For the first time, scientists have captured direct, whole-brain evidence that computerized cognitive training physically strengthens the aging brain’s cholinergic system—the network of acetylcholine-producing nerve terminals that underpins attention, learning, and neuroplasticity. The findings, published in the journal GeroScience, come from a rigorously controlled randomized clinical trial in which cognitively healthy older adults underwent positron emission tomography (PET) imaging before and after ten weeks of brain training, revealing measurable increases in cholinergic terminal density in key frontal brain regions that were absent in controls.
The study, known as the INHANCE trial, was conducted at McGill University in Montreal and led by Ana de Figueiredo Pelegrino and Etienne de Villers-Sidani, together with colleagues at Posit Science. It enrolled 92 cognitively intact adults aged 65 and older, with a mean age of 71.9 years, all of whom scored above the accepted threshold for cognitive intactness on the Montreal Cognitive Assessment. Participants were randomly assigned to one of two conditions: an intervention group that completed 35 hours of speed-based cognitive training using the BrainHQ exercises Double Decision and Freeze Frame, or an active control group that spent the same amount of time playing casual, non-speeded computer games such as Double Klondike Solitaire and Bricks Breaking Hex. Neither participants nor the researchers conducting assessments knew who was in which group, and the two programs were carefully matched in visual demands, delivery platform, session intensity, and rewards to eliminate placebo effects, practice effects, and differences in computer exposure.
What makes this trial a landmark in cognitive neuroscience is the imaging technology it deployed. The researchers used PET with the radiotracer [18F]fluoroethoxybenzovesamicol, or FEOBV, a high-affinity ligand that binds to the vesicular acetylcholine transporter, or VAChT—a protein embedded in the membranes of synaptic vesicles inside presynaptic cholinergic nerve terminals. Because VAChT is found only in terminals that release acetylcholine, the intensity of FEOBV signal serves as a direct, quantitative index of cholinergic terminal density and, by extension, the brain’s capacity for cholinergic neurotransmission. Each participant received an intravenous bolus injection of 350 to 400 MBq of the tracer, synthesized on-site the same day, and imaging began 180 minutes later on a high-resolution research tomograph capable of a spatial resolution of roughly 2.3 millimeters. Scans were repeated after the ten-week training period, allowing the team to track, voxel by voxel, how cholinergic integrity changed in each individual brain.
The cholinergic system has long been suspected to be a central gatekeeper of experience-dependent brain plasticity. Originating in the basal forebrain, cholinergic projections bathe the cortex in acetylcholine, optimizing the signal-to-noise ratio of neural circuits and permitting them to be reshaped by learning. When this system is pharmacologically enhanced, attention and cortical plasticity improve; when it is suppressed, they falter. Unfortunately, the system is also among the most vulnerable to aging. Post-mortem and imaging studies have documented progressive degeneration of cortical cholinergic projections with age, and FEOBV PET studies have shown reliable age-related declines in binding in the anterior cingulate cortex and other attention-related regions—declines that correlate with worsening cognitive performance and that are even more dramatic in Alzheimer’s disease and mild cognitive impairment. The tantalizing question was whether this fragile system retains enough residual plasticity to be strengthened by behavioral intervention alone.
The answer, according to the new data, is a resounding yes. Using a voxel-wise, whole-brain statistical approach called threshold-free cluster enhancement with family-wise error correction, the researchers compared pre- and post-training PET scans within each group. The training group showed significant increases in FEOBV binding across a network of frontal regions critical for attention and cognitive control: the anterior cingulate cortex, the medial prefrontal cortex, the insula, and the orbitofrontal cortex. Critically, these increases were significantly greater than those observed in the active control group, whose cholinergic signal did not change meaningfully over the same period. An earlier, region-of-interest analysis by the same team had estimated that 35 hours of speed-based training increased cholinergic terminal density in the anterior cingulate by approximately 2.3 percent—a figure the authors note effectively reverses about a decade of normal age-related cholinergic decline. The new whole-brain analysis extends that finding, showing that the plasticity is not confined to a single hotspot but engages a distributed cholinergic network.
The active control condition was far from a trivial comparison. The games in that arm—developed by an independent gaming company and rated suitable for everyone—required visual engagement and strategy but lacked the two ingredients hypothesized to drive neuromodulatory change: adaptivity and speed pressure. In the Double Decision exercise, participants must rapidly identify a central object while simultaneously localizing a peripheral target, with the task becoming progressively harder as display durations shrink and backgrounds grow more cluttered. Freeze Frame similarly demands that participants hold a target image in memory and respond selectively within streams of distractors, with difficulty calibrated continuously to each user’s performance ceiling. This adaptive escalation, the authors argue, keeps trainees operating near their maximum capacity, precisely the condition under which cholinergic systems are recruited most vigorously during learning.
Beyond the headline training effect, the study’s baseline data offer a sobering portrait of cholinergic aging. Cross-sectional analysis of the initial scans confirmed widespread, statistically reliable reductions in FEOBV binding with advancing age across frontal, striatal, and parietotemporal regions—mirroring the topography of decline previously reported in independent cohorts. The data also provided a functional validation of the tracer: older adults with higher baseline cholinergic binding in prefrontal and insular regions performed better on baseline tests of attention drawn from the NIH EXAMINER battery, which included flanker, set-shifting, and antisaccade tasks. In other words, the density of acetylcholine terminals in the frontal cortex is not merely an anatomical curiosity but tracks, in measurable ways, the attentional abilities that define everyday cognitive competence in later life.
The methodological rigor underpinning these results deserves emphasis. All participants underwent high-resolution structural MRI on a 3 Tesla Siemens Prisma scanner, which was used for precise anatomical registration and for Müller-Gärtner partial volume correction of the PET data—a step that corrects for the blurring of signal caused by the limited spatial resolution of PET and ensures that measured changes reflect genuine alterations in cholinergic terminals rather than tissue atrophy. Randomization was stratified to balance the groups on an acetylcholine index, defined as the ratio of anterior cingulate to occipital FEOBV binding, and on executive function scores. The trial was approved by institutional review boards and Health Canada, and the full protocol, along with the blinding procedures and inclusion and exclusion criteria, was published in advance. The radiotracer itself, with a mass dosage capped well below safety limits, has been validated across studies of healthy aging, mild cognitive impairment, and Alzheimer’s disease.
The implications stretch well beyond the laboratory. Speed-based cognitive training is one of the very few non-pharmacological interventions that has been associated, in prior large trials, with a reduced risk of dementia diagnosis, and it is scalable, inexpensive, and deliverable at home on a tablet—which is exactly how the INHANCE participants trained. Yet until now, the neurobiological mechanism behind those behavioral benefits has remained speculative, inferred indirectly from changes in functional connectivity, white matter organization, or blood-based markers of plasticity. By demonstrating that training can measurably regrow or upregulate presynaptic cholinergic terminals in the living human brain, the study elevates the cholinergic system from a passive casualty of aging to an actionable target for intervention. That reframing matters because the cholinergic system is also the primary pathway compromised in early Alzheimer’s disease, and it is the system targeted by existing cognitive-enhancing drugs, which boost acetylcholine signaling but do nothing to restore the terminals themselves.
Cautions remain, as with any single trial. The analyses linking cholinergic change to cognitive improvement were exploratory, and longer-term follow-up will be needed to determine whether the observed cholinergic gains persist after training ends and whether they translate into durable protection against cognitive decline or dementia. The participants were all cognitively intact volunteers in a single urban research setting, so generalization to clinical populations is untested. Still, the core result stands as a striking proof of principle: ten weeks of adaptive, speed-driven mental exercise can leave a chemical fingerprint on the aging brain that standard PET imaging can see. For a field long dominated by the gloomy arithmetic of neuronal loss, the message from Montreal is unexpectedly optimistic—the aging brain’s machinery of attention and plasticity is not merely fading, but can be actively rebuilt.
Subject of Research: People
Subject of Research: Medicine
Article Title: PET imaging reveals cholinergic brain changes after cognitive training in older adults
Article References: de Figueiredo Pelegrino, A., Toussaint, P.-J., Attarha, M., Ouellet, L., Grant, S.-J., Van Vleet, T., & de Villers-Sidani, E. (2026). Whole-brain cholinergic modulation following computerized cognitive training in healthy older adults: a [18F]FEOBV PET study. GeroScience. https://doi.org/10.1007/s11357-026-02499-y
Image Credits: AI Generated
DOI: 10.1007/s11357-026-02499-y
Keywords: aging brain neuroplasticity research, brain region-specific changes in cholinergic terminals, cholinergic system enhancement through brain training, Cognitive training and brain plasticity in older adults, effects of computerized cognitive exercises on brain health, impact of speed-based cognitive exercises on neurochemical systems, Montreal-based study, neuroimaging evidence of brain changes after cognitive training, neuroplasticity and acetylcholine in elderly, PET imaging of cholinergic system in aging, randomized clinical trials on cognitive interventions in seniors
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Cassandra Pierce. (September 9, 2026). PET imaging reveals cholinergic brain changes after cognitive training in older adults. Scienmag. https://scienmag.com/pet-imaging-reveals-cholinergic-brain-changes-after-cognitive-training-in-older-adults/
Cassandra Pierce. “PET imaging reveals cholinergic brain changes after cognitive training in older adults.” Scienmag, 9 September 2026, https://scienmag.com/pet-imaging-reveals-cholinergic-brain-changes-after-cognitive-training-in-older-adults/. Accessed 9 September 2026.
Cassandra Pierce. “PET imaging reveals cholinergic brain changes after cognitive training in older adults.” Scienmag. September 9, 2026. https://scienmag.com/pet-imaging-reveals-cholinergic-brain-changes-after-cognitive-training-in-older-adults/
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