Oxygenation and gender effects on photopic frequency-doubled contrast sensitivity.
Thresholds to a temporally modulated contrast stimulus were examined across the central visual field, at photopic luminance (100 cd m(-2)), under aviation-related respiratory disturbances. These were mild hypoxia (14.1% oxygen), hyperoxia (100% oxygen), and hypocapnia (voluntary hyperventilation), with control exposures breathing air at rest. Thresholds were analysed by retinal eccentricity and by visual field quadrant. Hypoxia compromised sensitivity away from fixation (p<.001). Gender differences in sensitivity were apparent over the nasal hemifield and in response to 100% oxygen. An unexpected and highly statistically significant effect of oxygen tension (PO2) exposure order (p<.001) implies the existence of short-term retinal 'memory' for recent PO2.
Connolly
Desmond M
DM
QinetiQ, Cody Technology Park, Ively Road, Farnborough, Hampshire GU14 0LX, UK. dmconnolly@qinetiq.com
Hosking
Sarah L
SL
D000328:Adult; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D015350:Contrast Sensitivity; D005260:Female; D005584:Fovea Centralis / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D010313:Partial Pressure; D010775:Photic Stimulation / Q000379:methods; D012684:Sensory Thresholds; D012737:Sex Factors
D002245:Carbon Dioxide; D010100:Oxygen