Researchers from the University of Barcelona have demonstrated that elevated progesterone levels during the menstrual cycle correlate with less differentiated brain activity patterns in emotion-control regions. The study analyzed MRI scans from 116 naturally cycling women and found that higher progesterone corresponded with reduced distinction between easy and difficult emotional situations in the lateral frontal pole, a brain area involved in emotion regulation.
Study participants completed mood questionnaires, provided saliva samples for hormone measurement, and underwent MRI scans while performing tasks involving emotional responses to facial expressions. Machine learning analysis revealed that when progesterone levels increased, “the patterns in one area of the brain called the lateral frontal pole were more similar to one another,” suggesting diminished capacity to differentiate emotional demands.
Dr. Macià Buades-Rotger, the lead researcher, stated: “higher progesterone levels were linked to brain activity patterns that made it harder to tell different emotion control situations apart.”
Interestingly, researchers observed no comparable effect for estradiol, though they acknowledge potential measurement limitations in saliva samples.
Journal: Psychological Medicine (Cambridge University Press)
DOI: 10.1017/S0033291726105315
Publication Date: September 2, 2026
Institution: University of Barcelona
Funding: Brain & Behavior Research Foundation Young Investigator Award
Source: EurekAlert