Leo M. Davidoff Department of Neurological Surgery, Albert Einstein College of Medicine, Bronx, New York 10461.
Section on Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892.
J Neurosci. 2022 Dec 7;42(49):9242-9252. doi: 10.1523/JNEUROSCI.0925-22.2022. Epub 2022 Nov 1.
The neural bases of attention, a set of neural processes that promote behavioral selection, is a subject of intense investigation. In humans, rewarded cues influence attention, even when those cues are irrelevant to the current task. Because the amygdala plays a role in reward processing, and the activity of amygdala neurons has been linked to spatial attention, we reasoned that the amygdala may be essential for attending to rewarded images. To test this possibility, we used an attentional capture task, which provides a quantitative measure of attentional bias. Specifically, we compared reaction times (RTs) of adult male rhesus monkeys with bilateral amygdala lesions and unoperated controls as they made a saccade away from a high- or low-value rewarded image to a peripheral target. We predicted that: (1) RTs will be longer for high- compared with low-value images, revealing attentional capture by rewarded stimuli; and (2) relative to controls, monkeys with amygdala lesions would exhibit shorter RT for high-value images. For comparison, we assessed the same groups of monkeys for attentional capture by images of predators and conspecifics, categories thought to have innate biological value. In performing the attentional capture task, all monkeys were slowed more by high-value relative to low-value rewarded images. Contrary to our prediction, amygdala lesions failed to disrupt this effect. When presented with images of predators and conspecifics, however, monkeys with amygdala lesions showed significantly diminished attentional capture relative to controls. Thus, separate neural pathways are responsible for allocating attention to stimuli with learned versus innate value. Valuable objects attract attention. The amygdala is known to contribute to reward processing and the encoding of object reward value. We therefore examined whether the amygdala is necessary for allocating attention to rewarded objects. For comparison, we assessed the amygdala's contribution to attending to objects with innate biological value: predators and conspecifics. We found that the macaque amygdala is necessary for directing attention to images with innate biological value, but not for directing attention to recently learned reward-predictive images. These findings indicate that the amygdala makes selective contributions to attending to valuable objects. The data are relevant to mental health disorders, such as social anxiety disorders and small animal phobias, that arise from biased attention to select categories of objects.
注意力的神经基础是一组促进行为选择的神经过程，是一个研究热点。在人类中，奖励线索会影响注意力，即使这些线索与当前任务无关。由于杏仁核在奖励处理中起作用，并且杏仁核神经元的活动与空间注意力有关，我们推断杏仁核可能对注意奖励图像至关重要。为了验证这一可能性，我们使用了一种注意力捕获任务，该任务提供了注意力偏向的定量测量。具体来说，我们比较了双侧杏仁核损伤的成年雄性恒河猴与未手术对照组在从高值或低值奖励图像向周边目标进行扫视时的反应时间 (RT)。我们预测：(1) 与低值图像相比，高值图像的 RT 会更长，这表明奖励刺激会引起注意力捕获；(2) 与对照组相比，杏仁核损伤的猴子对高值图像的 RT 会更短。为了比较，我们评估了相同组的猴子对捕食者和同类图像的注意力捕获，这些类别被认为具有先天的生物价值。在执行注意力捕获任务时，所有猴子对高值相对低值奖励图像的反应时间都变慢了。与我们的预测相反，杏仁核损伤并未能破坏这种效应。然而，当呈现捕食者和同类图像时，杏仁核损伤的猴子对注意力的捕获明显低于对照组。因此，分配注意力到具有学习和先天价值的刺激的独立神经途径。有价值的物体吸引注意力。杏仁核已知对奖励处理和物体奖励价值的编码有贡献。因此，我们研究了杏仁核是否有必要将注意力分配到奖励物体上。为了比较，我们评估了杏仁核对具有先天生物价值的物体注意力的贡献：捕食者和同类。我们发现，猕猴杏仁核对于引导注意力到具有先天生物价值的图像是必要的，但对于引导注意力到最近学习的奖励预测图像则不是。这些发现表明，杏仁核对注意有价值的物体做出了选择性的贡献。这些数据与心理健康障碍有关，例如社交焦虑障碍和小动物恐惧症，这些障碍源于对特定类别的物体的偏见注意力。
