It’s been more than twenty years since the first time scientists showed that brain cell (neuron) activity may be influenced by conscious effort. For example, research by Dr. Apostolos Georgopoulos’ team showed neurons in the motor cortex follow the mental rotation of a handle to a particular location (“Mental rotation of the neuronal population vector” published January 13, 1989 in Science.
A new paper takes the conscious influence of neural activity a step further. The paper “On-line, voluntary control of human temporal lobe neurons” published October 28, 2010 in Nature describes the affect of attention on neural activity in the medial temporal lobe. (The medial temporal lobe is involved in learning, memory, and emotions and includes the hippocampus, parahippocampal cortex, entorhinal cortex, and amygdala.)
For this research, electrodes were used to record neural activity to images of people or things familiar to the subject. Twelve patients who already had electrodes implanted in their medial temporal lobes for clinical reasons volunteered to be subjects in the experiment.
The team isolated activity from two neurons. One neuron responded best to the presentation of an image of Josh Brolin, for instance, and the other responded best to the image of Marilyn Monroe. (They isolated activity from two additional neurons for technical reasons we won’t go into here.) The two images were superimposed and the subject was asked to attend to just one of them. The subjects of the experiment received real-time feedback of the activity of their medial temporal lobe neurons on an external display.
When a person focused on one of the images, the activity of the neuron best driven by that image would increase while the activity of the neuron driven by the other image decreased. The research shows that conscious effort exerted to attend one thing at the expense of another was able to control the spiking (action potential) activity of neurons in the medial temporal lobes of their brain.