An advocacy group called on toymaker Fisher-Price to stop selling a baby seat designed to hold an iPad at the front. It said the product encourages parents to leave infants alone to watch screens that could be harmful. The bouncy seat with an iPad holder is claimed to be the "ultimate electronic babysitter". But the Campaign for a Commercial-Free Childhood, based in Boston, in the US, said it blocks a baby's view of the world, undermining the child's interaction with caregivers. The group cited research by the American Academy of Paediatrics that suggested screen time for children under the age of two was linked to language delays, sleep disturbance and learning problems later in childhood. There was no evidence it was advantageous, the group said. Babies left alone with iPads could also be deprived of activities shown to be beneficial to brain development, such as hands-on creative play and positive interaction with adults, the group said. "By manufacturing a device to restrain infants in front of a screen, even when they're too young to sit up, Fisher-Price actually discourages interactions that are crucial to learning and healthy development," said Dr Susan Linn, the group's director. "Babies thrive when they're talked to, played with and held - not when they're alone with a screen," Linn added. Juliette Reashor, a spokeswoman for Fisher-Price, a brand owned by toy manufacturer Mattel, said in a statement that consumers who purchased the Newborn-to-Toddler Apptivity Seat for iPad gave it positive reviews "that show strong parent involvement and support". The infant seat includes a mirror that can hold an iPad, providing "another way to stimulate and engage baby while protecting your device from baby's sticky fingers and preventing unintentional navigating to other apps", a product description on Fisher-Price's website said.