Abstract
Abstract: :
Purpose: Past studies have indicated that variations in blood pressure (BP) are positively related to critical flicker fusion frequency (CFF) thresholds and flicker sensitivity. In the current study, we assessed both the between- and within-subjects relationship between covariations in BP and CFF thresholds. Methods: Three separate designs were utilized: one between-subjects design and two within-subjects designs. In the first study, we measured the CFF and BP of 220 healthy, younger adults (97 males, 123 females; mean age = 19.6, SD = 2.44). In the second study, we measured the CFF and BP of 12 healthy adults (3 males, 9 females; mean age = 24.42, SD = 6.33) over 8-10 separate sessions. In the final study, we assessed the effects of BP medication on the CFF of one adult male (age 36 years). For a given session, CFF was measured over two separate trials using a 1-deg, 570-nm circular test stimulus. Thresholds were determined using the method of limits. Resting BP was measured over two trials (at the beginning and end of the session) at the brachial artery using an automatized sphygmomanometer. Results: A positive correlation was found between CFF and SBP (n = 220, r = 0.23, p < 0.0002) in the first study. Moreover, we found substantial covariation between CFF and SBP for 6 of the 12 subjects who participated in the within-subjects study. Finally, for the subject taking BP medication, CFF and BP were significantly lowered. Conclusion: The confluence of data indicate that CFF and BP are significantly inter-related.
Keywords: 596 temporal vision