1. ParameterFactor or combination of factorsEta² Peak GainTask0.628 Group0.214 Latency to Peak GainGroup0.256 Initial AccelerationTask0.153 Group0.305 Task x Group0.079 DecelerationTask0.249 Latency to DecelerationGroup0.143 Task0.746 Residual GainTask0.116 Group0.095 DriftVelocity0.444 Supplementary Table 1: Effect sizes (for significant ANOVA results only).

2. Correlation coefficient with age (control subjects) Initial Acceleration-0.088 (p=0.68) Pursuit Latency0.495 (p=0.014) Peak Gain-0.20 (p=0.34) Latency to Peak Gain0.285 (p=0.18) Deceleration0.290 (p=0.17) Latency to Deceleration0.430 (p=0.036) Residual Gain-0.391 (p=0.059) Drift-0.181 (p=0.41) Supplementary Table 2: Correlation coefficient of the parameters (averaged over tasks) with age in the control group.

3. mid-blank 150mid-blank 300Short ramp Controls 281(14)398(16)284(18) Schizophrenia patients 306(15)449(17)359(19) Bipolar patients344(17)453(19)305(21) Supplementary Table 3: Decleration latency and standard errors (in ms. means across target velocities).

4. Supplementary Table 4: correlations of eye movement parameters with psychopathological and clinical variables in the groups of schizophrenic (SZ) and bipolar patients. None of the correlations was significant. Disease duration PANSS total scoreCPZ equivalent dose Peak gainSZ-0.094-0.1940.067 Bipolar0.0630.043-0.032 Latency to peak gainSZ0.0130.266-0.244 Bipolar0.1290.0150.421 (p=0.051) Initial accelerationSZ-0.087-0.042-0.009 Bipolar0.092-0.072-0.249 Latency to accelerationSZ-0.1430.094-0.038 Bipolar-0.364-0.113-0.013 DeclerationSZ-0.0167-0.0310.175 Bipolar-0.102-0.032-0.102 Latency to decelerationSZ0.384 (p=0.094)0.349-0.299 Bipolar0.0700.1390.374 (p=0.087) Residual gainSZ0.0320.0010.038 Bipolar0.1780.1990.051 DriftSZ-0.017-0.191-0.007 Bipolar0.2360.2420.062