, 2003; Wetzel et al., 2006) similarly to the adult RON response or (ii) further assessment of auditory changes at a higher-order, cognitive level that follows the initial change detection reflected by the MMN (Čeponienė et al., 2004; Horváth et al., 2009a). These suggestions are not necessarily

mutually PF-02341066 ic50 exclusive as deviant sounds probably elicit multiple temporally overlapping but functionally distinct components in the LDN time range that are differentially activated depending on the stimuli and task. Even the relatively moderate deviant stimuli used in the current study elicited LDN-like responses. For the frequency, intensity, and location deviants, the LDN was not preceded by a P3a. Therefore, the deviant LDNs were probably not related to distraction contradicting the attentional reorienting interpretation. However, if the LDN indeed reflects higher-order evaluation of auditory changes (Čeponienė et al., 2004),

our results imply that this kind of processing is less pronounced in the children with high scores in the musical activities index. This suggests more economical use of these putative processing resources in children with more informal musical activities in their home environment. Irrespective of its functional role, however, it is evident that the LDN elicited by deviant RG7204 concentration tones in a passive condition diminishes in the course of brain development (Mueller et al., 2008; Bishop et al., 2011) to the extent that it is not usually seen in adults (Cheour et al., 2001). This indicates that the LDN is typical for immature processing of auditory changes. The current study shows that, in 2–3-year-olds, rich informal everyday musical experience is associated with reduced LDN and therefore links such musical experience to more mature processing of auditory changes. It is noteworthy that this association was not limited to specific deviant types but was seen across all of the change types employed. The late negativity elicited by the novel sounds was also significantly correlated with the overall

score for musical activities at home. As the acoustically salient novel sounds are likely to cause distraction (Escera et al., 1998), the attention interpretation seems more plausible here than for the LDNs elicited by the relatively subtle deviants. Therefore, this response was termed as RON according to the adult response (Schröger & Wolff, Succinyl-CoA 1998). Presumably, the children’s attention was involuntarily drawn to the novel sounds after which the children reoriented their attention towards the primary task (i.e. watching a movie) and therefore the RON was elicited. It should be noted, however, that the relation of the RON-like component reported here and the adult RON response is uncertain especially as the young age of the subjects precluded the use of behavioural measures of distraction. However, based on previous studies it seems likely that processes related to attention allocation contributed to this component.