The effect of betel nut on human performance.

The effects of low doses of betel nut on early-stage visual information processing were examined, using a cross-over experimental design. Three assessment measures were used, critical flicker fusion (an index of the efficiency of the visual processing system), heart rate, and analogue scales of subjective alertness. Only heart rate was shown to be significantly elevated, immediately following betel nut administration. From these results, it was concluded that there is no evidence to suggest that betel nut usage facilitates visual information processing at low-dose levels in habituated subjects, but there is some evidence that peripheral stimulation occurs.