2007 Wolfson Research Institute Annual Lecture
‘The Developing Visual Brain: Infants and Children’
Speaker: Professor Janette Atkinson, F.Med.Sci.
Director of the MRC Visual Development Unit,
University College London and University of Oxford
Author of The Developing Visual Brain,
Oxford University Press (2000)
All staff and students of the University, and all members of the general public, are very welcome to attend.
There will be an open reception after the Lecture.
"The Developing Visual Brain: infants and children"
Visual Development Unit
University College London & University of Oxford
Our work uses a neurobiological approach to understand and assess normal development of the eye-brain system in infants and children. My current model of early visual development delineates the onset of function in visual cortex in the first few months of life, with different onset times in brain networks sensing differences in colour, orientation or slant, motion and binocular disparity for depth. We have extended this basic model to chart the complex sequence of development in the two cortical streams, the ‘ventral’ stream for perceptual recognition of shapes, objects and faces and the ‘dorsal’ stream for spatial relations, movements and planning actions. It also chart dorsal stream development for specific visuo-motor skills such as reaching and grasping, navigation and walking down stairs.
Through this approach, we have developed age-appropriate and child-friendly techniques to assess visual and visuo-spatial functions over the entire range of abilities from rare severe problems such as ‘cortical blindness’, to milder common problems such as amblyopia, dyslexia, perceptual and attentional disorders (ADHD). In tests we use behavioural methods such as fixation shifts, and recordings of electrical ‘brain waves’, including high-density recordings with geodesic net. These tests can be used not only to assess visual status in infancy but also as ‘early surrogate outcome measures’ to predict neurological and cognitive outcome in later childhood, where it is important to measure the effectiveness of early intervention and treatment in clinical trials. Our portable test battery (‘ABCDEFV’- Atkinson Battery of Child Development for Examining Functional Vision) assesses sensory, perceptual, motor, cognitive and spatial aspects of vision between birth and 5 years of age, providing a way to relate functional vision to analysis of neonatal brain imaging, and to development in other domains, e.g. language and communication.
We compare dorsal and ventral stream function with measures of sensitivity to global visual form (ventral) and motion (dorsal) coherence. Children between 4-12 years can be tested with a ‘computer game’ task to ‘find the ball in the grass’ or ‘find the road in the snowstorm’. These tests of form and motion coherence show that a wide range of developmental disorders, including hemiplegia, Williams Syndrome, autism, Fragile X and dyslexia, all show greater impairment for global motion than global form; evidence for a general vulnerability of the dorsal stream in early brain development.
In our studies in progress, in collaboration with the neonatal brain imaging teams at the Hammersmith Hospital, we are finding that tests we have devised for use in the first months of life may provide a good indicator of future brain development and cognitive ability in children born very prematurely. One persistent problem in many of these clinical groups are attention difficulties, so one of our current aims is to devise sensitive tests of early attention to identify and help ‘high risk’ children in the preschool years. In 25 years we have learnt a great deal about the developing visual brain; our challenge now is to translate this research for the clinic and the schools so that we may help each child to reach their true ‘visual’ potential.
Two relevant references (full list of VDU publications on VDU website)
J Atkinson. The Developing Visual Brain. Oxford University Press (2000)
Milner AD and Goodale MA. The Visual Brain in Action Oxford University Press (1995)
Visual Development Unit website: http://www.psychol.ucl.ac.uk/vdu/publications/
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