CARGA ANIMAL

Although the current program of research has numerous strengths, it also has several limitations that warrant further discussion and that highlight important areas for further research. First, Waechter and colleagues (2014) have found that the reliability of eye

movement indices for first fixations and early time epochs is poor, which may account for the negative findings regarding the indices of early facilitated orienting. Although the

randomization of stimulus location in Study 3 was designed to reduce participant’s tendency to look at the left or top images first, the reliability of this approach has not yet been assessed and further research on the reliability of eye movement indices in general is needed.

Second, it is important to note that the “threatening” stimuli were simply static images. It may be the case that when presented with stimuli that represent more realistic threats (e.g., live spiders for people afraid of spiders) and fear schema are fully activated, that viewing patterns may more closely follow those proposed by models of ABT (e.g., Beck & Clark 1997; Eysenck, 1992; Mogg & Bradley, 1998). Furthermore, participants were presented with only two images at a time, knowing that threat images would be present, whereas environments generally are much more complex with multiple competing stimuli that one cannot as easily predict will contain potential threats. Future research would benefit from using more complex stimulus displays and experimental paradigms where threat is unexpected and more unpredictable (Richards et al., 2014) to emulate more real world experience.

It is also worthy to consider that vigilance and avoidance may have much to do with the extent to which the individual appraises the imminence and severity of the threat as well as their capacity to flee or fight (e.g., Craske, 1999). If one is afraid of spiders and a spider appears in the room, it may capture attention if it is on the move, is very close, or is

especially fearsome looking. However, if the spider stays at a distance and does not move, it may be less anxiety-provoking to ignore it. However, if one lacks the capacity for attentional control, such regulatory attempts may fail. It may be the case that attention retraining is successful in reducing anxiety (e.g., Amir, Beard, Taylor, Klumpp, Burns, & Chen, 2009) less because it overrides actual attentional biases and more because it helps individuals develop greater attentional control in the later stages of attentional processing (Koster, Baert, Bockstaele, & De Raedt, 2010). Thus, whereas bottom-up deployment of attention may depend to a large extent on detecting salient emotional stimuli, top-down deployment of attention may depend, at least to some extent, on the appraisal of the imminence, severity,

and control one has over the threat, as well as the capacity to master attentional deployment, which in turn may help account for inconsistencies in findings across studies. In future research it might be worthwhile to match eye movements with stream of consciousness verbalizations in addition to further assessment of threat appraisal and motivation to monitor versus avoid the stimuli as used in the current program of research.

Relatedly, as discussed in Study 3, the free viewing paradigm did not require participants to control or disengage their attention from threat, and thus it is unknown whether trait anxiety effects would have been observed if attentional control, or the ability to disengage from threat, was assessed more directly. Further research is needed to disentangle the effects of trait and state anxiety on attention to threat during controlled attention tasks (e.g., anti- saccade tasks). If trait anxiety is associated with a difficulty disengaging attention from threat, above and beyond the effect of state anxiety, then this result would suggest that a mechanism likely involved in trait anxiety-related ABT, and perhaps anxiety disorders, involves distractibility and the difficulty focusing attention on a goal/task when potential threat is present (Eysenck, 2007) rather than simply a preference to attend to threat.

Moreover, a recent theoretical distinction between selective attention and hypervigilance may account for the mixed results in the literature and improve our understanding of anxiety- related ABT beyond the current models (Richards et al., 2014). That is, facilitated attention may result from a preference for processing threat (i.e., selective attention) or an alertness for threat signals (i.e., hypervigilance) that occurs more generally, even before threat is present. These two processes rely on separate attentional systems (orienting versus alerting,

respectively), differ in mechanisms (e.g., broadening versus narrowing of attention, respectively) and result in distinct eye movement behaviours based on specific conditions (presence or absence of threat and task-relevance of threat) that indicate specific attentional outcomes, such as facilitated attention (common to both constructs), delayed disengagement (specific to selective attention) and difficulties focusing attention on a task (specific to hypervigilance). Richards and colleagues (2014) argue that eye movement research supporting anxiety-related selective attention of threat to date is mixed at best, while other research (e.g., using visual search and distraction paradigms) has more clearly indicated that

trait and clinical anxiety is associated with greater hypervigilance, as indicated by a broadening of attention and fewer eye movements or excessive and rapid scanning and numerous eye movements, that overall, increase distractibility and reduce attentional control (Eysenck et al., 2007). Interestingly, they suggest, as does Gerdes and colleagues (2008), that there may be an “unspecific hypervigilance followed by a specific disengagement deficit” (p. 7). That is, anxious individuals show hypervigilance for all stimuli, irrespective of threat value if threat is possible, and then once detected, there is a deficit in disengaging threat stimuli specifically, rather than stimuli in general. While this theory does not articulate distinctions in relative roles of trait and state anxiety on these attentional processes, it does provides a broader framework for understanding potential maladaptive attentional processing associated with anxiety and links the processes to observable eye movement behaviours that can be empirically tested in combination with state and trait anxiety effects. For instance, is hypervigilance associated with state anxiety, trait anxiety, or an interaction between the two?

Finally, the current study used an undergraduate sample that varied in levels of trait anxiety given that the effect sizes of ABT appear to be similar to clinical samples (e.g., Bar- Haim et al., 2007). However, further research is needed to assess the relative contribution of trait and state anxiety in a clinical sample with diagnosed anxiety disorders relative to non- anxious controls in order to extend the current research to the populations we are most interested in understanding and treating.