Scientists are now one step closer to understanding how the brain selects a single image for further processing from a steady stream of external stimulation.
Itzhak Fried, MD, PhD, professor of neurosurgery at the University of California, Los Angeles (UCLA), and colleagues at UCLA and the California Institute of Technology, Pasadena, found that users of a brain machine interface (BMI) were able to change images on a video screen through thought alone. The research has implications for the development of technology that could help paralyzed individuals communicate or control prosthetic limbs.
The 12 study participants, awaiting neurosurgery for treatment-resistant epilepsy at the UCLA Ronald Reagan Medical Center, had an array of 64 tiny electrodes implanted in their medial temporal lobes, the region of the brain associated with memory function that is a frequent source of epileptic seizures.
Patients in the study looked at two superimposed images on a video screen and were asked to enhance one of the images and minimize the other through thought. Even while using different cognitive strategies, subjects were able to make the targeted image completely visible while eliminating the competing image 70 percent of the time. Feedback on the computer screen was found to be essential. When subjects had no BMI, their success rates fell below one third.
Study findings were published online in Nature News magazine on October 27.
John Donoghue, PhD, professor of neuroscience and engineering at Brown University, Providence, Rhode Island, is quoted as saying that this research is exciting “because it shows how we can now peer into the process of thinking at a level we have not been able to get at before.” According to the Nature News article, Donoghue was responsible for the first successful transplantation of a chip into the motor cortex of a tetraplegic man, enabling him to move a computer cursor and manipulate a robotic arm with his mind.