Fig. 3. Typical EMG traces and video frames from strong and weak responses. (A) EMG traces. Traces from ipsilateral and contralateral sites are shown in orange and blue, respectively, and traces from anterior sites are darker than posterior. Periods of escape response muscle activity are shown in a brighter color and are indicated by a box, where the left (L) and right (R) sides signify onset and offset times, respectively, and the height of the box indicates average EMG amplitude. Vertical lines indicate the time of the numbered video frames, shown in B. (B) Video frames corresponding to the same kinematic events in each response. Events shown are (1) first visible motion, usually at the head, (2) maximum acceleration, (3) maximum velocity achieved during stage 1, (4) maximum curvature, (5) end of kinematic stage 1 and (6) maximum overall velocity. Note that the stage 2 muscle activity occurs before the beginning of the kinematic stage 2. Events 4 and 5 (maximum stage 1 velocity and the end of stage 1) for the weak response occur at different times during the same video frame, so that frame is repeated.

Return to article