Reduced interference in working memory following mindfulness training is associated with increases in hippocampal volume

Abstract

Proactive interference occurs when previously relevant information interferes with retaining newer material. Overcoming proactive interference has been linked to the hippocampus and deemed critical for cognitive functioning. However, little is known about whether and how this ability can be improved or about the neural correlates of such improvement. Mindfulness training emphasizes focusing on the present moment and minimizing distraction from competing thoughts and memories. It improves working memory and increases hippocampal density. The current study examined whether mindfulness training reduces proactive interference in working memory and whether such improvements are associated with changes in hippocampal volume. 79 participants were randomized to a 4-week web-based mindfulness training program or a similarly structured creative writing active control program. The mindfulness group exhibited lower proactive interference error rates compared to the active control group following training. No group differences were found in hippocampal volume, yet proactive interference improvements following mindfulness training were significantly associated with volume increases in the left hippocampus. These results provide the first evidence to suggest that (1) mindfulness training can protect against proactive interference, and (2) that these benefits are related to hippocampal volumetric increases. Clinical implications regarding the application of mindfulness training in conditions characterized by impairments to working memory and reduced hippocampal volume such as aging, depression, PTSD, and childhood adversity are discussed.

Regular Doses of Nature: The Efficacy of Green Exercise Interventions for Mental Wellbeing

“…Like with research that has focused on single bouts of GE, wellbeing was measured at the start and end of the interventions. Research into mindfulness training and arts and crafts indicates that engaging with regular doses of these activity types can lead to positive neurological changes such as cortical volume as soon as 4 weeks into engagement, and that these changes correlate with self-reported improvements in feelings and wellbeing [39,40]. As participation in the doses of nature activities of the current study occurred over 12 weeks and participants reported improvements in wellbeing, it is plausible to suggest that positive neurological changes may have occurred.…”

Strengthened Hippocampal Circuits Underlie Enhanced Retrieval of Extinguished Fear Memories Following Mindfulness Training

“…The hippocampus is critical to the consolidation and retrieval processes and gates the expression of either the conditioned fear or extinction memory, depending on contextual information (12)(13)(14)(15). Mindfulness training leads to improvements in memory (16,17) as well as to changes in hippocampal structure and function (18)(19)(20).…”

A neurobehavioral account for decentering as the salve for the distressed mind

“…Although speculative, taken together, these early findings are suggestive of a mindfulness-entrained brain network configuration characterized by coordinated increased within-network connectivity in FPCN (73) and SN [67] increased cross-network connectivity in FPCN-DMN [27,76,79,80] and FPCN-DAN [67], and altered patterns of cross-network connectivity between DMN and SN [39,76,80] [62,85], increased dmPFC-IPL connectivity [78], and increased dmPFC-insula anti-correlation [86]. Long-term meditation and MBIs also appear to lead to enduring alterations in the MTL-DMN, including greater hippocampal grey matter density [52, [87][88][89] and increased resting connectivity between hippocampus and PCC [85]. These findings suggest the possibility that MBI-induced changes in these DMN subsystems could be involved in increased capacity for disidentification to spontaneously generated painful autobiographic memories or catastrophic self-projections.…”

“…Mindfulness meditation has been proposed to reflect a form of exposure to feared and distressing spontaneous thoughts and internal experiences leading to decreased subjective and neural reactivity [57,[113][114][115]. MBI-related changes occur in the same limbic and orbitofrontal/prefrontal regions [52,[87][88][89]115] underlying fear conditioning, extinction, and extinction recall [50,100,116]. One study reports MBSR increased fear conditioning as well as extinction learning, and also increased structural connectivity (fractional anisotropy) with the uncinate fasciculus, a fiber tract involved in emotional regulation and associative learning [113].…”