- Email: [email protected]
Echoes in the brain open a window on yesterday
For daily news stories, visit newscientist.com/news
Echoes in the brain open a window on yesterday
potential alien ecosystems, either on Mars or on other promising spots for finding life (see “Keep Europa tidy, please”, left). “One of the purposes of planetary protection is to help keep us from suffering the consequences of our own ignorance,” says NASA planetary protection officer Catharine Conley. She adds that including such measures adds little to the overall budget of a modern bigticket mission such as the Curiosity rover, which cost about $2.5 billion. The procedures also force better design and more rigorous testing. “Many of the requirements prelanding also overlapped with those necessary for Curiosity to make sensitive and robust detections of Mars’s chemistry, particularly any organic materials,” says Ashwin Vasavada, Curiosity’s deputy principal investigator. But if we do contaminate Mars, at least we have a backup plan. The Search for Extraterrestrial
TOSS a stone into a pool and it leaves ripples long after it sinks. Ideas and experiences may have a similar effect on our brains: short bouts of intense neural activity leave ripples in the brain’s background activity that can still be detected 24 hours later. Studies have shown that it is possible to use brain activity to detect simple thoughts or even what image someone is looking at. But this is the first time activity reflecting the past has been observed in humans. Even when you are doing nothing, your brain is busy. Cut off from external stimuli and left to “idle” – when you are not focused on anything in particular, for example – the brain enters a resting state. “You would expect it to quieten down,” says Rafael Malach at the Weizmann Institute of Science in Rehovot, Israel. But instead, the brain switches gear, –Obsessed with hygiene– producing patterns of activity that are slower but no less busy. Malach and his colleagues Genomes (SETG) project, based wondered whether the activity might at the Massachusetts Institute in fact be a kind of echo. Could it tell of Technology, aims to send a us something about what the brain DNA sequencer to the planet. had been up to previously? “It might Such a device would be able to be a window into the previous day’s distinguish any uniquely alien components of genetic code from activity,” he says. To test the idea, the team those of, say, a hitch-hiking compared fMRI scans of 20 people microbe from Earth. taken before, during and after a The sequencer could also period of intense cognitive activity. tease out whether Martian life,
if discovered, was a distant cousin “Can today’s brain activity of Earth life that arrived on a tell us something about meteor millions of years ago and what the brain had been adapted, says Chris Carr of MIT. up to previously?” “We’re not quite there yet, but with the technologies that exist They focused on a region of the brain today, we could do it.” One thing is for sure: planetary called the dorsal anterior cingulate cortex (dACC), which is linked to protection will be a moot point decision-making and volition. when humans arrive on Mars, In the scanner, the postgraduate with all their attendant bacteria. participants were told to think about “There are opportunities to study life on Mars now, and when a new research project, triggering activity in the dACC. They were then humans do get there, there are asked to clear their minds and, certain questions we will no 6 minutes later, the researchers longer be able to answer,” says took a snapshot scan of the brains Conley. “It’s going to be a race in their resting states. against time.” n
The team found that patterns of firing neurons observed during the concentration task could still be seen when the brain was idle – even though they had not been active before the task. They took a further scan 24 hours later, again while the participants’ brains were resting. Remarkably, the pattern was even stronger then (The Journal of Neuroscience, doi.org/m4h). The findings cannot be explained simply as a memory of the task, says Malach, because the dACC is not involved in memory formation. The results are impressive, says Lila Davachi at New York University. “The way our brains are wired is a result of our experience,” she says. “Every time we learn something new we’re changing our brain a little.” Sam Schwarzkopf at University College London finds the results intriguing. “In theory, it seems possible that we could pick up more subtle things, like memories, feelings and associations,” he says. But he stresses that brain-imaging methods for humans are still relatively blunt and only capable of picking up signals from large chunks of brain tissue that contain millions of neurons. Davachi agrees that our current technology is not sophisticated enough to tease out individual thoughts, but says we may be able to in future. Malach now hopes to see whether the findings hold across the cerebral cortex in general and whether the patterns will show up even in the brain’s non-resting states. He thinks that one day we might be able to build a library of patterns linking experiences with the activity they produce. This could make it possible to read someone’s past from their resting brainwaves, at least to a limited extent. “We might have a method to tell us not just what we are thinking now, but what were the meaningful thoughts that we had in the last few days,” he says. Douglas Heaven n 6 July 2013 | NewScientist | 9
Echoes in the brain open a window on yesterday
potential alien ecosystems, either on Mars or on other promising spots for finding life (see “Keep Europa tidy, please”, left). “One of the purposes of planetary protection is to help keep us from suffering the consequences of our own ignorance,” says NASA planetary protection officer Catharine Conley. She adds that including such measures adds little to the overall budget of a modern bigticket mission such as the Curiosity rover, which cost about $2.5 billion. The procedures also force better design and more rigorous testing. “Many of the requirements prelanding also overlapped with those necessary for Curiosity to make sensitive and robust detections of Mars’s chemistry, particularly any organic materials,” says Ashwin Vasavada, Curiosity’s deputy principal investigator. But if we do contaminate Mars, at least we have a backup plan. The Search for Extraterrestrial
TOSS a stone into a pool and it leaves ripples long after it sinks. Ideas and experiences may have a similar effect on our brains: short bouts of intense neural activity leave ripples in the brain’s background activity that can still be detected 24 hours later. Studies have shown that it is possible to use brain activity to detect simple thoughts or even what image someone is looking at. But this is the first time activity reflecting the past has been observed in humans. Even when you are doing nothing, your brain is busy. Cut off from external stimuli and left to “idle” – when you are not focused on anything in particular, for example – the brain enters a resting state. “You would expect it to quieten down,” says Rafael Malach at the Weizmann Institute of Science in Rehovot, Israel. But instead, the brain switches gear, –Obsessed with hygiene– producing patterns of activity that are slower but no less busy. Malach and his colleagues Genomes (SETG) project, based wondered whether the activity might at the Massachusetts Institute in fact be a kind of echo. Could it tell of Technology, aims to send a us something about what the brain DNA sequencer to the planet. had been up to previously? “It might Such a device would be able to be a window into the previous day’s distinguish any uniquely alien components of genetic code from activity,” he says. To test the idea, the team those of, say, a hitch-hiking compared fMRI scans of 20 people microbe from Earth. taken before, during and after a The sequencer could also period of intense cognitive activity. tease out whether Martian life,
if discovered, was a distant cousin “Can today’s brain activity of Earth life that arrived on a tell us something about meteor millions of years ago and what the brain had been adapted, says Chris Carr of MIT. up to previously?” “We’re not quite there yet, but with the technologies that exist They focused on a region of the brain today, we could do it.” One thing is for sure: planetary called the dorsal anterior cingulate cortex (dACC), which is linked to protection will be a moot point decision-making and volition. when humans arrive on Mars, In the scanner, the postgraduate with all their attendant bacteria. participants were told to think about “There are opportunities to study life on Mars now, and when a new research project, triggering activity in the dACC. They were then humans do get there, there are asked to clear their minds and, certain questions we will no 6 minutes later, the researchers longer be able to answer,” says took a snapshot scan of the brains Conley. “It’s going to be a race in their resting states. against time.” n
The team found that patterns of firing neurons observed during the concentration task could still be seen when the brain was idle – even though they had not been active before the task. They took a further scan 24 hours later, again while the participants’ brains were resting. Remarkably, the pattern was even stronger then (The Journal of Neuroscience, doi.org/m4h). The findings cannot be explained simply as a memory of the task, says Malach, because the dACC is not involved in memory formation. The results are impressive, says Lila Davachi at New York University. “The way our brains are wired is a result of our experience,” she says. “Every time we learn something new we’re changing our brain a little.” Sam Schwarzkopf at University College London finds the results intriguing. “In theory, it seems possible that we could pick up more subtle things, like memories, feelings and associations,” he says. But he stresses that brain-imaging methods for humans are still relatively blunt and only capable of picking up signals from large chunks of brain tissue that contain millions of neurons. Davachi agrees that our current technology is not sophisticated enough to tease out individual thoughts, but says we may be able to in future. Malach now hopes to see whether the findings hold across the cerebral cortex in general and whether the patterns will show up even in the brain’s non-resting states. He thinks that one day we might be able to build a library of patterns linking experiences with the activity they produce. This could make it possible to read someone’s past from their resting brainwaves, at least to a limited extent. “We might have a method to tell us not just what we are thinking now, but what were the meaningful thoughts that we had in the last few days,” he says. Douglas Heaven n 6 July 2013 | NewScientist | 9