3It is possible that between-session habituation occurred for those participants who had already participated in the task during the EEG session, which could have led to different patterns of

habituation for these participants, relative to those participants who had not already participated in the task. We tested this possibility by examining whether moderation of neural habituation by anxiety type differed for those who had already participated in the EEG task and those who had not. Results revealed that there was no significant difference in moderation of habituation by anxiety type. Inhibitors,research,lifescience,medical This finding is consistent with research indicating that, even when within-session Inhibitors,research,lifescience,medical habituation occurs, multiple sessions of exposure

may occur before between-session habituation is evident, and peak fear activation may actually increase between early sessions (e.g., Nishith et al. 2002). 4In order to assess whether the specific stimuli used in the present study can elicit fear, we examined ratings of the ANEW data set provided by Stevenson et al. (2007). In this study, participants rated whether each word elicited fear (rating scale: [1] “not at all” to [5] “extremely”). We extracted the mean fear rating (across participants) for each of the words used in the present Inhibitors,research,lifescience,medical study and conducted t-tests to determine (1) whether words from the negative condition elicited significant levels of fear and (2) whether words from the negative condition elicited significantly Inhibitors,research,lifescience,medical greater fear than did words from the neutral condition. First, a one-sample t-test indicated that words from the negative condition elicited significant levels of fear (mean = 3.3, t(63) = 31.4, P < 0.001). Second, an independent samples t-test indicated that words from the negative condition elicited significantly greater levels of fear than did words from the neutral condition (mean difference = 1.9, t(190) = 29.8, P < 0.001). Therefore, the negative words

used in the present study can elicit fear. 5The relationship between MASQ-AD-LI and neural habituation Inhibitors,research,lifescience,medical was examined using a whole-brain gray-matter mask, because no a priori hypotheses were made regarding depression and habituation in specific brain areas. No significant clusters were observed in which MASQ-AD-LI moderated habituation to negative stimuli. 6The Broca’s area mask from Thymidine kinase the Juelich atlas (standard with FSL) was also examined. All clusters found using the IFG mask were also observed when using the Juelich Broca’s area mask, indicating that choice of mask did not drive present findings. 7It was possible that the PSWQ PARP signaling analyses were biased to be more liberal that the MASQ-AA analyses, because two smaller masks were used for the PSWQ analyses rather than one large mask (two masks were used because the tests for left IFG vs. the other regions were one-tailed in opposite directions).