Representation And Neural Mechanisms Of Three-digit Decimals And Integers Under Different Presentation Orientations

In studies on the representation of two-digit integers,researchers have proposed three models of representation:the holistic model,the decomposed model,and the hybrid model.The holistic model uses the holistic distance effect as an indicator and considers that numbers are represented on the mental number line in terms of overall number size.The decomposed model considers the representation of number size to follow a place-value system,indexed by the unit-decade compatibility effect,indicating the contribution of the number size at each position to the representation of quantity.The hybrid model includes both holistic and decomposed processing,which brings together indicators from both holistic and decomposed models,with both holistic distance and compatibility being significant predictors in the multiple liner model.In addition to the debate about the integers representation model,the similarities and differences between the decimals and integers representation mechanisms are also controversial.Some researchers have proposed the "natural number conversion hypothesis",suggesting that decimals use the same representation mechanism as integers,while others have pointed out that decimals have a unique direct retrieval representation mechanism to demonstrate the difference between decimals and integers representation models.In addition,it was found that there is a stable unit-decade compatibility effect for two-digit integers under different presentation orientation conditions.However,different results were found in the study of decimals:the study found that the representation of pure decimals was different from that of integers when presented horizontally,and the study found no difference between the representation of decimals and integers when presented vertically.This suggests that presentation orientation may have an effect on the representation of decimals.This study investigated the similarities and differences in the representations and neural mechanisms of three-digit decimals and three-digit integers,and the effects of different presentation orientations on their representation mechanisms.The study consists of two experiments.Experiment 1 explores the representational processing and neural mechanisms of three-digit decimals under different presentation orientations.Experiment 2 explores the representational processing and neural mechanisms of three-digit integers under different presentation orientations.Each experiment consisted of three parts,namely horizontal presentation,vertical presentation and diagonal presentation.Finally,a comparative analysis of the representational mechanisms of three-digit decimals and three-digit integers was performed.The experimental program was prepared using E-prime 2.0,and the EEG signal acquisition system from Brain products,Munich,Germany,was used for EEG signal acquisition during the experiments.The experimental results were as follows:(1)The three-digit decimals’representation was consistent with the hybrid representation model,and the P2 and N1 components of the frontal lobe were evoked by the horizontal and diagonal presented decomposed representations,respectively.(2)The three-digit integers’ representation was consistent with the hybrid representation model,and the decomposed representations evoked the P2 component in the frontal and parietal lobes when presented vertically and diagonally,respectively.(3)The similarity between the representational mechanisms of three-digit decimals and three-digit integers is that both are hybrid model,but the difference is that the decomposed representation facilitates the processing speed advantage of three-digit decimals,and the decomposed representation of three-digit decimals induces the N1 and P2 components of the frontal lobe,while the decomposed representation of three-digit integers induces the P2 components of the frontal and parietal lobe.(4)The effects of different presentation orientations on the decomposed representations of three-digit decimals and three-digit integers differed.The decomposed representation of three-digit decimals is influenced by vertical presentation,and the decomposed representation of three-digit integers is influenced by horizontal presentation.There is no significant effect of diagonal presentation on the decomposed representation of both three-digit decimals and three-digit integers.(5)Serial processing exists for both three-digit decimals and three-digit integers’representations,and the degree of serial processing is higher for three-digit decimals.The vertical presentation further facilitates the serial processing of both three-digit decimals and three-digit integers.The results show that the representations of both three-digit decimals and three-digit integers are hybrid representations,and they remain consistent under different presentation orientations.However,there are behavioral and neural differences in the components of the decomposed representations,and they are affected by the presentation orientation to different degrees.