[An estimation of the contrast sensitivity of kittens after termination of the critical developmental period].

Special contrast sensitivity was estimated in kittens at the age of 6, 9 and 12 months as well as in adult cats. Acuteness of perception of grating pattern remained the same in kittens of 6 as well as 12 months of age. However, the former kittens were shown to have a decreased contrast sensitivity at lower spatial frequencies (cycles/degree). The contrast sensitivity reached the adult level at 12-month age. This seems to reflect a maturation of the higher cortical areas involved in the recognition process.