This study investigates the distinction between the human dorsal and ventral attention systems based on spontaneous neuronal activity. Using functional MRI (fMRI) data from resting-state conditions, the researchers identified two distinct systems: a bilateral dorsal attention system and a right-lateralized ventral attention system. These systems were defined solely based on correlations in spontaneous fluctuations of the blood oxygen level-dependent (BOLD) signal, without the influence of external tasks or stimuli. The dorsal system, involving the intraparietal sulcus (IPS) and frontal eye field (FEF), showed bilateral correlations, while the ventral system, involving the right temporal-parietal junction (TPJ) and right ventral frontal cortex (VFC), showed right-lateralized correlations. The study also identified regions in the prefrontal cortex that correlated with both systems, suggesting a potential mechanism for their interaction. The findings suggest that the neuroanatomical substrates of human attention are present even in the absence of external events, reflected in the correlation structure of spontaneous activity. This challenges the traditional view that attention systems are only active in response to external demands. Instead, the study supports the idea that these systems are fundamentally organized in the brain's internal dynamics. The results demonstrate that the dorsal and ventral attention systems are largely segregated in their spatial topography, with only small regions of overlap in the prefrontal cortex. This segregation is important for the flexibility observed in task-response patterns, allowing the systems to be modulated together, independently, or in opposite directions. The study also highlights the importance of spontaneous activity in understanding brain function, as it reveals that the brain is active even in the absence of task, primarily driven by internal dynamics. This perspective is supported by the observation that most of the brain's energy consumption is in support of intrinsic functional activity. The findings have implications for understanding the functional organization of the brain and the mechanisms underlying attention and other cognitive processes.This study investigates the distinction between the human dorsal and ventral attention systems based on spontaneous neuronal activity. Using functional MRI (fMRI) data from resting-state conditions, the researchers identified two distinct systems: a bilateral dorsal attention system and a right-lateralized ventral attention system. These systems were defined solely based on correlations in spontaneous fluctuations of the blood oxygen level-dependent (BOLD) signal, without the influence of external tasks or stimuli. The dorsal system, involving the intraparietal sulcus (IPS) and frontal eye field (FEF), showed bilateral correlations, while the ventral system, involving the right temporal-parietal junction (TPJ) and right ventral frontal cortex (VFC), showed right-lateralized correlations. The study also identified regions in the prefrontal cortex that correlated with both systems, suggesting a potential mechanism for their interaction. The findings suggest that the neuroanatomical substrates of human attention are present even in the absence of external events, reflected in the correlation structure of spontaneous activity. This challenges the traditional view that attention systems are only active in response to external demands. Instead, the study supports the idea that these systems are fundamentally organized in the brain's internal dynamics. The results demonstrate that the dorsal and ventral attention systems are largely segregated in their spatial topography, with only small regions of overlap in the prefrontal cortex. This segregation is important for the flexibility observed in task-response patterns, allowing the systems to be modulated together, independently, or in opposite directions. The study also highlights the importance of spontaneous activity in understanding brain function, as it reveals that the brain is active even in the absence of task, primarily driven by internal dynamics. This perspective is supported by the observation that most of the brain's energy consumption is in support of intrinsic functional activity. The findings have implications for understanding the functional organization of the brain and the mechanisms underlying attention and other cognitive processes.