The article "Principles of Cortical Areas and Their Implications for Neuroimaging" by Steven E. Petersen and colleagues reviews the fundamental concepts of cortical organization, particularly the concept of arealization, which refers to the division of the cerebral cortex into discrete areas. The authors highlight how non-human animal studies have revealed key principles of cortical arealization, including what defines a cortical area, how these areas form, how they interact, and what functions they perform. They emphasize that these principles should guide neuroimaging research to ensure more accurate interpretations of neuroimaging data. In the first part of the article, the authors discuss how cortical areas are defined by their functional properties (F), architectonics (A), connectivity (C), and topography (T). They provide examples of well-studied areas such as primary visual cortex (V1) and middle temporal area (MT) to illustrate these principles. The formation of cortical areas during development is also explained, highlighting the role of thalamocortical inputs in refining continuous gradients into discrete areas. The second part of the article focuses on the implications of these principles for cognitive neuroscience and neuroimaging. It argues that neuroimaging studies should assume the presence of discrete areal boundaries and temporally invariant areas. The authors critique the common interpretation of neuroimaging data that assumes smooth gradients or moving areas, which contradicts established neurobiological principles. They emphasize that functional correlations between areas do not necessarily represent direct anatomical connections and that areas perform multiple specific functions while also allowing for some degree of plasticity. Overall, the article underscores the importance of incorporating neurobiological principles into neuroimaging research to enhance the accuracy and reliability of findings in human cognitive neuroscience.The article "Principles of Cortical Areas and Their Implications for Neuroimaging" by Steven E. Petersen and colleagues reviews the fundamental concepts of cortical organization, particularly the concept of arealization, which refers to the division of the cerebral cortex into discrete areas. The authors highlight how non-human animal studies have revealed key principles of cortical arealization, including what defines a cortical area, how these areas form, how they interact, and what functions they perform. They emphasize that these principles should guide neuroimaging research to ensure more accurate interpretations of neuroimaging data. In the first part of the article, the authors discuss how cortical areas are defined by their functional properties (F), architectonics (A), connectivity (C), and topography (T). They provide examples of well-studied areas such as primary visual cortex (V1) and middle temporal area (MT) to illustrate these principles. The formation of cortical areas during development is also explained, highlighting the role of thalamocortical inputs in refining continuous gradients into discrete areas. The second part of the article focuses on the implications of these principles for cognitive neuroscience and neuroimaging. It argues that neuroimaging studies should assume the presence of discrete areal boundaries and temporally invariant areas. The authors critique the common interpretation of neuroimaging data that assumes smooth gradients or moving areas, which contradicts established neurobiological principles. They emphasize that functional correlations between areas do not necessarily represent direct anatomical connections and that areas perform multiple specific functions while also allowing for some degree of plasticity. Overall, the article underscores the importance of incorporating neurobiological principles into neuroimaging research to enhance the accuracy and reliability of findings in human cognitive neuroscience.