Cognitive Reserve and Anxiety Interactions Play a Fundamental Role in the Response to the Stress

Figures

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  FIGURE 1. Procedure. Participants arrive at the experimental room (0 min). They are provided with the Cognitive Reserve (CR) and State-Trait Anxiety (STAI) scales for completion. Within 5 min of arriving in the experimental room, the first saliva sample (S0) is requested to establish the baseline cortisol concentration. Ten minutes after arriving in the experimental room, once the scales have been completed, the observational fear conditioning protocol is initiated. For this purpose, the electrodes for recording the electrical conductance of the skin are placed and the appropriate checks are made to ensure a correct recording of the signal. After these actions, the observational fear conditioning protocol is initiated. This protocol consists of two phases: vicarious and direct. During both phases, the electrical skin conductance (SCR) is recorded. At the end of the protocol, the skin conductance recording session is saved, and the electrodes are removed from the participant’s hand. After this, the second saliva sample (S1) is obtained. This sample expects to be able to detect peak cortisol concentrations from the beginning of the evaluation protocol (0 min). After 20 min of rest, the third…

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  FIGURE 2. Mean amplitudes of skin conductance responses to the CS−, CS+, and US stimuli during the vicarious phase of the fear conditioning paradigm, according to reported level of state anxiety. CS− and CS+ responses are distinguished as either before (pre-conditioned stage) or after (post-conditioned stage) the US was presented. No statistically significant differences were observed between CS-PRE vs. US (d = 0.747), between CS + PRE vs. CS + POST (d = 0.639), or between CS-POST vs. CS + POST (d = 1.490), indicating correct conditioning in the SA-Low group. The error bars show standard error. Significance levels p < 0.001 are represented with ***.

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  FIGURE 3. Mean amplitudes of skin conductance responses to CS− and CS+ stimuli during the direct phase of the fear conditioning paradigm, according to level of contingency learning. Figure (A) is for the COND-Low group, that is, those that did not show correct vicarious conditioning, while Figure (B) is for the COND-H group. In Figure (B) of the COND-High group, statistically significant differences are indicated between the first six CS+ versus CS− (d = 0.563). Beginning with seventh CS+ presentation, no differences were observed with respect to CS−. This indicates when habituation is produced. Statistically significant differences were also observed between CS + 1 versus CS + 5 (d = 0.646), indicating the start of this habituation. The error bars show standard error. The post hoc analyses have p < 0.001.

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  FIGURE 4. Linear regression between the skin conductance responses to CS + during the vicarious phase (post-conditioned stage, POST) and the skin conductance responses to CS + during the direct phase [r2 = 0.67, F(1, 38) = 77.304; p < 0.001]. A high predictive capacity of the vicarious conditioning on the conditioned response was observed during the direct phase, together with a greater response during the direct phase because the US becomes the anticipation of a possible aversive contingency [β = 1.27; t(38) = 8.792; p < 0.001]. This reinforces the idea of learning transfer.

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  FIGURE 5. Average concentrations of cortisol in saliva: before (baseline), after (cortisol response) and 20 min following (recovery) the end of the stress-inducing experimental paradigm, as a function of state-anxiety and cognitive reserve levels (Low versus High). Figure (A) is the CR-Low group, while Figure (B) is for the CR-High group. Statistically significant post hoc analyses are marked with (*) for comparisons between phases (baseline, cortisol response and recovery). The symbol (#) indicates statistically significant post hoc between SA-Low versus SA-High groups. The ($) symbol indicates statistically significant post hoc with p < 0.001 within the SA-High group, between the groups CR-Low (A) and CR-High (B). The p-values showing one, two, or three * or # represent values <0.05, <0.01, and <0.001, respectively. The error bars show standard error. (*) This symbol refers to within-group comparisons. While this (#) symbol refers to between-group comparisons.

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  FIGURE 6. Conceptual model of the role of cognitive reserve in anxiety-triggering situations: indirect relation with conditioning and effect of interaction with SA on the neuroendocrine response.