Which digit is larger? Brain responses to number and size interactions in a numerical Stroop task

When comparing the digits of different physical sizes, the processing of numerical value interacts with the processing of physical size. Given the universal use of Arabic numbers in mathematics and daily life, this study aims to elucidate the cognitive processes involved in the interactions of task-relevant and task-irrelevant features during information processing. We investigated this question by examining event-related potential (ERP) using a modified version of the size congruity comparison, which is a Stroop-like task. Numerical value and physical size were varied independently under task-relevant and task-irrelevant conditions. To better examine how the task-irrelevant features modulated the processing of the task-relevant attributes, a neutral condition was included in both tasks. For the physical task, congruent trials showed a less negative N200 response than neutral trials (indicating a facilitation effect), and incongruent trials elicited a larger N450 and smaller late positive complex (LPC) response than neutral trials (indicating an interference effect). For the numerical task, congruent trials showed a larger LPC response than neutral trials (indicating a facilitation effect). These ERP findings indicate that the sources of the facilitation and interference effects appear in different cognitive processes for each task. We further suggest that language characteristics may be a factor in the superior numerical processing exhibited in this study

Implicit target substitution and sequencing for lexical tone production in Chinese: an FMRI study.

In this study, we examine the neural substrates underlying Tone 3 sandhi and tone sequencing in Mandarin Chinese using fMRI. Tone 3 sandhi is traditionally described as the substitution of Tone 3 with Tone 2 when followed by another Tone 3 (i.e., 33→23). According to current speech production models, target substitution is expected to engage the posterior inferior frontal gyrus. Since Tone 3 sandhi is, to some extent, independent of segments, which makes it more similar to singing, right-lateralized activation in this region was predicted. As for tone sequencing, based on studies in sequencing, we expected the involvement of the supplementary motor area. In the experiments, participants were asked to produce twelve four-syllable sequences with the same tone assignment (the repeated sequences) or a different tone assignment (the mixed sequences). We found right-lateralized posterior inferior frontal gyrus activation for the sequence 3333 (Tone 3 sandhi) and left-lateralized activation in the supplementary motor area for the mixed sequences (tone sequencing). We proposed that tones and segments could be processed in parallel in the left and right hemispheres, but their integration, or the product of their integration, is hosted in the left hemisphere

Relative size of numerical magnitude induces a size-contrast effect on the grip scaling of reach-to-grasp movements

Previous research found that quantitative information labelled on target objects of grasping movement modulates grip apertures. While the interaction between numerical cognition and sensorimotor control may reflect a general representation of magnitude underpinned by the parietal cortex, the nature of this embodied cognitive processing remains unclear. In the present study, we examined whether the numerical effects on grip aperture can be flexibly modulated by the relative magnitude between numbers under a context, which suggests a trial-by-trial comparison mechanism to underlie this effect. The participants performed visual open-loop grasping towards one of two adjacent objects that were of the same physical size but labelled with different Arabic digits. Analysis of participants' grip apertures revealed a numerical size-contrast effect, in which the same numerical label (i.e., 5) led to larger grip apertures when it was accompa nied by a smaller number (i.e., 2) than by a larger number (i.e., 8). The corrected grip aperture over the time course of movement showed that the numerical size-contrast effect remained significant throughout the grasping movement, despite a trend of gradual dissipation. Our findings demonstrated that interactions between number and action critically depend on the size-contrast of magnitude information in the context. Such a size-contrast effect might result from a general system, which is sensitive to relative magnitude, for different quantity domains. Alternatively, the magnitude representations of numbers and action might be processed separately and interact at a later stage of motor programming.9 page(s

Static and dynamic functional connectivity supports the configuration of brain networks associated with creative cognition

Abstract Creative cognition is recognized to involve the integration of multiple spontaneous cognitive processes and is manifested as complex networks within and between the distributed brain regions. We propose that the processing of creative cognition involves the static and dynamic re-configuration of brain networks associated with complex cognitive processes. We applied the sliding-window approach followed by a community detection algorithm and novel measures of network flexibility on the blood-oxygen level dependent (BOLD) signal of 8 major functional brain networks to reveal static and dynamic alterations in the network reconfiguration during creative cognition using functional magnetic resonance imaging (fMRI). Our results demonstrate the temporal connectivity of the dynamic large-scale creative networks between default mode network (DMN), salience network, and cerebellar network during creative cognition, and advance our understanding of the network neuroscience of creative cognition

Neural correlates of merging number words

International audienceComplex number words (e.g., "twenty two") are formed by merging together several simple number words (e.g., "twenty" and "two"). In the present study, we explored the neural correlates of this operation and investigated to what extent it engages brain areas involved processing numerical quantity and linguistic syntactic structure. Participants speaking two typologically distinct languages, French and Chinese, were required to read aloud sequences of simple number words while their cerebral activity was recorded by functional magnetic resonance imaging. Each number word could either be merged with the previous ones (e.g., 'twenty three') or not (e.g., 'three twenty'), thus forming four levels ranging from lists of number words to complex numerals. When a number word could be merged with the preceding ones, it was named faster than when it could not. Neuroimaging results showed that the number of merges correlated with activation in the left inferior frontal gyrus and in the left inferior parietal lobule. Consistent findings across Chinese and French participants suggest that these regions serve as the neural bases for forming complex number words in different languages

Mixed sequence effect.

<p>Note: Thresholded at p<.001 (FDR corrected at cluster level, p<.05). BA = Brodman Area; <i>x</i>/<i>y</i>/<i>z</i> = Talairach-coordinates <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0083126#pone.0083126-Talairach1" target="_blank">[81]</a>.</p

LI in regions showing significant Tone 3 sandhi effect.

<p>Error bars represent 1 standard error of mean (SEM) across Participants after subtraction of each participant's individual mean. Bars in grey and star symbols indicate LI significantly different from zero.</p