Attention, Perception, & Psychophysics

, Volume 80, Issue 6, pp 1504–1511 | Cite as

Are two spaces better than one? The effect of spacing following periods and commas during reading

  • Rebecca L. JohnsonEmail author
  • Becky Bui
  • Lindsay L. Schmitt


The most recent edition of the American Psychological Association (APA) Manual states that two spaces should follow the punctuation at the end of a sentence. This is in contrast to the one-space requirement from previous editions. However, to date, there has been no empirical support for either convention. In the current study, participants performed (1) a typing task to assess spacing usage and (2) an eye-tracking experiment to assess the effect that punctuation spacing has on reading performance. Although comprehension was not affected by punctuation spacing, the eye movement record suggested that initial processing of the text was facilitated when periods were followed by two spaces, supporting the change made to the APA Manual. Individuals’ typing usage also influenced these effects such that those who use two spaces following a period showed the greatest overall facilitation from reading with two spaces.


eye-tracking reading punctuation spacing 



The order of authorship for the second and third authors was determined by a coin-toss. We would like to thank Tom Allen, Angela Persico, and Alexa Banculli for their assistance in data collection and analysis and Denis Drieghe for his helpful comments on a previous version of this manuscript. This research was funded in part with a Summer Collaborative Research Grant at Skidmore College. This work was previously presented at the 83rd Annual Meeting of the Eastern Psychological Association in Pittsburgh, PA. Correspondence concerning the paper should be addressed to Dr. Rebecca Johnson, Department of Psychology, Skidmore College, Saratoga Springs, NY 12866, USA. (email:


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Copyright information

© The Psychonomic Society, Inc. 2018

Authors and Affiliations

  • Rebecca L. Johnson
    • 1
    Email author
  • Becky Bui
    • 1
  • Lindsay L. Schmitt
    • 1
  1. 1.Department of PsychologySkidmore CollegeSaratoga SpringsUSA

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