What You See Ain't What You Get!!!

What  you see ain't always what you get--as far as your visual cortex is concerned. How, then, does this massive region of the brain right the world we see?

"What we see is not only based on the signals that our eyes send to our brain, but is influenced strongly by the context the visual stimulus is presented in, on our previous knowledge, and expectations," goes the writeup on Medical News Today. "Optical illusions, as the one shown here, illustrate how important such non-visual, contextual information is for our perception. The visual cortex receives this additional information from other brain areas and uses it to allow us to understand and interpret the visual world. Prof. [Sonja] Hofer and her team [at the biozentrum at the University of Basil, Switzerland] measured the specific signals transmitted to visual cortex from the Thalamus, and found that the Pulvinar not only conveyed visual signals but is also one of the brain areas that provide additional information about the context of visual stimuli." Nature Neuroscience published their results. Read more.

New Computer Model Simulates the Development of an Infant's Visual Cortex after Birth

"When newborn babies open their eyes for the first time, they already possess nerve cells specialized in particular stimuli in the visual cortex of their brains - but these nerve cells are not systematically linked with each other," reports Medical News Today. "How do neural networks that react in a particular way to particular features of a stimulus develop over the course of time? In order to better understand the steps of this development and explain the complicated processes of reorganization they involve, an international team of researchers has now developed a computer model that precisely simulates the biological processes. The results of the study by Prof. Dr. Stefan Rotter, Bernstein Center Freiburg (BCF) and Cluster of Excellence BrainLinks-BrainTools of the University of Freiburg, conducted in cooperation with Dr. Claudia Clopath from the Imperial College London, England, have now been published in the journals PLOS Computational Biology and PLOS ONE." Read more.

You See What You Hear

The extrastriate cortex (shown in orange and red) is believed to be involved in perceptual priming (Photo credit: Wikipedia)

"Scientists studying brain process involved in sight have found the visual cortex also uses information gleaned from the ears as well as the eyes when viewing the world," reports Medical News Today. "They suggest this auditory input enables the visual system to predict incoming information and could confer a survival advantage. Professor Lars Muckli, of the Institute of Neuroscience and Psychology at the University of Glasgow, who led the research, said: 'Sounds create visual imagery, mental images, and automatic projections. So, for example, if you are in a street and you hear the sound of an approaching motorbike, you expect to see a motorbike coming around the corner. If it turned out to be a horse, you'd be very surprised.'" Read more.

Reward Alone Stimulates Visual Cortex

“Once rhesus monkeys learn to associate a picture with a reward, the reward by itself becomes enough to alter the activity in the monkeys' visual cortex,” according to Medical News Today. “This finding was made by neurophysiologists Wim Vanduffel and John Arsenault (KU Leuven and Harvard Medical School) and American colleagues using functional brain scans and was published recently in the leading journal Neuron. Our visual perception is not determined solely by retinal activity. Other factors also influence the processing of visual signals in the brain.” Read more.

Rats Touch IR

“Researchers have given rats the ability to 'touch' infrared light, normally invisible to them, by fitting them with an infrared detector wired to microscopic electrodes implanted in the part of the mammalian brain that processes tactile information. The achievement represents the first time a brain-machine interface has augmented a sense in adult animals,” notes Medical News Today. MNT added the experiment showed that a cortical region specializing in another sense could process a novel sensory input “ without 'hijacking' the function of this brain area...This discovery suggests...that a person whose visual cortex was damaged could regain sight through a neuroprosthesis implanted in another cortical region, he said.” Read more.