Effects of visual stimulation and visual training on children with visual impairment

In March 2006 the InSight foundation invited as to apply for a research grant to study the effectiveness of visual stimulation for children with visual impairment. The invitation mentioned the following commission. “Insight invites you to design a study on the effectiveness of visual stimulation in children up till the age of 8 with ocular or cerebral visual impairment with or without intellectual disabilities. The intervention should consist of methods, materials, and visual tasks currently in use by early intervention service providers. The intervention will be implemented according to a standard protocol. Consensus on the content of this 'standard intervention' could be determined by an expert meeting." With the help of several experts in the Netherlands a proposal for two studies has been designed. The first study will concern the effectiveness of visual stimulation in young children in early intervention. The content of the intervention will be based on previous studies of the Institute of Child Health of the Great Ormond Street Hospital for Sick Children. This program was chosen because it proved to be effective with children in the UK and it seems to be suitable to current early intervention practices in the Netherlands, mostly because several aspects of the intervention are already in use. The exact content, assessment procedures, and as a consequence the number and kind of dependent variables will be determined in a consensus meeting. Professor Sonksen of the Institute of Child Health has kindly agreed to participate in this meeting. With the help of all the early intervention service providers in the Netherlands, 40 children with visual impairment will be asked to participate in this study. The intervention will take place in an experimental control group design with a pre-test (t0), one intermittent (t1), one post test (t2), and one follow up test (t3). Tests will be performed by the researcher with intervals of four months. Duration of the training will be 8 months. The children will be randomly assigned to the treatment or control group. Children in both the treatment and control group will receive normal early intervention services. Children in the control group will receive general information about visual training but not an individualized visual training program, the latter is only given to the children in the control group. The second study concerns children 4 years and older. With these children training can also be conducted at their schools, which may make it possible to have daily training sessions. The procedures described by Hall Lueck, Dornbusch and Hart (1999), Hall and Bailey (1989) and Hall Lueck (2004) will be used. In this kind of training a topdown approach for choosing intervention effects is used. Critical and relevant tasks given the child’s competencies, likes, dislikes and needs, and the parent’s and teacher’s priorities are chosen. Visual training is part of a larger intervention program and certainly not a goal in itself. The effectiveness of this intervention will be the subject of study 2. Five participants for study 2 will be recruited with the help of the schools for children with visual impairment. Training of several tasks to one individual and/or the same tasks to several subjects will be given by a trained MA-student after a comprehensive assessment of the child’s competencies and relevant tasks. Training procedures will be in accordance with Hall Lueck (2004), Hall and Bailey (1989) and Hall Lueck, Dornbusch, & Hart (1999) and will be applied in a nonconcurrent multiple baseline across variables and/or subjects design. In accordance with the recommendations of the commission the dependent variables in both studies will be measured at different levels of visual function, that is: - standard measures of visual functioning ( e.g. grating acuity, contrast sensitivity, recognition acuity) - behavioural measures of visual functions (e.g. the scale to measure visual progress; Near Detection Vision) - measures of visual perceptual functioning (e.g. popout task, motion coherence, biological motion) - test of visual attention - for the second study also task completion (reaction time and failure or success)