PsychMetal Demos

One stimulus engine, across Mac, iPhone and iPad. PsychMetal is an open-source platform for visual and auditory stimulus presentation in psychophysics and vision research. It uses native Apple Metal graphics and a shared engine behind its Python, MATLAB and Octave interfaces on Apple Silicon Macs. Develop stimuli on your Mac, then bring the same Python stimulus program to iPhone or iPad, adapting controls for touch where needed. PsychMetal Demos showcases the toolbox through interactive examples of spatial and temporal perception, motion, contrast, sound and objects hidden in noise. VISUAL DEMONSTRATIONS • Compare Gaussian spots flickering at different frequencies and drag them into new arrangements. • Explore drifting Gabor patterns, moving dots and rotating shapes. • Adjust the size, refresh rate and color of dynamic noise. • Move a hidden ring through noise to reveal its boundary through motion. • Drag images viewed through Gaussian, annular and other masks. • Compare HDR brightness levels on supported displays. • Explore GPU image processing, including blur, sharpening and color transformations. • View custom GPU-generated patterns, including an animated spiral. SOUND AND MOVIES • Match the phase or frequency of visual flicker and modulated sound. • Change the pitch of a streaming tone using touch. • View a live microphone spectrogram, record sound and play it back. Microphone recordings stay in memory on your device and are discarded when the demonstration ends. • Play movies with sound, record a stimulus, or export a generated stimulus movie and share it. OPTIONAL DIAGNOSTICS Turn on Diagnostic mode to inspect presentation timing, interval graphs and device information. Save and share reports using the system share sheet. Reports are not automatically sent to the developer. Each demonstration includes an explanation and touch controls. Tap with three fingers to return to the menu. Demonstrations run offline, with no account, advertisements or subscriptions. Microphone access is requested only for the sound recorder. The app includes bundled demonstrations; it does not download or run user-supplied scripts. Developers can adapt their own Python programs using the open-source toolbox and app project. Explore the toolbox and source code: https://github.com/keiths0/PsychMetal Some demonstrations contain rapid flicker. HDR availability, display characteristics and timing depend on the device and its settings. Software timing reports are not measurements of physical light or sound onset. This app demonstrates stimulus presentation; it is not a calibrated clinical instrument.