Propixx color projector

The apparatus is the same as used in our published study of behavioral oscillations (Zhang et al., 2019 (link)). For readability, it is described here again as follows. The experiment was run in a dimly lit room (ambient luminance, 2.1 cd/m²⁾. A PROPixx color projector (VPixx Technologies Inc., Bruno-de-Montarville, Quebec, Canada) was used to present visual stimuli on a matte white PVC screen (Epson ELP-SC21B, 1771 × 996 mm) with a resolution of 1920 × 1080, a frame rate of 120 Hz, and it cast an area of 117 × 66 cm (45.4° × 26.5° of visual angle). The projector was set to quadrant mode, thereby resulting in a resolution of 960 × 540 pixels and a frame rate of 480 Hz when displaying images. The luminance output of the projector was linearized. Participants’ heads were maintained as stationary by using a chin-and-forehead rest at a viewing distance of 1.4 m. The sound stimuli were delivered bilaterally through headphones (Sennheiser HD 380 pro; Sennheiser, Wedemark, Germany). All the experimental programs were developed with Matlab 2015a (MathWorks Inc., Natick, MA, USA) and Psychophysics Toolbox.

The experiment was run in a dimly lit room. The ambient luminance was 2.1 cd/m². Participants were seated in front of a matte white PVC screen (Epson ELP-SC21B, 1771 × 996 mm) with a viewing distance of 1.4 m. We used a PROPixx color projector (VPixx Technologies Inc.) to present visual stimuli on a casted area of 117 × 66 cm (45.4 × 26.5° of visual angle) at a resolution of 1920 × 1080 pixels at a refresh rate of 120 Hz. The projector was set to quadrant mode, resulting in a resolution of 960 × 540 pixels at a frame rate of 480 Hz when displaying images. The luminance output of the projector was linearized. Participants’ heads were maintained as stationary by using a chin-rest. We used headphones to deliver sound stimuli. Experimental programs for this study were developed with Matlab 2015a (MathWorks Inc., Natick, MA) and Psychophysics Toolbox^{52 (link),53 (link)}.