Hong Kong Peak Tram Illusion (image) Association for Psychological Science Caption In this schematic diagram of the Hong Kong Peak Tram illusion, the angle θ illustrates the approximate deviation of the perceived tilt relative to gravity for a mountain slope of α. Credit Chia-huei Tseng et al. (2013). Falling Skyscrapers: When Cross-Modal Perception of Verticality Fails. Psychological Science. DOI:10.1177/0956797612472344 Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.