Figure 1: Dynamic RMSE performance measure in degrees plotted on the ordinate axis, Mean and Standard Error for 48 participants, against time in ms from stimulus onset on the abscissa for gravity (black, G), anti-gravity (dark grey, AG) and control with horizontally accelerating gravity (light grey and dash/dot lines, CO) conditions. (a) For the horizontal direction in the slow condition. (b) Vertical direction, slow condition showing worse performance for AG from onset to 200ms. (c) Horizontal fast condition with catch up saccades around 100-300ms. (d) Vertical fast condition similar to (b) with better performance for G than AG.
ASD and SPQ traits and links to eye tracking
The Schizotypy Personality Questionnaire (SPQ) produced scores comparable to previous work with Median = 16 and IQR = 18.5. Participant scores were almost evenly distributed below 30 (See Figure 2A). The SATQ produced scores comparable to previous work with Median = 17.5 and IQR = 11.5 and scores were approximately normally distributed (Figure 2B). We ran a Pearson’s correlation between the SPQ and SATQ and found a strong relationship with r = 0.735, p = 2.73 x 10-9(Figure 2C). We did not decompose the SPQ and SATQ sub-clusters, to avoid expansion to the 15 permutations (3 SPQ clusters x 5 SATQ) and therefore used PCA. Instead, we first looked at the relationship between the inventories and the vertical RMSE-y at stimulus onset (0ms), which reflects anticipatory responses. For the four comparisons using a Pearson correlation, we adjusted alpha for significance to 0.0125. Under the gravity condition, there was a near-zero correlation between the SPQ and RMSE-y with r = -0.026, p = 0.86, and similarly a low correlation between SATQ and RMSE-y at with r = -0.074, p = 0.62. Under the antigravity condition, there was a low correlation between the SPQ and the RMSE-y with r = 0.065, p = 0.66, and similarly between SATQ and RMSE-y with r = 0.025, p = 0.86. There was therefore no significant relationship between the trait measures and the tracking performance in the gravity direction at onset (Figure 2D, E, G and H). We then analysed the relationship between the traits and the eight saccade measures, adjusting the alpha value for the Pearson correlations to 0.00625. Under the gravity condition, there was a non-significant negative correlation between the SPQ and the Saccade rate, r = -0.169, p = 0.25, and similarly for the SATQ and saccade rate, r = -0.153, p = 0.30. Under the antigravity condition, the correlation was near zero for the SPQ and the saccade rates, r = -0.047, p = 0.75, and the SATQ and the saccade rate, r = -0.039, p = 0.79. The traits showed little relation to the rates (Figure 3A-D). For the saccade amplitudes, under the gravity condition, there was a non-significant negative correlation between the SPQ and the amplitudes, r = -0.12, p = 0.40, and the SATQ and amplitudes, r = -0.12, p = 0.41. For the antigravity condition, these were again near zero for SPQ and amplitude, r = 0.041, p = 0.78, and SATQ and amplitude, r = -0.017, p = 0.91. Traits showed little relationship with the amplitudes (Figure 3E-H).