[Possible confounding variables on the flicker-fusion frequency: temperament, well-being, cognitive information processing speed].

: The aim of the present study was to investigate the influence of the response criterion, the current well-being, and the speed of cognitive processing on fusion and flicker frequency measured by method of limits, in 65 healthy subjects, aged between 20 and 30 years. The findings demonstrated that the fusion and flicker frequency could not be measured exactly. Evaluation of the reliability of the obtained results was not possible, mainly because the necessary basic psychological variables could not be recorded using the method.