Headbands that monitor concentration by reading brain signals have been trialled on thousands of Chinese schoolchildren.
The devices could soon be used on millions of students across China, according to the US tech company which designed them.
Massachusetts-based start-up BrainCo says its Focus 1 headbands can help teachers identify pupils who need extra assistance.
However, neuroscientists have questioned the devices’ effectiveness and the technology has also raised privacy concerns.
The headbands use electroencephalography (EEG) sensors to detect brain activity when the wearer is engaged in a task.