Finally, the present study found changes over time in brain activation, but these changes were not reflected in significant direct behavioral effects. An indirect effect of selleck inhibitor anxious apprehension on behavior through Broca’s area was observed, along with a nonsignificant effect through right SFG

that was in the expected direction for RT. Therefore, it is Inhibitors,research,lifescience,medical possible that more power is needed to detect the SFG indirect effect and/or there may be as yet unidentified selleck bio regions that mediate effects that are in the direction opposite to that of Broca’s area. Additionally, given that the hypothesized behavioral effect for anxious arousal was in the expected direction, although far from significant, lack of significance here may also be due to a lack of power rather than a true absence of behavioral findings. Furthermore, researchers

have begun to caution against discounting neural findings because behavioral effects are not evident, given that behavior is not necessarily the gold standard for the occurrence of relevant psychological processes (e.g., Wilkinson Inhibitors,research,lifescience,medical and Halligan 2004). However, caution should be maintained when making inferences about present findings given the lack of significant direct Inhibitors,research,lifescience,medical behavioral effects. Future research with either more potent threat stimuli (which may have a larger effect on behavior) or a sample size large enough to detect small overt behavioral effects is needed in order to determine whether the patterns of behavioral

habituation associated with anxious arousal and apprehension are consistent with the present neural findings. In summary, the present study provides evidence for differential time courses of neural habituation associated with Inhibitors,research,lifescience,medical anxious apprehension and anxious arousal in line with Corbetta et al.’s (2008) theory of brain mechanisms serving attention and Heller and colleagues (Heller et al. 1995, 1997; Nitschke et al. 1999, 2000; Engels et al. 2007, 2010) distinction between these two types of anxiety. Inhibitors,research,lifescience,medical Present findings suggest that anxious arousal is associated with immediate engagement with negative stimuli and a concurrent recruitment of an attentional surveillance Dacomitinib system, followed by habituation of this response. In contrast, anxious apprehension is associated with immediate engagement in worry and delayed engagement with negatively valenced stimuli that occurs only after worry decreases. Acknowledgments This work was supported by the National Institute of Mental Health (R01 MH61358, T32 MH19554, P50 MH079485). The authors wish to thank Katie Mimnaugh and Kyle Gerst for their assistance. Footnotes 1The present sample partially overlapped the samples used in Engels et al. (2010) and Spielberg et al. (2012) by 89% and 92%, respectively. However, these studies did not examine variance in activation across time or connectivity between brain regions. Therefore, the studies report independent findings.