The article reviews the hypothesis that the human dorsal anterior cingulate cortex (ACC) functions to signal and respond to conflicts in information processing, thereby triggering compensatory adjustments in cognitive control. Since the hypothesis was first proposed, extensive empirical evidence has largely corroborated it, with recent studies providing new insights and challenges. The ACC is known to respond to conflict in various contexts, including response override, underdetermined responding, and error commission. These responses are often associated with changes in cognitive control, such as increased focus on the task at hand or adjustments in top-down control. The article discusses the role of the ACC in conflict monitoring, its localization, and the relationship between conflict monitoring and other functions like action-outcome evaluation and reward-based decision-making. It also explores the possibility that conflict monitoring is part of a broader evaluative function of the ACC, suggesting that conflict detection might be linked to task difficulty and mental effort. The authors highlight the need for further research to integrate these perspectives and understand the complex role of the ACC in cognitive control.The article reviews the hypothesis that the human dorsal anterior cingulate cortex (ACC) functions to signal and respond to conflicts in information processing, thereby triggering compensatory adjustments in cognitive control. Since the hypothesis was first proposed, extensive empirical evidence has largely corroborated it, with recent studies providing new insights and challenges. The ACC is known to respond to conflict in various contexts, including response override, underdetermined responding, and error commission. These responses are often associated with changes in cognitive control, such as increased focus on the task at hand or adjustments in top-down control. The article discusses the role of the ACC in conflict monitoring, its localization, and the relationship between conflict monitoring and other functions like action-outcome evaluation and reward-based decision-making. It also explores the possibility that conflict monitoring is part of a broader evaluative function of the ACC, suggesting that conflict detection might be linked to task difficulty and mental effort. The authors highlight the need for further research to integrate these perspectives and understand the complex role of the ACC in cognitive control.