Recognition of tactile relief by children and adults

This study was designed to compare tactile sensitivity of children and adults on printed target stimuli covering a wide range of elevations and requiring different resolutions. A recognition-relief task using 9 digits at 6 levels of elevation from a surface (0.5, 0.4, 0.3, 0.2, 0.1, and 0.05 mm) was presented to 24 young adults and 24 children. As predicted, relief elevations as low as 0.05 mm were recognized above chance. As predicted, children performed significantly more poorly than the adults on recognition at all elevations, although the difference increased as elevation increased. Adults performed significantly better than children on high-resolution digit 8, but there was no reliable age difference on low-resolution digit 1. Recognition difference between the high- and low-resolution digits decreased nonlinearly as elevation increased, irrespective of age. Overall, the findings support previous research indicating greater tactile sensitivity in adults than in children, but the superiority was moderated by the elevation and resolution requirements of the stimuli.