Brainpower: who's really in control?
Imagine changing the TV channel just by thinking about it,a mental remote control. What was once a science-fiction fantasy is slowly becoming reality: a team of researchers has demonstrated simple mind control of a screen image. Scientists at the California Institute of Technology and University of California, Los Angeles taught patients to consciously change images on a computer screen through the use of individual brain cells. Their study, published last year in Nature, revealed an apparent ability to control the energy of an individual neuron.
Patients who volunteered for this study suffered from treatment-resistant epilepsy. While awaiting neurosurgery at the UCLA Ronald Reagan Medical Center, patients had an array of electrodes implanted into their brains to target the specific regions responsible for their severe seizures. The electrodes also enabled UCLA neurosurgeon Itzhak Fried to monitor neuronal firing.
MIND OVER MATTER
Our neurons communicate with each other through chemical and electrical signals. These chemicals, known as neurotransmitters, bind to specific receptors at the tip of a neuron and cause it to "fire," sending an electrical impulse down its long body, which then signals the release of neurotransmitters from its end to restart this process for the adjacent neuron.
Based on observations from prior experiments, Fried and his team determined that an individual neuron can fire when a subject either imagines or recognizes a particular object or person. This observation suggests that the brain can actually filter which sensory information to consider and which to ignore.
In this latest experiment, researchers showed twelve patients a series of familiar images,such as ones of Michael Jackson or Marilyn Monroe,and monitored the patients' electrical brain activity. An image that elicited strong, reliable activity from an individual neuron would then be superimposed over a different image that brought about a similar response from a different neuron. Patients were then instructed to select and think about only one of the images in this competing hybrid. For example, from a collage of Michael Jackson and Marilyn Monroe images, patients who chose to focus on Marilyn Monroe would cause the "Marilyn Monroe neuron" to increase its firing activity, and as a result, fade out the image of Michael Jackson and only be left with the iconic model and actress.
In more than two-thirds of the trials, subjects were successful in enhancing their target image and completely fading out the opposing image. With practice, patients quickly learned how to manipulate this ability by changing which image they wanted to enhance, and achieving this result more rapidly by increasing the firing rate of the related neuron. Live feedback from the computer screen was vital. Without the screen, subjects' success rate fell to less than one-third.
"[Our] environment offers some reality, but [our brains] can shape it and override it with its internal deliberations," said the study's lead author, Moran Cerf.
He believes these mind control results offer great potential for new technologies and capabilities. Cerf imagines that victims of quadriplegia and "locked-in" syndrome, who have no control of their bodies but still have healthy minds, might one day harness individual neurons to signal for concepts such as "water" and "food." But for the foreseeable future, our daily routines will still require the use of the TV remote control.