How can receptive fields change during perceptual learning?

During perceptual learning, the physiological properties of receptive fields can undergo significant modifications, reflecting the brain's neuroplasticity and its ability to reorganize in response to experience. These changes generally occur through the following mechanisms:12

• Expansion of Neural Representation: In some tasks, such as tactile discrimination, learning leads to an increase in the number of neurons that respond to a specific stimulus. This results in a larger area of the somatosensory cortex being devoted to encoding a particular region of the body, which helps improve behavioral performance.1
• Sharpening of Tuning Functions: Learning can narrow the range of stimulus attributes (such as orientation or frequency) to which a neuron responds. This "sharpening" reduces the overlap in responses between neighboring neurons, a process known as decorrelation. In some instances, this narrowing effectively increases the distance between neurons along the trained dimension, which may be accompanied by a reduction in the total number of neurons responding to a given stimulus.1
• Changes in Response Timing: Practice in discriminating temporal characteristics can increase the synchronicity of firing across an ensemble of neurons. This strategy, where the brain uses the relative timing of responses to represent information, has been observed in both tactile and auditory learning.1

These physiological adjustments allow the sensory system to become more efficient and precise in processing specific stimuli through practice.1