Haptic Performance in Later Life Figure 1. Development of haptic performance in later life. A. Individual haptic performance (i.e., number of errors) is depicted for male (blue squares, N = 31) and female (red squares, N = 47) subjects. Trend lines are inserted for male (solid blue), female (solid red), and all subjects (dashed black). Haptic performance declined with increasing age (Pearson correlation, N = 78, r = 0.479, p#0.001). B. Group data for haptic performance (i.e., number of errors) for younger adults (left squares; females: N = 29, 60.2467.07 years; males: N = 15, 58.5367.62 years) and older adults (right squares; females: N = 20, 76.9565.94 years; males: N = 17, 75.7666.71 years). There was a significant interaction of the subjects’ age and gender with their haptic performance (AGE*GENDER: F(1,31) = 17.535; p#0.001). Black bars indicate SEM. doi:10.1371/journal.pone.0030420.g001 correlation corrected for AGE, N = 43, r = 0.063, p = 0.341) (fig. 4A). Investigation of the subjects’ cognitive and haptic performance revealed a significant correlation between these 2 variables (partial correlation corrected for AGE, N = 74, r = 20.348, p = 0.001). This correlation was also found to be significant in subset of male subjects (partial correlation corrected for AGE, N = 28, r = 20.335, p = 0.036), but not among the female subjects (partial correlation corrected for AGE, N = 43, r = 20.210, p = 0.083) (fig. 4B). Finally, we found a significant correlation between the subjects’ cognitive performance and tactile acuity as assessed by the two-point discrimination test (partial correlation corrected for AGE, N = 76, r = 20.198, p = 0.041), which was not found in the subset of either the male subpopulation (partial correlation for AGE, N = 28, r = 20.302, p = 0.052) or the female subpopulation (partial correlation for AGE, N = 45, r = 20.153, p = 0.153) (fig. 4C). Comparing the correlation coefficients of haptic and tactile data (N = 74, r = 0.133; fig. 4A) with haptic and cognitive data (N = 74, r = 20.348, Fig. 4B) we found a significant difference (Fisher-Z- transformation, p = 0.003) indicating a stronger relationship between haptic performance and cognition as compared to haptic performance and tactile acuity. The comparison of the correlation coefficients of haptic and cognitive data (N = 74, r = 20.348, fig. 4B) with tactile and cognitive data (N = 76, r = 20.198, fig. 4C) revealed no significant differences (Fisher-Z-transforma- tion, p = 0.330). PLoS ONE | www.plosone.org 3 January 2012 | Volume 7 | Issue 1 | e30420