What’s different about the brains of heroes?

So it is that a new brain imaging study caught my attention. Marco Zanon and his colleagues scanned the brains of 43 young adults (30 women) while they took part in a virtual reality (VR) experience of a disaster. Wearing VR goggles and headphones, each participant began the study by meeting up with what they thought were three other volunteers in a virtual waiting room. In fact, these other avatars were computer controlled. After exploring the room for a while, the participants were surprised by the sound of a fire alarm. Having earlier been instructed to behave as they would in the real world, the participants raced to evacuate the building. Simulated smoke, flames and coughing and heart beat sound effects added to the drama.

Crucially, near the building exit, their “life energy” bar nearly depleted, the participants encountered one of the other people they’d met in the waiting room, finding them trapped injured under a fallen filing cabinet and surely doomed to die. Each participant faced the same choice – try to save the stricken individual (they’d earlier learned that objects could be moved by tapping a joystick key; saving the other human required 150 such button presses), or plough on to safety. Throughout this VR experience the researchers scanned the participants’ brains. They used an approach known as independent component analysis, which is about looking for networks of correlated activity across the brain.

There were 16 heroes, including 11 women, who rescued the trapped man. Nineteen others, including 12 women, passed by without helping. The remaining 8 tried to help but gave up – they were omitted from the subsequent brain analysis because they were so few in number. Zanon and his colleagues identified three functional hubs in the brain that they said were differently activated in the heroes and the more selfish folk. The first was more active (throughout the VR experience) in the selfish participants, and took in the anterior insula and the anterior mid-cingulate cortex (areas buried deep in the cerebral cortex), but also included other regions such as the thalamus and the cerebellum. Zanon’s team said this network has previously been associated with finding things salient, which is itself a state associated with anxiety. Activity in this network has also been linked with harm avoidance, the researchers said. In other words, greater activity in this functional hub may reflect the fact that the selfish participants felt more endangered (there was a trend for them to report feeling more anxious than the heroes, but this didn’t reach statistical significance) and a greater motivation to protect themselves.