Diamondplus 230 sb crt monitor

The experiments took place in a darkened room. Stimuli were displayed with a frame rate of 85 Hz on a Mitsubishi DiamondPlus 230 SB CRT monitor with a resolution of 1280 $\times$ 1024. The monitor was calibrated using a Cambridge Research Systems ColorCal or ColorCal MKII. The observer’s head was kept still using a chin rest placed 57 cm from the screen. The active video area subtended a visual angle of 14 ${}^{\circ }$ . Observers’ eye movements were not restricted and they could scan the video if they wished and time allowed. Experiments were programmed in Matlab using the Psychtoolbox psychophysics library³⁴ . Since our video data was recorded at 50 Hz and the monitor refreshed at 85 Hz, we calculated the optimal video frame to display and used Psychtoolbox’s Screen(‘Flip’) function to schedule frame updates.

The experimental programs were written in Matlab (Version 2013b, Mathworks; http://www.mathworks.co.uk/) using the PsychToolbox extension^{18 (link)} and stimuli were presented on a Mitsubishi Diamond Plus 230 SB CRT monitor. The screen resolution was 1280 × 1024 and the refresh rate was 60 Hz. Participants gave responses using a standard computer keyboard. Avatars were rendered using Poser Pro 9 software (SmithMicro; http://poser.smithmicro.com) and adjusted in Photoshop CS6 Extended (Adobe; http://www.adobe.com). The screen was viewed from 57 cm and the head subtended 10.7 by 8.1 degrees of visual angle (dva).
Horizontal movement was created by a change in gaze direction; these changes in gaze were consistent across all four experiments. Direct gaze shifts moved from leftwards at 70° rotation to straight ahead, near averted gaze shifts were from 35° of rotation left to 35° right, and far averted gaze shifts were from 70° of rotation left to 70° right. The extent of movement in the image corresponded to either 0.2 dva or 0.4 dva in the case of far averted to far averted. In all four experiments both upright and inverted faces were presented to test for the presence of specialised facial processing.