The article by Wolf Singer discusses the role of neuronal synchrony in the functional organization of cortical systems. Singer argues that while most research focuses on the firing patterns of individual neurons, internal coordination of distributed responses is equally important. Multielectrode recordings have revealed that neurons in the visual cortex synchronize their discharges with millisecond precision when activated by similar stimuli, and this synchronization is associated with oscillatory modulation in the γ frequency range (30-50 Hz). This synchronization is context-dependent and changes systematically with modifications in stimulus constellations, suggesting it results from dynamic interactions within the cortical network. Singer reviews evidence for the functional significance of internal synchronization, including its ability to enhance the saliency of responses and its potential to serve as a mechanism for binding distributed neuronal activity. He discusses two complementary binding strategies: "binding by convergence" (or "binding by conjunction cells") and "dynamic binding" (or "relational coding/assembly coding"). The former involves convergence of axonal projections to a common target cell, while the latter relies on dynamic selection and grouping of responses based on their saliency relative to other responses. The article also explores the precision of internal synchronization, noting that it can be as precise as externally induced synchronization, especially in an activated, desynchronized state. This precision is crucial for maintaining synchrony at high frequencies and reducing spurious correlations. Singer highlights the importance of internal synchronization in defining relations between distributed responses with high temporal resolution, complementing selection and grouping operations based on sustained enhancement of discharge rates. Finally, Singer discusses the potential for internal synchronization to serve as a signature of relatedness, similar to stimulus-locked synchronization. He outlines several criteria that internal synchronization must meet to be functionally significant, including rapid onset, independent adjustment of synchrony and discharge rate, high precision, and use-dependent modifications of synaptic gain. The article concludes by emphasizing the need for dynamic grouping mechanisms at all levels of cortical processing to handle complex and context-dependent relationships.The article by Wolf Singer discusses the role of neuronal synchrony in the functional organization of cortical systems. Singer argues that while most research focuses on the firing patterns of individual neurons, internal coordination of distributed responses is equally important. Multielectrode recordings have revealed that neurons in the visual cortex synchronize their discharges with millisecond precision when activated by similar stimuli, and this synchronization is associated with oscillatory modulation in the γ frequency range (30-50 Hz). This synchronization is context-dependent and changes systematically with modifications in stimulus constellations, suggesting it results from dynamic interactions within the cortical network. Singer reviews evidence for the functional significance of internal synchronization, including its ability to enhance the saliency of responses and its potential to serve as a mechanism for binding distributed neuronal activity. He discusses two complementary binding strategies: "binding by convergence" (or "binding by conjunction cells") and "dynamic binding" (or "relational coding/assembly coding"). The former involves convergence of axonal projections to a common target cell, while the latter relies on dynamic selection and grouping of responses based on their saliency relative to other responses. The article also explores the precision of internal synchronization, noting that it can be as precise as externally induced synchronization, especially in an activated, desynchronized state. This precision is crucial for maintaining synchrony at high frequencies and reducing spurious correlations. Singer highlights the importance of internal synchronization in defining relations between distributed responses with high temporal resolution, complementing selection and grouping operations based on sustained enhancement of discharge rates. Finally, Singer discusses the potential for internal synchronization to serve as a signature of relatedness, similar to stimulus-locked synchronization. He outlines several criteria that internal synchronization must meet to be functionally significant, including rapid onset, independent adjustment of synchrony and discharge rate, high precision, and use-dependent modifications of synaptic gain. The article concludes by emphasizing the need for dynamic grouping mechanisms at all levels of cortical processing to handle complex and context-dependent relationships.