ISSN 0439-755X
CN 11-1911/B

Acta Psychologica Sinica ›› 2017, Vol. 49 ›› Issue (5): 611-621.

### The processing of pure decimal numbers: Selective access or parallel access?

SUN Yueliang1,2; ZHENG Weiyi1; HE Xianyou1

1. (1 Center for Studies of Psychological Application, School of Psychology, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, China) (2 School of Education Science, Hanshan Normal University, Chaozhou, 521041, China)
• Received:2016-08-09 Published:2017-05-25 Online:2017-05-25
• Contact: HE Xianyou, E-mail: xianyouhe@163.com

Abstract:

The Spatial Numerical Association of Response Codes (SNARC) Effect and Spatial Shifts of Attention effect have demonstrated the connection between number processing and representation of space. However, previous studies on digital cognitive mechanisms have focused mainly on positive integers, whereas abstract numbers such as decimal numbers between 0 and 1 have drawn less attention. Varma & Karl (2013) first studied such pure decimal numbers, finding that there was a SNARC effect, as well as observing a semantic interference effect. Sashank proposed the parallel access hypothesis to explain the semantic interference effect. However, we argue that some defects existed in the methods used in the previous research, and the conclusion of processing and representation of pure decimal numbers still need further investigation. Whether the processing and representation of pure decimal numbers is also associated with space, and whether pure decimal numbers and natural numbers proximal to the displayed decimal point will be activated at the same time. Existing research has not yet provided an answer. Using the target detection task paradigm with number cues we conducted three experiments to test the processing of pure decimal numbers and its connection with space representation. The purpose of Experiment 1 was to explore whether pure decimal numbers as cues could result in the SNARC effect. The results showed that larger pure decimal numbers could cause the SNARC effect. Experiment 2 was to explore whether the pure decimal number characterization could activate the corresponding number at the same time. The results showed that the processing of pure decimal numbers with the same size and different natural number places (such as 0.2 and 0.20, 0.4 and 0.40) both could lead to the shift of spatial attention. Experiment 3 compared the processing intensity of pure decimal numbers and natural numbers after the decimal point. The results showed that the processing to the inconformity of judging the quantity size of pure decimal numbers and natural numbers after the decimal point failed to cause the effect of SNARC. The results showed participants used a parallel access pattern and caused the attention effect of SNARC when processing the decimal number in the target detection task paradigm. The pure decimal number and its natural number affected Spatial Shifts of Attention for the pure decimal number.