Marleen J. Janssen is a Professor Emeritus of Educational Psychology, in the research unit for Inclusive and Special Needs Education at the University of Groningen in the Netherlands. Her interests include communication development and learning in people with deafblindness. Her research is focused on communication assessment and intervention studies with people who are congenitally deafblind. Previously she was Editor-in-Chief of the Journal of Deafblind Studies on Communication, and Curriculum Coordinator of the MSc program in Pedagogical Sciences Communication and Deafblindness. She founded the University of Groningen Institute for Deafblindness and continues research and writing. Marleen was appointed Knight of the Order of the Netherlands Lion in 2019 and awarded the Deafblind International Lifetime Achievement Award in 2023.Timothy S. Hartshorne is a Professor Emeritus of Psychology, specialized in school psychology, at Central Michigan University. His interests include understanding the challenging behavior exhibited by many individuals with CHARGE syndrome, a rare genetic disorder, and how severe disability impacts the family. Prior to his retirement he was the grant holder for Deafblind Central, Michigan's deafblind project. He has been awarded a Star in CHARGE by the CHARGE Syndrome Foundation. He is first editor of the book CHARGE Syndrome, Second Edition. He holds a Diplomate in Adlerian Psychology from the North American Society of Adlerian Psychology.Walter Wittich is an Associate Professor at the School of Optometry, University of Montreal, in Canada. His research focuses on the rehabilitation of older adults with combined vision and hearing loss. His research domains include basic sensory science, as well as medical, psychosocial, and rehabilitation approaches to sensory loss. He is the inaugural chair of the Deafblind International Research Network, the 2020 recipient of the Canadian Helen Keller Centre 10th Annual JT Award, is a Fellow of both the American Academy of Optometry, and the Association for Research in Vision and Ophthalmology, and is Quebec's first Certified Low Vision Therapist.
