Back on the podcast today is our favourite neurologist, writer, podcaster, speaker and banjo player, Josh Turknett, MD. Josh’s many current projects include his Brainjo neuroscience-based educational courses, the Intelligence Unshackled podcast, and his virtual neurology practice.  He has recently authored two new books, Keto for Migraine and The Laws of Brainjo, with more on the way later this year. 

On this podcast, Josh talks about his working theory of cognitive decline and how to best avoid it. He calls it the Demand Driven Decline Theory and explains why we need to build up our brain’s ability to repair and recover while also mitigating cognitive damage. Josh shares the best strategies to do this, and it’s simpler (and more fun) than you think. 

Here’s the outline of this interview with Josh Turknett:

[00:00:33] Previous podcast with Josh on unschooling: How to Support Childhood Cognitive Development.

[00:00:44] Masters of Scale Podcast; episode with Nancy Lublin from the Crisis Text Line.

[00:02:20] Supporting cognitive function as we age.

[00:02:31] Podcast: The Postmenopausal Longevity Paradox and the Evolutionary Advantage of Our Grandmothering Life History, with Kristen Hawkes.

[00:08:52] Modern hunter-gatherers and cognitive decline.

[00:11:26] Podcast: How to Win at Angry Birds: The Ancestral Paradigm for a Therapeutic Revolution, with Josh Turknett, 4-quadrant model.

[00:13:20] Cognitive activity protective against neurodegenerative disease; The nun study: Iacono, D., et al. "The Nun study: clinically silent AD, neuronal hypertrophy, and linguistic skills in early life." Neurology 73.9 (2009): 665-673.

[00:15:19] Cognitive reserve.

[00:16:03] Rats in enriched environments have structurally superior brains; Study: Torasdotter, Marita, et al. "Environmental enrichment results in higher levels of nerve growth factor mRNA in the rat visual cortex and hippocampus." Behavioural brain research 93.1-2 (1998): 83-90.

[00:16:40] Auditory training program with rats reversed over 20 auditory processing deficits in the adult brain; Study: de Villers-Sidani, Etienne, et al. "Recovery of functional and structural age-related changes in the rat primary auditory cortex with operant training." Proceedings of the National Academy of Sciences 107.31 (2010): 13900-13905.

[00:17:21] Intelligence Unshackled Podcast: Pioneer of Plasticity Dr. Michael Merzenich.

[00:22:54] Maintaining cognitive activity as a predictor of physical activity; Study: Cheval, Boris, et al. "Relationship between decline in cognitive resources and physical activity." Health Psychology (2020).

[00:25:29] Demand-driven decline theory.

[00:26:20] Retiring earlier associated with higher mortality; Study: Wu, Chenkai, et al. "Association of retirement age with mortality: a population-based longitudinal study among older adults in the USA." J Epidemiol Community Health 70.9 (2016): 917-923.

[00:27:00] “Widowhood effect” - 66% increased chance of death in the first three months after your spouse dies. Study: Moon, J. Robin, et al. "Short-and long-term associations between widowhood and mortality in the United States: longitudinal analyses." Journal of public health 36.3 (2014): 382-389.

[00:29:56] The "better off dead" rule. 

[00:32:32] Why the young are protected from cognitive decline: early demands on the nervous system.

[00:37:57] How schools may undermine cognitive development.

[00:40:03] What to do: recreate the demands on the nervous system of youth.

[00:45:06] Book: The Laws of Brainjo: The Art & Science of Molding a Musical Mind, by Josh Turknett.

[00:48:19] Teaching children - what should learning look like?

[00:54:15] Book: The Gardener and the Carpenter: What the New Science of Child Development Tells Us About the Relationship Between Parents and Children, by Alison Gopnik.

[00:56:34] jturk.net.

[00:56:45] Derek Sivers.

[00:57:27] Transitioning to a virtual clinic.