Fig. 7.

LR and MR convergence force. Mean values of convergence force (the increase in force associated with convergence at a given eye position) are shown for the LR (abscissa) and MR (ordinate). In all cases, convergence force was found to be negative (P < 0.0001, binomial test, n = 14), meaning that convergence was associated with decreased LR and MR muscle forces. Data for the present study are shown as solid circles where both LR and MR data were available and as dashed lines where only MR data were available. Data from Miller (2002) are shown as shaded circles. Monkeys M1, M2, M3, and M4 are the four animals in the present study; monkeys ERL, MLS, and MRL are the three animals from the study of Miller (2002), in connection with which “asym” refers to asymmetric vergence trials with the MFT-instrumented eye aligned and “sym” refers to symmetric vergence trials at different horizontal gaze angles, from which near and far fixations with equal positions of the MFT-instrumented eye were extracted and compared.