Neurophysiology is a method of research used to obtain information produced by the electrical and magnetic signals in the active, functioning brain.   In a sense, scientists are looking to see how the brain works and communicates by measuring the electrical and magnetic potentials that occur in the brain.  Some examples of neurophysiology techniques include:  extra cellular single cell recordings, multiple-cell recordings, EEG/MEG, fMRI and PET.

Invasive and Non-Invasive Methods

Invasive:  Extra cellular recordings are obtained by the implementation of electrodes—which consist of long strands of metal wire.   An extension of this process is the collection of multiple-cell recordings gathered from a multi-electrode device.  Non-Invasive:  Other types of neuroimaging methods such as EEG, MEG, fMRI and PET allow for an active, dynamic view of the “brain at work” in a non-invasive fashion.

     Neuroscientists use these very sophisticated brain imaging and recording methods to see how the mind works and communicates.  Structural brain imaging techniques, such as computerized axial tomography (CAT scans), are useful to clinical physicians to get an anatomical picture of an individual’s brain structure.  It is common for researchers to use more than one of these techniques, such as fMRI and MEG, within the same experiment, by combining the unique strengths (fMRI-spatial, MEG-temporal) of each method.

Illustration

Preferred directions (unit vectors) of 475 motor cortical cells in three-dimensional space. (From Schwartz et al. J Neurosci 1988;8:2913-27)