HEART-RATE AND SUSTAINED ATTENTION DURING CHILDHOOD - AGE-CHANGES IN ANTICIPATORY HEART-RATE, PRIMARY BRADYCARDIA, AND RESPIRATORY SINUS ARRHYTHMIA

This study examined age changes in three aspects of heart rate respons ivity elicited in an auditory oddball task; anticipatory heart rate ch ange, primary bradycardia, and respiratory sinus arrhythmia. Three age groups (5-, 7-, and 9-year-old boys) were presented with series of ta rget (15%) and standard (85%) tones. The results were consistent with the findings reported previously in the adult literature. Heart rate d ecreased in anticipation of the target tone. The morphology of anticip atory deceleration was somewhat different for the 5-year-olds compared to the older children. Stimuli presented during the early part of the cardiac cycle induced added deceleration, but this primary bradycardi a did not differ between age groups. Respiratory sinus arrhythmia did not discriminate between age groups but was suppressed during the perf ormance of the oddball task relative to base level. It was concluded t hat these three aspects of heart rate responsivity show developmental constancy rather than change.