9 vs 93.6%). Error rates between the three groups did not significantly differ [F(2,51) = .632, p = .5358] and there were no interactions [F(4,102) = 2.205, p = .0736]. In RT there was a significant

effect of group [F(2,51) = 3.74, p = .0305]. Post hoc Tukey contrasts revealed that adolescents were 79 msec faster than middle-aged adults (p = .0235, 571 vs 650 msec). There were no other significant group interactions [F(4,102) = 1.888, p = .1181]. RT showed a significant congruency effect [F(2,102) = 101.41, ɛ = .950, p < .0001]. Post hoc Tukey contrasts revealed the congruent condition was 20 msec faster than the SC condition (p = .0001, 592 vs 612) and 41 msec faster than the RC condition (p = .0001, 592 vs 633 msec). The SC condition was 21 msec faster than the RC condition (p = .0001, 612 vs 633). The RT difference values that indicate specific types of conflict e.g., general conflict (RC − CON), stimulus conflict (SC − CON) and response conflict (RC − SC) were also examined. GDC-0068 in vitro Combined stimulus and response conflict [or general

conflict (RC − CON)] yielded the greatest increase in RT compared to the congruent condition and this was significant across all groups [F(2,102) = 24.209, ε = .6603, p < .0001]. Interestingly RT isolated during stimulus (SC − CON) and response (RC − SC) conflict did not significantly differ (p = .9965). Overall there were three important findings from the behavioural results. First the task was validated, as there was a significant difference in RT between the three conditions across all age groups. Second in terms of group differences, there were no significant group AZD2281 clinical trial differences in accuracy that is unexpected as we predicted that adolescents would perform less accurately than older adults. Also the RT of middle age adults and adolescents did not differ from young adults. We Adenosine expected that adolescents would be faster than young adults, however this is not the case, although they were significantly faster than middle age adults. Third, in terms of congruency effects, the two types of conflict did not differentially affect RT. This indicates that at the final overt level, RT is not differentially

sensitive to stimulus or response conflict in this task. Fig. 2 depicts the grand-averaged ERPs from a pool of centro-parietal electrodes (129, 55, 54, 42, 53, 52, 51, 59, 60, 61, 79, 62, 67, 66, 72, 85). For an overview of significant results refer to Tables 3 and 4. These results outline the two approaches described in the Introduction; first, group differences in the stimulus and response stages of information processing are presented. This is followed by any specific changes in either stimulus or response conflict processing as evident from significant congruency effects or from an analysis of the difference waves. The repeated measures ANOVA of congruency (3) × hemisphere (2) × group (3) revealed that the P1 (occipital) peak latency significantly differed between the three groups [F(2,51) = 5.607, p = .0062].