Neuromodulation with focused ultrasound (FUS) is being widely explored as a non-invasive tool to stimulate focal brain regions because of its superior spatial resolution and coverage compared with other neuromodulation methods. The precise effects of FUS stimulation on specific regions of the brain are not yet fully understood. Here, we characterized the behavioral effects of FUS stimulation directly applied through a craniotomy over the macaque frontal eye field (FEF). In macaque monkeys making directed eye movements to perform visual search tasks with direct or arbitrary responses, focused ultrasound was applied through a craniotomy over the FEF. Saccade response times (RTs) and error rates were determined for trials without or with FUS stimulation with pulses at a peak negative pressure of either 250 or 425 kPa. Both RTs and error rates were affected by FUS. Responses toward a target located contralateral to the FUS stimulation were approximately 3 ms slower in the presence of FUS in both monkeys studied, while only one exhibited a slowing of responses for ipsilateral targets. Error rates were lower in one monkey in this study. In another search task requiring making eye movements toward a target (pro-saccades) or in the opposite direction (anti-saccades), the RT for pro-saccades increased in the presence of FUS stimulation. Our results indicate the effectiveness of FUS to modulate saccadic responses when stimulating FEF in awake, behaving non-human primates.

与其他神经调节方法相比，聚焦超声 (FUS) 的神经调节作为一种非侵入性工具来刺激焦点大脑区域，正被广泛探索，因为它具有优越的空间分辨率和覆盖范围。FUS 刺激对大脑特定区域的确切影响尚未完全了解。在这里，我们描述了通过开颅手术直接应用于猕猴额眼场 (FEF) 的 FUS 刺激的行为影响。在猕猴进行定向眼球运动以执行具有直接或任意反应的视觉搜索任务时，通过 FEF 上的开颅术应用聚焦超声。对于没有或有 FUS 刺激的试验，在峰值负压为 250 或 425 kPa 的脉冲下确定了跳视反应时间 (RT) 和错误率。RT 和错误率都受到 FUS 的影响。在所研究的两只猴子中，在 FUS 存在的情况下，对位于 FUS 刺激对侧的目标的反应慢约 3 毫秒，而只有一只猴子对同侧目标的反应减慢。在这项研究中，一只猴子的错误率较低。在另一个需要使眼睛朝向目标（亲眼跳）或相反方向（反眼跳）移动的搜索任务中，在 FUS 刺激下，亲眼跳的 RT 增加。我们的结果表明 FUS 在刺激清醒的非人类灵长类动物的 FEF 时调节扫视反应的有效性。而只有一个表现出对同侧目标的反应减慢。在这项研究中，一只猴子的错误率较低。在另一个需要使眼睛朝向目标（亲眼跳）或相反方向（反眼跳）移动的搜索任务中，在 FUS 刺激下，亲眼跳的 RT 增加。我们的结果表明 FUS 在刺激清醒的非人类灵长类动物的 FEF 时调节扫视反应的有效性。而只有一个表现出对同侧目标的反应减慢。在这项研究中，一只猴子的错误率较低。在另一个需要使眼睛朝向目标（亲眼跳）或相反方向（反眼跳）运动的搜索任务中，在 FUS 刺激下，亲眼跳的 RT 增加。我们的结果表明 FUS 在刺激清醒的非人类灵长类动物的 FEF 时调节扫视反应的有效性。