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At Perkins, we are a gathering place of ideas. The CVI visual behaviors synthesize current research and build on the work of leading theorists in the field. CVI is a lifelong disability and we want to ensure that all individuals with CVI are fully understood. The CVI visual behaviors are an ongoing need, they can change and they can improve for some, but the need never goes away. No one area is separated from the other—the CVI visual behaviors are highly connected and all can impact the individual with CVI at any time.
Impact of Motion is emerging as a big, complex CVI behavior. It affects everything.
Look around you. Think about how many things move. You move and as you move, even just to turn your head, you create movement. We all live in a constant state of motion. So impaired motion perception is not something that will affect the person occasionally, it will affect them all the time.Dr. Gordon Dutton, Lesson on Dyskinetopsia
What is the Impact of Motion?
- Motion can be both a support and a big barrier to access for people with CVI.
- Some with CVI need the motion of a target or item (slower, more methodical motion) to help gain visual attention and support visual recognition.
- Motion in the environment can be distracting and distressing.
- An over-attention to movement with an inability to disengage.
- Many with CVI may have an inability to process fast-moving items.
- Many individuals with CVI demonstrate difficulty with determining the speed of motion, determining the direction of movement, and evaluating distance.
- Some with CVI prefer objects to stay still because moving items can be disorienting and frightening while they are in constant motion.
- Looming behavior is when a person with CVI may get startled, frightened or upset, or pull back to moving items/people in the environment and/or as they move through the environment.
Children with CVI may manifest motion perception deficits attributed to dorsal stream dysfunction, including abnormalities in detection of optic flow and global or biologically relevant motion, as well as visuomotor integration deficits leading to optic ataxia.Janette Atkinson (2017)
What are some compensatory strategies related to the Impact of Motion?
Some with CVI may:
- Use self-movement to support visual access and/or access to concept development (kinesthetic learning).
- Tap on tables to make items move.
- Go to an area of the room that has less movement.
- Manipulate and spin objects in their field of vision.
- Prefer TV shows with slow and predictable movement and/or watching videos at a reduced speed.
- Need movement breaks to help reset and reduce visual fatigue.
- Block out the visual noise of motion that is unpredictable, disorienting, and frightening.
Sometimes it’s hard for me to catch balls fast and keep up with running.Krish, elementary student with CVI
What are some look fors/questions when observing your child with CVI?
- To what extent does your child need an item to move in order to notice it, sustain visual attention, and support recognition? Is motion needed to notice something near and/or at a distance?
- Does your child frequently move objects while looking at them (spinning or other types of manipulation)?
- Is your child highly attentive and distracted by environmental movement but has a difficult time noticing still items/people?
- To what extent does motion in the environment impact your child’s ability to safely navigate?
- Does your child get startled at quick and/or unpredictable approaches by people or objects (looming)?
- Does your child go towards unsafe areas of motion (swings, moving cars, bicyclists)?
- Does your child watch TV visually? If so, does your child prefer slow or fast TV shows?
- Does your child show behaviors such as finger-flapping/flicking up at eye level and/or self-body movement? Does your child like to be in motion often?
My son has a tremendous amount of difficulty being outdoors. He had an outdoor school concert (he plays piano). He was in severe panic mode as there were birds flying everywhere and lots of noise and people around did not help. Birds in particular frighten him with their sudden and unpredictable movements. In addition, he only has central vision so they seem to come out of nowhere. Mara, CVI Parent
What are some examples of adaptations and accommodations?
All accommodations must be based on individual assessments. The following are meant to inspire and provide a general idea. Accommodations and instructional approaches must be student-specific. Access is individual.
Examples from a guide to common CVI IEP accommodations:
- Your child may need to face away from distracting motion (people or objects) in their central and peripheral visual fields.
- A school team might:
- use learning spaces and positioning that minimize movement of people and materials around your child, in their peripheral visual fields, to reduce visual and auditory distraction, so they can visually attend—for example, sitting facing two walls to block excess movement.
- allow self-motion that’s safe and is linked to support access to learning and for some, use of vision.
- If your child has difficulty with the perception of movement toward them (speed, direction, distance), educators should ensure safety in activities such as gym class, out-of-class activities, or travel through the community.
- When using movement to draw visual attention to an object or smaller details, educators may need to place the object slightly in front and off to the side and slowly move it, without noise, in a small area of space. They should allow time for your child to visually fixate.
- Use verbal descriptions to narrate moving objects or people in an environment. For example, “Anna is riding her bike and she will pass us soon, let’s make space for her.”
My eyes can get tired looking at things that move. My eyes go crazy.Aidan, teenager with CVI
Following the science
Connecting current research on the brain, our visual system, and CVI to better understand the CVI visual behaviors.
- People with CVI may have difficulty “correctly calculating how big or how far away the other people [or items] are” (due to optic ataxia). They may not see items/people that are moving too fast until the items/people slow down and they pop out of what seems like nowhere (due to dyskinetopsia). (CVIScotland.org)
- Dyskinetopsia is atypical movement processing and includes difficulty processing things that are moving quickly. Motion is processed more slowly because the brain has a hard time matching the real-time movement of the object. Dyskinetopsia is a spectrum. According to Dr. Gordon Dutton, “if it’s mild, some things may be missed or partly seen. If severe, much of the world around the person can be missed.” One way to help is to slow down movement. (Dyskinetopsia, CVI Scotland)
- Optic ataxia is difficulty with visually guided reach and moving through space—the impaired perception of depth and distance to guide movement. Why does this matter when it comes to impaired motion perception? If a person with CVI is not able to judge the distance of moving people or items around them, they will constantly feel like they are about to collide with those moving targets—”you can’t measure the distance between yourself and the people who are moving” (Optic Ataxia, CVI Scotland). Learn more about visual guidance of upper limbs and lower limbs.
- Optic flow is a monocular depth cue around motion and the ability to judge the distance and speed of an object or self. Think about a ball being thrown at you, the farther away it is the smaller it looks, and the closer it is the bigger it appears. The perceived size of the ball helps you judge how close or far away it is. The rate of change in the size of the ball also tells you how fast it is going. According to recent research, Zahide Pamire, et al. (2021) note, “On average, individuals with CVI require nearly three times the motion coherence signals in order to reliably detect the direction of movement of the optic flow stimulus.”
- Biological motion perception is the “ability to perceive the moving form of a human figure from a limited amount of stimuli, such as from a few point lights located on the joints of a moving body.” (Wang, Z. et al, 2016) If biological motion is impaired, it can be difficult to perceive body language, hand gestures, or the actions of a person moving in space.
Learn more about the development of the Perkins CVI Protocol.
- Atkinson, J. (2017). Visual Brain Development: A review of ‘‘Dorsal Stream Vulnerability’’—motion, mathematics, amblyopia, actions, and attention. The David Teller Award Lecture, 2016. Journal of Vision, 17(3): 26, 1-24.
- Chandna, A., Nichiporuk, N., Nicholas, S., Kumar, R., & Norcia, A. M. (2021). Motion processing deficits in children with cerebral visual impairment and good visual acuity. Investigative Ophthalmology and Visual Science 62(12).
- Chang, M. Y. & Borchert, M. S. (2020). Advances in the evaluation and management of cortical/cerebral visual impairment in children. Survey of Ophthalmology 65, 708-724.
- Gilaie-Dotan, S. (2016). Visual motion serves but is not under the purview of the dorsal pathway. Neuopsychologia, 89, 378-392.
- Lueck, A. H., & Dutton, G. N. (2015). “Intervention Methods: Overview and Principles.” A. H. Lueck & G. N. Dutton (eds). Vision and the Brain: Understanding Cerebral Visual Impairment in Children (pp. 497-536). New York, New York: American Foundation for the Blind Press.
- Pamir, Z., Bauer, C. M., Bailin, E. S., P. J., Somers, D. C., & Merabet, L. B. (2021). Neural correlates associated with impaired global motion perception in cerebral visual impairment (CVI). NeuroImage. Clinical, 32, 102821. Advance online publication.
- Philip, S.S. and Dutton, G.N. (2014), Cerebral visual impairment in children: a review. Clin Exp Optom, 97: 196-208.
- Roman-Lantzy, C. (2018). Cortical Visual Impairment: An Approach to Assessment and Intervention. 2nd ed., New York, NY: AFB Press.
- van der Zee, Y. J., Stiers, P., Lagae, L., & Evenhuis, H. M. (2021). Clinical Assessment of Visual Motion Perception in Children With Brain Damage: A Comparison With Base Rates and Control Sample. Frontiers in human neuroscience, 15, 733054.
- Wang Z, et al. (2016) Prediction of Biological Motion Perception Performance from Intrinsic Brain Network Regional Efficiency. Front. Hum. Neurosci. 10:552. doi: 10.3389/fnhum.2016.00552
- Weinstein, J., Gilmore, R., Shaikh, S., Runselman, A., Trescher, W., Tashima, L., Boltz, M., Mcauliffe, M., Cheung, A., & Fesi, J. (2011). Defective motional processing in children with cerebral visual impairment due to periventricular white matter damage. Developmental Medicine and Child Neurology, 54, e1-e8.