Ability To 'Tell The Difference' Declines As Infants Age

A new article suggests that infants fine-tune their visual and auditory systems to stimuli during the first year of life, essentially "weeding out" unnecessary discriminatory abilities. In one study, for example, 6-month-old infants were able to differentiate two human a faces as easily as two monkey faces whereas 9-month-olds could only differentiate between two human faces. Importantly, if infants are familiarized with monkey faces from 6 to 9 months, they maintain the ability to tell the difference between two monkey faces.