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Reach on sound: a key to object permanence in visually impaired children
Elisa Fazzi1, Sabrina Giovanna Signorini, Monica Bomba
1Unit of Child Neurology and Psychiatry, Spedali Civili, Mother and Child Department, University of Brescia, Italy. elisa.fazzi@gmail.com
Insights
Congenitally blind children without multiple disabilities develop object permanence by reaching for sounds. Those with multiple disabilities show delayed development in this cognitive skill.
Area of Science:
- Developmental Psychology
- Pediatric Neurology
Background:
- Reaching for objects based on sound cues in blind children signifies object permanence and cognitive development.
- Assessing this skill provides insights into cognitive maturation in early childhood.
Purpose of the Study:
- To evaluate cognitive development in congenitally blind children.
- To compare cognitive development between congenitally blind children with and without multiple disabilities.
Main Methods:
- A cohort study involving 37 congenitally blind subjects.
- Utilized Bigelow's protocol to assess "reach on sound" capacity from 6 to 36 months.
- Employed clinical, neurophysiological, and cognitive assessments.
Main Results:
- Mainly blind children acquired early "reach on sound" tasks by 12 months.
- A performance drop occurred at task 6, with less age-homogeneous acquisition of later tasks.
- Blind children with multiple disabilities exhibited lower task acquisition rates and struggled with complex tasks.
Conclusions:
- Mainly blind children overcame the "conceptual problem" of attributing identity and substance to sound-localized objects.
- Most blind children with multiple disabilities showed poor "reach on sound" performance and difficulty resolving this conceptual problem before 36 months.
Background:
The capacity to reach an object presented through sound clue indicates, in the blind child, the acquisition of object permanence and gives information over his/her cognitive development.
Aim:
To assess cognitive development in congenitally blind children with or without multiple disabilities.
Study Design:
Cohort study.
Subjects:
Thirty-seven congenitally blind subjects (17 with associated multiple disabilities, 20 mainly blind) were enrolled.
Outcome Measures:
We used Bigelow's protocol to evaluate "reach on sound" capacity over time (at 6, 12, 18, 24, and 36 months), and a battery of clinical, neurophysiological and cognitive instruments to assess clinical features.
Results:
Tasks n.1 to 5 were acquired by most of the mainly blind children by 12 months of age. Task 6 coincided with a drop in performance, and the acquisition of the subsequent tasks showed a less agehomogeneous pattern. In blind children with multiple disabilities, task acquisition rates were lower, with the curves dipping in relation to the more complex tasks.
Conclusions:
The mainly blind subjects managed to overcome Fraiberg's "conceptual problem"--i.e., they acquired the ability to attribute an external object with identity and substance even when it manifested its presence through sound only--and thus developed the ability to reach an object presented through sound. Instead, most of the blind children with multiple disabilities presented poor performances on the "reach on sound" protocol and were unable, before 36 months of age, to develop the strategies needed to resolve Fraiberg's "conceptual problem".
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