Those action-packed video games under many Christmas trees on Sunday morning may be loads of fun, but don't expect them to improve kids' grades, concentration, driving skills or other cognitive abilities, one group of psychologists says.

Some researchers also say they've found video games such as current top-seller "Call of Duty: Modern Warfare 3" won't damage players' brains or cause them to do real violence.

Those relatively recent findings conflict with other studies on both the positive and negative potential of gaming, but one thing experts on all sides tend to agree about is that the debate -- and their research -- is far from over.

"Play these games because they are fun and you enjoy doing them, and let's kind of wait for more research to suggest whether or not they are actually good for us," said Florida State University psychologist Walter Boot.

Boot and two colleagues say they have turned up flaws in various studies ascribing cognitive benefits to playing video games and that they they've been unable to replicate the results. Boot, Florida State doctoral student Daniel Blakely and University of Illinois researcher Daniel Simons wrote about their findings in a paper published in the journal Frontiers in Psychology three months ago.

It "happens to be a rather direct attack about our work," University of Rochester researcher Daphne Bavelier wrote in an email Thursday from France where she is on sabbatical.

Bavelier defended studies she and other scientists have conducted that show a causal link between video game playing and enhanced abilities.

She said it is Boot and his colleagues who have flaws in their work and wrote a point-by-point rebuttal of their paper's detailed findings. It's also the only negative position paper aligned against multiple, peer-reviewed studies by "world renowned experts," she wrote.

"This paper does not present new evidence, or even new analysis -- it is just an opinionated discussion of existing data," Bavelier wrote. "Quite simply put, there is not much controversy about the published effects so far."

Christopher Ferguson, a clinical psychologist at Texas A&M International University in Laredo, Texas, has focused on the perceived dark side of video gaming. As opposed to prior studies indicating violent games could beget violent actions, Ferguson said he found "nothing."

Studies on violence and video games have some of the same flaws Boot found for research on cognitive benefits, Ferguson said. He said that was probably because researchers drew conclusions before all the data was in.

"Video games had this sort of new toy effect," Ferguson said by phone from Orlando, where he was visiting relatives for the holidays. "People didn't know what to think about them and kind of got excited in both positive and negative ways."

This month's edition of the journal Nature Reviews/Neuroscience includes an article on video game research, describing it as being still in its early days. The journal posed several questions to prominent researchers and published their responses.

They include Bavelier, an assistant professor in Rochester's Department of Brain and Cognitive Science, and University of Minnesota psychologist C. Shawn Green, who submitted joint responses.

They maintained playing action video games "results in a wide range of behavioral benefits, including enhancements in low-level vision, visual attention, speed of processing and statistical inference."

Bavelier and Green also wrote there's no black-and-white answer to the question of whether video games improve cognitive function because there are millions of games and hundreds of genres that can be played on various devices including computers, consoles and cell phones.

"Simply put, if one wants to know what the effects of video games are, the devil is in the details," they wrote.

Two more scientists questioned by the journal also cited studies showing positive results two others wrote that effects on the brain and behavior are "uncertain" and that studies have not generally showing gaming enhances higher level reasoning.

Duke University cognitive neuroscientist Marty Woldorff said he falls in the middle between Boot and Bavelier. He said some of her findings have been replicated but others have not.

"The jury is still out," Woldorff said. "This is how science works."

Boot, 32, and Ferguson, 40, grew up playing video games. Ferguson said he still plays games such as Lego's Star Wars and Indiana Jones with his 8-year-old son. He suggested other parents do likewise.

"When they hear about Grand Theft Auto or Medal of Honor they get all freaky about it," Ferguson said.

But, he said, a colleague's research shows parents realize their fears were unjustified once they've played the games themselves.

Those trying to improve specific abilities such as driving a car or flying an airplane should look to simulators that focus on those skills instead of video games, Boot said.

"Simulate the demands that you'll actually encounter in those tasks rather than giving someone Grand Theft Auto and assuming there's going to be some kind of magical transfer of skills that you pick up in that game to actual driving performance," he said.

There's also a proven alternative for boosting brain power that has other beneficial effects as well, Boot said. It's called exercise.

"Don't sit down and play a game," he said. "Go out there for a walk."