The Effect Of Verbal Task Instruction On SNARC Effect Coding Of Spatial-Number Association

In people’s daily life,numbers play an important role.Spatial-numerical associations is a hot topic in the research of numerical cognition.Previous studies have shown that there is a close relationship between numerical processing and spatial cognition.Among the important phenomena of spatial-numerical association,Spatial-Numerical Association of Response Code(SNARC)effect is a unique and important phenomenon,which means that in the number size or parity judgment task,the subjects will show that the left-hand key response is faster than the right-hand key response for smaller numbers,while the right-hand key response is faster than the left-hand key response for larger numbers.SNARC effect shows that people can represent numbers in space.Previous studies have shown that visuospatial and verbal-spatial are the main encoding mechanisms of SNARC effect of spatial-numerical associations,and this encoding is affected by task instruction.However,previous studies have focused on the influence of visuospatial task instruction on SNARC effect coding,while less on the influence of verbal task instruction.This study used ERP technology,materials for Arabic numerals 1-9(excluding 5)and word labels(left and right).Experiment 1 used the number parity judgment task,through the system to change SOAs,to explore the influence of verbal task instructions on the spatial-numerical associations coding.Behavioral results show that the SNARC effect is dominated by verbal-spatial coding,and there is no significant SNARC effect when SOA is 200 ms,800ms and 1200ms;there is a significant standard SNARC effect when SOA is 0ms,and a significant reversal SNARC effect when SOA is 0ms;ERP results show that there is no dominant coding mode in N1 and P3 components.In Experiment 2,SOA0 ms which can produce significant SNARC effect was selected as the time interval based on Experiment 1,and the number size judgment task was used to further explore the encoding mode and encoding stage of SNARC effect.Behavioral results showed that the SNARC effect was mainly verbal-spatial coding,with significant standard SNARC effect in the condition of word consistency and significant reversal SNARC effect in the condition of word inconsistency;ERP results showed that significant verbal-spatial coding was found in the early forward deflection of LRP in the stimulus of lock time,and significant verbal-spatial coding was found in the latency of LRP in the response of lock time.The results show that verbal task instruction affects the encoding of SNARC effect of spatial-numerical associations,and the encoding of SNARC effect is affected by the processing degree of word information label.Moreover,the encoding of SNARC effect occurs in the early perceptual stage,which is characterized by the extension of reaction related stage.The change of time interval between word labels and numbers will affect the generation of SNARC effect.The characteristics of target numbers and reading habits have an important impact on SNARC effect.