NTT Communication Science Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, Japan.
Sci Rep. 2022 Sep 17;12(1):15632. doi: 10.1038/s41598-022-19941-8.
The ability to judge numerosity is essential to an animal's survival. Nevertheless, the number of signals presented in a sequence is often underestimated. We attempted to elucidate the mechanism for the underestimation by means of computational modeling based on population coding. In the model, the population of neurons which were selective to the logarithmic number of signals responded to sequential signals and the population activity was integrated by a temporal window. The total number of signals was decoded by a weighted average of the integrated activity. The model predicted well the general trends in the human data while the prediction was not fully sufficient for the novel aging effect wherein underestimation was significantly greater for the elderly than for the young in specific stimulus conditions. Barring the aging effect, we can conclude that humans judge the number of signals in sequence by temporally integrating the neural representations of numerosity.
判断数量的能力对动物的生存至关重要。然而，动物在序列中呈现的信号数量往往被低估。我们试图通过基于群体编码的计算建模来阐明这种低估的机制。在该模型中，对信号对数有选择性的神经元群体对序列信号做出反应，群体活动由时间窗口进行整合。通过整合活动的加权平均值来解码信号的总数。该模型很好地预测了人类数据的总体趋势，而对于新颖的老化效应，该预测并不完全充分，即在特定刺激条件下，老年人的低估程度明显大于年轻人。除了老化效应，我们可以得出结论，人类通过时间整合数量的神经表示来判断序列中的信号数量。
