Comparison of motor activity measured by two different methods: optical and inductive systems.

Motor activity of twelve rats was recorded by means of two different methods, an optical detection method (ODM) as a mass-independent system and an inductive detection method (IDM) as a mass-dependent system. The chronograms and power spectra obtained from the data were compared to find the essential aspects of both methods. The results suggest that the ODM is more appropriate in studying ultradian rhythms and small motor activity changes, while IDM is better suited to the study of circadian rhythms and gross motor activity variations.