Whereas themes 1 and 2 were driven by the aims of this thesis, theme 3 follows from reflection of the overall patterns found in the data. To summarise: task demands matter. That is to say, in this thesis overall, effects of social anxiety were only found when emotion was task-relevant.
For example, in the attentional blink task with explicit emotion judgement (face-T2; chapter 2, experiment 2), low socially anxious participants were not as accurate for happy faces as they were for disgusted faces, whereas high socially anxious participants processed both happy and disgusted faces accurately. However, in the implicit task (experiment 3) social anxiety related differences did not emerge. Furthermore, in the child sample (explicit emotion task) social anxiety related differences were found as well, this time as a main effect. In contrast, in the eye- tracking study (chapter 4) there was some evidence of social anxiety related attentional avoidance and perhaps delayed disengagement, as described above, but these findings were subtle at most. Finally, a social anxiety related effect emerged in the ssVEP study (chapter 5) which was designed with this task-relevance in mind. Again, social anxiety related differences were only found when emotion was task relevant. It would appear therefore that attentional biases may only surface when participants have a specific attentional set which promotes scanning of the environment for emotion.
The idea that task demands may affect attentional biases is consistent with an emerging body of research demonstrating that task relevance is important for
performance of emotional-attention tasks. For example, Stein et al. (2009) found a stronger attentional blink for fearful than for neutral faces when the emotion was task- relevant, but not when the emotion was task-irrelevant., It has recently been suggested that inconsistencies in the literature regarding anxiety-related attention bias might exist, at least in part, because of differences in the task-relevance of emotional stimuli (Dodd, Vogt, Turkileri, & Notebaert, 2016).
A recent theory (Richards, Benson, Donnelly, & Hadwin, 2014) provided one explanation for how task-relevance might affect attention. For biases that occur during
early stages of attentional processing, the terms hypervigilance and facilitated orienting might be confusing. These terms are often used interchangeably (e.g. Bar- Ham et al., 2007). However, Richards et al. (2014) proposed that early attentive biases can be divided into two distinct components that are unlikely to occur simultaneously: 1) hypervigilance and 2) selective attention. The review paper by Richards and
colleagues provides models of each mechanism under which the facilitated attention component discussed in this thesis acts differently. Under hypervigilance, which is related to alertness for threat signals and scanning of the environment, facilitated attention leads to enhanced threat detection. When attention is narrowed onto threat under selective attention however, facilitated attention is responsible for rapid engagement with threat rather than enhanced detection. Outcomes of impaired
attention are also different under hypervigilance than under selective attention. Under selective attention, when threat is present but task irrelevant, impaired attention can be reflected by attentional capture by threat or delayed disengagement from threat. However, under hypervigilance, when threat could be task relevant too, but also absent, impaired attention is reflected in difficulties focusing attention on the task. It is interesting to explore the results of the current experiments with these models in mind and have a closer look at task-relevance of threat.
In the saccade curvature task, threat was present but a) task-irrelevant, and b) not in a task-relevant location. Social anxiety related biases therefore would have emerged under conditions of hypervigilance, where the environment is excessively scanned. Under hypervigilance, impaired attention is highlighted by difficulties focusing on the task altogether and not necessarily by attentional capture by threat or delayed disengagement, which could explain why no strong evidence for either was found. From the ssVEP task, designed with task demands in mind, it could be derived
that facilitated attention under selective attention may not only result in faster and better performance on eye-tracking tasks as proposed by Richards et al. (2014), but also to reduced neural adaptation, and therewith sustained emotional attention.
However, a number of findings from this thesis do not align particularly well with the predictions of the Richards et al. (2014) model. When threat was task relevant in the attentional blink task (chapter 2, experiment 2), the model would predict that impaired attention would be reflected in threat capture, but the high socially anxious participants did not show a preferential capture of disgusted faces. Similarly, when threat was present but task-irrelevant in the attentional blink (chapter 2, experiment 3), the model would predict social anxiety should affect tasks
performance, but there was no social anxiety related general performance deficit. Nevertheless, it is important to highlight that the studies in this thesis were not designed to address the effects of task relevance per se and this was not one of the original aims of the thesis. However, the overall pattern of results presented here together with the recent progress in theory and research discussed suggests that is a promising area for future research which may help to reconcile seemingly inconsistent findings in the field.
Theme 3 conclusion. In hindsight, the overall pattern of results reported in
this thesis could potentially be explained by the varying task-demands affecting top down mechanisms of attention. Overall, stronger anxiety-related effects were found if participants’ attention was directed toward the emotion by task-demands. Fewer convincing anxiety related effects were found when emotion, or threat specifically, was task irrelevant. Different task demands and characteristics could evoke different attentional sets, such as alertness in hypervigilance or preferential processing in
selective attention. It is proposed that future studies should investigate under which conditions attention bias in social anxiety are present.