tDCS and TMS have been shown to enhance certain cognitive functions, such as episodic memory in older adults.1415 DBS, which has been successful for Parkinson’s and obsessive-compulsive disorder, has also alleviated some symptoms of Alzheimer’s disease in some participants in a small clinical trial.16 Other penetrating electrical brain implants are mooted to provide prosthetic memories for people with traumatic brain injuries.17
Further progress will come with “adaptive closed-loop systems”. These can read and decode brain signals, and respond by making decisions — often aided by AI — to engage stimulation in order to override, dampen or amplify a particular signal.18 Better materials19 and implantation devices and methods are also in the works; Neuralink, for instance, recently announced that it has earned FDA approval to trial its implants in humans.20
