It’s a high-risk scenario for any surgeon: A 65-year-old male patient with a high body mass index and heart disease is undergoing emergency surgery for a perforated appendix.

Internal bleeding was detected, anesthesia monitors malfunctioned and various pagers went off before an emergency call came in about an ectopic pregnancy on another ward.

This kind of drama often plays out in operating theatres, but in this case trainee surgeon Mary Goble is being put to the test by a team of researchers from Imperial College London, who are studying what happens inside the brain as surgeons carry out life circumstances—or death procedures.

As Goble had her silicone appendix removed laparoscopically, she looked calm and collected while avoiding a host of distractions. But monitoring her brain activity through a cap covered with optical probes might tell a different story.

Researchers led by Daniel Leff, a senior research fellow and consultant breast surgeon at Imperial College Healthcare NHS Foundation Trust, are working to detect tell-tale signs of cognitive overload based on brain activity. In the future, they say, this could help flag warning signs during surgery.

“The operating room can be a very chaotic environment, and as a surgeon you have to keep your wits about you when everyone is losing theirs,” Leif said. “As cognitive load increases, it has a significant impact on patient safety. We don’t have any tools to know if a surgeon is coping with the cognitive demands of that environment. What happens when a surgeon is exhausted?”

In the future, Leif envisions a system that could read brain activity in real time in the operating room and trigger intervention when surgeons are at risk of overload.

“If you really like listening to Whitney Houston, you could automatically play calming music. Or it might alert the lead nurse in the operating room so she can deal with the inevitable nonsense in the operating room,” Leif said. “It’s like a surgical minority report.”

More controversially, brain stimulation could also be used to improve surgeons’ performance if they are distracted.

The hat Goble is wearing uses functional near-infrared spectroscopy (fNIRS), a non-invasive technique that measures changes in blood oxygen in the brain, a proxy for underlying neural activity. Previously, the team had shown that novices had more prefrontal brain activity during surgery than experienced doctors.They also Prefrontal lobe activity appears to be more likely to be disrupted among doctors found to have reduced performance in stressful situations.

The latest work seeks to identify fNIRS signatures of cognitive overload, when doctors’ performance begins to decline because they can no longer cope with the volume of information and demands placed on them. The study, using trainee surgeons, will track brain activity and surgical performance as more and more demands are made. The simulated environment means every movement of the laparoscopic instruments can be tracked, and copper wires embedded in the silicon appendix can detect whether the incision is on target.

“You often don’t see any outward signs in people,” Leif said, adding that doctors often have a “don’t hesitate to deal with it” mentality.

Dr Goble, a surgical trainee and research participant at King’s College NHS Foundation Trust, said after the exercise that despite it being a simulation, her stress levels were soaring. “Surgery is a stressful environment,” she said. “On the night shift, it’s easy to feel overwhelmed when you’re alone and have to juggle competing clinical priorities. I use breathing as a way to focus my attention.”

Leif said simulated surgeries are increasingly used to teach in medical schools, so this kind of monitoring could be integrated into training to identify trainees who need more support and track progress. Future patient safety policies can also be informed by better evidence about how the operating room environment affects performance, like how findings of fatigue led to new rules for safe working patterns for doctors.

“I think if it’s about helping people be the best doctors they can be and it’s about patient safety, then there’s going to be a lot more acceptance,” Leff said. “When you try to use these things to judge whether someone is competent or not, you start to run into problems.”

It’s not yet possible to read brain activity in real time while surgeons are operating, and such an application may be more than a decade away.But brain-computer interface technology is advancing rapidly, including non-invasive helmet Designed to measure brain activity in healthy individuals.

The Imperial College team are also investigating the possibility of using a non-invasive technique called transcranial direct current stimulation (tDCS) to improve performance. It involves passing a weak electrical current – enough to feel a slight tingling – between two sponge electrodes placed on the scalp. Previously, they found that trainee surgeons learning laparoscopic suturing improved more quickly and reached higher performance levels if they received tDBS while practicing. However, experienced surgeons do not see the same effect.

“When it comes to neuroenhancement, it’s definitely more challenging and people become more skeptical,” Leff said. “When you’re talking about sending signals to someone’s brain, it’s going to be difficult for the field to get a lot of support. fNIRS does harmless monitoring of what’s going on, and we found that that’s much more acceptable.”