title: What's left? An eye movement study of the influence of interword spaces to the left of fixation during reading.
abstract: In English and other alphabetic systems read from left to right, the useful information acquired during each fixational pause is generally reported to extend 14-15 character spaces to the right of each fixation, but only 3-4 character spaces to the left, and certainly no farther than the beginning of the fixated word. However, this leftward extent is remarkably small and seems inconsistent with the general bilateral symmetry of vision. Accordingly, in the present study we investigated the influence of a fundamental component of text to the left of fixation-interword spaces-using a well-established eyetracking paradigm in which invisible boundaries were set up along individual sentence displays that were then read. Each boundary corresponded to the leftmost edge of a word in a sentence, so that as the eyes crossed a boundary, interword spaces in the text to the left of that word were obscured (by inserting a letter x). The proximity of the obscured text during each fixational pause was maintained at one, two, three, or four interword spaces from the left boundary of each fixated word. Normal fixations, regressions, and progressive saccades were disrupted when the obscured text was up to three interword spaces (an average of over 12 character spaces) away from the fixated word, while four interword spaces away produced no disruption. These findings suggest that influential information from text is acquired during each fixational pause from much farther leftward than is generally realized and that this information contributes to normal reading performance. Implications of these findings for reading are discussed.
authors: Faculty of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester, LE1 9HN, UK. prof.timjordan@gmail.com
authors: Timothy R
authors: TR
authors: Jordan
authors: Victoria A
authors: VA
authors: McGowan
authors: Kevin B
authors: KB
authors: Paterson
mesh_terms: D000293:Adolescent; D000328:Adult; D053483:Eye Movement Measurements; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011932:Reading; D012438:Saccades / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
references: Percept Psychophys. 1980 Jun;27(6):537-44
references: 7393701
references: J Exp Psychol Hum Percept Perform. 1990 May;16(2):268-81
references: 2142198
references: Psychol Aging. 2009 Sep;24(3):755-60
references: 19739933
references: Atten Percept Psychophys. 2012 Jan;74(1):5-35
references: 22042596
references: J Exp Psychol Hum Percept Perform. 1995 Jun;21(3):512-30
references: 7790831
references: Psychon Bull Rev. 2012 Dec;19(6):1108-13
references: 22791218
references: Percept Psychophys. 1982 Jun;31(6):537-50
references: 7122189
references: Psychol Sci. 2006 Mar;17(3):192-3
references: 16507057
references: Am J Optom Physiol Opt. 1980 Jun;57(6):378-87
references: 7406006
references: Q J Exp Psychol (Hove). 2009 Aug;62(8):1457-506
references: 19449261
references: Brain Lang. 1981 Sep;14(1):174-80
references: 7272722
references: Ophthalmology. 1996 Jan;103(1):181-2
references: 8628551
references: Cogn Neuropsychol. 2003 Jan 1;20(1):49-71
references: 20957564
references: J Exp Psychol Learn Mem Cogn. 2003 Sep;29(5):883-93
references: 14516221
references: Psychol Sci. 2009 Jun;20(6):721-8
references: 19470124
references: Neuropsychologia. 2009 Oct;47(12):2341-53
references: 18723038
references: J Exp Psychol Hum Percept Perform. 1999 Aug;25(4):1162-72
references: 10464948
references: Vision Res. 1998 Apr;38(8):1129-44
references: 9666972
references: Trends Cogn Sci. 2009 Mar;13(3):115-9
references: 19223223