Processing of novel identifiability and duration in children and adults

In a passive auditory oddball paradigm identifiability and duration of task-irrelevant novel sounds (novels) were varied in children aged 7-8 and in adults. Event-related potentials (ERPs) elicited by identifiable novels were augmented compared to ERPs elicited by non-identifiable novels around 200ms after stimulus onset. This identifiability effect occurs in children and adults, showing that identifiable novels are processed differently from non-identifiable novels in both age groups. However, only in children the identifiability effect continued for short novels after 300ms. This indicates that children cannot inhibit processing of meaningful task-irrelevant information as efficiently as adults. Moreover, long novels caused more positive amplitudes than short novels in a time-window of 400-600ms in children but not in adults, showing children's increased susceptibility to physically rich sounds. Results are discussed in the framework of current models of involuntary attention referring to the ERP-components N1/Mismatch Negativity, P2, early P3a, and late P3a.