Posted for Philip Ball
Talk about messing with your mind. A new study by neuroscientist Liane Young and colleagues at Harvard University does exactly that: the researchers used magnetic signals applied to subjects’ craniums to alter their judgements of moral culpability. The magnetic stimulus made people less likely to condemn others for attempting but failing to inflict harm, they report in PNAS.
Most people make moral judgements of others’ actions based not just on their consequences but also on some view of what the intentions were. That makes us prepared to attribute diminished responsibility to children or people with severe mental illness who commit serious offences: it’s not just a matter of what they did, but how much they understood what they were doing.
Neuroimaging studies have shown that the attribution of beliefs to other people seems to involve a part of the brain called the right temporoparietal junction (RTPJ). So Young and colleagues figured that, if they disrupted how well the RTPJ functions, this might alter moral judgements of someone’s action that rely on assumptions about their intention.
To do that, they applied an oscillating magnetic signal at 1 Hz to the part of the skull close to the RTPJ for 25 minutes in test subjects, and then asked them to read and respond to an account of an attempted misdemeanour. They also conducted tests while delivering the signal in regular short bursts. In one scenario, ‘Grace’ intentionally puts a white powder from a jar marked ‘toxic’ into her friend’s coffee, but the powder is in fact just sugar and the friend is fine. Was Grace acting rightly or wrongly?
Obvious? You might think differently with a magnetic oscillator fixed to your head. With the stimulation applied, subjects were more likely to judge the morality based on the outcome, as young children do (the friend was fine, so it’s OK), than on the intention (Grace believed the stuff was toxic).
That’s scary. The researchers present this as evidence of the role of the RTPJ in moral reasoning, with implications for how children do it (there is some evidence that the RTPJ is late in maturing) and for conditions such as autism that seem to involve a lack of ability to identify motives in other people. Fair enough. But to most of us it is news – and alarming news – that morality-related brain functions can be disrupted or suspended with a simple electromagnetic coil.
If ever a piece of research were destined to incite paranoid fantasies about dictators inserting chips in our heads to alter and control our behaviour, this is it.
Image: A. Herreid / iStockphoto