With a hundred billion cells, each connected in thousands of intricate ways, the human brain is arguably the most complex system in the universe.
From recognising faces in a crowd to wrapping oddly shaped Christmas gifts, many daily feats performed by our brains remain unmatched by any other species or technology, and continue to puzzle scientists.
However, our ability to record signals from individual brain cells through methods such as EEG – which records the voltage generated at the surface of the brain in real-time – and fMRI – which uses powerful magnetic fields to nudge atoms in the blood system and track how long it takes them to return to normal – are helping researchers to recreate three-dimensional maps of brain activity that correspond to actual thoughts.
Professor Christian Olivers at the Vrije Universiteit Amsterdam, in the Netherlands, compares the kind of activity reported by EEG and fMRI scans to a QR code. ‘Different patterns of activity in the brain are code for different mental images,’ he said. ‘Our objective is to crack that code.’
Prof. Olivers runs the TEMPLATE 2.0 project, funded by the EU’s European Research Council (ERC), which is looking at a function of our brains that neuroscience has yet to explain – our ability to hold a particular image in our head related to the task at hand. For example, if we are looking for a particular face in a crowd, we hold some representation of the face that we are looking for before we see it, and will see it more quickly than we see other people.
‘Different patterns of activity in the brain are code for different mental images. Our objective is to crack that code.’
Prof. Christian Olivers, Vrije Universiteit Amsterdam, the Netherlands
As part of his project, he has been asking test subjects to stare at a blank screen where they expect an object to appear. Sure enough, regions of the brain associated with the visualisation of that object tend to come to life before the object itself appears on the screen.
Prof. Olivers has even managed to distinguish between the objects that test subjects are thinking of by looking at the brain activations through techniques such as EEG and fMRI.
He believes the ability to visualise what we are looking for is one of humanity’s fortes. While a monkey takes weeks to learn to find blue socks, then weeks again to search for green ones, we can switch from one target to another in less than half a second.
‘Humans find things by creating an image in our mind of what we are looking for and filtering our surroundings through it,’ he said. This mental template is largely to thank for the unusual flexibility and adaptability of our species, but it does have its limitations.
By the end of the project, he hopes to have a better idea of how we carry these pictures in our heads, what distinguishes them from other types of memory, how many templates can be active at once and how training could alter them.
Professor Peter Janssen at the University of Leuven in Belgium says that our understanding of neurology is only just beginning. ‘We understand very little about how the brain works,’ he said.
For five years, Prof. Janssen has coordinated the BRAINSHAPE project with funding from the ERC. His research has investigated the ability of macaques to grasp and handle objects with the aid of both non-invasive techniques and small electrodes inserted in their brain.
Because the electrodes could both monitor and stimulate electrical signals, Prof. Janssen managed to record brain activity during the macaque’s natural behaviour and interfere with it to better understand the networks supporting grasping movements in these monkeys.
Noting that abstract thoughts can be detected as electrical signals and electrical signals can be used to control nervous systems, Prof. Janssen foresees that, within our lifetime, brain-machine interfaces could communicate directly between functioning brain cells and muscles, or even electronic circuits.
‘At present, we cannot heal severed spinal cords or repair the motor cortex of patients after a stroke,’ said Prof. Janssen. ‘But as we crack the code of the human brain, we could potentially bypass impaired components in its motor system.’
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Professor Martijn Nawijn, an immunologist at the University of Groningen in the Netherlands, tells Horizon about his quest to map every cell in a healthy human lung. He says this work should help to understand more about the causes of lung disease - which is comparatively understudied - and should lead to new therapies in the next 15 to 20 years.
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