More wondrous yet, the greater neuronal control achieved is shown to be associated to better performance on the cognitive function supported by those neurons.
These studies have important implications for individuals with attention deficit or with neurodegenerative conditions as they suggest that, using cerebral physiological landmarks, we could be training the brain to better regulate its own neuronal activity.
The first study, published in Science showed that monkeys could learn to voluntarily control neuronal activity in their frontal eye field (FEF), a brain area associated with visual attention in the pre-frontal cortex.
Using a pitch tone as feedback, the scientists taught the monkeys to regulate neuronal activity in the FEF. As if by magic, the monkeys were raising and lowering the pitch tone. They were doing this by increasing or decreasing FEF neuronal firing rate. With repeated trials the monkeys succeeded in modestly but reliably controlling neuronal firing rate. As extraordinary, when the researchers gave the monkeys a selective-attention visual search task and analyzed the monkeys' performance on this task, they found that that FEF voluntary (and not spontaneous) neuronal activity was related to better performance on selective attention.
Now, let's look at another experiment with humans. Imagine that while looking at two superimposed images, you are asked to use your thoughts to increase the clarity and sharpness of one image and, at the same time, make the other image fade away.
Imagine that intracranial electrodes have been implanted in your medial temporal lobes (MTL) to record neuronal activity while you attempt to perform this task. The results of such an experiment, published in Nature in 2010, show that participants were able to do just that.
By focusing on one picture, they successfully enhanced its shape and visibility while degrading the other picture. As if by magic, under their focused gaze one picture became sharper on the computer screen and the other more opaque. They succeeded rapidly, sometimes at the first attempt. The electrode-recorded data revealed that during this time the study participants were regulating neuronal activity. They accelerated the firing speed of some neurons and, concurrently decreased the speed of others. The intensity of their thought, of their focused attention, and the real-time feedback provided by the changing display on the screen, prevailed over the effect of the real world, the sensory visual information relayed to their brain by their own eyes. Using their MTL neurons, what they saw with their eyes changed into what they saw and willed in their mind.
What would the future look like if individuals with attention deficit disorders could be systematically trained at regulating the operation of neurons that support the specific cognitive functions impaired by the deficit? Such brain training would no doubt offer these individuals cognitive enhancements which, are unmediated by medication and which empower the brain to heal itself.
Research will say if training the brain to regulate and control the neurons associated with specific cognitive functions might be beneficial, not only for people with attention deficits but also for individuals with neurodegenerative conditions.
