Lynn Catherine, Curran William
School of Psychology, Queen's University Belfast, Belfast BT71NN, UK.
Vision Res. 2010 Oct 12;50(21):2137-41. doi: 10.1016/j.visres.2010.08.007. Epub 2010 Aug 10.
Single-cell recording studies have provided vision scientists with a detailed understanding of motion processing at the neuronal level in non-human primates. However, despite the development of brain imaging techniques, it is not known to what extent the response characteristics of motion-sensitive neurons in monkey brain mirror those of human motion-sensitive neurons. Using a motion adaptation paradigm, the direction aftereffect, we recently provided evidence of a strong resemblance in the response functions of motion-sensitive neurons in monkey and human to moving dot patterns differing in dot density. Here we describe a series of experiments in which measurements of the direction aftereffect are used to infer the response characteristics of human motion-sensitive neurons when viewing transparent motion and moving patterns that differ in their signal-to-noise ratio (motion coherence). In the case of transparent motion stimuli, our data suggest suppressed activity of motion-sensitive neurons similar to that reported for macaque monkey. In the case of motion coherence, our results are indicative of a linear relationship between signal intensity (coherence) and neural activity; a pattern of activity which also bears a striking similarity to macaque neural activity. These findings strongly suggest that monkey and human motion-sensitive neurons exhibit similar response and inhibitory characteristics.
单细胞记录研究为视觉科学家提供了对非人类灵长类动物神经元水平运动处理的详细理解。然而，尽管脑成像技术有所发展，但尚不清楚猴脑运动敏感神经元的反应特性在多大程度上反映人类运动敏感神经元的反应特性。我们最近使用运动适应范式——方向后效，提供了证据表明，猴和人类运动敏感神经元对不同点密度的移动点模式的反应功能有很强的相似性。在此，我们描述了一系列实验，其中方向后效的测量用于推断人类运动敏感神经元在观察透明运动和具有不同信噪比（运动连贯性）的移动模式时的反应特性。对于透明运动刺激，我们的数据表明运动敏感神经元的活动受到抑制，这与猕猴的情况类似。对于运动连贯性，我们的结果表明信号强度（连贯性）与神经活动之间存在线性关系；这种活动模式也与猕猴神经活动有显著相似性。这些发现有力地表明，猴和人类运动敏感神经元表现出相似的反应和抑制特性。
