Abstract
Categorisation is a cognitive ability to group individual stimuli into different categorical groups based on their common features. The categorisation ability is not limited to human and non-human primates. Evidence reported that the categorisation ability also exists in avian species, however, neural-based evidence of categorisation ability in birds is limited. In the present study, we recorded the neural activity from the left and right hemispheres in each of the nidopallium caudolaterale (NCL) and entopallium (ENTO), brain areas associated with memory and visual discrimination of the homing pigeons (Columba livia). Several images of the paintings by Picasso and by Monet that were used in Watanabe, Sakamoto and Wakita (1995) study served as stimuli in the present study. We found the first, to our knowledge, a neural evidence of categorisation in ENTO. On the contrary, a more likely reward-related activity was found in the NCL. Furthermore, the evidence of categorisation in ENTO and the reward-related activity in NCL were both lateralised. Our findings will be useful in the investigation of people with impairment in categorisation ability such as patients with autism and schizophrenia. Furthermore, our findings will serve as further evidence of avian cognitive abilities.