Words as Visual Objects: Neural and Behavioral Evidence for High-Level Visual Impairments in Dyslexia

Sigurdardottir, Heida Maria; Ólafsdóttir, Inga María; Devillez, Hélène

doi:10.3390/brainsci11111427

Cited by 14 publications

(5 citation statements)

References 175 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Form-level visual parsing is considered to happen around 170 ms or earlier (Tarkiainen et al, 1999;Salmelin, 2007Salmelin, , 2010Gwilliams, Lewis & Marantz, 2016;Sigurdardottir, Ólafsdóttir & Devillez, 2021). Based on the later time window of our LAN effect, it is thus likely to reflect abstract (i.e., non-visual) morpho-syntactic processes.…”

Section: Similarity Between "Syntactic" and "Morphological" Effectsmentioning

confidence: 96%

Shared neural computations for syntactic and morphological structures: evidence from Mandarin Chinese

Yu,

Mancha,

Tian

et al. 2024

Preprint

View full text Add to dashboard Cite

What are syntactic relations, and how does our brain infer them from a string of text characters? In the EEG study reported here we aimed to investigate these questions by contrasting syntactically separable compounds (zao4...fan3 -> 'rebel') and non-separable compounds (chi2yi2 -> 'hesitate') in Mandarin Chinese. Because both kinds of compounds have non-compositional meanings, their syntactic differences provide an elegant means for dissociating syntactic from semantic relations. Because non-separable compounds fit the traditional criteria for 'wordhood', this contrast also provides a means for asking whether syntactic and morphological relations are inferred in qualitatively different ways. We found that, relative to non-separable compounds, syntactically separable compounds elicited a left anterior negativity (LAN) effect between 275-400ms. Even though readers were always presented with the compounds in their unseparated form, our results suggest that the potentially separable compound forms drive the inference of a more complex set of underlying syntactic relations. In a companion manipulation in the same participants, we observed a qualitatively similar LAN effect when comparing non-separable compound nouns with simplex nouns. This finding raises doubts for the existence of a clear-cut distinction between 'syntax' and 'morphology', at least in processing.

show abstract

Section: Similarity Between "Syntactic" and "Morphological" Effectsmentioning

confidence: 96%

Shared neural computations for syntactic and morphological structures: evidence from Mandarin Chinese

Yu,

Mancha,

Tian

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…Such evidence of a specifically visual processing deficit in DD has been documented by studies investigating non-reading visual impairments that may be attributed to a dysfunctional left occipito-temporal cortex. This dysfunction not only reduces rapid and automatised recognition of letters and words (similar to the proposal of Wimmer, 1993) but is also implicated in speed of processing for other demanding visual stimuli (Behrmann & Plaut, 2013, 2020Behrmann et al, 1998;Kronbichler et al, 2008;Price & Devlin, 2011b;Sigurdardottir et al, 2021). For instance, this region is responsive when processing non-orthographic visual stimuli, such as faces and visually complex objects (Behrmann & Plaut, 2013, 2020Gabay et al, 2017a;Roberts et al, 2013Roberts et al, , 2015-stimuli which DD individuals are slow to process.…”

Section: Introductionmentioning

confidence: 69%

Shallow or deep? The impact of orthographic depth on visual processing impairments in developmental dyslexia

et al. 2022

View full text Add to dashboard Cite

The extent to which impaired visual and phonological mechanisms may contribute to the manifestation of developmental dyslexia across orthographies of varying depth has yet to be fully established. By adopting a cross-linguistic approach, the current study aimed to explore the nature of visual and phonological processing in developmental dyslexic readers of shallow (Italian) and deep (English) orthographies, and specifically the characterisation of visual processing deficits in relation to orthographic depth. To achieve this aim, we administered a battery of non-reading visual and phonological tasks. Developmental dyslexics performed worse than typically developing readers on all visual and phonological tasks. Critically, readers of the shallow orthography were disproportionately impaired on visual processing tasks. Our results suggest that the impaired reading and associated deficits observed in developmental dyslexia are anchored by dual impairments to visual and phonological mechanisms that underpin reading, with the magnitude of the visual deficit varying according to orthographic depth.

show abstract

“…The high-level visual dysfunction (HLVD) hypothesis is well supported by neuroscientific and behavioral evidence (Sigurdardottir, Ólafsdóttir, et al, 2021).…”

Section: High-level Visual Dysfunction Hypothesismentioning

confidence: 95%

The Role of Visual Factors in Dyslexia

Kristjánsson¹,

Sigurdardottir

2023

Journal of Cognition

Self Cite

View full text Add to dashboard Cite

What are the causes of dyslexia? Decades of research reflect a determined search for a single cause where a common assumption is that dyslexia is a consequence of problems with converting phonological information into lexical codes. But reading is a highly complex activity requiring many well-functioning mechanisms, and several different visual problems have been documented in dyslexic readers. We critically review evidence from various sources for the role of visual factors in dyslexia, from magnocellular dysfunction through accounts based on abnormal eye movements and attentional processing, to recent proposals that problems with high-level vision contribute to dyslexia. We believe that the role of visual problems in dyslexia has been underestimated in the literature, to the detriment of the understanding and treatment of the disorder. We propose that rather than focusing on a single core cause, the role of visual factors in dyslexia fits well with risk and resilience models that assume that several variables interact throughout prenatal and postnatal development to either promote or hinder efficient reading.

show abstract

Words as Visual Objects: Neural and Behavioral Evidence for High-Level Visual Impairments in Dyslexia

Cited by 14 publications

References 175 publications

Shared neural computations for syntactic and morphological structures: evidence from Mandarin Chinese

Shared neural computations for syntactic and morphological structures: evidence from Mandarin Chinese

Shallow or deep? The impact of orthographic depth on visual processing impairments in developmental dyslexia

The Role of Visual Factors in Dyslexia

Contact Info

Product

Resources

About