In human speech and communication across various species, recognizing and categorizing sounds is fundamental for the selection of appropriate behaviors. However, how does the brain decide which action to perform based on sounds? We explored whether the supplementary motor area (SMA), responsible for linking sensory information to motor programs, also accounts for auditory-driven decision making. To this end, we trained two rhesus monkeys to discriminate between numerous naturalistic sounds and words learned as target (T) or non-target (nT) categories. We found that the SMA at single and population neuronal levels perform decision-related computations that transition from auditory to movement representations in this task. Moreover, we demonstrated that the neural population is organized orthogonally during the auditory and the movement periods, implying that the SMA performs different computations. In conclusion, our results suggest that the SMA integrates acoustic information in order to form categorical signals that drive behavior.

在不同物种的人类语言和交流中，识别和分类声音是选择适当行为的基础。但是，大脑如何根据声音决定执行哪个动作？我们探讨了负责将感觉信息与运动程序联系起来的辅助运动区 (SMA) 是否也解释了听觉驱动的决策。为此，我们训练了两只恒河猴来区分大量自然声音和作为目标 (T) 或非目标 (nT) 类别学习的单词。我们发现，单个和群体神经元水平的 SMA 执行与决策相关的计算，在该任务中从听觉表示过渡到运动表示。此外，我们证明了神经群体在听觉和运动期间是正交组织的，这意味着 SMA 执行不同的计算。总之，我们的结果表明，SMA 整合了声学信息，以形成驱动行为的分类信号。