Taxi and ambulance drivers in the US show less susceptibility to Alzheimer's disease compared to workers in most other professions. This conclusion resulted from an analysis of nearly nine million death certificates in the US conducted in 2024.
The author, a professor of civil and environmental engineering from the University of Texas at San Antonio (USA), noted that these professions are similar to his own work because both require working with maps. He dedicated over two decades to studying digital maps with multiple layers of data, including overlaying flood zones onto cadastral blocks, mapping critical accident sites relative to road geometry, and using satellite imagery of rainfall over watersheds. Most of his work as an engineer is done using GIS—Geographic Information Systems.
Engineers like him constantly hold numerous spatial relationships in mind, analyzing the location of objects on scales ranging from a block to an entire watershed. Although the author previously believed that spatial reasoning across map layers was an exclusively professional skill, the study on taxi and ambulance drivers made him consider the potential benefit of this mental load for the brain.
Out of nine million death certificates covering the period from January 2020 to December 2022, taxi and ambulance drivers showed the lowest risk of developing Alzheimer's disease among 443 professions. After statistically adjusting the data for age, gender, ethnicity, and education level, approximately one in every hundred such drivers died from Alzheimer's, whereas the overall rate was one in every sixty people.
However, this positive effect did not extend to other driving-related professions. Researchers concluded that the decisive factor in reducing the risk of Alzheimer's is not the act of driving itself, but continuous real-time navigation—the constant need to determine one's location in space, track a destination, and update the mental map as conditions change. Drivers whose work was based on fixed or predetermined routes, such as bus drivers and pilots, did not demonstrate a similar advantage.
Scientists believe that the link between professions requiring intensive navigation and a reduced risk of Alzheimer's is related to the hippocampus—a part of the brain responsible for memory and spatial orientation. The hippocampus is one of the first areas affected by Alzheimer's disease; problems with spatial navigation and orientation are often the first signs of the disease, sometimes appearing even before obvious memory loss.
Similar correlations have been observed before. In a landmark 2000 study, neuroscientists compared the brains of licensed London taxi drivers with the brains of people who did not drive taxis. Their findings provided the first structural evidence that areas of the adult brain can undergo measurable changes under the constant demand for navigation. To get a taxi license, London taxi drivers must memorize over 25,000 streets within a six-mile radius of Charing Cross, a process known as 'The Knowledge' which takes an average of three to four years.
Researchers found that London taxi drivers had significantly more gray matter in the posterior hippocampus—an area of the brain associated with storing large-scale spatial maps. This volume increase correlated with the drivers' experience: the longer a person drove around the city, the larger this part of the brain was. This change was a result of practice, not an innate trait. Even if people with navigational abilities might be drawn to such work, the profession itself influences the brain.
Together, these two studies form a consistent argument: work that intensively trains the hippocampus may remodel it, and this modification may serve as protection against one of the most frightening age-related diseases.
Cartographers, urban planners, and geospatial analysts engage in continuous spatial thinking daily. A GIS specialist might use a computer to overlay demographic data onto flood zone maps to identify risk groups, or analyze satellite imagery to map vegetation cover after a forest fire. These researchers simultaneously work with multiple data layers, coordinate systems, and scales.
The question arises: does screen-based spatial thinking train the hippocampus as much as moving through a real city? When a taxi driver navigates within a scene, at the street level, GIS researchers visualize space from above, like on a map—what cognitive scientists call allocentric thinking. However, these two perspectives intersect in the brain: the hippocampus also builds maps from external viewpoints, not just based on the navigator's own position.
Studies of cognitive maps lead to the same conclusion as the taxi driver study. In 2023, researchers applied a machine learning model to over 22,500 people in a national dataset and were able to predict which zip codes had a higher incidence of Alzheimer's with 84% accuracy, based solely on environmental complexity. People living in spatially complex environments—such as dense street networks with numerous intersections, various points of interest and landmarks, and multiple route options—had a lower probability of developing Alzheimer's.
A subsequent study linked environmental geospatial complexity to larger volumes in brain areas responsible for spatial navigation. Researchers hypothesized that the routine construction of cognitive maps trains precisely those circuits that Alzheimer's disease attacks first. Reusing cognitive systems involved in spatial navigation may help slow the symptoms of the disease.
Nevertheless, these two studies focus on people's place of residence, not their work. It is not yet known whether screen-based spatial thinking trains the same circuits as real-city navigation.
The implications of continuous spatial thinking protecting the brain extend beyond cartographers and taxi drivers. Numerous studies have established a link between mentally demanding professions and slowing cognitive decline and reducing the risk of dementia, even when controlling for education level.
Studies of cognitive reserve—the brain's ability to continue functioning despite having a disease—may explain why two people with the same degree of illness can have a noticeably different level of cognitive impairment. If demanding spatial thinking protects the brain, then how societies structure education, professional training, and retirement becomes a matter of brain health.
Spatial thinking can be trained, and opportunities for such learning are widely available. GIS and remote sensing training is offered in geography, engineering, public health, and environmental science courses worldwide. If constant engagement in spatial thinking can help the brain strengthen the circuits primarily attacked by Alzheimer's disease, its value extends far beyond the technical skills it develops.