1. A method for prediction of cognitive decline, comprising: receiving input data corresponding to electrical brain activity of an individual; analyzing the input data to extract selected features therefrom; comparing the selected features to at least a portion of entries in a database including data corresponding to brain activity of a plurality of individuals, wherein entries in the database are separated into a plurality of categories corresponding to one of a degree of cognitive decline and a propensity for future cognitive decline of individuals relating to the entries; and determining a category most closely corresponding to the input data.