Abstract:
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.
摘要:
经典实验使用分层刺激来研究卷尾猴根据全局或局部线索报告的发现整合视觉信息的能力,这些发现表明对图像局部信息的行为偏好。已经对卷尾猴进行了许多使用马赛克的实验,以鉴定它们的一些感知表型。由于在马赛克中识别图像需要整合共享一些视觉特征的元素,我们评估了卷尾猴在固体和马赛克刺激中呈现的形状的辨别。在带有触摸屏视频监视器的实验室内测试了2只雄性成年卷尾猴的形状辨别性能,在三个实验中:(i)使用分层刺激评估全局和局部处理;(ii)使用简单的判别程序评估目标检测;(iii)使用简单的判别和延迟的样本匹配程序评估形状判别。我们观察到,当通过分层刺激进行测试时,两只猴子都对局部处理有偏好。此外,对固体和镶嵌目标的检测性能非常显著,但是对于形状区分任务,我们在使用可靠的数字时发现了显著的性能,在马赛克刺激中使用圆形和方形时,性能不显著,在马赛克刺激中使用字母X和数字8形状时,性能显著。我们的结果表明,猴子对马赛克刺激中的局部对比度和部分整体对比度有反应。