It has been debated whether acquiring verbal labels helps infants' visual processing and categorization of objects. Using electroencephalography, we investigated whether possessing or learning verbal labels for objects directly enhances one-year-old infants' neural processes underlying the perception of those objects. We found enhanced gamma-band (20 to 60 Hz) oscillatory activity over the visual cortex in response to seeing objects whose names one-year-old infants knew (Experiment 1), or for which they had just been taught a label (Experiment 2). No such effect was observed for objects with which the infants were simply familiar without having a label for them. These results demonstrate that learning verbal labels modulates how the visual system processes the images of the associated objects, and suggest a possible route of top-down influence of semantic knowledge on object perception.