Retrieval practice is associated with attenuated stress-related inference impairment and stronger reactivation of bridge-related category information

A hallmark of human memory is its ability to form novel inferences by linking discrete but related events. We examined whether acute stress impairs memory inference and if retrieval practice can buffer this effect. Participants were trained on image pairs, AB and BC, to establish interconnected triads (ABC) with a shared bridge element B. Twenty-four hours later, we induced acute stress in half of the participants and then tested their capacity to infer the indirect AC associations. Behavioral results indicated that acute stress reduced inference accuracy and slowed responses, and retrieval practice was associated with attenuation of stress-induced impairment in A-C inference accuracy and speed. Using multivariate decoding analysis of human electroencephalogram (EEG) recordings, we found neural evidence of rapid reactivation of bridge-related category information during inference, a neural signature predictive of subsequent successful inference. Importantly, stress was associated with reduced bridge-related category reactivation, whereas retrieval practice was associated with stronger reactivation under stress. Collectively, our findings link rapid reactivation of bridge-related category information to successful memory-based inference. Although susceptible to stress, this reactivation was stronger following retrieval practice, suggesting that robust memory traces may contribute to more resilient inference under stress.