Why can a larger neural representation improve perceptual decisions?

In the context of perceptual learning, an increase in the size of a neural representation improves perceptual decisions by enhancing the statistical reliability of the information processed by the brain.1

When the number of neurons responding to a specific stimulus increases within a given brain region, the system can effectively sum these responses. This summation process allows the brain to aggregate data across a larger ensemble of neural activity, which reduces noise and provides a more robust basis for making accurate decision making judgments. This mechanism has been observed across various sensory modalities, including tactile discrimination in the somatosensory cortex and frequency discrimination in the auditory cortex.1