Researchers found that applying gentle, non-invasive electrical stimulation to the brain during virtual reality training helped budding surgeons to more easily transfer the skills they’d learned to a real-life setting. In addition to training better future surgeons, the approach could help skill acquisition in other industries.
Motor learning allows us to develop new skills, like mastering a tennis serve or, in the case of a surgeon, developing precision suturing skills. These days, surgeons are likely to learn these types of skills in a virtual reality (VR) environment before they transition to the real world.
Researchers at Johns Hopkins University in the US have developed a method of improving how medicos learn surgical skills in a virtual environment so that their learned skills are transferred more effectively to a real-life scenario.
“Training in virtual reality is not the same as training in a real setting, and we’ve shown with previous research that it can be difficult to transfer a skill learning in a simulation into the real world,” said Jeremy Brown, a study co-author. “It’s very hard to claim statistical exactness, but we concluded people in the study were able to transfer skills from virtual reality to the real world much more easily when they had this stimulation.”
By “this stimulation”, Brown is talking about a gentle electric current delivered to the head, more specifically, the cerebellum, a part of the brain that plays a critical role in error-based learning. Non-invasive brain stimulation (NIBS) has been used before in attempts to improve motor learning. One form of NIBS, the one that was used in the current study, is anodal transcranial direct current stimulation (atDCS), the application of a constant electric current to specific areas of the brain. Anodal stimulation depolarizes the neurons, increasing the probability of an action potential – a rapid sequence of voltage changes – occurring. The action potential and subsequent neurotransmitter release enable one neuron to communicate with others.
The researchers recruited 36 participants, 17 females and 19 males, with a mean age of 27. While 12 had medical backgrounds, none had prior experience with laparoscopy, robotic surgery, or any other teleoperation device. Each was asked to perform a complex visuomotor surgical training task in a real or virtual environment and then switch to the opposite training environment. The task involved driving a curved surgical needle through three rings with a 2 mm radius distributed at 45-degree increments inside the vertical plane. ‘Real’ training environment in the context of this study meant performing the task using the da Vinci Research Kit (dVRK), an open-source research robot, to control the surgical instruments.
Participants received either atDCS or sham cerebellar stimulation during the training task, which they had to perform at three speeds: fast, medium, and slow. While all participants showed improvement from baseline, groups receiving cerebellar atDCS showed significantly improved skill transfer from the virtual to the real environment at fast and moderate speeds, whereas groups receiving the sham stimulation did not.
“The group that didn’t receive stimulation struggled a bit more to apply the skills they learned in virtual reality to the actual robot, especially the most complex moves involving quick motions,” said Guido Caccianiga, the study’s lead and corresponding author. “The groups that received brain stimulation were better at those tasks.”
The researchers say validating their findings using a larger sample could significantly impact robotic surgery training programs. Enhancing skill transfer through NIBS could speed up training time and shorten the learning curve. Outside of training surgeons, the approach could help with skill acquisition in other industries or learning more generally.
“What if we could show that with brain stimulation, you can learn new skills in half the time?” Caccianiga said. “That’s a huge margin on the costs because you’d be training people faster; you could save a lot of resources to train more surgeons or engineers who will deal with these technologies frequently in the future.”
The study was published in the journal Nature Scientific Reports, and the below video, produced by Johns Hopkins, shows a participant receiving cerebellar atDCS during training.
Source: Johns Hopkins University