Auditing Multimodal LLM Raters: Central Tendency Bias in Clinical Ordinal Scoring. - Jiaqing Zhang; Sandeep Elluri; Bhanu Cherukuvada; Yonah Joffe; Jessica Sena; Miguel Contreras; Scott Siegel; Subhash Nerella; Catherine Price; Parisa Rashidi (CoRR, 2026)