Identifying and Localizing Multiple Objects Using Artificial Ventral and Dorsal Cortical Visual Pathways

In our previous study (Han & Sereno, 2022a), we found that two artificial cortical visual pathways trained for either identity or space actively retain information about both identity and space independently and differently. We also found that this independently and differently retained information about identity and space in two separate pathways may be necessary to accurately and optimally recognize and localize objects. One limitation of our previous study was that there was only one object in each visual image, whereas in reality, there may be multiple objects in a scene. In this study, we find we are able to generalize our findings to object recognition and localization tasks where multiple objects are present in each visual image. We constrain the binding problem by training the identity network pathway to report the identities of objects in a given order according to the relative spatial relationships between the objects, given that most visual cortical areas including high-level ventral steam areas retain spatial information. Under these conditions, we find that the artificial neural networks with two pathways for identity and space have better performance in multiple-objects recognition and localization tasks (higher average testing accuracy, lower testing accuracy variance, less training time) than the artificial neural networks with a single pathway. We also find that the required number of training samples and the required training time increase quickly, and potentially exponentially, when the number of objects in each image increases, and we suggest that binding information from multiple objects simultaneously within any network (cortical area) induces conflict or competition and may be part of the reason why our brain has limited attentional and visual working memory capacities.