Regions in the human inferior temporal gyrus are engaged in numerosity processing across visual stimulus categories.

The visual number form areas, here referred to as inferior temporal gyrus-math (ITG-math), have gained recent attention as a neural substrate of mathematical cognition. Yet, the function of these regions remains debated with some research suggesting selectivity for digits and others suggesting a visual stimulus-independent role in mathematical processing. Here we addressed this debate by exploring the impact of different tasks and stimuli on neural responses in ITG-math. Participants were presented with digits and UFOs, while performing a 1-back task either on stimulus numerosity or on stimulus color. We collected 2 sessions of this experiment from 17 healthy adults and could identify voxels with higher responses in the numerosity than the color task in 92% of the participants, whereas contrasting digits with unidentified flying objects (UFOs) leads to selective responses in only 35% of the participants. Accordingly, in independent data, ITG-math showed a task preference, but no stimulus preference. Multivariate analyses further revealed task encoding, and a combination of task and stimulus encoding, in the left and right ITG-math, respectively. Our work hence supports the notion that the role of ITG-math in mathematical cognition goes beyond the encoding of digits.