September 4, 2012

Scientists Confirm Women And Men See Things Differently

Lee Rannals for redOrbit.com — Your Universe Online

Scientists have finally confirmed what most have already known for generations and generations, men and women see things differently.

Scientists reported in the journal Biology of Sex Differences that men have greater sensitivity to fine detail and rapidly moving stimuli, but women are better at discriminating between colors.

Researchers from Brooklyn and Hunter Colleges of the City University of New York compared the vision of men and women at the age of 16 and older from college and high school, including students and faculty. All of the volunteers in the study were required to have normal color vision and 20/20 sight.

When the study participants were required to describe colors shown to them across the visual spectrum, the researchers were able to find that the color of men was shifted, thus explaining most men's lack of ability to match clothing and drapes.

The scientists found that men required a slightly longer wavelength to experience the same hue as the women.

Males in the study had a broader range in the center of the spectrum where they were less able to discriminate between colors.

The team used an image of light and dark bars to try and measure contract-sensitivity functions (CSF) of vision. These bars were either horizontal or vertical and volunteers had to choose which one they saw. During each image, when the light and dark bars were alternated, the image appeared to flicker.

The team found by varying how rapidly the bars alternated, or how close together they were, that at moderate rates of image change, the viewer lost sensitivity for close together bars, and gained sensitivity when the bars were further apart.

Once the image change was faster, both men and women were less able to distinguish the images over all bar widths. Overall, the researchers determined that men were better able to resolve more rapidly changing images that were closer together than women.

"As with other senses, such as hearing and the olfactory system, there are marked sex differences in vision between men and women," Prof Israel Abramov, who led this study, said in a statement. "The elements of vision we measured are determined by inputs from specific sets of thalamic neurons into the primary visual cortex."

The team said that in the brain, there are high concentrations of male sex hormone (androgen) receptors throughout cerebral cortex, especially in the visual cortex.

These receptors are responsible for controlling the development of neurons in the visual cortex during embryogenesis, which means males have 25% more of these neurons than females.

"We suggest that, since these neurons are guided by the cortex during embryogenesis, that testosterone plays a major role, somehow leading to different connectivity between males and females," Abramov said in the statement. "The evolutionary driving force between these differences is less clear."