In today's health matters, babies start distinguishing pain from general touch from the time just prior to their birth.

Scientists looked at the brain activity of 46 babies. Twenty-one were born prematurely giving scientists the opportunity to measure activity at different stages of development.

Researchers measured the babies electrical brain activity during a routine heel lance, which is standard to collect blood samples. In premature babies the response to the heel lance was nonspecific.

After 35 to 37 weeks the babies response changed to localized activity in specific brain, which indicates they felt pain.

Findings appear in the journal 'current biology.