EEG and ECG from 5 to 10 months of age: developmental changes in baseline activation and cognitive processing during a working memory task.

We recorded electroencephalogram (EEG) and electrocardiogram (ECG) from 20 infants monthly between 5 and 10 months of age during baseline and during performance on the looking A-not-B task of infant working memory. Analyses of baseline data showed age-related increases in EEG power (medial frontal, central, temporal, medial parietal, lateral parietal, and occipital electrode sites) and coherence (frontal pole-medial frontal, medial frontal-lateral frontal, medial frontal-medial parietal, and medial frontal-occipital electrode pairs), and decreases in heart rate (HR). Patterns of age-related change were similar for EEG power, EEG coherence, and HR. Analyses of task data relative to baseline revealed task-related increases in EEG power (all electrode sites), but no task-related changes in EEG coherence (medial frontal pairings) and HR. There was some evidence of localized task-related changes in EEG power by 10 months of age. These data highlight age-related changes in EEG and ECG, as well as the functional significance of these psychophysiological measures during baseline and during cognitive processing in the first year.