Extended visual fixation in the early preschool years: Look duration, heart rate changes, and attentional inertia

Visual fixation in infants from 6 months to 2 years of age was examined for its fit to the theory of "attentional inertia." A children's movie ("Sesam e Street" movie, "Follow that Bird") or an extended audiovisual stimulus (c omputer-generated patterns) was presented to 40 children for a minimum of 2 0 min while fixation was videotaped and heart rate (HR) was recorded. Consi stent with attentional inertia theory, fixations toward the stimuli had a l ognormal distribution, HR decreased over the course of a look, and IIR retu rned to prestimulus levels immediately before look offset. Older children ( 18 months, 24 months) showed a distinction in the parameters describing the lognormal distribution for the "Sesame Street" movie and the audio visual patterns, whereas younger children (6 months, 12 months) responded similarl y to the two stimulus types. Fixation patterns of children in this age rang e suggest attention increases over the course of a look, and parameters con sistent with attentional inertia theory differentially develop in this age range.