Mind Over White Matter: Purpose in Life is Associated with Cognitive Resilience as we Age

Reference: Abellaneda-Pérez, K., Cattaneo, G., Cabello-Toscano, M. et al. (2023). Purpose in life promotes resilience to age-related brain burden in middle-aged adults. Alz Res Therapy 15, 49.

As your alarm blares from your bedside, your eyes heavy with sleep as the warmth of the blankets you’re nestled under in bed beckon you to stay, what drives you to push them away? To rise from the serenity of your dreams and safety of your bed? Do you feel like you are called by something within or beyond this world to live or are you simply going through the motions because it’s what everyone else does? If you are relating to the former, you may be protected against cognitive decline with aging. That’s right, a sense of purpose in life may actually protect your brain from the effects of physical deterioration.

A recent study performed by researchers Abellaneda-Pérez and colleagues found a protective effect of having a high purpose in life against age-related brain changes in executive function or behaviors required to plan and achieve goals. Any sort of planning, self-control, time management and organizational skills require executive functions, and these functions have been shown to deteriorate in certain age-related cognitive disorders like dementia or Alzheimer’s disease.

In their study, healthy middle-aged adults were asked questions pertaining to their purpose in life, scaling their answers from strongly agreeing to strongly disagreeing. A purpose in life can be referred to a feeling of meaning or direction with the goals we set feeling attainable. Based on these personal evaluations, participants categorized into a high or low purpose of life group. The researchers then administered various tasks assessing different components of cognition, including memory and executive function. Lastly, functional magnetic resonance imaging (fMRI) was used to capture brain images of the participants. With these fMRIs, researchers were looking for two things: (1) white matter lesions and (2) the functional connectivity of the default model network.

As our brain ages, it inevitably changes in ways that can sometimes negatively impact cognition. One unavoidable change is an increase in white matter lesions. Our brain is divided into white and gray matter, with white matter playing a critical role in helping our brain communicate with different brain regions. Parts of the brain often have specialized roles for certain tasks, like any sports team where each player has a certain position that is played in a specific way that contributes to the overall goal of the game. Just as each individual player must pass the ball to their teammate, parts of our brain communicate through axons that send electrical signals to one another. These axons can be myelinated, just like electrical wires can be insulated to send messages faster. Our white matter contains these myelinated axons, and damage to white matter in the form of lesions impairs our brain’s ability to send these messages and communicate. White matter lesions can be caused by genetic factors, environmental toxin exposure, migraines, inflammation, and artery plaques among other causes (1). 95% of individuals over the age of 45 have white matter lesions and the density of these lesions is associated with markers of stroke and Alzheimer’s disease and disease progression (2).

This result demonstrates that although the amount of white matter lesions between older adults with high and low purpose in life scores did not differ, a high purpose in life ameliorated the damaging effects of white matter lesions on executive function. This showed how a psychological dimension could combat the effects of physical damage to our brain’s communication networks.

Next, the researchers investigated if a higher degree of purpose in life was associated with any physical components of our brain’s communication networks to protect executive functioning. Indeed, older adults with a higher purpose in life score had more brain regions connecting to the default mode network. The default mode network is a region of the brain that is most active when we engage in tasks such as daydreaming, recalling memories, or thinking about the future (3). Executive functioning involves planning ahead and acting in ways beneficial for our future selves. These scans show that having a purpose in life increases connections from our thoughts to brain regions sensing the world around us, directing our attention towards our desired goals. This could mean that being motivated by a purpose allows for our abstract thinking to be intertwined with our reality, enabling us to put our future plans into action.

(On the left) Groups of brain scans categorized into high and low purpose in life scorers. Connections between various brain regions (in the middle) with their major roles shown color coated (on the right with the default mode networks are bolded). The higher purpose in life scorers have a much greater number of connections with brain centers involved in attention, our senses, motion, memory, language, and executive function (Adapted from Abellandeda-Pérez et al., 2023).

Do increased brain connections to the default mode network lead to a greater feeling a purpose in life, or does having purpose in life shape our brain? Although this study demonstrates a relationship between the two, we cannot draw causal conclusions. Future research could investigate if we can train our brains through finding meaning in our daily lives in order to become more resilient to age-related losses in executive functioning. Overall, it seems feeling like you have something to live for may overcome the physical damage to our brains caused by ageing, potentially through rewiring the way our internal self interacts with the physical world.

Additional References:

  1. Sharma R, Sekhon S, Cascella M. (2022). White Matter Lesions. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. PMID: 32965838.
  2. Lampe, L., et al. (2019). Visceral obesity relates to deep white matter hyperintensities via inflammation. Ann Neurol 85(2): 194-203
  3. Smallwood, J., Bernhardt, B.C., Leech, R. et al. (2021). The default mode network in cognition: A topographical perspective. Nat Rev Neurosci 22, 503–513. https://doi.org/10.1038/s41583-021-00474-4