Abstract
There is growing interest in how perceptual factors such as the spacing between letters within words modulate performance in visual word recognition and reading aloud. Extra-large letter spacing can strongly improve the reading performance of dyslexic children, and a small increase with respect to the standard spacing seems beneficial even for skilled word recognition in adult readers. In the present study we examined the effect of decreased letter spacing on perceptual identification and lexical decision tasks. Identification in the decreased spacing condition was slower than identification of normally spaced strings, thereby confirming that the reciprocal interference among letters located in close proximity (crowding) poses critical constraints on visual word processing. Importantly, the effect of spacing was not modulated by string length, suggesting that the locus of the spacing effect is at the level of letter detectors. Moreover, the processing of crowded letters was facilitated by top-down support from orthographic lexical representation as indicated by the fact that decreased spacing affected pseudowords significantly more than words. Conversely, in the lexical decision task only word responses were affected by the spacing manipulation. Overall, our findings support the hypothesis that increased crowding is particularly harmful for phonological decoding, thereby adversely affecting reading development in dyslexic children.
Similar content being viewed by others
Notes
We used limited stimulus exposure time and post-stimulus masking because the effect of the spacing manipulation was unreliable in a pilot LDT experiment in which the stimulus was presented until response.
References
Baayen, R. H. (2008). Analyzing linguistic data. Cambridge, UK: Cambridge University Press.
Baayen, R. H., Davidson, D. J., & Bates, D. M. (2008). Mixed-effects modeling with crossed random effects for subjects and items. Journal of Memory and Language, 59(4), 390–412.
Barr, D. J., Levy, R., Scheepers, C., & Tily, H. J. (2013). Random effects structure for confirmatory hypothesis testing: Keep it maximal. Journal of Memory and Language, 68(3), 255–278.
Bates, D., Maechler, M, Bolker B., & Walker, S. (2013). lme4: Linear mixed-effects models using Eigen and S4. R package version 1.0-4. http://CRAN.R-project.org/package=lme4
Besner, D., & Roberts, M. A. (2003). Reading nonwords aloud: Results requiring change in the dual route cascaded model. Psychonomic Bulletin & Review, 10, 398–404.
Bosse, M. L., Tainturier, M. J., & Valdois, S. (2007). Developmental dyslexia: The visual attention span deficit hypothesis. Cognition, 104(2), 198–230.
Bouma, H. (1970). Interaction effects in parafoveal letter recognition. Nature, 226, 177–178.
Burani, C., Barca, L., & Arduino, L. S. (2001). Una base di dati sui valori di età di acquisizione, frequenza, familiarità, immaginabilità, concretezza e altre variabili lessicali e sub-lessicali per 626 nomi dell’italiano. Giornale Italiano di Psicologia, 4, 839–854.
Callens, M., Whitney, C., Tops, W., & Brysbaert, M. (2013). No deficiency in left-to-right processing of words in dyslexia but evidence for enhanced visual crowding. The Quarterly Journal of Experimental Psychology, 66(9), 1803–1817.
Chanceaux, M., & Grainger, J. (2012). Serial position effects in the identification of letters, digits, symbols, and shapes in peripheral vision. Acta Psychologica, 141, 149–158. doi:10.1016/j.actpsy.2012.08.001
Chanceaux, M., Mathôt, S., & Grainger, J. (2013). Flank to the left, flank to the right: Testing the modified receptive field hypothesis of letter-specific crowding. Journal of Cognitive Psychology, 25(6), 774–780. doi:10.1080/20445911.2013.823436
Chicherov, V., & Herzog, M. H. (2013). Electrophysiological signatures of crowding are similar in foveal and peripheral vision. Journal of Vision, 13(9), 569.
Chicherov, V., Plomp, G., & Herzog, M. H. (2014). Neural correlates of visual crowding. NeuroImage, 93, 23–31.
Chung, S. T. L. (2002). The effect of letter spacing on reading speed in central and peripheral vision. Investigative Ophthalmology & Visual Science, 43, 1270–1276.
Cohen, L., Dehaene, S., Vinckier, F., Jobert, A., & Montavont, A. (2008). Reading normal and degraded words: Contribution of the dorsal and ventral visual pathways. NeuroImage, 40, 353–366.
Coltheart, M., Rastle, K., Perry, C., Langdon, R., & Ziegler, J. (2001). DRC: A dual route cascaded model of visual word recognition and reading aloud. Psychological Review, 108(1), 204.
Danilova, M. V., & Bondarko, V. M. (2007). Foveal contour interactions and crowding effects at the resolution limit of the visual system. Journal of Vision, 7(2), 1–18.
Dehane, S., & Cohen, L. (2011). The unique role of the visual word form area in reading. Trends in Cognitive Science, 15(6), 254–262.
Dufau, S., Stevens, M., & Grainger, J. (2008). Windows executable software for the progressive demasking task. Behavior Research Methods, 40(1), 33–37.
Facoetti, A., Trussardi, A., Ruffino, M., Lorusso, M. L., Cattaneo, C., Galli, R., & Zorzi, M. (2010). Multisensory spatial attention deficits are predictive of phonological decoding skills in developmental dyslexia. Journal of Cognitive Neuroscience, 22(5), 1011–1025.
Facoetti, A., Zorzi, M., Cestnick, L., Lorusso, M. L., Molteni, M., Paganoni, P., Umiltà, C. & Mascetti, G.G.. (2006). The relationship between visuo-spatial attention and nonword reading in developmental dyslexia. Cognitive Neuropsychology, 23(6), 841–855.
Grainger, J., & Segui, J. (1990). Neighborhood frequency effects in visual word recognition: A comparison of lexical decision and masked identification latencies. Perception & Psychophysics, 47, 191–198.
Grainger, J., Tydgat, I., & Isselé, J. (2010). Crowding affects letters and symbols differently. Journal of Experimental Psychology: Human Perception and Performance, 36, 673–688. doi:10.1037/a0016888
Jaeger, T. F. (2008). Categorical data analysis: Away from ANOVAs (transformation or not) and towards logit mixed models. Journal of Memory and Language, 59(4), 434–446.
Jehee, J. F. M., Roelfsema, P. R., Deco, G., Murre, J. M. J., & Lamme, V. A. F. (2007). Interactions between higher and lower visual areas improve shape selectivity of higher level neurons- Explaining crowding phenomena. Brain Research, 1157, 167–176.
Legge, G. E., Cheung, S. H., Yu, D., Chung, S. T. L., Lee, H. W., & Owens, D. P. (2007). The case for the visual span as a sensory bottleneck in reading. Journal of Vision, 7(2), 1–15.
Legge, G. E., Mansfield, J. S., & Chung, S. T. L. (2001). Psychophysics of reading. XX. Linking letter recognition to reading speed in central and peripheral vision. Vision Research, 41, 725–743.
Martelli, M., Di Filippo, G., Spinelli, D., & Zoccolotti, P. (2009). Crowding, reading, and developmental dyslexia. Journal of Vision, 9, 1–18.
McClelland, J. L., & Rumelhart, D. E. (1981). An interactive activation model of context effects in letter perception: I. An account of basic findings. Psychological Review, 88(5), 375.
Moll, K., & Jones, M. (2013). Naming fluency in dyslexic and nondyslexic readers: Differential effects of visual crowding in foveal, parafoveal, and peripheral vision. The Quarterly Journal of Experimental Psychology, 66(11), 2085–2091.
Montani, V., Facoetti, A., & Zorzi, M. (2014). Spatial attention in written word perception. Frontiers in Human Neuroscience, 8, 42. doi:10.3389/fnhum.2014.00042
Moores, E., Cassim, R., & Talcott, J. B. (2011). Adults with dyslexia exhibit large effects of crowding, increased dependence on cues, and detrimental effects of distractors in visual search tasks. Neuropsychologia, 49, 3881–3890.
O’Malley, S., & Besner, D. (2008). Reading aloud: Qualitative differences in the relation between stimulus quality and word frequency as a function of context. Journal of Experimental Psychology: Learning, Memory, and Cognition, 34(6), 1400.
Pelli, D. G., Robson, J. G., & Wilkins, A. J. (1988). The design of a new letter chart for measuring contrast sensitivity. Clinical Vision Sciences, 2, 187–199.
Pelli, D. G., & Tillman, K. A. (2008). The uncrowded window of object recognition. Nature Neuroscience, 11(10), 1129–1135.
Perea, M., & Gomez, P. (2012). Increasing interletter spacing facilitates encoding of words. Psychonomic Bulletin & Review, 19(2), 332–338.
Perea, M., Moret-Tatay, C., & Gómez, P. (2011). The effects of interletter spacing in visual-word recognition. Acta Psychologica, 137, 345–351.
Perea, M., Panadero, V., Moret-Tatay, C., & Gómez, P. (2012). The effects of inter-letter spacing in visual-word recognition: Evidence with young normal readers and developmental dyslexics. Learning and Instruction, 22, 420–430.
Perry, C., Ziegler, J., & Zorzi, M. (2007). Nested incremental modeling in the development of computational theories: The CDP+ model of reading aloud. Psychological Review, 114, 273–315.
Perry, C., Ziegler, J. C., & Zorzi, M. (2010). Beyond single syllables: Large-scale modeling of reading aloud with the Connectionist Dual Process (CDP++) model. Cognitive Psychology, 61(2), 106–151.
Perry, C., Ziegler, J. C., & Zorzi, M. (2013). A computational and empirical investigation of graphemes in reading. Cognitive Science, 37(5), 800–828.
Perry, C., Ziegler, J. C., & Zorzi, M. (2014). CDP++.Italian: Modelling sublexical and supralexical inconsistency in a shallow orthography. PLoS ONE, 9(4), e94291.
R Core Team (2013). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL http://www.R-project.org/
Rayner, K. (1998). Eye movements in reading and information processing: 20 years of research. Psychological Bulletin, 124, 372–422.
Schneider, W., Eschman, A., & Zuccolotto, A. (2002). E-Prime 1.0. Pittsburgh, PA: Psychological Software Tools.
Singmann, H. (2013). afex: Analysis of Factorial Experiments. R package version 0.6-82. http://CRAN.R-project.org/package=afex
Spinelli, D., De Luca, M., Judica, A., & Zoccolotti, P. (2002). Crowding effects on word identification in developmental dyslexia. Cortex, 38, 179–200.
Tydgat, I., & Grainger, J. (2009). Serial position effects in the identification of letters, digits, and symbols. Journal of Experimental Psychology: Human Perception and Performance, 35, 480–498. doi:10.1037/a0013027
Weekes, B. S. (1997). Differential effects of number of letters on word and nonword naming latency. The Quarterly Journal of Experimental Psychology Section A, 50(2), 439–456.
Whitney, D., & Levi, D. M. (2011). Visual crowding: A fundamental limit on conscious perception and object recognition. Trends in Cognitive Sciences, 15(4), 160–168.
Woods, R. J., Davis, K., & Scharff, L. F. V. (2005). Effects of typeface and font size on legibility for children. American Journal of Psychological Research, 1, 86–102.
Yu, D., Cheung, S. H., Legge, G. E., & Chung, S. T. L. (2007). Effect of letter spacing on visual span and reading speed. Journal of Vision, 7, 1–10.
Ziegler, J. C., Perry, C., & Zorzi, M. (2009). Additive and interactive effects of stimulus degradation: No challenge for CDP+. Journal of Experimental Psychology: Learning, Memory, and Cognition, 35(1), 306–311.
Ziegler, J. C., Perry, C., & Zorzi, M. (2014). Modelling reading development through phonological decoding and self-teaching: Implications for dyslexia. Philosophical Transactions of the Royal Society, B: Biological Sciences, 369(1634), 20120397.
Zorzi, M. (2010). The connectionist dual process (CDP) approach to modelling reading aloud. European Journal of Cognitive Psychology, 22(5), 836–860.
Zorzi, M., Barbiero, C., Facoetti, A., Lonciari, I., Carozzi, M., Montico, M., & Ziegler, J. C. (2012). Extra-large letter spacing improves reading in dyslexia. PNAS, 109(28), 11455–11459.
Zorzi, M., Testolin, A., & Stoianov, I. P. (2013). Modeling language and cognition with deep unsupervised learning: A tutorial overview. Frontiers in Psychology, 4, 515. doi:10.3389/fpsyg.2013.00515
Acknowledgments
This study was supported by grants from the European Research Council (grant no. 210922) and the University of Padova (Stategic Grant 2013 "NEURAT") to M.Z.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Montani, V., Facoetti, A. & Zorzi, M. The effect of decreased interletter spacing on orthographic processing. Psychon Bull Rev 22, 824–832 (2015). https://doi.org/10.3758/s13423-014-0728-9
Published:
Issue Date:
DOI: https://doi.org/10.3758/s13423-014-0728-9