The Naked Scientists are joined by marine biologist Dannielle Green, physicist Stuart Higgins, psychologist Duncan Astle and astrophysicist Carolin Crawford, to tackle your questions. This week, find out whether you can hear screams in space, how to clean a beach, and just how giant is a Giant Squid?

Brain training is a popular subset of games many people use daily, but is there any Brainevidence that gaming can actually change our brains? And with younger people in particular so enamoured of video games, can we use this as a teaching tool to boost classroom learning? Duncan Astle researches this at the MRC's Cognition and Brain Sciences Unit in Cambridge, and he went over his findings with Chris Smith.

We've been hearing a lot in the news recently about the effects video games haveon children. This week, a scientific paper from Oxford says video games could actually be beneficial, even improving cognitive or intellectual ability. However a paper by scientists from Dartmouth College claims there are negative social impacts if children play violent games. So who, and what, should we believe? Ginny Smith went to talk to Duncan Astle, from the Medical Research Council's Cognition and Brain Sciences Unit in Cambridge...