Abstract
Objectives: converging research suggests that mindfulness training exerts its therapeutic effects on depression by reducing rumination. Theoretically rumination is a multifaceted construct that aggregates multiple neurocognitive aspects of depression including poor executive control negative and overgeneral memory bias and persistence or stickiness of negative mind states. Current measures of rumination most-often self-reports do not capture these different aspects of ruminative tendencies and therefore are limited in providing detailed information about the mechanisms of mindfulness. Methods: we developed new insight into the potential mechanisms of rumination based on three model-based metrics of free recall dynamics. These three measures reflect the patterns of memory retrieval of valenced information: the probability of first recall (Pstart) which represents initial affective bias the probability of staying with the same valence category rather than switching which indicates strength of positive or negative association networks (Pstay) and probability of stopping (Pstop) or ending recall within a given valence which indicates persistence or stickiness of a mind state. We investigated the effects of Mindfulness-Based Cognitive Therapy (MBCT; N = 29) vs. wait-list control (N = 23) on these recall dynamics in a randomized controlled trial in individuals with recurrent depression. Participants completed a standard laboratory stressor the Trier Social Stress Test to induce negative mood and activate ruminative tendencies. Following that participants completed a free recall task consisting of three word lists. This assessment was conducted both before and after treatment or wait-list. Results: while MBCT participant's Pstart remained relatively stable controls showed multiple indications of depression-related deterioration toward more negative and less positive bias. Following the intervention MBCT participants decreased in their tendency to sustain trains of negative words and increased their tendency to sustain trains of positive words. Conversely controls showed the opposite tendency: controls stayed in trains of negative words for longer and stayed in trains of positive words for less time relative to pre-intervention scores. MBCT participants tended to stop recall less often with negative words which indicates less persistence or stickiness of negatively valenced mental context. Conclusion: MBCT participants showed a decrease in patterns that may perpetuate rumination on all three types of recall dynamics (Pstart Pstay and Pstop) compared to controls. MBCT may weaken the strength of self-perpetuating negative associations networks that are responsible for the persistent and "sticky" negative mind states observed in depression and increase the positive associations that are lacking in depression. This study also offers a novel objective method of measuring several indices of ruminative tendencies indicative of the underlying mechanisms of rumination.
Original language | English |
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Article number | 257 |
Journal | Frontiers in Human Neuroscience |
Issue number | SEPTEMBER |
State | Published - 19 Sep 2012 |
Externally published | Yes |
Keywords
- Emotional processing
- Free recall
- Memory
- Mindfulness
ASJC Scopus subject areas
- Neuropsychology and Physiological Psychology
- Neurology
- Psychiatry and Mental health
- Biological Psychiatry
- Behavioral Neuroscience