New research has found that exposure to high ambient temperatures may be linked to changes in brain function among children. The study, which analysed data from over 2,000 preadolescents, identified a correlation between increased temperatures and lower connectivity in key brain networks. The findings were published in the Journal of the American Academy of Child & Adolescent Psychiatry.
The research was conducted as part of the Generation R Study in the Netherlands, which follows children from birth to examine the factors influencing their health and development. The study used advanced neuroimaging techniques to assess how short-term exposure to varying temperatures impacted brain connectivity. Findings revealed that higher temperatures in the week leading up to brain scans were associated with reduced functional connectivity in specific networks responsible for cognitive processes, including memory and attention.
Laura Granés, MD, a medical research fellow at Bellvitge Biomedical Research Institute-IDIBELL, explained: “The motivation for this study was to explore the effects of temperature on brain function using neuroimaging tools, since temperature effects on cognition and mental health have been described, but no evidence was available regarding the underlying neural mechanisms.”
According to the analysis, temperatures between 17.7°C and 25.5°C were particularly associated with reduced connectivity in the medial parietal network, salience network, and hippocampus. These areas of the brain play a crucial role in attention regulation, decision-making, and memory consolidation. The effects were most pronounced on the day before the brain scans, suggesting a time-sensitive relationship between temperature exposure and neural activity.
Dr Granés highlighted the relevance of the findings, stating, “We found that exposure to higher temperatures was associated with lower functional connectivity in three brain networks, suggesting that the regions within these networks function in a less synchronised manner. In the context of the ongoing climate crisis, with increasingly high temperatures, our findings are relevant as they indicate a potential impact of heat exposure on children’s brain function, which could influence their cognitive and behavioural development.”
Researchers considered multiple factors that could influence the results, including socioeconomic status and access to green spaces. However, no consistent pattern of effect modification was observed, highlighting the need for further investigation into potential social and environmental influences on brain function. Dehydration and sleep disruption due to heat exposure were suggested as possible mechanisms behind the observed changes in brain connectivity. Previous studies have linked poor sleep quality with alterations in brain function, and higher nighttime temperatures could be contributing to this effect.
While the study provides valuable insights, researchers acknowledged several limitations. The analysis was based on residential temperature estimates rather than direct indoor measurements, meaning the actual temperature exposure of participants may have varied. Additionally, while the findings show an association between temperature and brain function, they do not establish a causal link. Future research will need to examine whether these changes have long-term implications for cognitive development and mental health.
Dr Granés outlined future plans: “Next steps include investigating the effects of temperature on cognition in children, as most studies have focused on adults and young people rather than children. We also aim to replicate the study in other settings with a different climate, such as Spain.”
