Cognitive And Neural Mechanism Of Duration And Numerosity Processing

The three dimensions of time,quantity and space are ubiquitous in our daily life.Life in the world processes all kinds of information every moment.Time,space and quantity are one of the important information.An influential theoretical framework is the “A Theory Of Magnitude”(ATOM)proposed by Walsh(Walsh,2003;Bueti & Walsh,2009).According to this theory,the specializations for number,time and space processing develop from a single magnitude system.Time,space and quantity are the components of the common magnitude system and share the cognitive and neural mechanism of the magnitude processing.Indeed,a number of studies support the existence of shared processing mechanisms between numerosity,time and space(Cai & Connell,2015;Hubbard,Piazza,Pinel,& Dehaene,2005;Schwiedrzik,Bernstein,& Melloni,2016;Srinivasan & Carey,2010).However,it is currently debated whether numerosity is a primary sensory property processed by dedicated neural mechanisms,or whether it is part of a unified magnitude system which processes all kinds of quantity information(Kadosh,Lammertyn,& Izard,2008;Leibovich,Katzin,Harel,& Henik,2016;Grondin,2010;De Hevia,Izard,Coubart,Spelke & Streri,2014).Previous studies on the neural mechanism of quantitative and temporal cognitive processing are numerous,and the results from neuroimaging and neuropsychology are inconsistent(Fabbri et al.,2012;Agrillo& Pifer,2012;Hayashi et al.,2013;Vicario et al.,2013).In order to further explore the cognitive and neurological mechanisms of time and quantity processing,this study explores whether there is a "common magnitude processing system" in the individual brain from both cognitive and neurological perspectives.We assume that if the number and time perception depend on the common neural network,then the quantity adaptation will affect the time discrimination,and the time adaptation will affect the quantity discrimination.The present study assumes that both time and quantity processing tasks will activate the IPS region,which is the central region of this common magnitude processing system.Firstly,in experiment 1,we used cross-dimensional visual adaptation to explore whether time perception or quantity perception would be affected by quantity adaptation.From the perspective of psychophysics,the cognitive processing mechanism of time and numerosity is verified by the interaction between them.The results show that different levels of time adaptation will affect quantitative discrimination,and different levels of time adaptation process will also affect temporal discrimination.Explain the cognitive processing mechanism of time-quantity cognitive sharing.Based on the behavioral results ofexperiment 1,Experiment 2 was carried out.From the perspective of neuroimaging,the cognitive processing tasks of time and quantity were carried out simultaneously in the same study by using fNIRS technology.The cortical basis of cognitive processing of time and quantity was revealed by analyzing the changes of concentration of oxyhemoglobin and deoxyhemoglobin in IPS region.In duration and quantity discrimination tasks,the reaction time and accuracy of the subjects reach statistical significance under two different conditions(experimental conditions and control conditions).The analysis of fNIRS data showed that the concentration of oxyhemoglobin in IPS cortex was significantly higher than that in control conditions under two task conditions,indicating that the subjects were under experimental conditions.The activation of IPS region is greater,and the high activation reflects the processing of stimulus materials under experimental conditions,which is more than that under controlled conditions.The results indicate that the IPS region of parietal cortex is related to the dimension processing,and the IPS region plays a key role in the formation of quantitative representation in each dimension,which further supports the quantitative theory(ATOM).This study consists of two experiments,each of which contains two sub-experiments,and draws the following conclusions:(1)There is a close relationship between the quantity and time.After adjusting to the amount and time,the subjects will affect the accuracy of the subsequent task of time-distance and quantity discrimination.After adjusting to different levels of quantity(high/low)or duration(long/short),they will overestimate or underestimate the time-distance or quantity judgment.The change of one dimension magnitude affects the perception of another dimension magnitude.Supports the magnitude theory(ATOM)and the time ? numerosity sharing the common cognitive mechanism.(2)IPS region is related to the processing of various dimensions.IPS region plays a key role in the formation of quantitative representation in each dimension,and shows right-sided advantage in the time and quantity processing.It further supports the theory of magnitude(ATOM),time and quantityt sharing the common cognitive processing mechanism.