The Brain's Sound Map & Perceptual Bias

Why do mice—and likely all mammals—consistently make the same perceptual mistakes on certain sounds? Researchers at the University of Mainz used large-scale two-photon calcium imaging in the mouse auditory cortex to map how hundreds of neurons respond to 189 rhythmically varied pulsed sounds. They found that subtle sound features such as click timing, pulse imbalance, and rhythmic grouping are encoded on axes that are geometrically entangled with the task-relevant feature of click rate, and that this representational entanglement—measured in untrained mice—accurately predicts which sounds will systematically mislead trained mice in a categorization task. Reference: Seiler et al. (2026) "Representational geometry of sounds in the auditory cortex explains biases in perceptual decision-making in mice" Cell Reports. https://doi.org/10.1016/j.celrep.2026.117221