A person’s proficiency for mathematics can be predicted by measuring their neurotransmitter levels, according to a new study in the journal PLoS Biology. More specifically, the chemical signals GABA and glutamate – which inhibit and excite neurons, respectively – appear to directly influence the number-crunching capacities of each individual.
The balance between neuronal inhibition and excitation is believed to be crucial to our ability to form new brain connections, which in turn enables us to learn new information and develop skills. According to the study authors, the maturation of GABA neurons has been shown to trigger neural plasticity in early childhood, particularly during “sensitive periods” of brain development.
However, the ability of these neurotransmitters to influence complex learning that takes place over many decades remains poorly understood. To investigate, the study authors measured GABA and glutamate levels in the brains of 255 people, ranging from children as young as six years old to university students.
The researchers decided to focus exclusively on a brain region called the left intraparietal sulcus (IPS), as previous studies have highlighted the importance of this region for numerical and mathematical cognition.
Participants also completed a series of mathematical challenges, enabling the researchers to evaluate the connection between neurotransmitter levels and arithmetic capabilities.
Results indicated that among young people, higher levels of GABA in the IPS corresponded with greater mathematical performance, while increased glutamate was linked to lower proficiency. Interestingly, however, this relationship appears to flip at some point during our neurodevelopment, as adults with higher GABA concentrations tended to display a reduced capacity for math, with the reverse being true for glutamate.
Participants were then given a second math test roughly 18 months later, with the researchers successfully predicting how each individual would perform simply by observing their neurotransmitter levels.
Commenting on these findings, study author Roi Cohen Kadosh explained in a statement that the “developmental switches in the link between GABA and glutamate and academic achievement highlights a general, unknown principle of plasticity… [and] suggests that the link between plasticity and brain excitation and inhibition across different stages is unlikely to be immutable.”
“Our findings have also important implications for the development of brain-based interventional programs, which we hope to examine in the future.”
Why and how the role of these two neurotransmitters becomes inverted is currently unknown, although the study authors tentatively speculate that it may have something to do with the way that the brain alters its mathematical “processing strategies” as we age. According to the researchers, the IPS plays a central role in numerical cognition during childhood, hence the need for more GABA in this region. Later in our development, however, our reliance on the IPS diminishes as areas such as the hippocampus become increasingly relevant.
While this hypothesis remains to be fully investigated, the study authors insist that their discovery “provides a novel understanding of the human brain and its impact on formal education.”