Double-blind fMRI test at Yale links hydrocortisone to stronger emotional memories

Many brain regions serve several functions. That makes it hard to tell whether cortisol alters the emotional response, memory formation or both ^[9]. Corresponding author Elizabeth Goldfarb described the two stages the team wanted to pull apart. "Forming memories for emotional experiences involves different processes in the brain: first, perceiving an experience as emotional or intense, and second, encoding that experience into long-term memory," said Goldfarb ^[8].

In our view the two outcome measures map onto those stages. The picture ratings capture how emotional an image felt, and the next-day test captures whether it was retained ^[5][13].

The controls matter as much as the scanner. Every participant completed both sessions, once on hydrocortisone and once on placebo, so differences between people cannot explain a difference between sessions ^[3]. Neither the participants nor the experimenter knew which substance was given in a session ^[4]. That removes expectation as an explanation on both sides of the experiment.

The ScienceDaily account breaks off as it reaches the results. It does not report how many people took part, the hydrocortisone dose, which networks changed, how large the change in memory was, or the order in which sessions were run. Until the paper's methods and results are in hand, the finding rests on Yale University's summary that cortisol strengthens emotional memories by changing how emotion and memory networks function and communicate ^[1].