Fig 1.
Experimental design and stimuli configuration.
Panel A. Trial sequence of Experiments 1–3. Participants were instructed to maintain fixation and to make a saccade towards a square appearing to the right side of the fixation cross at 7.7° of eccentricity as soon as the central dot turned green. Participants reported the orientation of a Gabor patch presented for 30 ms and tilted either clockwise or counterclockwise. In mask trials, patches of white noise were displayed at each refresh rate filling in the placeholders before and after the Gabor presentation. In the current figure, a mask trial is depicted with the flankers all set as vertical, as in Experiments 1 and 2 (2 also included a random orientation condition). In Experiment 3 and 4, the flankers were constructed in a way that if the central Gabor was oriented to the left, the average of the orientation of the flankers was oriented to the right (and vice-versa). We manipulated the mean orientation so that it spanned from -20 to +20 degrees. Stimuli are not drawn to scale, but rather to illustrate the configuration.
Table 1.
Estimated upper and lower confidence interval for each experiment and condition.
Fig 2.
Mean performance in Experiment 1A and 1B.
Panel A. Fixation condition (Experiment 1A). The squares represent the estimated mean proportion of correct responses at each target-flanker distance (TFD). Panel B. Saccade condition (Experiment 1B). The circles represent the estimated mean proportion of correct responses along the pre-saccadic interval. The first bin (square symbol) represents the mean performance at fixation and its 95% confidence interval (CI). The data are subdivided in three columns according to each TDF: 1.5 degrees of TFD (gray), 2 degrees of TFD (white), 3.5 degrees of TFD (gray). Data are displayed relative to saccade onset. In all the graphs, shaded areas represent the bootstrapped 95% CI. Continuous lines represent the GLM fit across the dimension of interest (TFD: Experiment 1A; pre-saccadic interval: Experiment 1B). Blue symbols indicate no-mask trials, while red symbols show mask trials. Single asterisks indicate a significant difference between the fixation and the saccade condition. Double asterisks indicate a significant slope across the dimension of interest.
Fig 3.
Mean performance at fixation in Experiment 2A and 2B.
Squares represent the estimated mean proportion of correct responses at each TFD. Panel A. Mean performance when the flankers were all vertical (Experiment 2A). Panel B. Mean performance when the flankers were random (Experiment 2A). Panel C. Mean performance when the flankers were all random and a larger TFD range was used (Experiment 2B). All other graphical conventions (lines, colors, asterisks) are identical to those used in Fig 2.
Fig 4.
Fixation condition in Experiment 3A.
The squares represent the estimated mean proportion of correct responses for each flanker mean orientation bin. Subpanels (A-B) represent 1.5 degrees of TFD, (C-D) 2 degrees of TFD and (E-F) 5 degrees of TFD. All other graphical conventions (lines, colors, asterisks) are identical to those used in Fig 2.
Fig 5.
Mean performance in the saccade condition for Experiment 3B and 4.
The circles represent the estimated mean proportion of correct responses along the pre-saccadic interval. The first bin (square symbol) represents the mean performance at fixation and its 95% CI. The data are subdivided in two columns according to each flanker mean: 6 degrees (white background), 18 degrees (gray background). Panel A. No-mask condition (blue). Panel B. Mask condition (red).
Fig 6.
Design and results for Experiment 4.
Panel A. In Experiment 4, during incongruent blocks, an empty placeholder was located 40° away from the horizontal plane, at the same eccentricity as the perceptual target, to serve as saccadic target. In the current figure, a no-mask trial is depicted with the flanker orientation randomized and its mean orientation pointing to the left. Target orientation is instead pointing to the right. Panel B. Data for Experiment 4 are organized according to flanker mean: 6 degrees (white background) and 18 degrees (gray background). The congruent condition is displayed in blue while the incongruent condition is depicted in red. The black square represents mean the performance at fixation and its 95% CI. Data are displayed relative to saccadic onset. All other graphical conventions (lines, asterisks) are identical to those used in Fig 2.