Neurocognitive foundations of fraction processing

Many children and adults experience fractions as a challenging mathematical content. Behavioral studies have extensively documented typical errors in fraction tasks and identified various factors that contribute to their occurrence. However, the cognitive mechanisms of fraction processing and fraction learning are still not fully understood. In recent years, brain imaging studies have begun to unravel the neural underpinnings of fraction processing. This chapter briefly summarizes key findings from behavioral reaction time and eye-tracking studies and reviews more extensively the available neuroscientific studies on fraction processing. Research using functional magnetic resonance imaging (fMRI), which has high spatial resolution, suggests that fractions can be processed holistically as whole numerical magnitudes and that the intraparietal sulcus (IPS) plays a key role in such processing. On the other hand, studies that used electroencephalography (EEG), which has a high temporal resolution, provide a more differentiated picture. In line with reaction time and eye-tracking studies, these studies suggest that fractions can be processed holistically or componentially, depending on task requirements. Based on the reviewed literature and previous models on number processing, we propose a tentative temporal model of fraction processing. We conclude that further research should focus specifically on the temporal characteristics of fraction processing during problem-solving to better understand how the brain constructs and represents holistic fraction magnitude.