The physiology and anatomy of human cognitive processing are among the most complex and compelling problems in biology, owing to a lack of a technique for measuring the activity of populations of cortical neurons within the intact human brain. Neuromagnetometry, a newly developed imaging technique, promises a solution to this dilemma. By measuring the magnetic field produced by brain electrical currents, it is possible to localize the intracranial sources of these currents with millimeter precision. However, the presence of contaminating environmental magnetic noise has necessitated extensive signal averaging. Thus, the neuromagnetic study of the weak signals associated with higher cognitive functions has remained a difficult problem because higher cognitive processes do not remain static for long periods of time. The solution is to reduce the background noise through the use of a magnetically shielded chamber. This proposal requests funding for the purchase of such a chamber to be used by investigators studying the neurobiology of cognition. Specific research topics include early vision, early audition, language, and selective attention.
