Chapter 2
Developmental Sequences
Use the Developmental Sequences Chart (DSC) (Table 2.1) and Appendix A: Continuum of Visual Development to determine skills and accommodations for learning media in priority activities by comparing current performance to visual behaviors as they develop typically from birth. Keep in mind that visual behaviors emerge and mature in children at different ages. For children who develop typically, one sequence of visual behaviors may reach maturity in infancy while another may mature in kindergarten. For students who are developmentally 3 years old or older, the DSC and Appendix A will be most helpful if the Activity Inventory shows consistently low visual efficiency performances across activities. This can indicate that very basic visual skills need attention.
Table 2.1 Developmental Sequences Chart.1
Emergence | Maturity | |
---|---|---|
Awareness | Attention | Understanding |
Lights | People | Objects |
Fixating | Tracking | Scanning |
Near | Far | |
Peripheral | Central | |
Familiar | Novel | |
Large | Small | |
High contrast | Low contrast | |
Part | Whole | |
Black and white | Colors | |
Simple | Complex | |
Outer edges | Internal details |
For some students, the DSC and Appendix A may help identify developmental gaps related to lack of experience in a certain area. When skill gaps are identified, list the related developmental sequences (e.g., simple/complex) from the DSC in column 3 of the Intervention Guide (IG), using the letter “V” (visual). After you list the behaviors affecting performance with a media item, use Appendix A to determine appropriate interventions and list them in column 4 of the IG. For example, observation of a dressing activity during which there is a high need for instruction may indicate that fixations are poor when clothing items have complex color patterns. The accommodation described in column 4 of the IG related to the simple/complex sequence might be to improve fixations by providing clothing items limited to two colors.
When visual behaviors are extremely delayed or when gaps are identified, different kinds of interventions must be considered. For example, you may find during your observation of activities that a student’s responses to colors are poor. You indicate that the black-white/colors sequence needs evaluation. When you check the Continuum of Visual Development in Appendix A, you see that color perception is typically near adult levels by 4 months (Ferrell, 2010). Your student is 6 years old. When gaps such as this exist, start by checking your student’s clinical eye report. Diabetic retinopathy, glaucoma, keratoconus, optic nerve atrophy, retinitis pigmentosa, and Leber’s amaurosis are conditions associated with reduced color perception (Lueck, 2004). If your student has had a clinical low vision evaluation, color perception may have been evaluated and information about capacity may be found there. If not, you may want to consider a referral.
Physical capacities—determined by maturation or by impairment—must be part of the evaluation that determines intervention methods. But, keep in mind two things:
- Development of visual behaviors is not totally a product of physiological factors such as myelination of nerves and structural changes in the eye that result in improved acuities. It is also a product of experience—interactions with things in the environment.
- Limitations imposed by visual impairments vary significantly from individual to individual. Functional efficiency is influenced by a variety of factors, including experience.
When performance in a sequence is delayed, accommodations are essential interventions. They ensure that, to the maximum extent possible, your student will have access to the kinds of experiences that result in development of visual behaviors. For example, children cannot move from simple to more complex unless they have many enjoyable experiences in which they interact visually with things in their environments that are simple. They may not have that opportunity without accommodations. When you have reason to believe that early visual experiences may have been inadequate or absent, instruction may be an appropriate intervention. Consider these two points:
- The research available to date indicates that the visual performance of children with low vision improves over time with and without instruction (Ferrell, 2010; Hatton, Bailey, Burchinal, & Ferrell, 1997; Leguire, Fellows, Rogers, & Fillman, 1992; Mamer, 1999).
- We know that some children with low vision develop visual behaviors in a different order (Ferrell, 2010). What is normal for them may not be exactly like the milestones that are normal for children without visual impairments.
The Continuum of Visual Development in Appendix A presents information about behaviors related to visual capacity such as cognitive and motor abilities. Use this information to help you determine whether visual efficiency, cognitive skills, or motor skills should be the primary focus of instruction.
The sample Intervention Guide (Table 2.2) shows how to document identified developmental sequences and interventions for learning media and objects in priority activities.
Table 2.2 Sample Intervention Guide Showing Related Developmental Sequences and Accompanying Intervention Accommodations and Skills
Priority Activities | Media/Objects affected by poor visual efficiency | Related visual developmental sequences (V) and/or Related perceptual skill deficits (P) |
Intervention Accommodation (A) Skill (S) Strategy (St) |
---|---|---|---|
Arrival time | Name tag on cubby | V: High contrast/low contrast | A: Enhance contrast with wide tip, black marker on white background |
Hook on coat rack | V: Fixating/tracking/scanning | S: Scan from left to next hook in row until empty hook is located | |
Journal time | Notebook | V: High contrast/low contrast | A: Use bold line paper to enhance contrast |
Centers | Picture books | V: Simple/complex | S: Identify single element in scene |
Puzzles | V: Part/whole | S: Assemble two halves of single-object pictures cut in half | |
Morning circle | Weather pictures | V: Outer edges/internal detail | A: Outline outer edges of salient feature |
Playground | Anything in bright sunlight | V: Fixating/tracking/scanning | A: Sunglasses |
Arts and Crafts | Lines for cutting | V: High contrast/low contrast | A: Used bold marker to enhance contrast |