A maze test is a cognitive assessment that measures planning ability, spatial memory, and impulse control by asking a person (or animal) to navigate through a maze. The most well-known version for humans is the Porteus Maze Test, a paper-and-pencil tool used in neuropsychological evaluations for over a century. Maze tests also play a major role in animal research, where rodents navigate physical mazes to help scientists study memory and brain function. The term occasionally comes up in cardiology, where the “maze procedure” is a heart surgery, not a diagnostic test.
The Porteus Maze Test
The Porteus Maze Test is the classic human maze assessment, designed to measure planning, foresight, and impulsivity. It’s used for anyone aged 3 and older and works by presenting a series of increasingly difficult printed mazes. You trace a path through each one with a pencil, and the goal is to reach the exit without entering any dead ends or retracing your steps.
There are three versions: the Vineland Revision (the original), the Porteus Maze Extension, and the Porteus Maze Supplement (an advanced form). The Vineland Revision includes 12 mazes. The earlier, simpler ones ask you to follow a path around corners and return to the starting point. Mid-level mazes have a clear start and end point. The hardest mazes give you a starting location but don’t tell you where the exit is, forcing you to plan ahead and adjust on the fly.
Clinicians look at two main things: whether you completed each maze successfully and the types of errors you made. Entering a blind alley, lifting your pencil, or retracing a line all count against you. These errors reveal different things. Someone who repeatedly enters dead ends may struggle with planning ahead, while someone who keeps retracing paths may have difficulty with impulse control or cognitive flexibility.
What Maze Tests Reveal About the Brain
Maze tests are particularly useful for evaluating executive function, the set of mental skills that lets you plan, pay attention, and resist doing the first thing that comes to mind. This makes them valuable in clinical settings where those abilities may be compromised.
Research on children who sustained traumatic brain injuries found that the Porteus Maze Test was highly sensitive to injury severity. In a study of 276 pediatric patients tested at least three years after their injuries, maze performance tracked closely with both how serious the injury had been and the volume of damage to the prefrontal cortex, the brain region most responsible for planning and decision-making. The test has also been used to study impulsivity in people with developmental disabilities and attention-related conditions.
Animal Maze Tests in Research
In neuroscience labs, maze tests are one of the primary tools for studying how memory works. Several types exist, each designed to probe a different aspect of learning.
Morris Water Maze
The Morris water maze is one of the most widely used tests in brain research, though it isn’t a maze in the traditional sense. It’s an open circular pool filled partway with water. For rats, the pool is about 210 cm across; for mice, about 122 cm. A small platform sits just below the water’s surface (typically 1 to 2 cm deep) in one section of the pool, invisible to the animal.
The animal is placed in the water at different starting points around the edge and must learn to find the hidden platform using visual landmarks placed around the room. Over repeated trials, a healthy animal learns to swim directly to the platform. Scientists measure how long each trip takes and how direct the path is. When researchers remove the platform entirely, they can test reference memory by watching whether the animal still searches in the area where the platform used to be. The test correlates strongly with activity in the hippocampus, a brain structure critical for spatial memory, making it a go-to tool for studying Alzheimer’s disease, drug effects, and brain injuries.
Radial Arm Maze
The radial arm maze looks like a wheel with spokes. A central platform connects to several arms (usually eight), some of which contain food rewards. The animal needs to remember which arms it has already visited and which still have food. This setup tests both working memory (remembering what happened during the current session) and reference memory (remembering the general rules across sessions). It’s well suited for repeated testing over time, making it useful for tracking gradual memory decline or the long-term effects of a treatment.
How the Two Compare
The Morris water maze excels at isolating spatial learning and is a strong single-session assessment tool, but it’s less ideal for repeated measurements or tracking long-term memory loss. The radial arm maze is better at detecting steady-state memory problems over time but doesn’t isolate the specific cognitive processes involved as precisely. Researchers often choose between them based on what question they’re trying to answer.
Computerized Maze Tests
Modern versions of maze tests have moved to screens. Computerized maze tasks use touch screens or pointer devices and can record not just whether someone makes errors, but exactly how long each movement takes and what types of mistakes occur. The Groton Maze Learning Test, for example, tracks three distinct error types: legal errors (wrong turns within the rules), perseverative errors (repeating the same wrong choice), and rule-break errors (violating the task instructions entirely). Each type points to a different cognitive issue.
These digital mazes have found practical applications beyond the lab. One study found that a brief computerized maze navigation task predicted real-world driving performance in people with early Alzheimer’s disease about as well as a full battery of standard neuropsychological tests. The maze captured processing speed, visual scanning, attention, and working memory all in a single task, making it a quick screening tool for assessing whether older adults can drive safely.
The Cardiac Maze Procedure
If you came across “maze” in the context of heart conditions, it refers to something completely different. The maze procedure is a surgical treatment for atrial fibrillation, a type of irregular heartbeat. It involves creating a pattern of scar tissue on the heart’s upper chambers to redirect electrical signals into an orderly path. Before the surgery, patients typically undergo an echocardiogram to check the size of the left atrium and look for valve problems, along with a chest CT scan. Some people use “maze procedure” loosely to describe any ablation for atrial fibrillation, but technically it refers to a specific technique that treats both upper chambers of the heart.