This scientific commentary refers to ‘Visual-spatial memory may be enhanced with theta burst deep brain stimulation of the fornix: a preliminary investigation with four cases’, by Miller et al. (doi:10.1093/brain/awv095). Loss of memory is one of the most devastating afflictions of the human condition. With ageing of the population, the looming spectre of neurological disorders affecting cognition in huge numbers of individuals is a critical societal concern. While major efforts are being directed toward prevention of degenerative diseases such as Alzheimer’s disease and Parkinson’s disease, notable success has already been achieved in the treatment of motor symptoms in Parkinson’s disease and other movement disorders using direct stimulation of specific brain centres. The extension of this therapeutic modality known as deep brain stimulation (DBS) to neuropsychiatric conditions such as severe major depression or refractory obsessive-compulsive disorder is underway. The ultimate frontier may well be the application of neuromodulation to the cognitive domain in general and to memory specifically. Several studies have explored the effect of DBS on memory in humans, focusing on the medial temporal lobe with its efferent and afferent associated pathways. In this issue of Brain , Miller et al. (2015) provide intriguing preliminary data on the effect of fornix stimulation on spatial memory, in patients implanted with intracranial depth electrodes for the treatment of refractory epilepsy. The transition from basic science to clinical application is complex and highly challenging. In a much publicized article, Alivisatos et al. (2012) proposed the Brain Activity Map Project, a large-scale recording effort to map brains in a stepwise progression from Caenorhabditis elegans with its 302 neurons, through various species including the …