Figure 2.

Neuromuscular and behavioral responses of freely behaving socially isolated, dominant, and subordinate crayfish to an unexpected unilateral touch stimulus. The trace at the top of each panel shows the depressor neuromuscular activity recorded by the implanted fifth leg electrode in response to touch (upward arrow) of the abdominal fringe hairs. The numbered dots below each trace correspond to the time at which correspondingly numbered video frames were captured. The labeled brackets above the video frames indicate the periods of the electrical recording when the leg position was similar to that shown in the video frame. Video frames illustrate the animal's behavioral response to the brush stimulus. At the top of each video frame, the reflected oscilloscope screen was videotaped along with the behavior. Drawings illustrate the animal's posture and leg position in the video frame. Arrows on animals illustrate the rotation of body movements in response to the stimulus. M, Mirror; B, brush. A, Responses of a social isolate to touch to the left side of the abdomen; EMGs were recorded from right depressors. Turning occurs by depressing the left leg (Ipsi) while lifting the implanted right leg (Impl. contra). B, Responses of a dominant to touch of the right side of the abdomen; EMGs were recorded from right depressors. Depressor muscle activation was displayed on the oscilloscope (Dep. EMG). C, Push response and right leg depressor EMGs of a subordinate to touch of the right side of the abdomen. D, Drop response and right leg depressor EMGs of a subordinate to touch of the right side of the abdomen.