Neck electromyography is an effective measure of fear behavior

Conventional methodology for examining conditioned fear has involved visual-based technologies such as cameras and direct observation. These methods are excellent screening tools of fear behavior (i.e. freezing). However, they do not provide a physiological output, which could be useful to examine neurophysiological correlates of fear. We found that dorsal neck electromyography can be used as a method to score fear behavior and is as effective as visual-based scoring. Since electronnyogram is a physiological measure it can be used in either the light or dark to score freezing behavior, without use of any camera or visual observation. We also show that electromyogram-based scoring methodologies, in conjunction with electroencephalogram, are useful to discriminate fear from sleep. (C) 2008 Elsevier B.V. All rights reserved.