Research suggests that socially anxious individuals pay particular attention to threat-relevant information (e.g., Hope, Rapee, Heimberg, & Dombeck, 1990
; Mathews & MacLeod, 2002
). According to cognitive theories of anxiety, selective attention to negative social cues heightens anxiety and biases judgments of social events, thereby leading to ineffective social behavior. This, in turn, may prevent disconfirmation of fear-related beliefs and maintain social anxiety (e.g., Clark, 2001
; Clark & Wells, 1995
; Rapee & Heimberg, 1997
Researchers have used probe detection tasks with faces to examine attention bias to threat in social anxiety. In one version of the dot probe task, participants see two faces, one above the other, on a computer screen. One face is neutral, and the other face is threatening (e.g., anger or disgust). On critical trials, either the upper or the lower face is replaced with a probe (e.g., the letter E), and participants are asked to press a button to identify the probe. Faster response latencies in detecting probes replacing threatening faces, compared with response latencies in detecting probes replacing neutral faces, reflect an attention bias toward threatening information.
Several studies have found evidence of an attention bias for threat (i.e., anger or disgust faces) using probe detection tasks in socially anxious individuals and patients diagnosed with social phobia (Mogg & Bradley, 2002
; Mogg, Philippot, & Bradley, 2004
; Pishyar, Harris, & Menzies, 2004
). For example, in two studies Pishyar et al. (2004)
found that socially anxious participants demonstrated an attentional bias toward disgust faces but not toward social threat words, relative to nonanxious controls. However, other studies have failed to find evidence for attention bias for threat in social anxiety (Chen, Ehlers, Clark, & Mansell, 2002
; Gotlib et al., 2004
; Mansell, Clark, Ehlers, & Chen, 1999
). Bögels and Mansell (2004)
suggested that studies that have paired one face with another face (as opposed to pairing a face with an object such as a chair) and presented faces for 500 ms or less find evidence for attention bias for threat, whereas studies using different parameters do not. However, using these same parameters, at least two studies did not find a significant attention bias for threat in socially anxious individuals (Bradley et al., 1997
; Pineles & Mineka, 2005
One explanation for these inconsistencies is that even when an effect exists (i.e., is nonzero in the population), one would not expect every study of that effect to achieve significant results unless the effect size is very large—an extremely unlikely situation in psychological inquiry. In such cases, it is possible to demonstrate that the average effect size across these studies is significantly different from zero. Five articles have reported six studies examining attention bias to threat in social anxiety using the parameters described above by Bögels and Mansell (2004)
. We calculated effect sizes based on reported statistics for the interaction of group (socially anxious vs. nonanxious control) by face type (threat vs. neutral), or group comparison for attention bias for threat faces. These studies suggest that the average effect size is large and significantly different from zero (Cohen’s d
= 1.14, z
(5) = 3.72, p
< .01). Accordingly, we used the parameters suggested by Bögels and Mansell in the current study.
In summary, there is evidence for a relationship between attention bias to threat and social anxiety. However, because these studies have used a correlational design, it is not possible to determine the causal nature of this relationship. Conclusions regarding the causal role of attention bias in the maintenance of anxiety can be made only from research designs in which participants are randomly assigned to conditions and their attention is experimentally manipulated. We now turn to this source of evidence.
To our knowledge, two published studies have examined the effect of attention training on anxiety using the probe detection task. Harris and Menzies (1998)
attempted to induce attention bias either toward or away from spider-relevant words in a nonclinical sample. Participants were randomly assigned to one of two attention training conditions. In each condition they saw word pairs comprising a spider-relevant word and a neutral word. In the attention-toward-threat condition, the probe always replaced the spider-relevant words. In the attention-away-from-threat condition, the probe always replaced the neutral words. As expected, after the training tasks the former group was faster in identifying probes replacing novel spider-relevant words, whereas the latter group was faster in identifying probes replacing neutral words. However, training did not generalize to an independent measure of attention bias (i.e., emotional Stroop), nor did it affect self-report of anxiety.
MacLeod, Rutherford, Campbell, Ebsworthy, and Holker (2002)
manipulated attention bias toward general anxiety words. They screened a large pool of participants and selected those individuals who were in the middle third of the distribution of a self-report measure of trait anxiety. In the Attend Threat condition, probes appeared in the position of the threat word on 93% of the trials. In the Attend Neutral condition, probes appeared in the position of the neutral word on 93% of the trials. After the training, the authors induced stress by presenting their participants with a series of unsolvable anagrams and telling them that their videotaped performance would be shown in other classes should they perform particularly well or poorly. MacLeod et al. (2002)
found that, after training, participants in the Attend Threat condition showed faster response latencies for detecting probes following threat words than they did for neutral words. Participants in the Attend Neutral condition showed the opposite pattern of results. Moreover, participants in the Attend Threat condition responded more negatively (higher levels of depression and anxiety) to the experimental stressor than did those in the Attend Neutral condition.
Although these results are consistent with the hypothesis that an attention bias toward threat cues confers a vulnerability to heightened negative affectivity in response to stress, an alternative explanation is that obtained differences in anxiety reflect immediate and direct effects of the training task on participants’ mood rather than differential vulnerability to stress between groups. To test this alternative explanation, MacLeod et al. (2002)
had participants report their levels of anxiety and depression at seven points during the training tasks as well as immediately prior to the experimental stressor. The groups did not differ in their levels of anxiety or depression during the training procedure or prior to the stressor. Thus, the difference between the two groups appears to reflect the creation of differing affective vulnerabilities to stress that endures, at least over a short time, after training. Similar results were obtained in two unpublished studies by this group of researchers (cited in Mathews & MacLeod, 2002
) who found that highly trait-anxious students trained to repeatedly direct their attention away from threatening cues over 10 sessions reported a significant reduction in trait anxiety scores from pre- to posttraining. Considered together, these studies provide the strongest support to date for the hypothesis that individual differences in the allocation of attention to threat-relevant and negative information are causally important in mediating vulnerability to negative affectivity. At the practical level, these findings suggest that it may be possible to use such attention training procedures clinically.
More recently, other researchers have used different computerized training procedures to modify attention to threat cues. In a series of studies with undergraduate students, Dandeneau and colleagues demonstrated that repeatedly training participants to locate a single smiling (accepting) face in a grid of frowning (rejecting) faces significantly reduced participants’ attention bias toward rejection words on an emotional Stroop task relative to participants who completed a control training task (Dandeneau & Baldwin, 2004
; Dandeneau, Baldwin, Baccus, Sakellaropoulo, & Pruessner, 2007
). In a subsequent study, Dandeneau, Baldwin, Baccus, Sakellaropoulo, & Pruessner (2007
, Study 3a) found that students completing the attention training procedure 5 consecutive days prior to a final exam reported feeling less stressed and more confident about their exam and less anxious immediately after the exam compared with participants in the control condition. Similarly, a second study (Study 3b) demonstrated that attention training completed daily for 1 week by a group of telemarketers (who routinely experience rejection as part of their work) led to higher self-esteem, lower cortisol levels, lower self-reported stress, higher confidence, and improved work performance relative to control participants.
Although the above research is consistent with the hypothesis that change in attention bias can lead to change in anxiety, several issues need further examination. First, because the two conditions in the MacLeod et al. (2002)
study actively trained attention (i.e., either toward threat or away from threat), it is not possible to determine whether attention bias to threat can be reduced via probe detection tasks and whether this change decreases anxiety vulnerability. These uncertainties exist because previously observed effects of the dot probe training task might reflect only the capacity to increase attention bias to threat and subsequent anxiety in the “attend threat” condition. Thus, in the current study, we attempted to create a baseline condition in which there was no contingency between the location of the probe and the location of the threat or neutral information.
Second, previous research using the probe detection task to modify attention has relied on catch trials of novel stimuli imbedded within the training task to assess change in attention over the course of training (MacLeod et al., 2002
). However, demonstrating a change in bias on the same task used to manipulate attention may be limited in providing support for the hypothesis that the training procedure changed attention processes in general. A more parsimonious explanation for changes in participants’ responses to the probe detection task would be that they mastered the task. To address this issue, it would be necessary to administer an independent measure of attention bias before and after the training. To the extent that this assessment task differed from the training task, we could be assured that the training was effective in changing attention processes. Accordingly, we chose to use a modified version of the Posner paradigm (Posner, 1980
) as an independent measure of attention.
Third, it remains to be established whether attention training procedures are capable of modifying attention biases and emotional reactivity in individuals with high levels of social anxiety. Accordingly, we examined the effect of attention training in a sample of individuals with high levels of social anxiety. Finally, MacLeod et al. (2002)
evaluated the impact of attention modification on self-reported emotional reactivity. Exclusive reliance on self-report measures prevents ruling out the competing hypothesis that the attention modification procedures influenced the response tendencies or decision rules that participants employed when making judgments about their emotional reactions to the stressor (MacLeod, 1993
). To address this issue, we included an independent assessment of participants’ behavioral responses during a social stressor (i.e., speech task).
To investigate whether attention bias to threat is causally involved in the maintenance of social anxiety, we examined the effect of a single attention training session similar to that described by MacLeod et al. (2002)
in reducing anxiety response to a social stressor in individuals with social anxiety. Consistent with earlier work (MacLeod et al., 2002
), we predicted that, compared with the Attention Control Condition (ACC), the Attention Modification Program (AMP) would decrease attention bias toward threat, lower anxiety, and improve social performance during a stressor.