Gender difference for detecting global motion in adults and children

AIM: To investigate if there is a gender difference in detecting global motion in adults and children aged 6 to 15y, respectively. METHODS: A total of 46 adults aged between 20 and 24y, and 227 children aged between 6 and 15y who were divided into five age groups, participated in this study. Global motion detection was evaluated with a random dot kinematogram test, with the proportion of the dots moving at the same direction (up vs down, or left vs right) varied in each trial. The speed of each dot consisted of 1.0 and 5.0 deg/s, therefore four conditions of dots moving were examined in this study. Subjects were asked to identify the direction of the perceived global motion in a three-down-one-up staircase algorithm. The minimal proportion of signal dots moving at the same direction for global motion to be perceived is defined as the threshold. Each subject was measured five times and the mean value was recorded in each condition. Two-way analysis of variance was used for data analysis to accommodate the interaction between the two factors: age and sex maturation. RESULTS: For signal dots moving vertically with 1.0 deg/s, the influence of gender and age on global motion detection was statistically significant (gender: F=10.533, P=0.001; age: F=8.599, P<0.001). The thresholds for adult females and 14-15y girls were significantly higher than that in adult males (P=0.013) and 14-15y boys (P=0.030). There was also a similar effect of gender and age for signal dots moving horizontally with 1.0 deg/s (gender: F=12.073, P=0.001; age: F=8.724, P<0.001). The thresholds for adult females and 14-15y girls were significantly higher than that in adult males (P=0.004) and 14-15y boys (P=0.009). For signal dots moving vertically with 5.0 deg/s, the influence of gender on global motion detection was statistically significant (F=6.826, P=0.010), while there was no difference between adults and children (F=1.085, P=0.369). The threshold for adult females was significantly higher than that in adult males (P=0.002). Finally, for signal dots moving horizontally with 5.0 deg/s, there was a similar effect as dots moving vertically with the same speed (gender: F=7.775, P=0.006; age: F=1.794, P=0.114). The thresholds for adult females and 14-15y girls were significantly higher than that in adult males (P=0.001) and 14-15y boys (P=0.017). CONCLUSION: Gender difference in detecting global motion exists only in adults and children older than 14y.