“…Unless stated otherwise, we report the mean squared error (MSE), the structural similarity index (SSIM; Wang, Bovik, Sheikh, & Simoncelli, 2004 ), and either the peak signal to noise ratio (PSNR) or the feature similarity index (FSIM; Zhang, Zhang, Mou, & Zhang, 2011 ) between the reconstruction and the input image, as evaluated using the Scikit-image library (version 0.16.2) for Python ( Van Der Walt et al, 2014 ). Where MSE and PSNR are image quality assessment metrics that operate on pixel intensity, SSIM and FSIM are popular alternatives that better reflect perceptual quality ( Preedanan, Kondo, Bunnun, & Kumazawa, 2018 ). In addition to these performance metrics, we report the average percentage of activated electrodes as a measure for sparsity.…”