Analog numerical representations in rhesus monkeys: Evidence for parallel processing
Analog numerical representations in rhesus monkeys: Evidence for parallel processing
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DOI：
10.1162/089892904970807
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发表时间：
2004-06-01
影响因子：
3.2
通讯作者：
Miller, EK
中科院分区：
文献类型：
--
作者：
Nieder, A;Miller, EK
猴子已被引入作为模型生物来研究数字能力的神经相关性，但数字判断的许多行为特征仍然是推测性的。因此，我们分析了两只恒河猴在延迟样本匹配任务中判断数字 1 到 7 的行为表现。无论刺激的具体物理外观如何，猴子都表现出相似的辨别能力，这证实了这种能力是基于数字信息的。随着数值的增加，表现平稳下降，并在数值“4”时达到辨别阈值。猴子的非语言数值表示基于模拟量值，对象跟踪过程（“subitizing”）无法解释这些发现，因为小数和大数的连续体显示出明显的韦伯分数特征。随着集合大小的增加，缺乏额外的扫描眼球运动，以及具有不同首选数量的神经元的神经元反应延迟难以区分，这都支持数字信息的并行编码。随着数量的增加，反应时间略有但显着的增加可以用任务难度和因此耗时的决策过程来解释。将行为结果与同一受试者前额皮质的单细胞记录进行比较。讨论了可能解释这些结果的数量歧视模型。
Monkeys have been introduced as model organisms to study neural correlates of numerical competence, but many of the behavioral characteristics of numerical judgments remain speculative. Thus, we analyzed the behavioral performance of two rhesus monkeys judging the numerosities 1 to 7 during a delayed match-to-sample task. The monkeys showed similar discrimination performance irrespective of the exact physical appearance of the stimuli, confirming that performance was based on numerical information. Performance declined smoothly with larger numerosities, and reached discrimination threshold at numerosity "4.'' The nonverbal numerical representations in monkeys were based on analog magnitudes, object tracking process ("subitizing'') could not account for the findings because the continuum of small and large numbers shows a clear Weber fraction signature. The lack of additional scanning eye movements with increasing set sizes, together with indistinguishable neuronal response latencies for neurons with different preferred numerosities, argues for parallel encoding of numerical information. The slight but significant increase in reaction time with increasing numerosities can be explained by task difficulty and consequently time-consuming decision processes. The behavioral results are compared to single-cell recordings from the prefrontal cortex in the same subjects. Models for numerosity discrimination that may account for these results are discussed.