IntroductionStress de ned in terms of perceptions of uncontrollability and unpredictability has been one of the central issues in behavioural medicine, partly because of its negative impact on physical and mental health [1]. Though recent studies have underlined the e ects of stress on brain functioning, stress-related changes in cognitive processes of emotion regulation have been under-investigated [2].Emotion regulation has been de ned as the physiological, motivational, behavioural, and cognitive processes responsible for monitoring, evaluating, and modifying emotional reactions in order to accomplish one's goals [3], and has been considered to be important for understanding the onset, maintenance, and treatment of anxiety disorders (see [4] for review).Cognitive regulation of emotion refers to conscious cognitive methods of emotion regulation including attentional and evaluative processes [5,6]. A possible way to characterize cognitive strategies of emotion regulation is in terms of the involvement of the executive functions [7,8]. Executive cognitive emotion regulation, e.g. reappraisal, implies the use of higher cognitive processes such as mental set-shifting, evaluation, planning, working memory, and information updating and monitoring, whereas non-executive cognitive strategies, such as rumination, are associated with deficits in executive functions, e.g. attentional in exibility or inhibitory de cits [8]. For example, reappraisal was shown to be associated with enhanced a ective exibility [9], interference resolution [10], and working memory capacity [11], while rumination was associated with decreased cognitive exibility [12] and internal shifting impairments in working memory [13].Converging results have revealed that negative emotional states are strongly related to the excessive use of non-executive cognitive emotion regulation strategies, particularly rumination, catastrophizing, and self-blame.Low use of executive strategies, such as positive reappraisal, has also been found to be connected to psychopathology [e.g. 14-17], as well as to negative emotional states such as irritability and anger [18].Executive functions depend on the structural and functional integrity of the prefrontal cortex (PFC) [19], which guides emotions and behaviour through projections to subcortical regions like the hypothalamus and the amygdala [20]. Under safe conditions, the amygdala, which has been suggested to serve as a rapid detector of potential threats, is under tonic inhibitory control by the PFC.Under stressful conditions, critical areas of the PFC become hypoactive, resulting in a hyperactivation of the amygdala, which leads to the evocation of adaptive fear responses, but might also lead to chronic threat perception and sustained fear in unpredictable conditions (see [21] for review).
Recent research in animal modelsdemonstrates that exposure to stress is regulation has yet to be investigated. The present study explores the possible role of cognitive emotion regulation strategies in mediating the well-establishe...