The development of memory and processing capacity

Area of Science:

• Cognitive Psychology
• Developmental Psychology
• Neuroscience

Background:

• Developmental theories often assume short-term memory (STM) serves as the workspace for higher cognitive processes, implying span measures processing capacity.
• This assumption is questioned by the working memory (WM) literature, which suggests distinct components for storage and processing.
• Understanding the relationship between STM span and WM processing capacity is crucial for accurate models of cognitive development.

Purpose of the Study:

• To investigate whether short-term memory span directly reflects the processing capacity component of working memory.
• To contrast a unitary model of memory/processing with a dual-component model of working memory in children.
• To examine developmental trends in the relationship between STM and WM processing across childhood.

Main Methods:

• Four experiments were conducted with children aged 5 to 12 years.
• Experiments manipulated processing load while holding duration constant, and examined information loss from STM with age.
• Measures included short-term memory recall, processing load, counting speed, rehearsal rates, and age-related differences.

Main Results:

• Increased processing load had minimal impact on short-term memory recall.
• Older children's enhanced processing efficiency did not correlate with slower information loss from short-term memory.
• While counting and rehearsal rates increased with age and correlated with span, they did not predict memory loss rates.

Conclusions:

• Short-term memory span and the processing space of working memory represent distinct cognitive systems.
• Short-term memory span measures do not provide a clear indication of overall working memory development.
• The findings support a model where STM and WM processing capacity are at least partly separate entities.