-s period. This implies that DV survivors with high PTSS (DV-High PTSS) maintained attention on trauma-related threatening stimuli. In addition to PTSD effects, we suggested an effect of traumatic exposure because the DVPTSD and TC groups paid more attention to dysphoric stimuli and less attention to happy stimuli than the NDV group. However, the groups did not differ in the location of the first fixation. These findings may be explained as follows: either immediate attentional vigilance may not be a critical characteristic of individuals with PTSD or violent images may not be sufficiently salient to induce rapid detection through fear mechanisms. In addition, our experimental design (four visual stimuli
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presented on a single screen) may not be appropriate for assessing immediate attentional vigilance because participants may have difficulty in simultaneously evaluating four visual stimuli. The present study advances the findings of Lee and Lee (2012) using emotional faces as the stimuli. Emotional faces offer more salient information for humans than do words or pictures. In particular, angry faces are biologically relevant stimuli similar to snakes or spiders, which automatically induce direct attention (Öhman, Dimberg, & Öst, 1985). In addition, angry faces can serve as trauma-related stimuli for DV survivors because DV perpetrators express frequent and intense feelings of anger (Fonzo et al., 2010). This study also included fearful faces to determine whether DV survivors’ attentional bias is specific only to trauma-related stimuli or whether it also extends to other types of negative stimuli. Fearful faces are considered to be effective stimuli for capturing attention and eliciting vigilance by a threat-processing system. Finally, the study also used happy faces to examine the emotionality hypothesis. To overcome the methodological limitations of previous studies’ assessments of immediate attentional vigilance, the present study displayed only two visual stimuli on single screen, for example, each trial employed an angry, fearful or happy face paired with a neutral face. In addition, the study included additional experimental conditions composing negative (angry or fearful) faces paired with positive (happy) faces because some brain-imaging studies have argued that neutral faces may not be processed as neutral by anxious individuals (Bryant & Harvey, 1995). It was hypothesised that in the emotionalneutral and negative-happy pair conditions, DV survivors with high PTSD symptoms would demonstrate a greater dwell time on angry faces than would survivors with low PTSD symptoms and non-traumatised controls. Further, it was hypothesised that in both experimental conditions, DV survivors with low PTSD symptoms would spend more time on angry faces than would non-traumatised controls. It was also hypothesised that DV survivors would attend more to fearful faces than would non-traumatised controls.
METHODS Participants Participants were selected from a large pool of female undergraduate students, using the Revised Conflict Tactic Scale (CTS-R; Straus, Hamby, Boney-McCoy, & Sugarman, 1996) and the PostTraumatic Stress Diagnostic Scale (PDS; Foa, Cashman, Jaycox, & Perry, 1997). The CTS-R measures the existence and severity of the partner’s psychological, physical and sexual aggression during dating conflicts. The participants rated 25 items on a 5-point Likert scale. The higher the score, the more frequent and severe the aggression was in the relationship. We selected 42 DV survivors who reported at least one occasion of being physically abused by their partner and scored above 40 on the CTS-R. The survivors were divided into two groups based on their PDS scores: the DV survivors with high post-traumatic stress symptoms (DV-High PTSS group) and the DV survivors with low posttraumatic stress symptoms (DV-Low PTSS group). The PDS comprised 17 items, and each item corresponded to DSM-IV criteria for PTSD. Participants rated the frequency of each of the 17 symptoms in the last month on a 4-point Likerttype scale. To be included in the DV-High PTSS group, the individual had to meet a diagnostic cutoff value of 15 (Sheeran & Zimmerman, 2002) or above on the PDS. To be included in the DV-Low PTSS group, the individual needed a total score below 15. We selected additional female students with no history of DV or any other form of interpersonal violence for the NDV group. Consequently, a total of 63 participants were gathered: 20 in the DV-High PTSS group (age M = 20.85, SD = 2.11), 22 in the DV-Low PTSS group (age M = 20.82, SD = 2.22) and 21 in the NDV group (age M = 21.10, SD = 2.05). All the participants read and signed an informed consent form before the experiment. They also completed the Beck Depression Inventory (BDI; Beck, Ward, Mendelson, Mock, & Erbaugh, 1961) and the State-Trait Anxiety COGNITION AND EMOTION, 2014, 28 (6)
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Table 1. Means (standard deviations) of self-report measures
CTS-R PDS BDI STAI-T STAI-S
DV-High PTSS ( N = 20)
DV-Low PTSS ( N = 22)
NDV ( N = 21)
46.95 (10.60) 23.10 (5.81) 15.20 (7.19) 48.65 (10.22) 41.05 (10.96)
46.27 (6.17) 1.73 (1.83) 9.45 (7.72) 42.55 (8.48) 39.50 (8.15)
25.71 (1.15) 11.71 (9.45) 40.90 (8.05) 35.52 (5.85)
F(2, 60) = 61.92, p < .001 t(22.42) = 15.75, p < .001 F(2, 60) = 2.60, p < .10 F(2, 60) = 4.26, p < .05 NS
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Note: CTS-R, Revised Conflict Tactic Scale; PDS, Post-traumatic Stress Diagnostic Scale; BDI, Beck Depression Inventory; STAI-T, State-Trait Anxiety Inventory-Trait form; STAI-S, State-Trait Anxiety Inventory-State form.
Inventory (STAI; Spielberger, Gorsuch, Lushene, Vagg, & Jacobs, 1983) (Table 1).
Materials and apparatus The stimuli were obtained from the Korean version of a set of emotional facial expressions (Korea University Facial Expression Collection; Lee, Lee, Lee, Kim, & Choi, 2007). For the emotional-neutral condition, we selected 24 pairs: 8 angry, 8 fearful and 8 happy facial expressions matched with a neutral face of the same individual. The negative–positive condition included 16 pairs: 8 angry and 8 fearful facial expressions were matched with a happy face of the same individual. The paired images included an equal number of males and females. The location of each image was counterbalanced. That is, males/females and emotional/neutral faces or negative/positive faces appeared on either side of the screen (visual angle of 10.18° from the centre of face stimuli presented on the left to the centre of face stimuli presented on the right) with equal frequency. Eight additional neutral pairs were selected for practice trials. All images were converted into greyscale images and were resized to 5.64 × 8.64°. The stimuli were presented on a 21-inch widescreen monitor, and the iView × RED-IV system (SensoMotoric Instruments, Teltow, Germany) recorded the participants’ eye movements. The system sampled data at 50 Hz, and gaze position accuracy was below 0.5°. Participants’ head location was fixed using a chin rest and a forehead bar to maximise measurement accuracy and reduce data loss.
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Procedure After the participants signed the informed consent form, they were requested to fill out the selfreport questionnaires. They were then taken to a soundproof room, seated and requested to place their chin on a chin rest located approximately 60 cm from the monitor for the eye movement recording. To minimise the demand effect, the actual aim of the study was concealed by explaining that the eye-tracking device was designed to measure their pupil size during the task (Armstrong, Olatunji, Sarawgi, & Simmons, 2010). Before their exposure to the stimuli, the participants followed a dot consecutively presented at five different locations for calibration purposes. Eight practice trials were then conducted followed by two experimental conditions: the emotionalneutral and negative-happy conditions. The order of experimental conditions was counterbalanced and randomised for each participant. The emotional-neutral condition included 32 trials, and the negative-happy condition included 16 trials. Each trial began with a one-s, centrally located fixation cross. A pair of faces then appeared for 10 s, followed by a blank screen for 1000, 1500 or 2000 ms randomly, which alleviated the participants’ fatigue (Armstrong et al., 2010). After each condition, the participants were provided with a short break and then repeated the 5-point calibration. The participants were instructed to keep their heads still on the chin rest during the task and to focus on the fixation cross at the beginning of each trial. Participants were also requested to look at the screen freely while the stimuli were
ATTENTIONAL BIAS TOWARD EMOTIONAL FACES
presented. The entire experiment took approximately 15 minutes, and the participants were then debriefed and provided with some monetary compensation.
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Data analysis The data on eye movements were prepared using BeGaze 1.0 software (SensoMotoric Instruments, Teltow, Germany), and the gaze direction was measured every 20 ms. To assess vigilance bias, we computed the number of trials in which emotional faces (in the emotional-neutral condition) or negative faces (in the negative-happy condition) captured the first fixation and then divided the result by the total number of trials in each condition. Finally, a two-way repeated-measures analysis of variance (ANOVA) was conducted to examine the differences among the three groups in terms of the location of the first fixation. To examine whether the participants would avoid or have difficulty with disengagement, the dwell time was analysed at multiple intervals across the trials by dividing each 10-s trial into five 2-s intervals: 0–2, 2–4, 4–6, 6–8 and 8–10 s (Kellough, Beevers, Ellis, & Wells, 2008). Next, the attentional bias score was calculated by subtracting the amount of time spent fixating on the accompanying neutral/ happy face from the amount of time spent fixating on the emotional/negative face for each time interval. A three-way repeated-measures ANOVA was conducted to assess group differences in the dwell time for each target face at each time interval. In addition, a one-way ANOVA and a t-test were conducted to examine group differences in terms of each selfreport measure.
RESULTS Dwell time in the emotional-neutral condition We conducted a 3 (group: DV-High PTSS, DVLow PTSS, NDV) × 3 (emotional expression: angry, fearful, happy) × 5 (time interval: 0–2, 2–4, 4–6, 6–8, 8–10 s) repeated-measures ANOVA. The main effect of emotional expression was significant [F(2, 120) = 17.86, p < .001,
g2p ¼ .23], and there was a significant group × emotional expression interaction [F(4, 120) = 5.67, p < .001, g2p ¼ .16]. The results of a follow-up comparison of simple effects indicated that the DV-High PTSS group showed significantly longer dwell times on angry faces than the DV-Low PTSS and NDV groups. In addition, the DV-Low PTSS group showed longer dwell times on angry faces than the NDV group. For fearful faces, the DV-High PTSS group showed significantly longer dwell times than the NDV group; however, the times were not significantly longer than those of the DV-Low PTSS group. There were no differences among groups for happy faces. For a more detailed analysis, we conducted separate 3 (group: DV-High PTSS, DV-Low PTSS, NDV) × 5 (time interval: 0–2, 2–4, 4–6, 6–8, 8–10 s) repeated-measures ANOVAs for each stimulus type. For angry faces, there were significant differences among the groups at 0–2 s [F(2, 60) = 3.99, p < .05, g2p ¼ .12], 4–6 s [F(2, 60) = 6.73, p < .01, g2p ¼ .18], 6–8 s [F(2, 60) = 9.96, p < .001, g2p ¼ .25] and 8–10 s [F(2, 60) = 7.75, p < .01, g2p ¼ .21]. The results of group comparisons at each time interval indicate that over time the DV-High PTSS group showed significantly longer dwell times for angry faces than the DV-Low PTSS group, with marginal differences at 0–2 s and 8–10 s and significant differences at 4–6 s and 6–8 s. In addition, the DV-High PTSS group showed significantly longer dwell times for angry faces than the NDV group, with a marginal difference at 2–4 s and significant differences at 0–2, 4–6, 6–8 and 8–10 s. The DV-Low PTSS group showed significantly longer dwell times than the NDV group at 8–10 s. For fearful faces, there were significant differences at 4–6 s [F(2, 60) = 3.55, p < .05, g2p ¼ .11] and 6–8 s [F(2, 60) = 3.20, p < .05, g2p ¼ .10] as well as a marginal difference at 8–10 s [F(2, 60) = 2.82, p < .10, g2p ¼ .09]. The results of group comparisons indicate that the DV-High PTSS group showed significantly longer dwell times for fearful faces than the NDV group during the last 8 s. In general, the DV-Low PTSS group showed longer dwell times for fearful faces than the NDV group during the last 2 s (see Figure 1). COGNITION AND EMOTION, 2014, 28 (6)
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Angry Face 600
Bias Score (ms)
400 200 0 -200
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-400 1
2
3
4
5
Time Interval (2s) Fearful Face DV-High PTSS
Bias Score (ms)
600
DV-Low PTSS
400
NDV 200 0 -200 -400 1
2
3
4
5
4
5
Time Interval (2s) Happy Face
Bias Score (ms)
600 400 200 0 -200 -400 1
2
3
Time Interval (2s) Figure 1. Group differences in the bias score for the dwell time for angry, fearful and happy faces in the emotional-neutral condition.
Dwell time in the negative-positive condition We conducted a 3 (group: DV-High PTSS, DVLow PTSS, NDV) × 2 (emotional expression: angry, fearful) × 5 (time interval: 0–2, 2–4, 4–6,
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6–8, 8–10 s) repeated-measures ANOVA. Emotional expression [F(1, 60) = 15.41, p < .001, g2p ¼ .20] and group [F(1, 60) = 3.35, p < .05, g2p ¼ .10] had significant main effects on dwell time.
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To identify the groups showing longer dwell times for negative faces, separate 3 (group: DV-High PTSS, DV-Low PTSS, NDV) × 5 (time interval: 0–2, 2–4, 4–6, 6–8, 8–10 s) repeated-measures ANOVAs were conducted for each emotional expression. For angry faces, there was a significant group difference at 0–2 s [F(2, 60) = 5.48, p < .01, g2p ¼ .16] and a marginal group difference at 2–4 s [F(2, 60) = 2.79, p < .10, g2p ¼ .09]. The DV-High PTSS group showed significantly longer dwell times than the NDV group during the first 2 s. The DV-Low PTSS group showed significantly longer dwell times for angry faces than the NDV group during the first 4 s. For fearful faces, there was a significant group difference at 2–4 s [F(2, 60) = 5.52, p < .01, g2p ¼ .16] and a marginal group difference from 4– 6 s [F(2, 60) = 2.62, p < .10, g2p ¼ .08]. The DVHigh PTSS group spent more time on fearful faces than the DV-Low PTSS group at 2–4 s and 4–6 s as well as the NDV group at 2–4 s.
Location of the first fixation For emotional-neutral pair condition, we conducted a 3 (group: DV-High PTSS, DV-Low PTSS, NDV) × 3 (emotional expression: angry, fearful, happy) repeated-measures ANOVA to examine vigilance bias. There were no significant main or interaction effects. For the negative-happy condition, we also observed no significant main or interaction effects. These results indicate no differences among the three groups in terms of the location of the first fixation across emotional expressions.
DISCUSSION This study primarily examined the characteristics of DV survivors’ attentional bias by changing the types of threatening stimuli from violent images to social threat cues. Although violent images are associated with DV survivors’ traumatic events, such images may not induce immediate atten‐ tional vigilance because they do not resemble
evolutionary threat cues such as snakes and spiders. However, emotional facial expressions may serve functions similar to those of other evolutionary threat cues (Öhman et al., 1985). In addition, emotional facial expressions may be direct stimuli for DV survivors because negative emotions are often expressed by faces during conflicts in the context of dating relationships. Further, we examined the presence of traumaspecific bias or general-negativity bias in DV survivors by including angry and fearful faces as negative stimuli. Building on a previous study, we focused on differences between groups for each type of stimulus at multiple time intervals to assess the maintenance of attentional bias. As expected, when angry, fearful and happy faces were presented with neutral faces, the DV-High PTSS group was more likely to show a prolonged attentional bias towards angry faces than were the DV-Low PTSS and NDV groups. This suggests that the DV-High group may have difficulty with attentional disengagement from trauma-related information. By contrast, the DVHigh PTSS group was no more likely to show immediate attentional vigilance than were the DV-Low PTSS and NDV groups. This is consistent with the findings of Lee and Lee (2012), who used four visual stimuli, and Pineles et al. (2009), who used a visual search task; however, these results are inconsistent with the findings of Bryant and Harvey (1995). Our results suggest that difficulty in disengaging from trauma-related stimuli may be an important characteristic of DV survivors with PTSD. Angry faces may have reminded the DVHigh PTSS group of physically abusive partners because perpetrators often express anger on their faces. Acute emotional arousal induced by reminders of traumatic events may lead DV survivors to pay more attention to trauma-related threatening stimuli by activating the brain’s fear system (Foa, Feske, Murdock, Kozak, & McCarthy, 1991; Pineles et al., 2009). Another possible explanation is that DV survivors with PTSD are characterised by rumination on traumatic events. Recent stu‐ dies have provided considerable evidence that COGNITION AND EMOTION, 2014, 28 (6)
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rumination, especially “what-if” type scenarios, plays an important role in prolonging PTSD (Michael, Halligan, Clark, & Ehlers, 2007). PTSD survivors appear to use rumination as an avoidance strategy; however, during and after rumination, PTSD survivors experience negative emotions that trigger further rumination. Thus, unlike other anxiety disorders such as spider phobia that are characterised by the rapid detection of threatening stimuli followed by avoidance, attentional facilitation may be an unimportant or non-existent feature of PTSD. The DV-High PTSS and DV-Low PTSS groups did not differ in attentional bias towards fearful faces, which is consistent with the findings of previous studies of DV survivors and other PTSD studies (Lee & Lee, 2012; Pineles et al., 2009). This indicates that trauma survivors with PTSD symptoms may maintain attention only on trauma-specific information, and this attentional bias cannot be generalised to a broad range of threatening stimuli. Angry faces may be associated with DV perpetrators; thus, angry faces may be direct reminders of traumatic events for DV survivors. Conversely, fearful faces are more likely to be related to DV survivors themselves. However, such faces cannot be directly linked to traumatic events because DV survivors cannot see their own faces during the aggression. The results indicate that attentional bias may be induced by the experience of the traumatic event itself. The significant differences between the DV-High PTSS and NDV groups in bias scores for angry and fearful faces were maintained over time. In addition, for some intervals, there were significant as well as marginal differences for angry and fearful faces between the DV-Low PTSS and NDV groups. Although the effect of traumatic exposure did not match the strength of PTSD, mere exposure of DV survivors to traumatic events considerably influenced their attentional bias. Finally, the emotionality hypothesis was examined; however, no evidence of attentional bias for happy faces was observed. The DV-High PTSS group did not show higher attentional bias scores for happy faces than the DV-Low PTSS and
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NDV groups. In contrast to studies of anxiety that reported an attentional bias towards positive information (Calvo & Avero, 2005; Garner, Mogg, & Bradley, 2006), the present study and Lee and Lee (2012) demonstrate no such bias towards positive stimuli related to PTSD symptoms. However, because only two studies have employed positive stimuli to investigate the emotionality hypothesis, these studies should be replicated. This study had several limitations. First, our sample size was small, considering the number and nature of the analyses. Second, the DV participants were selected from a large pool of undergraduate students on the basis of self-reported scores without considering legal or medical evidence of physical abuse in their dating relationships. In addition, the DV-High PTSS participants were not clinically diagnosed with PTSD. Although each DV-High PTSS participant scored above the clinical cut-off point on the PDS and 15 of 20 scored above 21 (indicating severe PTSD symptoms), we did not consider PTSD diagnostic criteria, which is based on DSM-IV: at least one re-experiencing symptom, three avoidance symptoms and two arousal symptoms. Thus, a replication study with a clinical sample who meets DSM-IV criteria is required. Third, although typically, DV perpetrators are men and survivors are women, it is necessary to include male DV survivors to generalise the results of this study. Finally, although the participants’ past exposure to other types of traumatic events was controlled, it was not determined whether they were abused by more than one partner in dating relationships. Overall, this study provides additional evidence that DV-High PTSS may maintain their attention to trauma-specific stimuli more than DV survivors with low or no PTSS, as well as non-DV individuals. In addition, the study indicates the coexistence of trauma and PTSD effects. Finally, although the present study was somewhat methodologically modified from previous studies to enhance the detection of attentional vigilance, no differences between groups were observed in immediate attentional vigilance for any emotional stimuli. This indicates that DV-PTSD may
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exhibit attentional bias and that difficulty with disengagement is the most evident component. These results suggest that DV survivors have difficulty in controlling their attentional resources in relation to trauma-related information. Thus, appropriate treatment, such as Attentional Bias Modification (ABM), is required to help DV survivors. Recent research has suggested that ABM treatments are associated with symptom reduction in certain anxiety disorders, such as generalised anxiety disorder (GAD) and social phobia (Bar-Haim, 2010). The effectiveness of ABM treatments for PTSD survivors must be investigated. Manuscript received 30 April Revised manuscript received 15 November Manuscript accepted 18 November First published online 17 December
2012 2013 2013 2013
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Cognition and Emotion Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/pcem20
Attentional bias towards emotional facial expressions in survivors of dating violence a
Jeong-Ha Lee & Jang-Han Lee
a
a
Department of Psychology, Chung-Ang University, Seoul, Korea Published online: 17 Dec 2013.
Click for updates To cite this article: Jeong-Ha Lee & Jang-Han Lee (2014) Attentional bias towards emotional facial expressions in survivors of dating violence, Cognition and Emotion, 28:6, 1127-1136, DOI: 10.1080/02699931.2013.867834 To link to this article: http://dx.doi.org/10.1080/02699931.2013.867834
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COGNITION AND EMOTION, 2014 Vol. 28, No. 6, 1127–1136, http://dx.doi.org/10.1080/02699931.2013.867834
BRIEF REPORT Attentional bias towards emotional facial expressions in survivors of dating violence Downloaded by [Eindhoven Technical University] at 15:40 21 November 2014
Jeong-Ha Lee and Jang-Han Lee Department of Psychology, Chung-Ang University, Seoul, Korea
This study identified components of attentional bias (e.g. attentional vigilance, attentional avoidance and difficulty with disengagement) that are critical characteristics of survivors of dating violence (DV). Eye movements were recorded to obtain accurate and continuous information regarding attention. DV survivors with high post-traumatic stress symptoms (DV-High PTSS group; n = 20) and low post-traumatic stress symptoms (DV-Low PTSS group; n = 22) and participants who had never experienced DV (NDV group; n = 21) were shown screens displaying emotional (angry, fearful and happy) faces paired with neutral faces and negative (angry and fearful) faces paired with happy faces for 10 s. The results indicate that the DV-High PTSS group spent longer dwelling on angry faces over time compared with the DV-Low PTSS and NDV groups. This result implies that the DV-High PTSS group focused on specific trauma-related stimuli but does not provide evidence of an attentional bias towards threatening stimuli in general. Keywords: Dating violence survivors; Attentional bias; Emotional faces; Eye-tracking.
Dating violence (DV) refers to physical, psychological and/or sexual aggression in a dating relationship and is a serious social problem in terms of its negative sequela and high prevalence (Straus, 2004). Several studies have suggested that DV victims are likely to suffer from depression, anxiety and posttraumatic stress disorder (PTSD; Campbell, 2002). In addition, cognitive models postulate that an
attentional bias towards negative stimuli is a crucial feature that may maintain and even induce PTSD symptoms, such as flashbacks, concentration deficits and avoidance behaviours (see Ehlers & Clark, 2000). Early studies that adopted the emotional Stroop test to investigate attentional bias demonstrated that individuals with PTSD are more likely to exhibit delayed response times to
Correspondence should be addressed to: Jang-Han Lee, Department of Psychology, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Korea. Email: [email protected] This work was supported by the National Research Foundation of Korea funded by the Korea government (MEST) [grant number 2011-0003012]. © 2013 Taylor & Francis
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threatening stimuli than those without PTSD (Beck, Freeman, Shipherd, Hamblen, & Lackner, 2001; Bryant & Harvey, 1995). Recent studies have suggested that attentional bias comprises distinguishable components such as immediate attentional vigilance (or facilitated attention), difficulty with disengagement (or attentional interference) and attentional avoidance (Cisler & Olatunji, 2010). Many studies have investigated threat-related attentional bias in different subtypes of anxiety disorders. However, there are disagreements regarding the components of attentional bias underlying anxiety disorders (Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, & van IJzendoorn, 2007). For more detailed and precise information regarding the cognitive mechanisms underlying PTSD and thus for more appropriate treatment, it is important to distinguish between these components of attentional bias. From this perspective, two studies have identified components of attentional bias towards threatening stimuli that are present in PTSD patients (Pineles, Shipherd, Mostoufi, Abramovitz, & Yovel, 2009). These studies consistently indicate that the only issue encountered by individuals with clear PTSD symptoms is disengaging from such stimuli. However, these findings may be inconclusive because they were based on reaction time tasks such as a visual search task, which are unduly influenced by extraneous factors such as mood and motor speed. Eye-tracking experiments have been considered direct and appropriate methods for measuring attentional processing. However, few eye-tracking studies have considered PTSD. Bryant and Harvey (1995) focused on the initial direction of the participant’s gaze (first fixation) as an index of immediate attentional vigilance and observed that the participants with PTSD were more likely to be vigilant about threatening stimuli than those without a history of trauma. Kimble Fleming, Bandy, Kim, and Zambetti (2010) assessed the focus time (dwell time) as well as the first fixation and suggested that individuals with clear PTSD symptoms are likely to maintain their attention on threatening stimuli. Kimble et al. (2010) also observed a trend showing individuals with PTSD symptoms to be more vigilant about threatening
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stimuli. However, because these studies did not include positive stimuli, it remains unclear whether individuals with PTSD exhibit only trauma-related attentional biases or whether they are sensitive to all emotional stimuli. Thus, for a better understanding of the mechanisms inducing attentional bias in individuals with PTSD, it is necessary to examine whether attentional bias is induced exclusively by reminders of traumatic events or whether it is also induced by general emotional stimuli. Further, because previous studies separately examined the effects of PTSD and those of mere traumatic exposure, both trauma victims with/without PTSD and non-traumatised individuals must be simultaneously considered (Bryant & Harvey, 1995; Kimble et al., 2010). To address these issues, our previous study (Lee & Lee, 2012) assessed the location of the first fixation and the dwell time for DV survivors with high post-traumatic symptoms (DV-PTSD), DV survivors with low post-traumatic symptoms (Trauma Control: TC) and non-DV (NDV) controls by simultaneously presenting violent, dysphoric, happy and neutral images. On the basis of previous eye-tracking studies, we presented visual stimuli for a relatively long time period to examine the time course of attentional bias (Kimble et al., 2010). We divided 10-s trials into five 2-s intervals to determine whether group differences would be maintained; we observed that the DV-PTSD group was more likely to spend more time on violent stimuli compared with the TC or NDV group throughout the 10-s period. This implies that DV survivors with high PTSS (DV-High PTSS) maintained attention on trauma-related threatening stimuli. In addition to PTSD effects, we suggested an effect of traumatic exposure because the DVPTSD and TC groups paid more attention to dysphoric stimuli and less attention to happy stimuli than the NDV group. However, the groups did not differ in the location of the first fixation. These findings may be explained as follows: either immediate attentional vigilance may not be a critical characteristic of individuals with PTSD or violent images may not be sufficiently salient to induce rapid detection through fear mechanisms. In addition, our experimental design (four visual stimuli
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presented on a single screen) may not be appropriate for assessing immediate attentional vigilance because participants may have difficulty in simultaneously evaluating four visual stimuli. The present study advances the findings of Lee and Lee (2012) using emotional faces as the stimuli. Emotional faces offer more salient information for humans than do words or pictures. In particular, angry faces are biologically relevant stimuli similar to snakes or spiders, which automatically induce direct attention (Öhman, Dimberg, & Öst, 1985). In addition, angry faces can serve as trauma-related stimuli for DV survivors because DV perpetrators express frequent and intense feelings of anger (Fonzo et al., 2010). This study also included fearful faces to determine whether DV survivors’ attentional bias is specific only to trauma-related stimuli or whether it also extends to other types of negative stimuli. Fearful faces are considered to be effective stimuli for capturing attention and eliciting vigilance by a threat-processing system. Finally, the study also used happy faces to examine the emotionality hypothesis. To overcome the methodological limitations of previous studies’ assessments of immediate attentional vigilance, the present study displayed only two visual stimuli on single screen, for example, each trial employed an angry, fearful or happy face paired with a neutral face. In addition, the study included additional experimental conditions composing negative (angry or fearful) faces paired with positive (happy) faces because some brain-imaging studies have argued that neutral faces may not be processed as neutral by anxious individuals (Bryant & Harvey, 1995). It was hypothesised that in the emotionalneutral and negative-happy pair conditions, DV survivors with high PTSD symptoms would demonstrate a greater dwell time on angry faces than would survivors with low PTSD symptoms and non-traumatised controls. Further, it was hypothesised that in both experimental conditions, DV survivors with low PTSD symptoms would spend more time on angry faces than would non-traumatised controls. It was also hypothesised that DV survivors would attend more to fearful faces than would non-traumatised controls.
METHODS Participants Participants were selected from a large pool of female undergraduate students, using the Revised Conflict Tactic Scale (CTS-R; Straus, Hamby, Boney-McCoy, & Sugarman, 1996) and the PostTraumatic Stress Diagnostic Scale (PDS; Foa, Cashman, Jaycox, & Perry, 1997). The CTS-R measures the existence and severity of the partner’s psychological, physical and sexual aggression during dating conflicts. The participants rated 25 items on a 5-point Likert scale. The higher the score, the more frequent and severe the aggression was in the relationship. We selected 42 DV survivors who reported at least one occasion of being physically abused by their partner and scored above 40 on the CTS-R. The survivors were divided into two groups based on their PDS scores: the DV survivors with high post-traumatic stress symptoms (DV-High PTSS group) and the DV survivors with low posttraumatic stress symptoms (DV-Low PTSS group). The PDS comprised 17 items, and each item corresponded to DSM-IV criteria for PTSD. Participants rated the frequency of each of the 17 symptoms in the last month on a 4-point Likerttype scale. To be included in the DV-High PTSS group, the individual had to meet a diagnostic cutoff value of 15 (Sheeran & Zimmerman, 2002) or above on the PDS. To be included in the DV-Low PTSS group, the individual needed a total score below 15. We selected additional female students with no history of DV or any other form of interpersonal violence for the NDV group. Consequently, a total of 63 participants were gathered: 20 in the DV-High PTSS group (age M = 20.85, SD = 2.11), 22 in the DV-Low PTSS group (age M = 20.82, SD = 2.22) and 21 in the NDV group (age M = 21.10, SD = 2.05). All the participants read and signed an informed consent form before the experiment. They also completed the Beck Depression Inventory (BDI; Beck, Ward, Mendelson, Mock, & Erbaugh, 1961) and the State-Trait Anxiety COGNITION AND EMOTION, 2014, 28 (6)
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Table 1. Means (standard deviations) of self-report measures
CTS-R PDS BDI STAI-T STAI-S
DV-High PTSS ( N = 20)
DV-Low PTSS ( N = 22)
NDV ( N = 21)
46.95 (10.60) 23.10 (5.81) 15.20 (7.19) 48.65 (10.22) 41.05 (10.96)
46.27 (6.17) 1.73 (1.83) 9.45 (7.72) 42.55 (8.48) 39.50 (8.15)
25.71 (1.15) 11.71 (9.45) 40.90 (8.05) 35.52 (5.85)
F(2, 60) = 61.92, p < .001 t(22.42) = 15.75, p < .001 F(2, 60) = 2.60, p < .10 F(2, 60) = 4.26, p < .05 NS
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Note: CTS-R, Revised Conflict Tactic Scale; PDS, Post-traumatic Stress Diagnostic Scale; BDI, Beck Depression Inventory; STAI-T, State-Trait Anxiety Inventory-Trait form; STAI-S, State-Trait Anxiety Inventory-State form.
Inventory (STAI; Spielberger, Gorsuch, Lushene, Vagg, & Jacobs, 1983) (Table 1).
Materials and apparatus The stimuli were obtained from the Korean version of a set of emotional facial expressions (Korea University Facial Expression Collection; Lee, Lee, Lee, Kim, & Choi, 2007). For the emotional-neutral condition, we selected 24 pairs: 8 angry, 8 fearful and 8 happy facial expressions matched with a neutral face of the same individual. The negative–positive condition included 16 pairs: 8 angry and 8 fearful facial expressions were matched with a happy face of the same individual. The paired images included an equal number of males and females. The location of each image was counterbalanced. That is, males/females and emotional/neutral faces or negative/positive faces appeared on either side of the screen (visual angle of 10.18° from the centre of face stimuli presented on the left to the centre of face stimuli presented on the right) with equal frequency. Eight additional neutral pairs were selected for practice trials. All images were converted into greyscale images and were resized to 5.64 × 8.64°. The stimuli were presented on a 21-inch widescreen monitor, and the iView × RED-IV system (SensoMotoric Instruments, Teltow, Germany) recorded the participants’ eye movements. The system sampled data at 50 Hz, and gaze position accuracy was below 0.5°. Participants’ head location was fixed using a chin rest and a forehead bar to maximise measurement accuracy and reduce data loss.
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Procedure After the participants signed the informed consent form, they were requested to fill out the selfreport questionnaires. They were then taken to a soundproof room, seated and requested to place their chin on a chin rest located approximately 60 cm from the monitor for the eye movement recording. To minimise the demand effect, the actual aim of the study was concealed by explaining that the eye-tracking device was designed to measure their pupil size during the task (Armstrong, Olatunji, Sarawgi, & Simmons, 2010). Before their exposure to the stimuli, the participants followed a dot consecutively presented at five different locations for calibration purposes. Eight practice trials were then conducted followed by two experimental conditions: the emotionalneutral and negative-happy conditions. The order of experimental conditions was counterbalanced and randomised for each participant. The emotional-neutral condition included 32 trials, and the negative-happy condition included 16 trials. Each trial began with a one-s, centrally located fixation cross. A pair of faces then appeared for 10 s, followed by a blank screen for 1000, 1500 or 2000 ms randomly, which alleviated the participants’ fatigue (Armstrong et al., 2010). After each condition, the participants were provided with a short break and then repeated the 5-point calibration. The participants were instructed to keep their heads still on the chin rest during the task and to focus on the fixation cross at the beginning of each trial. Participants were also requested to look at the screen freely while the stimuli were
ATTENTIONAL BIAS TOWARD EMOTIONAL FACES
presented. The entire experiment took approximately 15 minutes, and the participants were then debriefed and provided with some monetary compensation.
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Data analysis The data on eye movements were prepared using BeGaze 1.0 software (SensoMotoric Instruments, Teltow, Germany), and the gaze direction was measured every 20 ms. To assess vigilance bias, we computed the number of trials in which emotional faces (in the emotional-neutral condition) or negative faces (in the negative-happy condition) captured the first fixation and then divided the result by the total number of trials in each condition. Finally, a two-way repeated-measures analysis of variance (ANOVA) was conducted to examine the differences among the three groups in terms of the location of the first fixation. To examine whether the participants would avoid or have difficulty with disengagement, the dwell time was analysed at multiple intervals across the trials by dividing each 10-s trial into five 2-s intervals: 0–2, 2–4, 4–6, 6–8 and 8–10 s (Kellough, Beevers, Ellis, & Wells, 2008). Next, the attentional bias score was calculated by subtracting the amount of time spent fixating on the accompanying neutral/ happy face from the amount of time spent fixating on the emotional/negative face for each time interval. A three-way repeated-measures ANOVA was conducted to assess group differences in the dwell time for each target face at each time interval. In addition, a one-way ANOVA and a t-test were conducted to examine group differences in terms of each selfreport measure.
RESULTS Dwell time in the emotional-neutral condition We conducted a 3 (group: DV-High PTSS, DVLow PTSS, NDV) × 3 (emotional expression: angry, fearful, happy) × 5 (time interval: 0–2, 2–4, 4–6, 6–8, 8–10 s) repeated-measures ANOVA. The main effect of emotional expression was significant [F(2, 120) = 17.86, p < .001,
g2p ¼ .23], and there was a significant group × emotional expression interaction [F(4, 120) = 5.67, p < .001, g2p ¼ .16]. The results of a follow-up comparison of simple effects indicated that the DV-High PTSS group showed significantly longer dwell times on angry faces than the DV-Low PTSS and NDV groups. In addition, the DV-Low PTSS group showed longer dwell times on angry faces than the NDV group. For fearful faces, the DV-High PTSS group showed significantly longer dwell times than the NDV group; however, the times were not significantly longer than those of the DV-Low PTSS group. There were no differences among groups for happy faces. For a more detailed analysis, we conducted separate 3 (group: DV-High PTSS, DV-Low PTSS, NDV) × 5 (time interval: 0–2, 2–4, 4–6, 6–8, 8–10 s) repeated-measures ANOVAs for each stimulus type. For angry faces, there were significant differences among the groups at 0–2 s [F(2, 60) = 3.99, p < .05, g2p ¼ .12], 4–6 s [F(2, 60) = 6.73, p < .01, g2p ¼ .18], 6–8 s [F(2, 60) = 9.96, p < .001, g2p ¼ .25] and 8–10 s [F(2, 60) = 7.75, p < .01, g2p ¼ .21]. The results of group comparisons at each time interval indicate that over time the DV-High PTSS group showed significantly longer dwell times for angry faces than the DV-Low PTSS group, with marginal differences at 0–2 s and 8–10 s and significant differences at 4–6 s and 6–8 s. In addition, the DV-High PTSS group showed significantly longer dwell times for angry faces than the NDV group, with a marginal difference at 2–4 s and significant differences at 0–2, 4–6, 6–8 and 8–10 s. The DV-Low PTSS group showed significantly longer dwell times than the NDV group at 8–10 s. For fearful faces, there were significant differences at 4–6 s [F(2, 60) = 3.55, p < .05, g2p ¼ .11] and 6–8 s [F(2, 60) = 3.20, p < .05, g2p ¼ .10] as well as a marginal difference at 8–10 s [F(2, 60) = 2.82, p < .10, g2p ¼ .09]. The results of group comparisons indicate that the DV-High PTSS group showed significantly longer dwell times for fearful faces than the NDV group during the last 8 s. In general, the DV-Low PTSS group showed longer dwell times for fearful faces than the NDV group during the last 2 s (see Figure 1). COGNITION AND EMOTION, 2014, 28 (6)
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Angry Face 600
Bias Score (ms)
400 200 0 -200
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-400 1
2
3
4
5
Time Interval (2s) Fearful Face DV-High PTSS
Bias Score (ms)
600
DV-Low PTSS
400
NDV 200 0 -200 -400 1
2
3
4
5
4
5
Time Interval (2s) Happy Face
Bias Score (ms)
600 400 200 0 -200 -400 1
2
3
Time Interval (2s) Figure 1. Group differences in the bias score for the dwell time for angry, fearful and happy faces in the emotional-neutral condition.
Dwell time in the negative-positive condition We conducted a 3 (group: DV-High PTSS, DVLow PTSS, NDV) × 2 (emotional expression: angry, fearful) × 5 (time interval: 0–2, 2–4, 4–6,
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6–8, 8–10 s) repeated-measures ANOVA. Emotional expression [F(1, 60) = 15.41, p < .001, g2p ¼ .20] and group [F(1, 60) = 3.35, p < .05, g2p ¼ .10] had significant main effects on dwell time.
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To identify the groups showing longer dwell times for negative faces, separate 3 (group: DV-High PTSS, DV-Low PTSS, NDV) × 5 (time interval: 0–2, 2–4, 4–6, 6–8, 8–10 s) repeated-measures ANOVAs were conducted for each emotional expression. For angry faces, there was a significant group difference at 0–2 s [F(2, 60) = 5.48, p < .01, g2p ¼ .16] and a marginal group difference at 2–4 s [F(2, 60) = 2.79, p < .10, g2p ¼ .09]. The DV-High PTSS group showed significantly longer dwell times than the NDV group during the first 2 s. The DV-Low PTSS group showed significantly longer dwell times for angry faces than the NDV group during the first 4 s. For fearful faces, there was a significant group difference at 2–4 s [F(2, 60) = 5.52, p < .01, g2p ¼ .16] and a marginal group difference from 4– 6 s [F(2, 60) = 2.62, p < .10, g2p ¼ .08]. The DVHigh PTSS group spent more time on fearful faces than the DV-Low PTSS group at 2–4 s and 4–6 s as well as the NDV group at 2–4 s.
Location of the first fixation For emotional-neutral pair condition, we conducted a 3 (group: DV-High PTSS, DV-Low PTSS, NDV) × 3 (emotional expression: angry, fearful, happy) repeated-measures ANOVA to examine vigilance bias. There were no significant main or interaction effects. For the negative-happy condition, we also observed no significant main or interaction effects. These results indicate no differences among the three groups in terms of the location of the first fixation across emotional expressions.
DISCUSSION This study primarily examined the characteristics of DV survivors’ attentional bias by changing the types of threatening stimuli from violent images to social threat cues. Although violent images are associated with DV survivors’ traumatic events, such images may not induce immediate atten‐ tional vigilance because they do not resemble
evolutionary threat cues such as snakes and spiders. However, emotional facial expressions may serve functions similar to those of other evolutionary threat cues (Öhman et al., 1985). In addition, emotional facial expressions may be direct stimuli for DV survivors because negative emotions are often expressed by faces during conflicts in the context of dating relationships. Further, we examined the presence of traumaspecific bias or general-negativity bias in DV survivors by including angry and fearful faces as negative stimuli. Building on a previous study, we focused on differences between groups for each type of stimulus at multiple time intervals to assess the maintenance of attentional bias. As expected, when angry, fearful and happy faces were presented with neutral faces, the DV-High PTSS group was more likely to show a prolonged attentional bias towards angry faces than were the DV-Low PTSS and NDV groups. This suggests that the DV-High group may have difficulty with attentional disengagement from trauma-related information. By contrast, the DVHigh PTSS group was no more likely to show immediate attentional vigilance than were the DV-Low PTSS and NDV groups. This is consistent with the findings of Lee and Lee (2012), who used four visual stimuli, and Pineles et al. (2009), who used a visual search task; however, these results are inconsistent with the findings of Bryant and Harvey (1995). Our results suggest that difficulty in disengaging from trauma-related stimuli may be an important characteristic of DV survivors with PTSD. Angry faces may have reminded the DVHigh PTSS group of physically abusive partners because perpetrators often express anger on their faces. Acute emotional arousal induced by reminders of traumatic events may lead DV survivors to pay more attention to trauma-related threatening stimuli by activating the brain’s fear system (Foa, Feske, Murdock, Kozak, & McCarthy, 1991; Pineles et al., 2009). Another possible explanation is that DV survivors with PTSD are characterised by rumination on traumatic events. Recent stu‐ dies have provided considerable evidence that COGNITION AND EMOTION, 2014, 28 (6)
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rumination, especially “what-if” type scenarios, plays an important role in prolonging PTSD (Michael, Halligan, Clark, & Ehlers, 2007). PTSD survivors appear to use rumination as an avoidance strategy; however, during and after rumination, PTSD survivors experience negative emotions that trigger further rumination. Thus, unlike other anxiety disorders such as spider phobia that are characterised by the rapid detection of threatening stimuli followed by avoidance, attentional facilitation may be an unimportant or non-existent feature of PTSD. The DV-High PTSS and DV-Low PTSS groups did not differ in attentional bias towards fearful faces, which is consistent with the findings of previous studies of DV survivors and other PTSD studies (Lee & Lee, 2012; Pineles et al., 2009). This indicates that trauma survivors with PTSD symptoms may maintain attention only on trauma-specific information, and this attentional bias cannot be generalised to a broad range of threatening stimuli. Angry faces may be associated with DV perpetrators; thus, angry faces may be direct reminders of traumatic events for DV survivors. Conversely, fearful faces are more likely to be related to DV survivors themselves. However, such faces cannot be directly linked to traumatic events because DV survivors cannot see their own faces during the aggression. The results indicate that attentional bias may be induced by the experience of the traumatic event itself. The significant differences between the DV-High PTSS and NDV groups in bias scores for angry and fearful faces were maintained over time. In addition, for some intervals, there were significant as well as marginal differences for angry and fearful faces between the DV-Low PTSS and NDV groups. Although the effect of traumatic exposure did not match the strength of PTSD, mere exposure of DV survivors to traumatic events considerably influenced their attentional bias. Finally, the emotionality hypothesis was examined; however, no evidence of attentional bias for happy faces was observed. The DV-High PTSS group did not show higher attentional bias scores for happy faces than the DV-Low PTSS and
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NDV groups. In contrast to studies of anxiety that reported an attentional bias towards positive information (Calvo & Avero, 2005; Garner, Mogg, & Bradley, 2006), the present study and Lee and Lee (2012) demonstrate no such bias towards positive stimuli related to PTSD symptoms. However, because only two studies have employed positive stimuli to investigate the emotionality hypothesis, these studies should be replicated. This study had several limitations. First, our sample size was small, considering the number and nature of the analyses. Second, the DV participants were selected from a large pool of undergraduate students on the basis of self-reported scores without considering legal or medical evidence of physical abuse in their dating relationships. In addition, the DV-High PTSS participants were not clinically diagnosed with PTSD. Although each DV-High PTSS participant scored above the clinical cut-off point on the PDS and 15 of 20 scored above 21 (indicating severe PTSD symptoms), we did not consider PTSD diagnostic criteria, which is based on DSM-IV: at least one re-experiencing symptom, three avoidance symptoms and two arousal symptoms. Thus, a replication study with a clinical sample who meets DSM-IV criteria is required. Third, although typically, DV perpetrators are men and survivors are women, it is necessary to include male DV survivors to generalise the results of this study. Finally, although the participants’ past exposure to other types of traumatic events was controlled, it was not determined whether they were abused by more than one partner in dating relationships. Overall, this study provides additional evidence that DV-High PTSS may maintain their attention to trauma-specific stimuli more than DV survivors with low or no PTSS, as well as non-DV individuals. In addition, the study indicates the coexistence of trauma and PTSD effects. Finally, although the present study was somewhat methodologically modified from previous studies to enhance the detection of attentional vigilance, no differences between groups were observed in immediate attentional vigilance for any emotional stimuli. This indicates that DV-PTSD may
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exhibit attentional bias and that difficulty with disengagement is the most evident component. These results suggest that DV survivors have difficulty in controlling their attentional resources in relation to trauma-related information. Thus, appropriate treatment, such as Attentional Bias Modification (ABM), is required to help DV survivors. Recent research has suggested that ABM treatments are associated with symptom reduction in certain anxiety disorders, such as generalised anxiety disorder (GAD) and social phobia (Bar-Haim, 2010). The effectiveness of ABM treatments for PTSD survivors must be investigated. Manuscript received 30 April Revised manuscript received 15 November Manuscript accepted 18 November First published online 17 December
2012 2013 2013 2013
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