What Do We Actually 'See'?

Medical News Today asks: "Glance out the window and then close your eyes. What did you see? Maybe you noticed it's raining and there was a man carrying an umbrella. What color was it? What shape was its handle? Did you catch those details? Probably not. Some neuroscientists would say that, even though you perceived very few specifics from the window scene, your eyes still captured everything in front of you. But there are flaws to this logic, MIT researchers argue in an Opinion published in Trends in Cognitive Sciences. It may be that our vision only reflects the gist of what we see." Read more.

Can Seeing Make You "Deaf"?

"Concentrating attention on a visual task can render you momentarily 'deaf' to sounds at normal levels, reports a new UCL study funded by the Wellcome Trust," notes Medical News Today. "The study, published in the Journal of Neuroscience, suggests that the senses of hearing and vision share a limited neural resource. Brain scans from 13 volunteers found that when they were engaged in a demanding visual task, the brain response to sound was significantly reduced. Examination of people's ability to detect sounds during the visual demanding task also showed a higher rate of failures to detect sounds, even though the sounds were clearly audible and people did detect them when the visual task was easy." Read more.

Should Seeing Be Believing?

"Our vision and hearing aren't as reliable as we might think, according to a study by life scientists at UCLA," writes Medical News Today. "'Our basic sensory representation of the world -- how information from our eyes and ears is processed by neurons in the brain -- is inaccurate,' said Ladan Shams, an associate professor of psychology in the UCLA College and senior author of the research, which was published in the journal PLOS Computational Biology. 'We tend to view our senses as flawless and think that to see is to believe,' she said. 'So it's eye-opening to learn that our perceptions are flawed.' Shams and her colleagues conducted the research in part because there had never been a comprehensive study to examine whether humans' 'spatial localization' ability -- that is, whether we can immediately and accurately perceive where an object is located -- is as well-honed as we believe it to be." Read more.

Seeing Is Not as Simple as Black and White, Says Scientists

"While some things may be 'as simple as black and white,' this has not been the case for the circuits in the brain that make it possible for you to distinguish black from white," reports Medical News Today. "The patterns of light and dark that fall on the retina provide a wealth of information about the world around us, yet scientists still don't understand how this information is encoded by neural circuits in the visual cortex--a part of the brain that plays a critical role in building the neural representations that are responsible for sight. But things just got a lot clearer with the discovery that the majority of neurons in visual cortex respond selectivity to light vs dark, and they combine this information with selectivity for other stimulus features to achieve a detailed representation of the visual scene." Read more.

Humans Have the Best of Al Visual Worlds, Prove Scientists

"Humans have the best of all possible visual worlds because our full stereo vision combines with primitive visual pathways to quickly spot danger, a study led by the University of Sydney has discovered," notes Science Digest. "The surprising finding published today in Current Biology shows that in humans and other primates, information from the eyes is not only sent to the visual cortex for the complex processing that allows stereoscopic vision, but also could feed directly into deep brain circuits for attention and emotion. 'The brain cells that we identified suggest that human and other primates retain a visual pathway that traces back to the primitive systems of vertebrates like fish and frogs,' said University of Sydney's Professor Paul Martin from the Sydney Medical School, who led the team that made the discovery." Read more.

Vision Loss Increases Risk for Death, Says Study

“Vision loss can adversely affect the ability of older adults to perform instrumental activities of daily living (IADL), such as using the telephone, shopping and doing housework, which are all measures of an individual's ability to live independently, and that subsequently increases the risk for death,” reports Medical News Today. “Visual impairment (VI) can have negative effects on a person's physical and psychosocial health. VI is associated with a variety of functional and health outcomes. The authors used data from the Salisbury Eye Evaluation study to examine the extent to which visual acuity (VA) loss increased the risk for death because of its effect on functional status over time. The study included 2,520 older adults (65 to 84 years) from September 1993 through July 2003 from the greater Salisbury, Md., area. Study participants were reassessed at 2, 6 and 8 years after baseline.” Read more.

'Living in the Moment' Ain't Happening

"The sought-after equanimity of 'living in the moment' may be impossible, according to neuroscientists who've pinpointed a brain area responsible for using past decisions and outcomes to guide future behavior," goes the Science Daily write-up. "The study, based on research conducted at the University of Pittsburgh and published...in the professional journal Neuron, is the first of its kind to analyze signals associated with metacognition -- a person's ability to monitor and control cognition (a term cleverly described by researchers as 'thinking about thinking.')" Read more about how this is connected to vision.