32 display lcd monitor

Visual stimuli were presented on a calibrated 32″ Display++ LCD monitor (Cambridge Research Systems, Rochester, UK) with a spatial resolution of 1920 × 1080 pixels and a refresh rate of 120 Hz (non-interlaced) using the Psychophysics Toolbox (Brainard, 1997 (link); Kleiner, 2010 ) in Matlab (The Mathworks, Inc., Natick, MA, USA). The background was average gray. Participants sat at a table in a darkened room with their head stabilized on a chin rest. The eye monitor distance was 100 cm, leading to a display size of 41° × 23°. Luminance of white and black pixels was 112.7 and 0.1 cd/m², respectively, as measured with a CS-2000 Spectroradiometer (Konica Minolta, Tokyo, Japan). Tactile stimuli were applied by custom-made vibrotactile devices (Engineering Acoustics Inc., Casselberry, FL, USA). They were attached on the tip of both index fingers using silicone finger sleeves. Participants comfortably rested their hands shoulder-width apart on foam pads in front of them. Because of the setup for tactile stimulation, manual response input was excluded. Thus we used gaze positions as response input. Eye positions were recorded using an SR Research Eyelink 1000 Desktop Mount system (SR Research Ltd., Mississauga, Ontario, Canada).