Objective: We investigated differences between children and adults in selective attention.
Methods: Event-related potentials of 9 year-old children and adults were studied. Subjects performed an active dichotic novelty oddball task. We examined age-related differences in early selection by comparing non-target tones and late selection by comparing target tones in the attended and unattended channels.
Results: In children, an attention effect was seen on the N1 response to standard tones. For the targets, both children and adults displayed enhanced P3b amplitudes on the attended side, and in adults, an attention effect was also seen on the N2 response. In children, novelty-elicited N2 responses were larger to left ear stimuli irrespective of the direction of attention. Adults displayed enhanced novelty-elicited N2 amplitudes on the attended side.
Conclusions: Developmental changes occur both in early attentional selection and target detection. Children employed efficiently the mechanisms of early selection when processing standard stimuli, whereas their processes in relation to novel stimuli were attention-independent and even varied with ear. Adults were able to maintain their attentional focus in the presence of unexpected stimuli.
Significance: The results of this study contribute to elucidation of the development of selective attention.