Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Color contrast is 'seen' by the brain early doors

Color contrast is 'seen' by the brain early doors

September 10, 2007

Colour contrast is detected much earlier in the brain than previously thought, a new study shows.

Scientists at Durham University have confirmed that colour contrast is first detected by part of the brain called primary visual cortex, which is located at the very back of the head where visual information first enters the cortex of the brain. This was recently discovered to be the case in animals but has not been tested on human beings until now.




The research also confirms that the brain does most of the work in seeing the difference between colours, rather than the eye.

The team of neuropsychologists identified a patient with damage to this specific part of the brain. They showed the patient visual illusions in which the contrast between the coloured spots in the foreground and their background colour affected the way the spots looked. People with this part of the brain intact would see the spots as different as they look different on varying backgrounds. The patient was not able to detect that difference.

The research, which is published in the Proceedings of the National Academy of Sciences this week, makes a significant contribution to the understanding of how the brain functions.

Dr Robert Kentridge, lead researcher and lecturer in Durham University's Psychology Department explains: "Colour is a product of our nervous system - it is a 'pigment' of our imagination. The colours that we see are more related to the materials that things are made of than the light reflected from them into our eyes. Making this happen involves many complex processes. One of the earliest involves seeing contrast between pairs of colours. We have found that this important step of seeing colour contrast happens much earlier in the brain than we had realised up to now."

The research study used a common approach in neuropsychology, that of extensive testing of a single patient, in this case one who had portions of the right primary visual cortex surgically removed in 1973 for treatment of abnormal blood vessels in the brain.

Professor Charles Heywood, who leads Durham's Psychology Department, added: "People can distinguish between colours partly because of the contrast with its background. If someone has lost that ability through brain damage, it means that they might see colours as changing all the time. The colour of clothes, and indeed everything else we see, would change dramatically, depending on the colour of light which shines on them."

Durham University



Related Visual Cortex Current Events and Visual Cortex News Articles Visual Cortex Current Events and Visual Cortex News RSS Visual Cortex Current Events and Visual Cortex News RSS
Clues to visual variant Alzheimer's; myopia and diabetic retinopathy risk
Two studies are of particular note in today's Scientific Program of the 2009 Joint Meeting of the American Academy of Ophthalmology (AAO) and the Pan-American Association of Ophthalmology (PAAO): a report by Swiss neuro-ophthalmic researchers about vision exam clues that should make ophthalmologists suspect an atypical variant of Alzheimer's disease; and new evidence from a Singapore National Eye Center study that diabetics who are nearsighted may be less susceptible to diabetic retinopathy.

Treating ROP in tiny preemies; better glaucoma follow-up in urban clinic
Highlights of today's Scientific Program of the 2009 American Academy of Ophthalmology (AAO) - Pan-American Association of Ophthalmology (PAAO) Joint Meeting include: John T. Flynn, MD, Columbia University School of Medicine, discussing the ever-tougher challenges Eye M.D.s face in caring for the vision of the tiniest premature babies; and a report by Bradford W. Lee, MD, Stanford University School of Medicine, on barriers to glaucoma follow-up as perceived by patients in an urban, culturally diverse clinic.

Can we 'learn to see?': Study shows perception of invisible stimuli improves with training
Although we assume we can see everything in our field of vision, the brain actually picks and chooses the stimuli that come into our consciousness.

Scans show learning 'sculpts' the brain's connections
Spontaneous brain activity formerly thought to be "white noise" measurably changes after a person learns a new task, researchers at Washington University School of Medicine in St. Louis and the University of Chieti, Italy, have shown.

Babies see it coming
Do infants only start to crawl once they are physically able to see danger coming? Or is it that because they are more mobile, they develop the ability to sense looming danger?

Perceptual learning relies on local motion signals to learn global motion
Researchers have long known of the brain's ability to learn based on visual motion input, and a recent study has uncovered more insight into where the learning occurs.

Study Finds Needle Biopsies Safe in 'Eloquent' Areas of Brain
After a review of 284 cases, specialists at the Brain Tumor Center at the University of Cincinnati (UC) Neuroscience Institute have concluded that performing a stereotactic needle biopsy in an area of the brain associated with language or other important functions carries no greater risk than a similar biopsy in a less critical area of the brain.

MIT: Long-distance brain waves focus attention
Just as our world buzzes with distractions - from phone calls to e-mails to tweets - the neurons in our brain are bombarded with messages.

'Singing brains' offers epilepsy and schizophrenia clues
Studying the way a person's brain 'sings' could improve our understanding of conditions such as epilepsy and schizophrenia and help develop better treatments.

Preclinical work shows how one gene causes severe mental retardation
Researchers at Duke University Medical Center and the University of North Carolina have discovered in mice how a single disrupted gene can cause a form of severe mental retardation known as Angelman syndrome.
More Visual Cortex Current Events and Visual Cortex News Articles
Computational Maps in the Visual Cortex

Computational Maps in the Visual Cortex
by Risto Miikkulainen (Author), James A. Bednar (Author), Yoonsuck Choe (Author), Joseph Sirosh (Author)

This book presents a unified computational approach to understanding the structure, development, and function of the visual cortex. It reviews the current theories of the visual cortex and the biological data on which they are based, and presents a detailed analysis of the laterally connected self-organizing map model and results obtained to date. Together with the software package Topographica, it serves as a comprehensive foundation for future research in computational neuroscience of the visual cortex.

Moonshine Movies Presents AV:X.05 - Transambient Two

Moonshine Movies Presents AV:X.05 - Transambient Two
Starring: Spiral3, Visual Cortex

Moonshine Movies presents AV:X, the Audio Visual Xperience that comes from the fusion of film and electronic music. Transambient 2's Audio Visual Xperience continues with another voyage through the landscape of your own imagination. 7 unique Audio Visual Tracks. 84 minutes of audio visual mind food.

Transambient 2 presents more organic audiovisual mixes, with musical styles ranging from drum 'n' bass to trance to ambient grooves. The vision behind the project was to create something that wasn't just music with visuals or visuals with music, but a real synergy of the two.

Track Listing:

1. Mind by Spiral3
2. Earthbound by Visual Cortex & Mark Summers
3. Bleeps by Addictive TV & Geraint Hughes
4. Ram(a) by Spiral3
5. Daytrip by Graham Daniels & Geraint...

Visual Cortex: New Research

Visual Cortex: New Research
by Thomas A. Portocello (Editor), Rudolph B. Velloti (Editor)

All visual information that the human mind receives is processed by a part of the brain known as visual cortex. The visual cortex is part of the outermost layer of the brain, the cortex, and is located at the dorsal pole of the occipital lobe; more simply put, at the lower rear of the brain. The visual cortex obtains its information via projections that extend all the way through the brain from the eyeballs. The projections first pass through a stopover point in the middle of the brain, an almond-like lump known as the Lateral Geniculate Nucleus, or LGN. From there they are projected to the visual cortex for processing.Visual cortex is broken down into five areas, labelled V1, V2, V3, V4, and MT, which on occasion is referred to as V5. V1, sometimes called striate cortex because of its...

Visual Perception, Fourth Edition: A Clinical Orientation

Visual Perception, Fourth Edition: A Clinical Orientation
by Steven Schwartz (Author)

The text that bridges the gap between basic visual science and clinical application – now in full color

Includes 3 complete practice exams!

This comprehensive text on visual science is unique in that it highlights the fundamental aspects of monocular visual perception that are necessary to successful clinical practice. Recognized for its engaging, enjoyable style and ability to explain difficult topics in simple, easy-to-understand terms, Visual Perception goes well beyond the basics, including information from anatomy to perception.

Covering a broad range of clinically-relevant topics, including color vision and its defects, spatial vision, temporal aspects of vision, psychophysics, physiology, and development and aging, the Fourth Edition...

Moonshine Movies Presents AV:X.01 - Transambient

Moonshine Movies Presents AV:X.01 - Transambient
Starring: Justin Eade, Visual Cortex

Moonshine Movies presents AV:X, the Audio Visual Xperience that comes from the fusion of film and electronic music. Transambient's organic visual mixes open a new chapter in film-making. Taking you on a journey through the landscape of your own imagination, the project presents a startling new take on the world.

With musical styles ranging from drum 'n' bass to trance to ambient grooves, the vision behind the project was to create something that wasn't just music with visuals or visuals with music, but a real synergy of the two. Transambient incorporates 8 twelve-minute audiovisual tracks with an approximate run time of 94 minutes.

Track Listing:

1. Free Range - Justin Eade and Fructose
2. Transambient (Blossom Mix) - Visual Cortex and Mark Summers
3. Coma - Nigel...

The Visual Brain in Action (Oxford Psychology Series)

The Visual Brain in Action (Oxford Psychology Series)
by David Milner (Author), Mel Goodale (Author)

First published in 1995, 'The Visual Brain in Action' remains a seminal publication in the cognitive sciences. It presents a model for understanding the visual processing underlying perception and action, proposing a broad distinction within the brain between two kinds of vision: conscious perception and unconscious 'online' vision. It argues that each kind of vision can occur quasi-independently of the other, and is separately handled by a quite different processing system. In the 11 years since publication, the book has provoked considerable interest and debate - throughout both cognitive neuroscience and philosophy, while the field has continued to flourish and develop.

For this new edition, the text from the original edition has been left untouched, standing as a coherent...

The Primate Visual System (Methods & New Frontiers in Neuroscience Series.)

The Primate Visual System (Methods & New Frontiers in Neuroscience Series.)
by Jon H. Kaas (Editor), Christine E. Collins (Editor)

The last 20 years of research have been marked by exceptional progress in understanding the organization and functions of the primate visual system. This understanding has been based on the wide application of traditional and newly emerging methods for identifying the functionally significant subdivisions of the system, their interconnections, the response properties of their neurons, and the population responses to stimulus events.While primates vary greatly in morphology and behavioral adaptations, all primates share certain features of the visual system. Although there are several books on vision in the market, until now no book has provided a comprehensive overview of the primate visual system. This book synthesizes the current knowledge on the anatomical and functional organization...

Circuits in the Brain: A Model of Shape Processing in the Primary Visual Cortex

Circuits in the Brain: A Model of Shape Processing in the Primary Visual Cortex
by Charles R. Legéndy (Author)

Dr. Charles Legéndy's Circuits in the Brain: A Model of Shape Processing in the Primary Visual Cortex is published at a time marked by unprecedented advances in experimental brain research which are, however, not matched by similar advances in theoretical insight. For this reason, the timing is ideal for the appearance of Dr. Legéndy's book, which undertakes to derive certain global features of the brain directly from the neurons.

Circuits in the Brain, with its "relational firing" model of shape processing, includes a step-by-step development of a set of multi-neuronal networks for transmitting visual relations, using a strategy believed to be equally applicable to many aspects of brain function other than vision. The book contains a number of testable predictions at the...

The Visual Neurosciences, 2 Volume Set, (Bradford Books)

The Visual Neurosciences, 2 Volume Set, (Bradford Books)
by Leo M. Chalupa (Editor), John S. Werner (Editor)

Visual science is the model system for neuroscience, its findings relevant to all other areas. This massive collection of papers by leading researchers in the field will become an essential reference for researchers and students in visual neuroscience, and will be of importance to researchers and professionals in other disciplines, including molecular and cellular biology, cognitive science, ophthalmology, psychology, computer science, optometry, and education. Over 100 chapters cover the entire field of visual neuroscience, from its historical foundations to the latest research and findings in molecular mechanisms and network modeling. The book is organized by topic--different sections cover such subjects as the history of vision science; developmental processes; retinal mechanisms...

Map-Seeking Circuits in Visual Cognition: A Computational Mechanism for Biological and Machine Vision

Map-Seeking Circuits in Visual Cognition: A Computational Mechanism for Biological and Machine Vision
by David W. Arathorn (Author)

This work presents a bold new theory of the cognitive circuitry of the brain, with emphasis on the functioning of human vision. Departing from conventional precepts in the fields of artificial intelligence, neuroscience, and visual psychophysics, the author has developed a computational theory that provides a unitary explanation for a wide range of visual capabilities and behaviors, most of which have no accepted theoretical explanation. He describes a cortical mechanism termed “map-seeking” and demonstrates its explanatory power in areas as diverse as limb-motion planning and perceptual deficits associated with schizophrenia.

The author argues that map-seeking is a fundamental, broadly applicable computational operation with algorithmic, neuronal, and analog electronic...

© 2009 BrightSurf.com