Using Scalar Products to Refine the Interpretative Value of an Orientation Choice Test

摘要: Choice tests, which are often used to examine animal preferences, can be difficult interpret when no clear choice has been made or using very young animals exclude test repetition. We present a new method evaluate the behavior in based on orientation of and illustrate its use facing those conditions. Using rat pups an open field maze with odors, we obtained x,y coordinates 2 markers (head body center) videotracking freeware. Two vectors were calculated: vector (body head) perfect odor source). The angle between each frame was converted into scalar product ranging from 1 (pup oriented directly towards source) −1 (facing opposite direction). A mean calculated for source, difference mean products indicating degree preference odor. information provided by (MSPD) could not other measures, such as binary choice, velocity, distance moved. MSPD provides single, noncategorical value describe test. This variable more effective differentiating animals, thus allowing reduction number tests necessary reach significance.