Sex differences in response to red and blue light in human primary visual cortex: a bold fMRI study

• Published in: Psychiatry research Vol. 100; no. 3; pp. 129 - 138
• Main Authors: Cowan, Ronald L, Frederick, Blaise de.B, Rainey, M, Levin, Jonathan M, Maas, Luis C, Bang, J, Hennen, John, Lukas, Scott E, Renshaw, Perry F
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 22.12.2000; Elsevier
• Subjects: Adult; Biological and medical sciences; Brain Mapping; Color Perception - physiology; Color vision; Dopamine; Dopamine - physiology; Estrogen; Estrogens - physiology; Female; Fundamental and applied biological sciences. Psychology; Gender differences; Humans; Image Enhancement; Magnetic Resonance Imaging; Male; Oxygen - blood; Perception; Photic Stimulation; Primary visual cortex; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Sensory Thresholds - physiology; Sex Factors; Substance abuse; Vision; Visual Cortex - physiology; Primary visual cortex; Gender differences; Substance abuse; Dopamine; Color vision; Estrogen; Human; Regional blood flow; Volumetric analysis; Visual cortex; Blue; Sex; Central nervous system; Experimental study; Nuclear magnetic resonance imaging; Light stimulus; Red; Dopaminergic transmission; Vision; Young adult; Medical imagery; Perception; Comparative study; Brain (vertebrata); Functional imaging
• ISSN: 0925-4927; 0165-1781; 1872-7506
• DOI: 10.1016/S0925-4927(00)00074-3

Studies using a variety of investigative methods, including functional brain imaging and electroencephalography (EEG), have suggested that changes in central nervous system (CNS) dopamine function result in altered visual system processing. The discovery of abnormal retinal blue cone, but not red cone, electroretinogram in association with cocaine withdrawal and Parkinson's disease suggests that visual system response to blue light might be a marker for CNS dopamine tone. As there are numerous sex-related differences in central nervous system dopamine function, we predicted that blue and red light stimulation would produce sex-specific patterns of response in primary visual cortex when studied using the blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) technique. We analyzed the BOLD response to red and blue light in male and female human volunteers ( N=20). Red and blue light responses in primary visual cortex (V1) to stepped intensities of red and blue light were compared by sex for threshold to detectable BOLD signal increase and for stimulus intensity vs. BOLD signal response. Near threshold, males and females showed similar BOLD signal change to red light, but males showed a threefold greater increase (0.52%) to blue light stimulation when compared to females (0.14%). Log-linear regression modeling revealed that the slope coefficients for the red light stimulus intensity vs. signal change curve were not significantly different for males and females ( z=0.995, P=0.320), whereas the slope coefficients for the blue light stimulus intensity vs. signal change curve were significantly larger in males ( z=2.251, P=0.024). These findings support a sex and color-dependent differential pattern of primary visual cortical response to photic stimulation and suggest a method for assessing the influence of specific dopamine agonist/antagonist medications on visual function.