Fig. 6. Discrimination between left and right M-axon activity. Ai-Aiv and Bi-Biv are from two separate experiments, with the implanted electrode closer to the left or right M-axon, respectively. (Ai,Bi) Superimposed fields obtained when the fish turned to the right (solid trace) or to the left (broken trace). Note that in each case the larger M-spike corresponds to activation of the closer M-axon. (Aii,Bii) Plots of M-spike amplitudes versus trial number. Silhouettes demonstrate corresponding C-start direction. Closed square, open square, and open triangle indicate pip, ramped sound wave or visual looming stimuli, respectively. (Aiii,Aiv,Biii,Biv) Examples of responses associated with C-starts away from the side of the implanted electrode, i.e. to the right and left, respectively. Stimuli were sound pips in Aiii,Biii, a ramped sound wave in Aiv, and a visual looming stimulus in Biv; asterisk indicates M-spike.