Brain function can be tested through quick screening questionnaires, detailed neuropsychological evaluations, brain imaging, blood-based biomarkers, and even digital tools you can use at home. The right approach depends on what you’re trying to learn: whether you’re tracking normal age-related changes, investigating a specific concern like memory loss, or establishing a baseline before a contact sport. Here’s how each method works and what it actually measures.
Quick Screening Tests
The most widely used clinical screening tool is the Montreal Cognitive Assessment, or MoCA. It takes about 10 minutes and covers seven scored areas: visuospatial and executive skills, naming, attention, language, abstract reasoning, delayed recall, and orientation. The maximum score is 30, and a score of 26 or above is considered normal. If you have fewer than 12 years of formal education, one point is added to your total to account for that.
The MoCA is designed to catch early cognitive problems that a simpler test might miss. It’s commonly administered in a doctor’s office, often as a first step when someone raises concerns about memory, thinking speed, or confusion. A low score doesn’t diagnose a specific condition on its own, but it flags the need for deeper evaluation.
Neuropsychological Testing for Specific Skills
When a screening test raises questions, a neuropsychologist can run a more detailed battery of tests targeting individual brain functions. These assessments break cognition into components and measure each one separately.
Executive Function
Executive function is your brain’s ability to plan, switch between tasks, and resist automatic impulses. Three tests dominate this area. The Trail Making Test Form B asks you to connect numbers and letters in alternating sequence (1-A-2-B-3-C) as quickly as possible, measuring mental flexibility and working memory. The Stroop Test shows you color words printed in mismatched ink (the word “red” printed in blue) and asks you to name the ink color rather than read the word, testing your ability to override an automatic response. The Wisconsin Card Sorting Test requires you to sort cards by rules that change without warning, measuring how well you adapt when the pattern shifts.
Processing Speed
The Symbol Digit Modalities Test measures how quickly your brain processes information. You’re given a key that pairs abstract symbols with numbers, then asked to fill in as many correct number-symbol matches as possible in 90 seconds. Among adults aged 65 to 69, the average score is about 37 correct responses, dropping to around 31 for those 80 and older. Education level matters too: people with 17 or more years of education average about 41, while those with fewer than 9 years average closer to 31.
Memory
The Rey-Osterrieth Complex Figure Test evaluates visual memory by asking you to copy a complicated geometric drawing, then reproduce it from memory a few minutes later. Each of the 12 elements in the figure is scored on accuracy and placement, with a maximum of 2 points per element for a correctly drawn piece in the right location. This test reveals how well your brain encodes and retrieves visual-spatial information.
Language and Verbal Fluency
The Controlled Oral Word Association Test is a straightforward measure of how fluidly your brain retrieves words. You’re given a letter and asked to say as many words starting with that letter as you can in 60 seconds. Your score is simply the number of valid words you produce. This test is particularly sensitive to problems in the frontal lobes, the brain regions responsible for organizing thoughts and generating speech. A related version uses categories instead of letters (naming as many animals as possible, for instance), which taps into different brain networks.
Brain Imaging
Imaging technologies let doctors observe the brain’s structure and activity directly, each capturing a different dimension of brain function.
An MRI scan shows detailed brain anatomy, revealing shrinkage, tumors, or damage to specific regions. Functional MRI (fMRI) goes further by tracking blood oxygen levels in real time, showing which brain areas are active during a task or at rest. It’s often used to map connectivity between brain networks, particularly when evaluating consciousness disorders or planning surgery.
PET scans measure metabolic activity by tracking how the brain uses glucose. Areas that are more active consume more glucose, so a PET scan creates a map of brain energy use. This is especially useful for distinguishing between different states of consciousness and for detecting the protein deposits associated with Alzheimer’s disease.
EEG (electroencephalography) records the brain’s electrical activity through sensors placed on the scalp. It captures brain wave patterns in real time, making it useful for diagnosing seizure disorders, sleep problems, and certain types of brain injury. Specific wave patterns, particularly in the delta frequency range, have shown value as a prognostic marker for recovery after brain injury.
Blood Tests for Brain Health
A newer and rapidly advancing approach uses blood samples to detect proteins linked to brain disease. One biomarker in particular, a phosphorylated form of the tau protein called p-tau217, has shown strong accuracy for identifying Alzheimer’s-related brain changes. In clinical studies, this blood test achieved 95% sensitivity (meaning it correctly identified nearly all people with the disease) and roughly 75% specificity (correctly ruling out most people without it). When the test uses a higher threshold for a positive result, specificity climbs above 94%.
This type of testing is significant because, until recently, confirming Alzheimer’s pathology required either a PET scan or a spinal fluid sample. A blood draw is far simpler and less expensive, making it practical for wider use. These tests are already entering clinical practice and may change how early brain diseases are detected.
Concussion and Sports Baseline Testing
Athletes in contact sports often complete baseline cognitive testing before their season starts, giving medical staff a personal reference point in case of a head injury. The most commonly used platform is ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), a computerized test that generates four composite scores: verbal memory, visual memory, visual motor speed, and reaction time. These scores come from six test modules measuring attention, recognition memory, visual working memory, and learning.
After a suspected concussion, the athlete retakes the test, and the results are compared against their own baseline. A significant drop in any composite score, combined with a 22-item symptom checklist covering headache, dizziness, fogginess, and other complaints, helps guide return-to-play decisions. The value of baseline testing is that it accounts for individual variation. Two healthy people can have very different “normal” scores, so comparing post-injury results to a population average is less informative than comparing them to the person’s own pre-injury performance.
Digital and At-Home Tools
A growing number of apps and websites offer self-administered cognitive tests, but the quality varies dramatically. A systematic review of available tools found that only 7 out of all identified platforms provided any information about their scientific quality, and only one (DANA, a tool originally developed for military veterans and cleared by the FDA) reported data on performance norms, reliability, validity, and diagnostic accuracy.
One well-validated digital option is eSAGE (the electronic Self-Administered Gerocognitive Examination), an online version of a paper test developed at Ohio State University. It correlates strongly with the MoCA and achieves 90% sensitivity and 87% specificity for distinguishing dementia from normal cognition. For identifying mild cognitive impairment specifically, its sensitivity is 71% with 90% specificity. Another platform, BrainCheck, offers a collection of neurocognitive tests for tracking cognitive health over time, with seven-day test-retest reliability ranging from 0.6 to 0.9 depending on the subtest.
These tools can be useful for monitoring trends over time, but they’re not substitutes for professional evaluation. A low score on a self-administered test is a reason to bring your concerns to a clinician, not a diagnosis.
What Normal Cognitive Aging Looks Like
Not every change in brain function signals a problem. After age 60, processing speed, working memory, and executive functions typically decline to some degree, while short-term memory, autobiographical knowledge, and emotion processing tend to hold steady. This is considered normal aging.
Mild cognitive impairment (MCI) sits between normal aging and dementia. People with MCI show noticeable decline, and often notice it themselves, but they still manage daily life independently. The key distinction with dementia is that cognitive decline becomes severe enough to interfere with independent living, affecting personal, professional, and social functioning. Interestingly, spatial navigation (your ability to find your way through unfamiliar environments) has emerged as one skill that may help distinguish very early Alzheimer’s-related changes from ordinary aging, even before memory loss becomes obvious.
If you’re concerned about changes in your thinking, starting with a screening test like the MoCA gives you and your doctor a concrete score to work from, rather than relying on a vague sense that something feels off. From there, the path might lead to neuropsychological testing, imaging, or blood biomarkers, depending on what the initial results suggest.