The similarity structure of distributed neural responses reveals the multiple representations of letters
David Rothlein, Brenda Rapp, David Rothlein, Brenda Rapp
Abstract
Most cognitive theories of reading and spelling posit modality-specific representations of letter shapes, spoken letter names, and motor plans as well as abstract, amodal letter representations that serve to unify the various modality-specific formats. However, fundamental questions remain regarding the very existence of abstract letter representations, the neuro-topography of the different types of letter representations, and the degree of cortical selectivity for orthographic information. We directly test quantitative models of the similarity/dissimilarity structure of distributed neural representations of letters using Multivariate Pattern Analysis-Representational Similarity Analysis (MVPA-RSA) searchlight methods to analyze the BOLD response recorded from single letter viewing. These analyses reveal a left hemisphere ventral temporal region selectively tuned to abstract letter representations as well as substrates tuned to modality-specific (visual, phonological and motoric) representations of letters. The approaches applied in this research address various shortcomings of previous studies that have investigated these questions and, therefore, the findings we report serve to advance our understanding of the nature and format of the representations that occur within the various sub-regions of the large-scale networks used in reading and spelling.
Keywords: Abstract letter identity; Letter representation; Multivariate Pattern Analysis (MVPA); Reading and spelling networks; Representational Similarity Analysis (RSA); Visual Word Form Area (VWFA).
Copyright © 2013 Elsevier Inc. All rights reserved.
Figures
![Figure 1. The multiple formats of letter…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f1.jpg)
![Figure 2. Depiction of the four basic…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f2.jpg)
![Figure 3. Unthresholded Group Feature Sensitivity Maps…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f3.jpg)
![Figure 4. Group ANOVA Selectivity Comparison Maps…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f4.jpg)
![Figure 5. Group Permutation Selectivity Maps depicting…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f5.jpg)
Figure 6. Group Regression Map
Each group…
Figure 6. Group Regression Map
Each group regression map was obtained by carrying out, at…
Figure 7. The significant clusters identified in…
Figure 7. The significant clusters identified in each of the three selectivity analyses
For each…
Figure 8. The contribution of each feature…
Figure 8. The contribution of each feature dimension to the brain regions identified by the…
Figure 9. Sensitivity of visually similar vs.…
Figure 9. Sensitivity of visually similar vs. visually dissimilar cross-case, same identity pairs within the…
- Decoding levels of representation in reading: A representational similarity approach.Fischer-Baum S, Bruggemann D, Gallego IF, Li DSP, Tamez ER. Fischer-Baum S, et al. Cortex. 2017 May;90:88-102. doi: 10.1016/j.cortex.2017.02.017. Epub 2017 Mar 18. Cortex. 2017. PMID: 28384482
- Accessing orthographic representations from speech: the role of left ventral occipitotemporal cortex in spelling.Ludersdorfer P, Kronbichler M, Wimmer H. Ludersdorfer P, et al. Hum Brain Mapp. 2015 Apr;36(4):1393-406. doi: 10.1002/hbm.22709. Epub 2014 Dec 12. Hum Brain Mapp. 2015. PMID: 25504890 Free PMC article.
- Visual Experience Shapes Orthographic Representations in the Visual Word Form Area.Wimmer H, Ludersdorfer P, Richlan F, Kronbichler M. Wimmer H, et al. Psychol Sci. 2016 Sep;27(9):1240-8. doi: 10.1177/0956797616657319. Epub 2016 Jul 19. Psychol Sci. 2016. PMID: 27435995 Free PMC article.
- Local response heterogeneity indexes experience-based neural differentiation in reading.Purcell JJ, Rapp B. Purcell JJ, et al. Neuroimage. 2018 Dec;183:200-211. doi: 10.1016/j.neuroimage.2018.07.063. Epub 2018 Aug 1. Neuroimage. 2018. PMID: 30076891 Free PMC article.
- The neural signature of orthographic-phonological binding in successful and failing reading development.Blomert L. Blomert L. Neuroimage. 2011 Aug 1;57(3):695-703. doi: 10.1016/j.neuroimage.2010.11.003. Epub 2010 Nov 5. Neuroimage. 2011. PMID: 21056673 Review.
- Neural Components of Reading Revealed by Distributed and Symbolic Computational Models.Staples R, Graves WW. Staples R, et al. Neurobiol Lang (Camb). 2020;1(4):381-401. doi: 10.1162/nol_a_00018. Epub 2020 Oct 1. Neurobiol Lang (Camb). 2020. PMID: 36339637 Free PMC article.
- Task modulates the orthographic and phonological representations in the bilateral ventral Occipitotemporal cortex.Qu J, Pang Y, Liu X, Cao Y, Huang C, Mei L. Qu J, et al. Brain Imaging Behav. 2022 Aug;16(4):1695-1707. doi: 10.1007/s11682-022-00641-w. Epub 2022 Mar 5. Brain Imaging Behav. 2022. PMID: 35247162
- From Hand to Eye With the Devil In-Between: Which Cognitive Mechanisms Underpin the Benefit From Handwriting Training When Learning Visual Graphs?Fernandes T, Araújo S. Fernandes T, et al. Front Psychol. 2021 Oct 27;12:736507. doi: 10.3389/fpsyg.2021.736507. eCollection 2021. Front Psychol. 2021. PMID: 34777123 Free PMC article.
- The Effects of Handwriting Experience on Literacy Learning.Wiley RW, Rapp B. Wiley RW, et al. Psychol Sci. 2021 Jul;32(7):1086-1103. doi: 10.1177/0956797621993111. Epub 2021 Jun 29. Psychol Sci. 2021. PMID: 34184564 Free PMC article.
- Innate connectivity patterns drive the development of the visual word form area.Li J, Osher DE, Hansen HA, Saygin ZM. Li J, et al. Sci Rep. 2020 Oct 22;10(1):18039. doi: 10.1038/s41598-020-75015-7. Sci Rep. 2020. PMID: 33093478 Free PMC article.
- Research Support, N.I.H., Extramural
- Adolescent
- Adult
- Brain / physiology*
- Brain Mapping
- Female
- Humans
- Magnetic Resonance Imaging
- Male
- Models, Neurological
- Nerve Net / physiology*
- Reading*
- Visual Perception*
- Young Adult
- Full Text Sources
- Other Literature Sources
- Medical
![Figure 6. Group Regression Map](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f6.jpg)
![Figure 7. The significant clusters identified in…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f7.jpg)
Figure 8. The contribution of each feature…
Figure 8. The contribution of each feature dimension to the brain regions identified by the…
Figure 9. Sensitivity of visually similar vs.…
Figure 9. Sensitivity of visually similar vs. visually dissimilar cross-case, same identity pairs within the…
![Figure 8. The contribution of each feature…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f8.jpg)
![Figure 9. Sensitivity of visually similar vs.…](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3980450/bin/nihms562605f9.jpg)
Source: PubMed