The purpose of the current study was to examine learning effects in the King-Devick (K-D) test and to determine whether K-D scores differed across age and sex in young adolescents and adults. Composite and trial scores of the K-D test were evaluated in 60 health participants. The K-D composite scores revealed main effects for trial order, card number, age, and sex. Post-hoc comparisons showed faster times across trials. Females took longer than males to complete the test. Participants were faster across trials within each card except for card 3, from trial 2 to trial 3. As reported in other studies, participants demonstrated a learning effect that varied across the 3 cards of the K-D test. Our findings suggest that an additional practice trial of the K-D test should be completed before recording a baseline composite score.
