Conscious and unconscious perseverative cognition: Is a large part of prolonged physiological activity due to unconscious stress?

Prolonged physiological activity is believed to be a key factor mediating between stress and later disease outcomes. Few studies, however, have investigated the crucial psychological factors that cause prolonged activity. This article proposes that conscious as well as unconscious perseverative cognition are the critical factors. Perseverative cognition indicates repetitive or sustained activation of cognitive representations of past stressful events or feared events in the future. In daily life, most prolonged physiological activity is not due to stressful events but to perseverative cognition about them. We and others have already found evidence that conscious perseverative cognition, i.e., worry, has physiological effects, in both laboratory and real life settings, and that perseverative cognition mediates prolonged responses to stressful events. Yet, there are convincing reasons to expect that unconscious perseverative cognition has an even larger role in stress-related prolonged activity. Firstly, since the greater part of cognitive processing operates without awareness, a considerable part of perseverative cognition is likely to be unconscious too. People may not be aware of most of their stress-related cognitive processes. Secondly, our recent studies have shown that increased activity of the autonomic nervous system continues after conscious perseverative cognition has stopped: It goes on for several hours and even during sleep. This and several other findings suggest that a considerable part of increased physiological activity may be due to unconscious perseverative cognition. The article closes with suggesting methods to test unconscious perseverative cognition and ways to change it, and concludes with stating that the notion of unconscious perseverative cognition potentially opens an entirely new area within stress research. (C) 2010 Elsevier Inc. All rights reserved.