Toronto, May 29 (IANS): Inadequate and poor sleep quality may adversely affect the performance of children in intelligence tests, suggests a research.

"This is an important discovery that confirms the major role of sleep in consolidating cognitive abilities," said researcher Roger Godbout, professor at the University of Montreal in Canada.

The study involved 13 autistic children and 13 neurotypical children - children with a mean age of 10 years without an intellectual deficiency or sleep problem and who were not on medication.

The researchers found that disruptions in protective brain waves during sleep are associated with lower results on verbal IQ (intelligence quotient) tests.

These observations apply for both groups of children, the researchers said.

It also appears that the quality of sleep over the whole night, and not only before midnight or at the end of the night, promotes good intellectual functioning, they said.

"This study establishes a doubt that children and adolescents are particularly affected by lack of sleep, especially because they are in an important developmental period," Godbout said.

The study was published in the International Journal of Psychophysiology.