Rol moderador de la reserva cognitiva en el afrontamiento del estrés

Resumen

The current thesis aims to deepen the understanding of cognitive reserve basis and the mechanisms of his protective effect against brain damage. For this purpose, an original hypothesis was formulated on cognitive reserve understood as a variable of resilience in challenging contexts or stress coping. To test whether cognitive reserve has an effect on stress responses in dealing with psychologically stressful events, the following actions were carried out: Firstly, two such stress-inducing paradigms were selected (the observational fear conditioning protocol and an ad hoc task of high cognitive and social demands); Secondly, the participants' electrodermal activity was recorded during paradigms execution and salivary samples were obtained at specific moments of the protocols to study cortisol levels; Thirdly, the inclusion and exclusion criteria were established and the sample was recruited. The sample was composed of healthy, middle-aged men, without pathologies that affect their stress responses; Fourthly, previously to the application of the stress-inducing paradigms, the participants were provided with the following psychometric instruments: firstly, the Cognitive Reserve Scale and, secondly, the State-Trait Anxiety Inventory. Therefore, scores were determined for the factor variables, such as cognitive reserve and state-anxiety. State-anxiety was included because of its potential influence on the stress levels when performing the paradigms and its possible effect on the paradigm performance; Finally, the data obtained were processed and the models used were analysed to refute the null hypothesis. The results indicate a protective effect of cognitive reserve against phasic cortisol responses after a stressful psychological event. This effect is especially significant in individuals with high anxiety. In conjunction with this reduced endocrine reactivity, it is observed that cognitive reserve is associated with a more efficient capacity for sympathetic regulation. It is characterized by ending stress paradigms at electrodermal activity values equal to or lower than basal levels. In addition, an indirect relationship between cognitive reserve and emotional learning capacity is observed through anxiety levels. In this way, cognitive reserve facilitates contingency learning in individuals with high anxiety, which hinders such learning. Despite the limitations in the generalizability of the results obtained in the studies included in the current thesis, we propose an explanatory mechanism for cognitive reserve at the endocrine and sympathetic level. This postulates the cognitive reserve as a factor of resilience in the face of stress, which would allow a greater plastic capacity and neuronal adaptation to brain damage.