Effect of Proactive Mode of Processing on Event-related Oscillatory Brain Responses in Children

Proactive cognition is characterized by the formation and active maintenance of an internal task representation. The aim of this study was to explore if the internal task representation might affect the processing of incoming stimuli. For that aim, the effects of proactive and reactive modes of processing on sensory and cognitive information processing were compared by using event-related oscillatory responses in a developmental model. Thirty six children aged 7-10 years were studied in a sensorimotor task with fixed stimulus sequences. Children were divided into two groups according to their proactive or reactive mode. Auditory event-related potentials were recorded and decomposed in the time-frequency domain to analyze amplitude and phase synchronization of oscillatory responses. Major results demonstrated that proactive mode of processing was characterized by enhanced pre-stimulus theta activity accompanied by a significant decrease of the temporal synchronization of event-related theta/alpha oscillations in the first 300 ms after stimulus. These results provide evidence that maintaining internal task representations in working memory engages oscillatory circuits, which can modulate the processing of incoming sensory information.