Social Influences on Neuroplasticity: Stress and Interventions to Promote Well-Being

Davidson, R. J., & McEwen, B. S. (2012). Social influences on neuroplasticity: stress and interventions to promote well-being. Nature Neuroscience, 15(5), 689-695.

More research is needed to explore brain plasticity in response to social influences. What is known is that stress affects humans and animals similarly in changing the activation and physical structure of different parts of the brain. It also appears that positive emotional qualities can be acquired through training of the mind.

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Objective

  1. To review of some key findings at the animal level that establish experience-induced structural brain plasticity in response to social influences

Design—Descriptive literature review

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Findings

  1. Evidence at the animal level:
    1. Several different mechanisms of plasticity, including dendritic and synaptic turnover and neurogenesis, have been identified.
    2. The animal and human evidence is consistent in demonstrating that many forms of stress promote excessive growth in sectors of the amygdala, whereas effects in the hippocampus tend to be opposite.
    3. Whether critical or sensitive periods exist for plasticity in response to social influences has not been thoroughly addressed and more systematic developmental studies are required. The reversibility of structural changes following alterations in social and emotional conditions has not been systematically examined.
  2. Evidence at the human level:
    1. Research is beginning to document the effect of explicit interventions designed to decrease stress and promote pro-social behavior and well-being on brain structure and function. These studies are consistent with basic research in demonstrating increases in specific sectors of prefrontal activation and decreases in amygdala activation.
    2. These functional alterations are accompanied by structural changes that show increases in prefrontal volume and decreases in amygdala volume.
    3. The precise differences among the various interventions that have been developed for this general purpose have not been systematically studied, nor has the relation between functional and structural changes been carefully documented.
    4. It is apparent that both structural and functional connectivity between prefrontal regions and subcortical structures is extremely important for emotion regulation and that these connections represent important targets for plasticity-induced changes.
  3. The studies on interventions explicitly designed to promote positive emotional qualities, such as kindness and mindfulness, imply that such qualities might best be regarded as the product of skills that can be enhanced through training, just as practice will improve musical performance and produce correlated regionally-specific anatomical changes.
  4. Whether these interventions simply modulate the adverse effects of stress or whether they result in a profile of neurobehavioral functioning that is better than normal will require considerably more evidence, although the available evidence points toward the latter possibility.