The effects of processing speed and cognitive load demands on working memory performance in young adults born very preterm

Abstract

Objective: To examine working memory performance in young adults born very preterm (VP) and full-term (FT) in the context of information processing.

Methods: A cohort of 118 young adults born VP (mean age 20.1 years) and 48 young adults born at term (mean age 19.9 years) completed a n-back task (both 1- and 2-back) and a Keeping Track Task which systematically manipulated working memory (cognitive) load and information processing speed.

Results: Across all tasks the VP group performed worse than the FT group, with the magnitude of differences increasing as cognitive load increased. Contrary to expectations, the magnitude of group differences remained similar as information processing speed demands increased.

Conclusions: Our findings provide further evidence that working memory difficulties in those born VP persist into adulthood. However, the between group difference in working memory performance in this population did not decrease or ameliorate when individuals were provided more time for the task. This study gives evidence that information processing speed demands do not drive the working memory difficulties seen in those born VP. These results provide important information regarding the cognitive phenotype of those born VP and their development.

Keywords: Very preterm; information processing speed; interstimulus interval; working memory.