English: Supplementary Movie 1 Fine-grained tracking of locust palp movements in an appetitiveconditioned behavioral assay: (a) Palp-opening response to a conditioned stimulus (hexanol in this case) is shown in the top left panel. The green boxes indicate tracked palp locations. The entire video is 12 seconds long and contains the following segments: a 5 seconds pre-stimulus baseline period, followed by a 4 seconds exposure of hexanol, and finally a 3 seconds post stimulus period. (b) A filtered version of the same video using a custom-written image processing software is shown. The two blobs of white pixels identify the location of the two palps in each video frame. (c) The centroids of the two blobs are plotted as a function of time. Centroid locations in consecutive frames are linked using a line to show the evolution of the behavioral response. (d) Distance between the two tracked palps is shown over time. The y-axis corresponds to the number of pixels between the centroids of the two palps (arbitrary units). The colored box identifies the odor presentation period. Note that all four panels are synchronized in time.