Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy.
Neuropsychologia. 2012 Apr;50(5):754-61. doi: 10.1016/j.neuropsychologia.2012.01.009. Epub 2012 Jan 16.
Visual enumeration of small numerosities critically depends on the capacity of our visual system to process multiple objects as distinct entities. We assessed the functioning of this mechanism-individuation-during computation of quantities in cluttered scenes by using ERP measures. Participants saw a variable number of targets (1, 3, 5, 7) presented among distracters, and reported their quantities. Results showed that the N2pc amplitude was modulated by target numerosity and reached a plateau at five elements, in line with the supposed limit of the individuation mechanism. In addition, the N2pc asymptote varied depending on participants' enumeration efficiency, being smaller in participants with poor enumeration performance. The results indicate that computation of small quantities is based on multiple object individuation and suggest that individual neural differences during simultaneous individuation are strongly associated with enumeration performance.
视觉枚举小数量数严重依赖于我们的视觉系统将多个物体作为不同实体进行处理的能力。我们通过使用 ERP 测量来评估这种机制——即辨别——在杂乱场景中计算数量时的功能。参与者在分心物中看到了可变数量的目标（1、3、5、7），并报告了他们的数量。结果表明，N2pc 振幅受目标数量的调制，并在五个元素处达到平台，与辨别机制的假设限制一致。此外，N2pc 渐近线取决于参与者的计数效率，在计数表现差的参与者中较小。结果表明，小数量的计算基于多个物体的辨别，并且表明同时辨别过程中的个体神经差异与计数性能密切相关。
