Development of an ability to maintain verbally instructed central gaze fixation studied in 8- to 10-year-old children.
Development of an ability to maintain verbally instructed central gaze fixation was studied in 8-, 9- and 10-year-old boys. The stability of central gaze fixation was tested by the sudden appearance of a novel, peripheral stimulus triggering reflexive saccade. In Experiment I, the ability to maintain verbally instructed central gaze fixation upon nonsense geometrical pattern was found to be equal in 8 and 9 years of life. This ability increased markedly between 9 and 10 years of age. Gaze fixation upon gradually appearing shapes during a TV-like game reducing volitional effort of subject was, however, equal in all age groups. Concentration of attention upon central stimulus as reflected by saccade latency (Experiment I) and P3-N3 amplitude of evoked potentials to peripheral flashes (Experiment II) was equal in both tasks in 8-year-olds. In contrast, higher concentration of attention upon meaningful central stimulus presented during the TV-like game was found in 9- as well as in 10-year-old boys. Developmental changes of the ability to maintain verbally instructed central gaze fixation might be related to the late structural maturation of frontal cortex.