Figure 3.

The development of contrast sensitivity in macaque monkeys and humans. Contrast sensitivity is plotted as a function of age for an individual macaque infant tested longitudinally (a) and group data from multiple studies of human infants and children (b). The pattern of improvement in contrast sensitivity with age is similar in the two species. The macaque data are from Boothe et al. (1988). The human data were compiled as average sensitivity at the spatial frequencies tested. The 1 and 3 month data are from Banks and Salapatek (1978). The 8 month data are from Peterzell et al. (1995). The 48 month data are from Ellemberg et al. (1999). Redrawn from Kiorpes (2008).