The results of the study demonstrated that the mechanisms for visual perception change drastically in the second half of the first year of life, from the bottom-up system to the system incorporating top-down processing.
Summary: Study reveals very young infants can perceive objects that older infants, children, and adults can not see due to a phenomenon called visual backward masking.
Source: Chuo University
We can generally recognize an object, even if it is presented for a very brief time. However, if another object appears immediately following the first object, the perception on the first object is impaired such that we do not notice its existence.