Dear colleagues, The following Open Access article develops a unified theory of prefrontal cortex and its functions: Grossberg, S. (2018). Desirability, availability, credit assignment, category learning, and attention: Cognitive-emotional and working memory dynamics of orbitofrontal, ventrolateral, and dorsolateral prefrontal cortices. Brain and Neuroscience Advances. May 8, 2018. http://journals.sagepub.com/doi/full/10.1177/2398212818772179 Abstract: Background: The prefrontal cortices play an essential role in cognitive-emotional and working memory processes through interactions with multiple brain regions. Methods: This article further develops a unified neural architecture that explains many recent and classical data about prefrontal function, and makes testable predictions. Results: Prefrontal properties of desirability, availability, credit assignment, category learning, and feature-based attention are explained. These properties arise through interactions of orbitofrontal, ventrolateral prefrontal, and dorsolateral prefrontal cortices with the inferotemporal cortex, perirhinal cortex, parahippocampal cortices; ventral bank of the principal sulcus, ventral prearcuate gyrus, frontal eye fields, hippocampus, amygdala, basal ganglia, hypothalamus, and visual cortical areas V1, V2, V3A, V4, MT, MST, LIP, and PPC. Model explanations also include how the value of visual objects and events is computed, which objects and events cause desired consequences and which may be ignored as predictively irrelevant, and how to plan and act to realize these consequences, including how to selectively filter expected vs. unexpected events, leading to movements towards, and conscious perception of, expected events. Modeled processes include reinforcement learning and incentive motivational learning; object and spatial working memory dynamics; and category learning, including the learning of object categories, value categories, object-value categories, and sequence categories, or list chunks. Conclusions: This article hereby proposes a unified theory of prefrontal cortex and its functions. Best, Steve Grossberg Stephen Grossberg http://en.wikipedia.org/wiki/Stephen_Grossberg http://scholar.google.com/citations?user=3BIV70wAAAAJ&hl=en https://youtu.be/9n5AnvFur7I https://www.youtube.com/watch?v=_hBye6JQCh4 Wang Professor of Cognitive and Neural Systems Professor of Mathematics & Statistics, Psychological & Brain Sciences, and Biomedical Engineering Director, Center for Adaptive Systems Boston University http://cns.bu.edu/~steve steve@bu.edu<mailto:steve@bu.edu> <mailto:steve@bu.edu>