Morphometry and connectivity of the fronto-parietal verbal working memory network in development

Area of Science:

• Neuroscience
• Developmental Psychology
• Cognitive Science

Background:

• Brain maturation from childhood to adulthood involves distinct processes: cortical thinning and white matter maturation.
• Understanding the differential contributions of these processes to complex cognitive functions, such as working memory, is crucial.

Purpose of the Study:

• To investigate the independent and joint contributions of cortical thickness and white matter microstructure to verbal working memory performance.
• To examine how these maturational processes relate to working memory development in healthy individuals aged 8-19 years.

Main Methods:

• Utilized a regions of interest approach with 108 healthy participants (aged 8-19 years).
• Employed Magnetic Resonance Imaging (MRI), including anatomical and Diffusion Tensor Imaging (DTI).
• Assessed verbal working memory using a digit span task.

Main Results:

• Cortical thickness in the supramarginal gyrus and rostral middle frontal cortex, and white matter's radial diffusivity in the left superior longitudinal fasciculus (SLF), were negatively associated with digit span forwards performance, independent of age.
• Radial diffusivity of the SLF was also negatively related to digit span backwards performance.
• Multi-modal analysis revealed that cortical thickness and SLF microstructure were complementary in explaining working memory span, with distinct developmental impacts.

Conclusions:

• Both cortical thinning and white matter maturation play unique and complementary roles in the development of working memory.
• These findings suggest a complex interplay between gray matter and white matter development in shaping cognitive abilities during adolescence.