Short answer

When designing for individuals with developmental disorders, consider the entire developmental trajectory and potential compensatory strategies rather than treating the condition as a static deficit analogous to adult brain injury.

Field
Human Factors
Source
Behavioral and Brain Sciences (2002)
Method
Computational modelling and simulation
Evidence
Strong effect

The way a cognitive system develops significantly influences the nature of behavioral deficits, even when the underlying 'damage' or atypicality is conceptually similar to adult brain injury. This human factors research insight is drawn from a 2002 study published in Behavioral and Brain Sciences. Using Computational modelling and simulation, researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing for individuals with developmental disorders, consider the entire developmental trajectory and potential compensatory strategies rather than treating the condition as a static deficit analogous to adult brain injury.

Study
Human FactorsHigh ImpactStrong effect

Developmental Trajectory, Not Just Damage, Shapes Cognitive Deficits

The way a cognitive system develops significantly influences the nature of behavioral deficits, even when the underlying 'damage' or atypicality is conceptually similar to adult brain injury.

Behavioral and Brain Sciences · 2002

01

Key Findings

  • 01Damage occurring before or during the learning process in a developmental model can produce distinct outcomes compared to damage to a fully trained adult model.
  • 02The assumption that developmental disorders result in selective deficits while the rest of the system develops normally ('Residual Normality') is often computationally unviable due to compensatory mechanisms within the system.
  • 03Developmental processes play a crucial role in explaining the specific end-state impairments observed in developmental disorders.
02

Application

Design takeaway

When designing for individuals with developmental disorders, consider the entire developmental trajectory and potential compensatory strategies rather than treating the condition as a static deficit analogous to adult brain injury.

How to apply

When designing educational software for children with dyslexia, for instance, consider how the software might interact with or support the child's ongoing learning and compensatory strategies, rather than just presenting information in a 'simplified' way that assumes a static deficit.

Project actions

  • 01When researching a user group with a developmental condition, look for studies that consider the developmental aspect of their condition, not just the current symptoms.
  • 02If using computational models in your design project, be mindful of the assumptions you make about how the system 'learns' or 'develops'.
03

Method & Evidence

AimTo investigate whether atypical developmental processes lead to different cognitive outcomes compared to acquired damage in adult cognitive systems, specifically in the domains of reading and past tense processing.
MethodComputational modelling and simulation
ProcedureConnectionist models were used to simulate both acquired brain damage in adults and developmental disorders. Simulations explored the effects of 'damage' occurring at different stages of the model's 'development' (training) and examined the viability of the 'Residual Normality' assumption.
ContextCognitive psychology, developmental disorders, computational neuroscience

Variables

IVTiming of 'damage' (during development vs. after development).
DVBehavioral deficits (e.g., reading errors, past tense errors).
CVModel architecture, training data, specific learning rules.
04

Strengths & Limitations

Strengths

  • +Provides a computational basis for understanding developmental disorders.
  • +Challenges prevailing assumptions about modularity and the direct mapping of behavior to structure.

Limitations

The models used are simplifications of complex biological systems. The specific computational architectures might not perfectly represent all aspects of human cognition.

Reliability & validity

The reliability of the findings depends on the robustness of the connectionist models used. Validity is enhanced by exploring multiple domains (reading, past tense) and by the computational demonstration of the 'Residual Normality' assumption's limitations.

Think critically

If behavioral similarities between developmental disorders and adult brain damage can be misleading, what other assumptions are commonly made in design that might be oversimplified due to a lack of consideration for developmental processes?

05

Design Principles

"Design for developmental plasticity and compensatory mechanisms, not just for deficits."

This challenges the assumption that behavioral similarities between developmental disorders and adult brain damage imply identical underlying causes or modular cognitive structures. Designers must consider the dynamic nature of development when creating assistive technologies or educational tools for individuals with developmental differences.

06

What This Means for Your Design

Imagine a computer program that learns to play a game. If you break it while it's still learning, it will behave differently than if you break a fully trained, expert version of the program. This research suggests that developmental disorders are more like the 'broken while learning' scenario, and we can't just assume the problems are the same as if an adult who already knew how to play the game suddenly got a glitch.

How to use in your project

  • 1.Cite this research when discussing the cognitive profiles of users with developmental disorders, particularly if you are contrasting their situation with acquired conditions.
  • 2.Use the findings to justify a design approach that supports learning and adaptation rather than solely compensating for perceived deficits.
07

Add to My Project

08

Quick Cite

Paragraph starter

Research by Thomas and Karmiloff-Smith (2002) highlights that developmental disorders are not merely analogous to adult brain damage, as the developmental process itself fundamentally shapes the resulting cognitive impairments. Their work with connectionist models demonstrates that 'damage' occurring during a system's learning phase leads to different outcomes than damage to a fully developed system. This underscores the importance of considering the dynamic nature of development and potential compensatory mechanisms when designing for individuals with developmental conditions, suggesting that interventions should support ongoing learning and adaptation rather than assuming a static deficit.

09

Source

Behavioral and Brain Sciences

Are developmental disorders like cases of adult brain damage? Implications from connectionist modelling

journal · 2002

View source

Questions About This Research

What does the research say about developmental trajectory, not just damage, shapes cognitive deficits?
When designing for individuals with developmental disorders, consider the entire developmental trajectory and potential compensatory strategies rather than treating the condition as a static deficit analogous to adult brain injury. Evidence: Behavioral and Brain Sciences (2002).
Why does "Developmental Trajectory, Not Just Damage, Shapes Cognitive Deficits" matter for design?
This challenges the assumption that behavioral similarities between developmental disorders and adult brain damage imply identical underlying causes or modular cognitive structures. Designers must consider the dynamic nature of development when creating assistive technologies or educational tools for individuals with developmental differences.
How can designers apply this research?
When designing for individuals with developmental disorders, consider the entire developmental trajectory and potential compensatory strategies rather than treating the condition as a static deficit analogous to adult brain injury.
What were the main findings?
Damage occurring before or during the learning process in a developmental model can produce distinct outcomes compared to damage to a fully trained adult model.. The assumption that developmental disorders result in selective deficits while the rest of the system develops normally ('Residual Normality') is often computationally unviable due to compensatory mechanisms within the system.. Developmental processes play a crucial role in explaining the specific end-state impairments observed in developmental disorders.
What research method was used?
Computational modelling and simulation.
How strong is the evidence?
Evidence strength is rated Strong effect, based on a 2002 journal from Behavioral and Brain Sciences.
What should I do differently in my next project?
When designing educational software for children with dyslexia, for instance, consider how the software might interact with or support the child's ongoing learning and compensatory strategies, rather than just presenting information in a 'simplified' way that assumes a static deficit.
What are the limitations?
The study relies on simplified computational models, which may not fully capture the complexity of human cognition and development. The specific domains (reading, past tense) may not generalize to all developmental disorders.