Critical Flicker Fusion

Critical Flicker Fusion




Assessment of the central-nervous activation (arousal) with the help of threshold values, when high frequency light is recognized as constant light. To be used with adults.

Main areas of application: clinical psychology, neuropsychology, medicine and pharmacology. Physiological studies prove that the activation (arousal) of the organism is centrally controlled. The flicker fusion frequency is regarded, next to other criteria as on indicator for this central-nervous function capacity.


In the increasing process the frequency of a flickering light is augmented until a constant light is perceived: In the decreasing process the frequency of a higher frequency light, that the respondent perceives as constant, is reduced until it is subjectively perceived as flickering. The respondent has to confirm every change of perception by pressing a key. The critical frequency is than stored.

The median values of the critical frequencies in the ascending or descending process are threshold values and they are caleld “Fusion frequency (VF)” and “Flicker frequency (FF)”


1 Fusion frequency- 5 to 70Hz.

2 Frequency in Ascending and Descending mode.

3 Two color light facility- Red & Green.

4 Auto mode.

5 LED Display for frequency counts.

6 9V adaptor operated.

7 LED Eye piece movable at 360*

About Medi Systems

We have our own dedicated team in Research & Development of entire range of equipments in Psychiatry & Psychology. MEDI SYSTEMS Quality Management system is certified in accordance with ISO 9001:2015 standards.

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