Working memory is a cognitive function that combines memory and attention, and allows us to retain information for a short time while performing specific tasks. This function is used, for example, when we speak, learn, reason and solve problems. Several epidemiological studies have shown that greener residential environments, that is, those with more trees, vegetation and green spaces, could contribute to better neurodevelopment in children. In these studies, children and adolescents who lived in greener environments scored higher on intelligence tests, working memory and other executive functions than those who lived in less green areas. However, recent systematic reviews show that these results have been confirmed in less than half of the articles.

The aim of this work was therefore to generate more scientific evidence to help clarify this issue. To do this, the research team used the infrastructure of the LifeCycle consortium, a European consortium of cohort studies, of which the INMA-Gipuzkoa cohort is a member. Specifically, they examined whether greater residential greenness was positively associated with working memory test scores in children and adolescents aged 6 to 12 years in three European cohorts: INMA, Born in Bradford (BiB) and the Avon Longitudinal Study on Parents and Children (ALSPAC). In total, data from more than 6,000 participants who completed memory tests were analyzed using computer analysis.

The research team was able to confirm the relationship between a greener environment and working memory tests for participants in the INMA cohort when they were between 6 and 8 years old, and for those in the BiB cohort when they were between 7 and 10 years old. However, they did not find this relationship for participants in the INMA or ALSPAC when they were between 10 and 12 years old. These results are consistent with previous studies that have found that the relationship between green spaces and the cognitive benefits of urban vegetation is not strong. Therefore, it cannot be clearly stated that they are beneficial for cognitive development in childhood and adolescence, which recommends caution when interpreting the scientific evidence on this matter.

In fact, today, there are many news reports that report on the benefits of green spaces and nature for many aspects of people's health. Among other things, there are works that link them to mental health and neurodevelopment, respiratory health, birth weight and many other health variables. However, the scientific evidence behind these statements is not always as strong and univocal as we would like. In our case, and from a population and public health perspective, it cannot be safely said that green spaces and urban vegetation make a positive contribution to neuropsychological development and cognitive activity.

As the authors of the work highlighted, "We are very pleased with the work we have done, since we have been able to take advantage of data from several European cohorts, and therefore have been able to publish a work of international importance." And they hope that “the results will be useful for advancing scientific knowledge.” They added, “We would like to thank all the INMA families who participate in advancing the research year after year, for their efforts and participation. In this case, we would also like to thank the families from Bradford and Bristol in the United Kingdom for their participation.”

In addition to the volunteer families, this work was made possible thanks to the invaluable work of many researchers and organizations that have made it possible to establish and continue the LifeCycle consortium, and thanks to the European funding received for it.