1. A system for prediction of cognitive decline of a patient during a future time period, comprising: an input receiving input data corresponding to brain activity of a patient; and a processor coupled to the input for analyzing the input data to obtain an input set of values for a selected set of features, the processor being configured to compare the input values to a comparison set of values for the selected set of features derived from at least a portion of entries in a database corresponding to brain activity of a plurality of individuals, wherein entries in the database have been separated into a plurality of categories corresponding to a degree of cognitive decline of the individuals when the data was collected and a degree of cognitive decline of the individuals during a period of time subsequent to the collection of the data, the processor determining, based on the comparison, a category most closely corresponding to the selected set of features.