The Cognitive And Neural Mechanism Of The Attentional SNARC Effect

The Attention Spatial-Numerical Association of Response Codes Effect refers to that when individuals process shallow perception of Numbers,they could also automatically activate the corresponding spatial representation.When the decimal number was used as a clue,the subjects responded more quickly to the left target.When large Numbers were used as cues,subjects responded more quickly to the target on the right.In recent years,more and more researchers have been paid attention to Att-SNARC effect(Attentional SNARC).The main difference focus on Att-SNARC effect was that a spatial representation of digital automatic activation,whether influenced by bottom-up or top-down cognitive processing.In order to further to explore the cognitive mechanism of note Att-SNARC effect,the present study adopted the high temporal resolution of event related potential technology,at the same time improving the Fischer,Castel,Dodd,Pratt(2003)and Shen,Tian,Ding(2006)clues-target detection model.Therefore,to study space code is part of the digital representation,and explore to shallow cognition processing on digital pay attention to the time process and brain mechanisms Att-SNARC effect,to pay attention to the Att-SNARC effect of cognitive processing mechanism to provide empirical basis.On the basis of the experiment of Fischer et al.(2003),the first experiment of this study added the median condition,and adopted the internal design of 3(number size: decimal 1~3,median 4~6,and large number 7~9)×2(target position: left,middle,and right).Twenty-two randomly invited subjects completed the experimental task.When the Arabic numerals 1~9 were presented in the center of the screen as cues unrelated to the task.Then,a target stimulus was presented to the left,center or right of the screen and the subject needs to respond to the target stimulus with the dominant hand as soon as possible.The results of this study showed that the subjects were affected by the inhibition of return.And the response to the stimulus in the middle position was the slowest.There was no significant of Att-SNARC effect.Experiment 2 improved the study of Shen et al.(2006),using 3(number size:decimal,medium,large number)x 2(target position: left,right)in the subject design.The experimental program presents 1,2,5,8 and 9 in the center of the screen.Then,a target stimulus was randomly presented on the left or right side of the screen.The 21 subjects were asked to press the space bar as soon as possible after seeing the target stimulus,and were told that the number was not related to with the task.The behavioral results of the study showed that the subjects responded to the decimal rate relatively more quickly.And there is not existed of Att-SNARC effect.The results of ERP show that,when the lock was stimulated by cues.(1)the components P1,N1 and P2 in the top and the occipital all have a major effect,in which the amplitude of small number was more negative than that of large number,and the amplitude of medium number was more and more positive with the passage of time.(2)for the P2 component of the forehead,the amplitude of large numbers is the largest,and the amplitude of small numbers is the smallest,and the amplitude of the three Numbers was significantly different in twos;(3)in the P3 component of the forehead,the amplitude of the middle number was significantly larger than that of the decimal number,and the amplitude of the decimal number was significantly larger than that of the large number.At the same time,no significant EDAN and ADAN components were found,indicating that the number size does not have spatial representation.When the target was stimulated,(1)on the parietal,parietal-occipital and frontal components of P1,N1 and P3,the wave peak of the target stimulus on the right hemisphere was larger under the left condition;On the contrary,the peak of the target stimulus in the left hemisphere was larger under the condition of the right side.(2)in the N1 component at the parietal,the wave peak induced by the target stimulus on the right side is larger under the condition of median and large number;(3)in the parietal and parietal-occipital regions,N1 wave peak is larger when the target stimulus appears on the right side,and N1 wave peak is larger in the left hemisphere on the parietal;(4)on P3 at the parietal and frontal regions,the target stimulus presented greater amplitude induced on the left side,especially on the right hemisphere at the parietal.Conclusion: the evidence from electrophysiology indicates that spatial codes are not part of digital representation,so numbers will not automatically cause the distribution of spatial attention,which negates the bottom-up view of automatic processing and provides experimental basis for the demonstration of the instability of Att-SNARC effect.