Interindividual variability in daily sleep amount. Mean values of daily sleep amount (min/24 h) from day 1 to day 28 per each fly (same flies as in Fig. 1). * indicates lines in which the null hypothesis (normal distribution) was rejected (p < 0.05, Lilliefors test of normality).
Bushey et al. BMC Neuroscience 2010 11:56 doi:10.1186/1471-2202-11-56