"You can see the baby's eye movements are anticipating the train coming out again," notes Iain Jackson, an assistant at the University of Manchester's "Babylab," in the northwest of England.
And, as CBS News correspondent Richard Roth reports, it's showing she finds something interesting in what she sees. It's measuring her pupils as the train enters the tunnel red, and comes out blue.
"Now pupils are great because they don't lie," said Babylab's director, Sylvain Sirois. "Pupils grow larger when something arouses your interest and in the case of that particular experiment the pupil data is certainly consistent with our minimalist interpretation of babies."
That minimalist interpretation is challenging some modern thinking.
Sirois says the babies are noticing a new color, but insists they don't know enough to find the sudden color change odd.
"I would say that from the get-go, babies don't know anything and that the world is their learning environment and from that they will have to turn themselves into intelligent people," Sirois said. "I'm very much a fan of learning theory."
But more modern research has suggested infants may be innately "smart," born with the ability to understand something about gravity, for instance, or that an object can still exist, even when it can't be seen.
According to Sirois, that's misreading the babies' minds.
"There's a difference between saying they don't know much and have to learn everything and saying they're dumb," Sirois said. "I wouldn't frame it as dumb so much as naive."
The fact is, scientists argue as much as the rest of us over just how much babies know and when they know it.
Though it's hardly surprising, parents tend to side with the "smart baby" theory.
"She knows a lot more than we think she does," one mother said of her infant.
She likes going to Starbucks and I sit with her in front and read the Times and she likes to read it, only because it's black and white," another mother says. "I don't think she can actually read the newspaper."
But who knows? Surprises from baby labs like this may eventually influence the sort of advice parents get about nurturing development, about learning, about playing. The sort of advice, it turns out, almost everyone wants.
"I work on babies, but as a parent I'm as helpless as the next one," Sirois said. "But what we do know from research and so forth is that babies are very good at telling us when they like something and when they don't like something. So if you are keen about stimulating your baby in an optimal fashion just pay attention to your baby, which is probably what you do already."
These psychologists are doing that by watching the infants' eyes. Parents, of course, find their own ways to read the minds of babies too young to talk.
"I find myself thinking — what is SHE thinking — more than anything," one mother attests.