Brodmann Areas

The early brain map that keeps on giving.

Chances are, if you’re curious about the brain, neuroscience, or cognition, you’ll eventually come across Brodmann Areas as a reference or part of some other system or brain-related explanation. Here, we’ll take a closer look at them with an eye towards their functions.

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The basics

For the newcomer, Brodmann areas are a system of defining and mapping specific regions of the human brain based on the structure of the cerebral cortex, specifically the cytoarchitecture or types, density and connections of neurons in any given area.

This mapping was first proposed by German neuroanatomist Korbinian Brodmann in 1909. The Brodmann areas are divided into 52 different regions, each of which is thought to have a unique function, here’s the original illustration with the numbered areas:

Source: Public domain, see here.

Yes but no…

Like many science-related things, time has had both good and bad effects on early maps. On one hand, the areas have been subdivided and boundaries refined. We also now know that the brain works in a parallel system of systems way with complex temporal dynamics ( still being researched ), so Brodmann areas have lost some shine in the utility department. Yet, they stand as the de facto map we use when partitioning the brain, even though more modern approaches like multimodal parcellation exist, and we can even peak into the working brain via imaging like FMRI.

FMRI BOLD activation in an emotional Stroop task, note we don’t use Brodmann Areas but anatomical names and abbreviations- Source.

In essence, a specific task would be lost among various Brodmann areas. Intensity, parallelization, and temporal dynamics (the change from one task to another) are also not present, begging the question: What are they good for?

Utility

Nobody would mistake a map of a city or an exploded machine diagram for precise instructions on how the city…