The Impact Of Luminance On The Numerical Spatial Representation

Digital plays a very important role in people's daily lives.Since Dehaene found SNARC effect in 1993,digital processing has become a hot research in the field of cognitive psychology in recent years.About the universality of the SNARC effect has been confirmed by many studies,brightness as a continuous stimuli also exits SNARC-like effect.Since brightness and digital are to characterize by the way of spatial encoding,so the brightness and digital exist at the same time will influence each other? Studies have shown that the physical properties of a number(physical size,number of digits)will have an impact on the numerical spatial representation.Brightness as the other physical properties of numbers,will also affect the numerical spatial representation? Recalling the previous studies of brightness and digital,when the digital contain different brightness level and value information would have mutual influence between them.However,consistency effect was the examining index in previous studies,mainly discussed the consistency of the relationship between brightness and digital,and did not come to the same conclusion.After studies have pointed out the luminance contrast(between number and background)and numerical values influenced each other.Summarizing previous studies,we found that did not involve explore the influence of luminance on numerical spatial representation.In addition,previous studies asked subjects to complete brightness and numerical comparison task,it needs to be processed directly and intentionally,and more likely to result in interference between various magnitude of two dimensions.In view of the above problem,this study on the basis of previous studies,and the SNARC effect as examining index.By controlling the digital stimuli and the brightness of the background to set the different levels of luminance contrast,and improved the experimental paradigm,subjects were asked to complete a classic parityjudgment task,which to reduce the interaction between different dimensions.The present study aimed to explore whether the luminance could affect the numerical spatial representation and its mechanisms.The stimuli consisted of Arabic digits from1 to 9(except for 5),which were printed in white and were presented on the black background(the luminance value was 0)in three experiments.So the luminance value of numbers was the luminance contrast of numbers and background.In Experiment 1,the digits were printed in the highest luminance value(255)of the HSL color pattern in the Microsoft Office Word 2007.That is required subjects in the normal brightness of visual to complete classic parity judgment task.In line with previous studies,a typical SNARC effect was found in this study.Left-hand responses were faster for the small relative to large numbers,whereas the right-hand responses were faster for the large relative to small numbers.These results suggested the SNARC effect was automatic processing when the luminance contrast was large.Experiment 2 set two higher luminance values of the numbers(255 vs.213).Results demonstrated that the SNARC effect was found for both luminance conditions.Indicating that numerical spatial representation was still automatically activated.In Experiment 3,in order to further reduced the level of luminance contrast,we increased luminance contrast value of 42,and continue to follow the previous 213 in the experiment 2.The results indicated the SNARC effect disappeared,even if the luminance value was the same as experiment 2(213).When the luminance was very low,more attention and cognitive resources might be used to distinguish digits.Thus,when luminance contrast is very low,we speculated that the numerical spatial representation was suffered interference and inhibition.According to these results,this study drew the following conclusion: Brightness could promote or inhibit the impact on numerical spatial representation,which was associated with the size for value of luminance contrast specificily.When the luminance contrast was high,the SNARC effect was observed,which indicated that high luminance contrast was connected with automatically activate of numerical spatial representation.When the luminance contrast was low,there was no SNARC effect,which indicated that very low luminance contrast will interfere with the numerical spatial representation.