Núcleo de Teoria e Pesquisa do Comportamento, Universidade Federal do Pará, Belém, Brazil.
Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Brazil.
PLoS One. 2024 May 29;19(5):e0303562. doi: 10.1371/journal.pone.0303562. eCollection 2024.
Classical experiments using hierarchical stimuli to investigate the ability of capuchin monkeys to integrate visual information based on global or local clues reported findings suggesting a behavioral preference for local information of the image. Many experiments using mosaics have been conducted with capuchin monkeys to identify some of their perceptual phenotypes. As the identification of an image in a mosaic demands the integration of elements that share some visual features, we evaluated the discrimination of shapes presented in solid and mosaic stimuli in capuchin monkeys. Shape discrimination performance was tested in 2 male adult capuchin monkeys in an experimental chamber with a touchscreen video monitor, in three experiments: (i) evaluation of global and local processing using hierarchical stimuli; (ii) evaluation of target detection using simple discrimination procedures; (iii) evaluation of shape discrimination using simple discrimination and delayed matching-to-sample procedures. We observed that both monkeys had preferences for local processing when tested by hierarchical stimuli. Additionally, detection performance for solid and mosaic targets was highly significant, but for shape discrimination tasks we found significant performance when using solid figures, non-significant performance when using circle and square shapes in mosaic stimuli, and significant performance when using Letter X and Number 8 shapes in mosaic stimuli. Our results are suggestive that the monkeys respond to local contrast and partly to global contrast in mosaic stimuli.
经典实验使用层次化刺激来研究卷尾猴整合视觉信息的能力，这些实验基于全局或局部线索，报告的结果表明，猴子在图像中存在对局部信息的行为偏好。许多使用镶嵌图的实验已经在卷尾猴身上进行，以确定它们的一些感知表型。由于在镶嵌图中识别图像需要整合共享某些视觉特征的元素，我们评估了卷尾猴在实心和镶嵌刺激中呈现的形状的辨别能力。在一个带有触摸屏视频监视器的实验室内，对 2 只成年雄性卷尾猴进行了形状辨别性能测试，共进行了 3 项实验：（i）使用层次化刺激评估全局和局部加工；（ii）使用简单辨别程序评估目标检测；（iii）使用简单辨别和延迟匹配样本程序评估形状辨别。我们观察到，当用层次化刺激进行测试时，两只猴子都更喜欢局部加工。此外，实心和镶嵌目标的检测性能非常显著，但对于形状辨别任务，我们发现使用实心图形时的性能显著，使用镶嵌刺激中的圆形和方形图形时的性能不显著，而使用镶嵌刺激中的字母 X 和数字 8 图形时的性能显著。我们的结果表明，猴子对镶嵌刺激中的局部对比和部分全局对比有反应。
