2007); an according association with right IFG has also been reported (Bergerbest et al. 2004). In line with these findings, the naming RTs in the present study were lowest
(see Abel et al. 2009a) and IFG deactivations most prominent for the associative facilitators as also shown in parameter estimates (Fig. 6). Thus, the IFG appears to be a good indicator for a successful response to priming. Contrary, this brain area was even enhanced for categorical distractors (see Fig. 3, Fig. S1), which might mirror reduced semantic priming effects due to high semantic selection demands. For phonological distractors, the effort for semantic retrieval appears to be somewhat in-between, as middle frontal gyrus (BA Inhibitors,research,lifescience,medical 11) was even enhanced to a small extent. Furthermore, regions related to conflict processes were prominently suppressed for facilitatory distractors (Table 5). Conflict processes Inhibitors,research,lifescience,medical can be split into distinct components. The detection of conflict/competition was located in ACC (Carter et al. 1998; Botvinick et al. 2004) and inhibitory control in OMPFC (Fuster et al. 2000; for monitoring and control in prefrontal areas, see Badre and Wagner 2004; Amodio and Frith 2006).
The SMA can be divided into an anterior part responsible for higher level planning, including the selection and encoding of words to be produced (pre-SMA), Inhibitors,research,lifescience,medical and a posterior part implicated in overt articulation and motor execution (SMA-proper) (Alario et al. 2006). Pre-SMA also has shown to be engaged in error-related processing (Ullsperger and von Cramon 2004; Abel et al. 2009b), altogether indicating its role in conflict processing. Notably, in the present study SMA-proper was suppressed for the phonological but not associative distractors. Therefore, speech execution in the associative AVL-301 nmr condition Inhibitors,research,lifescience,medical appears to be equally demanding as in the unrelated condition, while speech planning and conflict processes were primed. Instead of high demands (effort), dual activation Inhibitors,research,lifescience,medical may be the reason for the missing priming effect: SMA-proper (with peak in left paracentral lobule, BA 6) was bilaterally enhanced for the associative condition when compared
to the categorical condition, which was attributed to high facilitatory forward activations to phonetic processing for the former (Abel et al. 2009a). Remarkably, several regions ADP ribosylation factor involved in the present priming effect have previously shown to be engaged in error-related and effortful processing (e.g., Ullsperger and von Cramon 2004; Christoffels et al. 2007; Abel et al. 2009b). Abel et al. (2009b) reported that spontaneously occurring errors in overt naming yielded activations in bilateral pre-SMA/ACC, IFG/insula, prefrontal and premotor regions, OMPFC, thalamus, as well as right parahippocampal gyrus. Moreover, right STG and cerebellum were implicated. As most of these areas were also involved in correct naming, the monitoring of one’s own speech was taken to be part of the naming process in general.