The Advertising Law of the Macao SAR of the People’s Republic of China was adopted in 1989. Like similar laws adopted in Europe at the time, the Macao law features a prohibition of subliminal advertising. The term “subliminal” usually refers to the perception of information through sensory channels below the threshold of awareness. While the issue of “subliminal messages” or “hidden persuaders” as they were also called, had received greater attention in the late 1960s in the context of marketing experiments, it has widely fallen into oblivion since then. However, the rise of artificial intelligence, digitization, big data, machine learning and related novel technologies may renew the relevance of the prohibition of subliminal messages. Fact is that in early 2021 the European Union presented its draft Artificial Intelligence Act (AIA), which also contains a wider prohibition of “use of an AI system that deploys subliminal techniques beyond a person’s consciousness” (Art. 5 (1) AIA). Similar concerns about subliminal techniques having a manipulative and negative effect on the human mind were later enshrined in the UNESCO Draft Text of the Recommendation on the Ethics of Artificial Intelligence (November 2021).
The present paper will thus briefly present the context of the Macau Advertising Law and the European Union’s Artificial Intelligence Act to assess. It will also provide an overview of the present and future AI systems that make use of subliminal techniques as well as some related regulatory problems of establishing absolute threshold of sensory perception. Finally, the paper aims to address the principal question, namely to what extent the issue of “subliminal perception” should receive greater attention in the age of AI within the legal system of Macau as well as other jurisdictions in Asia and the world.