High-intensity stress elicits robust cortisol increases, and impairs working memory and visuo-spatial declarative memory in Special Forces candidates: A field experiment

Figures & data

Figure 1.  Experimental time frame (minutes) for both groups (no-stress vs. stress), including: baseline saliva sampling (C₀ at T − 75), filler tasks or POW stress induction (Phases I–III), test instructions, performance tests (DS test and ROCF), cortisol saliva sampling (C₁ at T and C₂ at T+15), completion of NASA TLX, and clinical debriefing. Timings are in minutes, unless stated otherwise.

Figure 2.  Salivary cortisol concentrations (means ± SEM) for the no-stress control (n = 14) and the stress group (n = 13) (C₀ at T-75 min, C₁ at T, and C₂ at T+15 min). Exclusively for information purposes, the figure includes differences in mean salivary cortisol increment for high (n = 6) vs. low cortisol responders (n = 7) in the stress group (cut-off by median split).

Figure 3.  Representation of the mean performance scores ( ± SEM) for the no-stress control (n = 14) and the stress group (n = 13) on the memory performance tasks; the DS test for WM (a) and the ROCF for visuo-spatial declarative memory (b). In (a) and (b) the No-stress and Stress group means are significantly different from each other (p < 0.05, p < 0.01).

Figure 4.  Two representative performance examples of the ROCF for the no-stress control (a) vs. the stress (b) group. While the original ROCF strongly resembles Figure 4(a), a full view of the original ROCF can be consulted in Knight and Kaplan (2003) (The handbook of ROCF usage: Clinical and research applications. Psychological Assessment Resources, Inc., Lutz, FL, USA).

Knight J, Kaplan E. 2003. The handbook of Rey–Osterrieth complex figure usage: Clinical and research applications. Lutz, FL: Psychological Assessment Resources, Inc.

 Google Scholar