Attentional biases for betel nut cues in heavy and light chewers.

The betel nut (Areca catecu) is regarded by the World Health Organization as the fourth most prevalent human carcinogen. Our study aims to investigate whether habitual chewers show bias in their attention toward betel nut usage. In the current study, heavy and light betel nut chewers were instructed to respond to a probe presented immediately after either one of a pair of areca-related picture and non-areca-matched picture. The presentation durations of these pictures were manipulated to investigate attentional biases under awareness threshold (17 ms), in initial orienting (200 ms), and maintenance of attention (2,000 ms). Faster response to the probe replacing the areca-related picture, in comparison with a matched picture, indicated attentional bias. The results showed that neither group showed subliminal attentional biases. Further, heavy chewers, but not light chewers, exhibited supraliminal biases toward betel nut cues in initial orienting of attention and maintained attention. Moreover, attentional bias scores at 2,000 ms were also shown to be positively associated with betel nut craving and dependence. Implications of the current findings are thoroughly discussed in the article.