What the evidence currently shows
The Washington Post's piece on smell training and cognition has entered the conversation, but the published details remain limited. What we can confirm: the column frames olfactory training as a potential cognitive intervention. No specific study parameters, sample sizes, or effect magnitudes were available from the source material.
This matters because smell training—systematic exposure to distinct odorants at defined intervals—has been studied primarily in post-viral anosmia recovery. Its extension into broader cognitive domains is a hypothesis, not a settled protocol. The olfactory bulb's direct anatomical connection to the hippocampus and amygdala provides a plausible mechanistic pathway, but plausible is not the same as proven.
Parallel signal: video gaming's measurable (if modest) cognitive gains
A separate meta-analysis, covering over 130 studies, reports that video gaming correlates with small but statistically significant improvements in memory, visual attention, and spatial reasoning. The effect sizes are modest—this is not a substitute for sleep, exercise, or targeted training—but the signal is real and replicable across populations.
The methodological takeaway: when researchers aggregate large study pools and still find a consistent directional effect, even a small one, the underlying mechanism deserves attention. Gaming taxes working memory, rapid visual parsing, and spatial updating simultaneously. That cognitive load profile may share overlap with olfactory discrimination tasks, which recruit attentional control and associative memory circuits.
What to monitor
Neither finding constitutes a clinical recommendation. For smell training specifically, the critical gaps are: standardized dosage (how many odorants, what concentration, how many sessions per week), minimum effective duration, and whether benefits transfer beyond olfactory-specific domains to generalized fluid intelligence.
The broader pattern is worth noting. Cognitive interventions are proliferating across domains—from institutional partnerships building infrastructure in finance to sensory protocols in neuroscience. The distinguishing factor for practitioners and clients remains the same: demand controlled trials with active comparators before allocating time or resources. The olfactory hypothesis is intriguing. The data behind it, at this stage, is incomplete.