As befits the child of a scientist, Martin Picard’s young son, 3, is already learning about biology with an age-appropriate textbook, “Cell Biology for Babies.” Picard winces a little whenever the book calls mitochondria the “powerhouses of the cell” but figures he has plenty of time as his son grows older to explain why the tiny organelles are much more than simple energy sources.

Picard is a leading proponent of mitochondrial psychobiology (a phrase he coined), an emerging field that examines how psychological states like stress influence mitochondrial functions, which in turn influence mental and physical health.

“The powerhouse analogy is outdated and one-dimensional and can impede science by limiting researchers’ perceptions of what mitochondria can do,” says Picard, associate professor of behavioral medicine in psychiatry and neurology.

Children whose mothers had a higher exposure to certain phthalates during pregnancy tend to show smaller total gray matter in their brains at age 10. This is one of the main conclusions of a study led by the NYU Grossman School of Medicine and the Barcelona Institute for Global Health (ISGlobal), and published in Molecular Psychiatry.

The study also found that maternal exposure to plasticizers during pregnancy is associated with lower child IQ at age 14, which confirmed the results of two previous study on the topic. Moreover, the research team observed that this relationship between exposure to certain phthalates and lower child IQ is partially influenced by total gray matter volumes. In other words: exposure to plasticizers before birth could lead to smaller total gray matter in childhood, which in turn could be related to a lower IQ.

Finally, the results showed an association between gestational exposure to plasticizers and smaller white matter volumes in girls.