The cover story on today’s New Scientist is about recent efforts to determine what people are thinking by viewing their brain scans.
Although you may think this is what neuroscientists already do, in most brain-scanning experiments the researchers will know exactly what the participants are experiencing in the scanner, and they just link the measured brain activity to the known task.
Recently, researchers have been able to work out what the participants are viewing by only looking at their brain scans.
Although these experiments are quite simple so far – the researchers typically know that the participant is viewing one of several simple options and just have to work out which – the idea that mental states can be ‘read’ is causing some excitement. Not least because this has been the subject of many science-fiction novels and films.
The accuracy of these experiments is typically much better than chance, although it is far from perfect and so far has largely relied on very simple tasks (viewing lines and the like):
In published results, Tong and Kamitani were able to predict correctly 56 per cent of the time which of eight orientations of lines people were seeing, compared with 12.5 per cent for chance. When subjects were shown a grid of criss-crossing lines, the researchers predicted correctly 80 per cent of the time which lines were being attended to (Nature Neuroscience, vol 8, p679, pdf).
Unsurprisingly, this has sparked some neuroethical concerns. For example, the technology might advance to the stage where it could be used to narrow down what people were thinking regardless of whether they consented (e.g. in interrogations).
The article isn’t freely available online, but your local library or newsagent should have a copy.