OPTIMIZED METHOD OF ESTIMATION OF CRITICAL FLICKER FREQUENCY (CFF)

The threshold frequency for perception of a flickering light (CFF) is an indicator of arousal of the cerebral cortex, and widely used both f or clinical and research purposes [1]. The measurement is often based on the method of limits (MOL), presenting a flickering stimulus of ste adily increasing or decreasing frequency. This method is not free from biases [2]. The method of constant stimuli (MCS) is more precise but may take more time, so the state of the subject cannot be considered a s invariable [2]. We describe a time-saving, computer-controlled metho d based on MCS modified with feedback from previous responses.