Learned cognition mainly refers to a cognitive process in which organisms strengthened the training of the external targets and their own behaviors through acquired learning and form a conditioned reflex. It is not clear how the response of ectostriatum neurons in pigeons changes after cognition compared to before. In this study, pigeons were trained to recognize specific target and neural population signals were recorded from their ectostriatum with planted MEA. Response features in different training stages were extracted and compared, including firing rate based on Spike, power of local field potentials (LFP) in the gamma sub-band, multual information between each two neurons and so on. The results showed that, 1) response of neurons shifted from target presentation stage to decision stage after the establishment of learned cognition; 2) The synchrony between different trials was gradually enhanced with the establishment of learned cognition, and showed more stable and reliable response characteristics; 3) The mutual information between the neurons populatiom was significantly weaker than that before learned cognition, which indicated that the learned cognition weakened the redundant information among neuron population and improved neuronal encoding efficiency.