SAM_sAA_Cortisol

Analyses of saliva Alpha-Amylase and Cortisol in SAM study, as described in:

• Sep, M.S.C., van Ast, V.A., Gorter, R., Joëls, M., & Geuze, E. (2019) Time-dependent effects of psychosocial stress on the contextualization of neutral memories. Psychoneuroendocrinology, 108, 140–149. https://doi.org/10.1016/j.psyneuen.2019.06.021
• Sep, M.S.C., Gorter, R., van Ast, V.A., Joëls, M., & Geuze, E. (2019) No Time-Dependent Effects of Psychosocial Stress on Fear Contextualization and Generalization: A Randomized-Controlled Study With Healthy Participants. Chronic Stress, 3, 247054701989654. https://doi.org/10.1177/2470547019896547

Step 1: Data and Preprocessing

Datasets (will be available on Dataverse):

• List with subject numers and experimental conditions: SAM_Experimental_Conditions.csv
• Cortisol values: SAM_sCortisol.csv
• alpha-amylase values: SAM_sAA.csv

Data can be loaded and preprocessed for analysis using the script (in the 'R' folder):

• Load_sAA_sCORT_Lab_Results.R This script returns the following R-dataset in the folder 'processed_data':
• sAA_sCORT_condition_dataset.rds

Step 2: Check Assumptions linear mixed effect models (LMM)

• LMM_Assumptions.r

Step 3: Perform LMM analyses

• sAA_sCORT_Analysis.R Note, the script sources LMM_Results_to_Word.R and LMM_Assumptions.R (available in 'R' folder). The datasets SAM_MCT.csv or SAM_FGT.csv (also available from Dataverse) can be used to perform the analyses for subjects that completed the MCT or FGT tasks respectively.

Step 4: Export LMM results to tables and figures

• Tables: LMM_Results_to_Word.R
• Figures: Saliva_Results_Design_to_Plot.R