In the study, researchers at the University of Massachusetts analysed about 50 kids between the age group of 1-3 years, each of whom was with one parent.
Half of the one-hour session, parents and children were in a playroom without TV, while in the other half-hour, parents chose an adult-directed program to watch (such as Jeopardy!).
The researchers observed how often parents and children talked with each other, how actively involved the parents were in their children's play, and whether parents and children responded to each other's questions and suggestions.
It was found that when the TV was on, both the quantity and the quality of interactions between parents and children dropped.
Specifically, parents spent about 20 percent less time talking to their children and the quality of the interactions declined, with parents less active, attentive, and responsive to their youngsters.
"Although previous research found that background television disrupts young children's solitary play, this is the first study to demonstrate its impact on the quantity and quality of parent-child interactions," said the researchers.
"Given that high-quality parent-child interaction plays an important role in children's development, the study challenges the common assumption that background TV doesn't affect very young children if they don't look at the screen. We need to pay greater attention to children's early, chronic exposure to TV," they added.
The study has been published in the journal Child Development.