The complexities of complex span: explaining individual differences in working memory in children and adults

Area of Science:

• Cognitive Psychology
• Neuroscience
• Developmental Psychology

Background:

• Working memory is crucial for cognitive tasks.
• Previous models proposed a shared resource pool for processing and storage.
• Understanding the constraints on working memory is essential for cognitive development and academic success.

Purpose of the Study:

• To investigate the independent contributions of processing efficiency and storage capacity to working memory performance.
• To examine the predictive power of these components on complex span tasks.
• To test the validity of a multiple-component model versus a shared resource pool model of working memory.

Main Methods:

• Two studies were conducted involving children and adults.
• Independent measures of processing efficiency and storage capacity were assessed.
• Performance on complex span tasks was used to measure working memory capacity.

Main Results:

• Complex span performance was independently predicted by individual differences in domain-general processing efficiency.
• Complex span performance was also independently predicted by domain-specific storage capacity.
• Residual variance, potentially reflecting storage-processing coordination, predicted academic achievement.

Conclusions:

• Working memory capacity is constrained by separate factors of processing efficiency and storage capacity.
• Results support a multiple-component model of working memory, not a single limited-capacity resource pool.
• The findings have implications for understanding cognitive development and academic achievement.