row, a plot of the rates of change of the mean values (developmental rates) in both the visual and auditory modalities. The male slopes are much larger in absolute value than the female slopes until about age 20. In order to emphasize the decrease in absolute values of the slopes, the y-axis has been inverted. Within genders the rates of change of the mean values exhibit only slight differences between modality. Family type was only sporadically statistically significant in an irregular temporal pattern.
