The addictive nature of some computer games was also leading to serious social disorders, doctors giving presentations at this year's Australian Council on Children and the Media conference said.
While many parents worry whether they should give small children access to technology, a lecturer at the Institute of Early Childhood at Macquarie University, Kate Highfield, said a small amount of screen time with the right apps or games could help a child's development.
However, too much time with technology or the wrong kind of content could be harmful, the Sydney Morning Herald reported.
Dr Highfield said that since [screens] are mobile they are able to be taken anywhere, which increases their use and can be key in displacing other activities and engaging with others.
Her research found 85 per cent of the apps purchased for children were just "drill and practice" apps that asked children to repeat an action or recall simple facts.
These "consumption" based apps led to lower-level neural development while excessive in-game rewarding led to unrealistic expectations.
Parents and teachers should provide a range of technology, she said, because "if a child is only playing those types of basic drill and practice apps, that's not a healthy digital diet".
She recommended apps like Artmaker, My Story, Explain Everything, Toca Builders and Creatorverse, which require input from the child.
Current health regulations suggest children under two years of age have no screen time at all, including television, and children under five years have less than an hour a day.
Surprisingly, even adults should have no more than two hours of screen-based entertainment a day.