Novel digital test provides tool to assess brain chemistry\” />
A new imaging study from researchers at McGill University has found the first-ever digital assessment to provide a valid scientific measurement of brain chemistry and cognitive performance.
This new assessment, developed by Posit Science, creators of BrainHQ, can be self-administered in a few minutes over an internet-connected phone, tablet, or computer — to provide a scientific estimate of acetylcholine production in the brain.
Acetylcholine (the “pay attention” chemical) is a biomarker known to be downregulated in older adults and even more so in patients with pre-dementia and Alzheimer’s disease and related dementias. Currently, there is no clinically useful way to measure this marker.
Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter.
Positron Emission Tomography (PET) brain imaging techniques can be used; however, this method is costly, requires specialized expertise, and exposes participants to radiation, limiting preventing its use in clinical practice. This new research highlights a potential breakthrough in accessibility for doctors and patients to assess brain health.
According to Dr. Henry Mahncke, CEO of Posit Science: “Currently, it’s impossible for doctors to monitor this brain chemical despite its importance because it requires expensive imaging equipment and special expertise available at few research centres. This breakthrough shows a new path for routine monitoring of brain health by doctors and individuals.”
The brain’s neuromodulatory system produces brain chemicals that impact mood, learning, attention, responsiveness, and memory. Brain scientists have known for decades that the system (and its subsystems that produce various brain chemicals) operate more sluggishly (downregulate) with aging and various health conditions.
The assessment focuses on the cholinergic system — a subsystem that produces the brain chemical acetylcholine — sometimes called the “pay attention” chemical, because it is produced when you pay attention. The production of acetylcholine is known to down regulate with normal aging, and even more severely with pre-dementia and with Alzheimer’s disease and related dementias (ADRD).
Cholinergic function is recognized as a key biomarker of overall brain health, regulates the ability of the brain to change (“plasticity”), and is associated with stronger cognitive performance (in sensory processing, attention, learning, memory, and executive function). Poor cholinergic function is linked to the production of plaque and tangles associated with ADRD, as well deficits in other conditions.
Currently there is no easily accessible way to measure cholinergic function. No standardized blood test to directly measure it exists. Positron Emission Tomography (PET) brain imaging techniques can be used; however, this method is costly, requires specialized expertise, and exposes participants to radiation, limiting its use in clinical practice.
The imaging study enrolled 92 healthy older adults (average age 72). Each was measured using: a BrainHQ assessment (Double Decision); two other validated neuropsychological assessments; and a PET scan using tracer to evaluate cholinergic neurotransmission.
The study showed better scores on the Double Decision assessment correlated with higher cholinergic function, indicating that the assessment could estimate cholinergic function without the complexity and risk of doing a PET scan. These results align with prior studies showing a significant relationship between cholinergic function and cognitive performance as measured by clinician-administered tools.
The assessment was brief, taking an average of 3 minutes to complete, and demonstrated good usability with reasonable descriptive and psychometric properties. It was sensitive to age within the narrow band measured of 65-83 years and was not influenced by demographic factors such as years of education or gender.
The researchers conclude: “The results support the adoption of this scalable form of biomarker-informed cognitive assessment available to individuals with an internet-connected device.”
The research appears in the journal JMIR, titled “Association of a Brief Computerized Cognitive Assessment With Cholinergic Neurotransmission: Assessment Validation Study.”
