Department of Psychology, Paris-Lodron University Salzburg, Hellbrunnerstrasse 34, A-5020, Salzburg, Austria.
Centre for Cognitive Neuroscience, Paris-Lodron University Salzburg, Hellbrunnerstr 34, A-5020, Salzburg, Austria.
Biol Sex Differ. 2018 Jan 8;9(1):3. doi: 10.1186/s13293-017-0162-6.
Global-local stimuli are hierarchical structures consisting of a larger global structure which is composed of smaller local stimuli. Numbers are also constructed hierarchically, with multi-digit numbers being made up from single digits. During two-digit number comparison, compatible items (larger number contains larger unit digit, e.g., 53 vs. 68) are processed faster and more accurately than incompatible items (smaller number contains larger unit digit, e.g., 58 vs. 63). This so-called unit-decade-compatibility effect has challenged the holistic model of number processing and suggests that the processing of number magnitudes occurs at least in part, decomposed, i.e., separately for each digit. Thus, the compatibility effect is indicative of how decomposed numbers are processed, thereby sharing similarities with traditional global-local processing of hierarchical stimuli. The goal of this study was to investigate whether factors that have been shown to reliably influence global-local processing also affect the compatibility effect during number comparison. Those include visual hemifield, sex, and menstrual cycle phase in women.
One hundred sixty participants, 77 naturally cycling women and 83 men, completed a two-digit number comparison task twice, with test-sessions time-locked to the early follicular or mid-luteal cycle phase in women. Number comparison stimuli were presented to the right or left hemifield, respectively.
We observed a stronger compatibility effect in the right visual hemifield compared to left visual hemifield and in women compared to men, but no evidence for an influence of menstrual cycle phase in women could be found.
Hemispheric asymmetries in holistic versus decomposed number processing could be demonstrated for the first time, suggesting a similar hemispheric modulation for number magnitude processing as for global-local processing.
全局-局部刺激是一种层次结构，由较大的全局结构组成，全局结构由较小的局部刺激组成。数字也是按层次结构构建的，多位数字由单个数字组成。在两位数比较中，相容项目（较大的数包含较大的单位数字，例如 53 与 68）的处理速度比不相容项目（较小的数包含较大的单位数字，例如 58 与 63）更快、更准确。这种所谓的单位-十位数兼容性效应挑战了数字处理的整体模型，表明数字大小的处理至少部分是分解的，即分别针对每个数字。因此，兼容性效应表明分解后的数字是如何被处理的，从而与传统的层次刺激的全局-局部处理具有相似性。本研究的目的是调查那些已被证明能可靠影响全局-局部处理的因素是否也会影响数字比较过程中的兼容性效应。这些因素包括视觉半视野、性别和女性的月经周期阶段。
160 名参与者，77 名自然循环的女性和 83 名男性，两次完成两位数比较任务，测试阶段时间锁定在女性的卵泡早期或黄体中期。数字比较刺激分别呈现给右或左半视野。
与左半视野相比，我们在右半视野中观察到更强的兼容性效应，在女性中观察到比男性更强的兼容性效应，但在女性中没有发现月经周期阶段的影响证据。
首次证明了整体与分解数字处理的半球不对称性，这表明对数字大小处理的半球调制类似于全局-局部处理。
