Brain mapping and its techniques

Brain based diagnostic systems have recently gained attention as a means in the analysis and diagnosis of a number of neurological and psychiatric impairments. Brain activity is actually an electrical activity having voltage fluctuations which results from ionic currents within the neurons of the brain. These fluctuations depend upon the part of the brain which is active and the activity being performed. These electrical signals when collaborated with an interface can command external activity. This paper examines the modalities in neuroimaging for signal acquisition. Each of these monitors a magnetic and electrical functionality of brain. We discuss salient features, shortcomings and survey different techniques of neurological modalities that are given in literature. The review incorporates some signal improvement techniques used to enhance the performance. The paper also furnishes an overview of some algorithms used for feature extraction and conditioning steps which renders the electrical signals into control commands that manage a computer or some other utility devices.