Using the delayed spatial alternation task to assess environmentally associated changes in working memory in very...

Area of Science:

• Developmental Psychology
• Neuroscience
• Pediatrics

Background:

• Working memory (WM) is crucial for cognitive functions like problem-solving and reasoning.
• Assessing WM in very young children is challenging due to limited validated tests.
• Early WM assessment is vital for identifying developmental issues and susceptibility to neurotoxicants like lead.

Purpose of the Study:

• To evaluate the feasibility of the Delayed Spatial Alternation Task (DSAT) for measuring WM in 18- and 24-month-old infants.
• To compare DSAT performance with child's age and general cognitive development.
• To investigate the impact of prenatal lead exposure on infant WM performance.

Main Methods:

• Administered the DSAT and Bayley Scales of Infant Development (BSID-III) to 457 mother-child pairs in Mexico City.
• Measured lead levels in maternal blood during pregnancy (MBPb) and child blood at 24 months (CPBb).
• Utilized regression analyses to assess predictors of DSAT performance, including lead exposure, sex, maternal education, and household smoking.

Main Results:

• Children at 24 months demonstrated significantly better DSAT performance than 18-month-olds.
• Female infants outperformed males on the DSAT. Maternal education positively correlated with performance, while household smoking negatively correlated.
• DSAT performance showed a positive association with BSID-III cognitive and language scales; lead exposure did not significantly predict DSAT outcomes.

Conclusions:

• The DSAT is a valid measure of infant development, evidenced by improved performance with age.
• DSAT results correlate positively with established cognitive assessments (BSID-III) and known sociodemographic predictors.
• The study highlights the DSAT's utility in assessing early cognitive development and potential neurodevelopmental impacts.