Benedict Carey discusses work showing that deep brain stimulation delivered through electrodes inserted into the brains of epilepsy patients being prepared for surgery sharply improved performance on a virtual driving game that tests spatial memory, the neural mapping ability that allows people to navigate a new city without a GPS:
Ross Andersen does an article in The Atlantic that describes ethical debates that have risen over the use of transcranial direct current stimulation (TDCS) to improve cognition in human beings.
Recent years have seen some encouraging, if preliminary, lab results involving TDCS, a deep brain stimulation technique that uses electrodes placed outside the head to direct tiny painless currents across the brain. The currents are thought to increase neuroplasticity, making it easier for neurons to fire and form the connections that enable learning. There are signs that the technology could improve language acumen, math ability, and even memory.Finally in PloS Biology Knafo et al. note that a pharmacological cognitive enhancer that improves spatial learning and memory (in rats) by enhancing synaptic transmission in the hippocampus.