FLICKR, REIGH LEBLANCTo define human consciousness at the neuronal level is among the most difficult of tasks for neuroscience. Still, researchers have made inroads, most recently by sinking electrodes deep with the brains of epilepsy patients and recording the activity of single neurons as the awake patients described whether they observed an image flashed before them.
Previous work had found that the stronger the individual neuron activity, the more likely it is to be associated with conscious perception. In this latest study, published today (September 21) in Current Biology, researchers from the University of Bonn Medical Center in Germany find a second factor—timing—that appears important to the brain’s conscious awareness. Firing of single neurons within the medial temporal lobe (MTL), which is important for long-term memory, was weaker and delayed when human subjects were not aware of seeing an image compared to when they reported seeing one.
“[The authors] contribute a major piece of the puzzle of human consciousness with a set of data that is very impressive,” says Rafael Malach, a neurobiologist who studies the human brain at the Weizmann ...
