Poster Session D, Monday, March 25, 8:00 – 10:00 am, Pacific Concourse
Identifying biomarkers to predict behavioral responses to stress in criterion shifting during recognition memory
Tyler Santander1, Mary MacLean1, Thomas Bullock1, Alexander Boone1, Jamie Raymer1, Liann Jimmons1, Alexander Stuber1, Gold Okafor1, Scott Grafton1, Barry Giesbrecht1, Michael Miller1; 1University of California, Santa Barbara
Successful recognition memory relies both on the ability to discriminate previously-studied items from novel stimuli and on the placement of an appropriately-biased decision criterion. While it is well-established that there are vast individual differences in these factors, the present study sought to determine: 1) how they are modulated following acute exposure to stress; and 2) whether there are neurological, physiological, or hormonal variables that predict susceptibility/resilience to stress. Thirty healthy young adults performed a recognition memory and criterion shifting task following 90 seconds of exposure to a cold pressor task (CPT; here, dunking feet in ice water); warm water served as a control in a separate session. The study phase was performed prior to any stress induction, and testing occurred approximately one hour later (separated by other tasks beyond the scope of this analysis). We additionally collected electroencephalography (EEG), cardiography, and a number of salivary cortisol samples within-session: putative biomarkers included spectral measures of brain activity (e.g. frontal theta), heartrate variability (e.g. entropy), and cortisol dynamics (estimated as a latent growth function). A linear mixed model demonstrated that there were no significant effects of CPT exposure on discriminability. However, there was a significant effect on criterion placement, such that individuals became more extreme on average. These effects were further modulated by frontal theta and the rate of cortisol activity. Together, our results suggest that—while acute stress affects decisional processes in memory—there are a host of biological factors that may lead one to be more susceptible or resilient to CPT.
Topic Area: LONG-TERM MEMORY: Episodic