Authors: Sylviane Valdois, Thierry Phénix, Mathilde Fort & Julien Diard.
Article: Atypical viewing position effect in developmental dyslexia: A behavioural and modelling investigation.
Publication: Cognitive Neuropsychology (Taylor and Francis). Published online: 24 Nov 2021 2021 | DOI: 10.1080/02643294.2021.2004107
The probability of recognizing a word depends on the position of fixation during processing. In typical readers, the resulting word-recognition curves are asymmetrical, showing a left-of-centre optimal viewing position (OVP). First, we report behavioural results from dyslexic participants who show atypical word-recognition curves characterized by the OVP being right of centre with recognition probability being higher on the rightmost than on the leftmost letters. Second, we used BRAID, a Bayesian model of word recognition that implements gaze position, an acuity gradient, lateral interference and a visual attention component, to examine how variations in the deployment of visual attention would affect the OVP curves. We show that the atypical dyslexic curves are well simulated assuming a narrow distribution of visual attention and a shifting of visual attention towards the left visual field. These behavioural and modelling findings are discussed in light of current theories of visual attention deficits in developmental dyslexia.
Sylviane Valdois, Thierry Phénix, Mathilde Fort & Julien Diard (2021) Atypical viewing position effect in developmental dyslexia: A behavioural and modelling investigation, Cognitive Neuropsychology, DOI: 10.1080/02643294.2021.2004107