Left minineglect or inverse pseudoneglect in children withdyslexia?

Abstract

This study compared the visuospatial asymmetries in children with dyslexia and healthy children by using the manual line bisection task, and investigated the processing of spatial context with a 'local' cueing paradigm consisting of geometric symbols placed on the extremities of the lines. The performance between healthy children (leftward bias) and children with dyslexia (rightward bias) was significantly different. Furthermore, the bisection mark was shifted in the direction of the unilaterally cued extremities in all children. As children with dyslexia showed a rightward bias in their spatial representation, which did not interfere with local context processing, we proposed the term 'inverse pseudoneglect' to depict their behaviour in line bisection.

Space representation in children with dyslexia and children without dyslexia: Contribution of line bisection and circle centering tasks

“…In children with dyslexia, the present results showed a significant rightward bias for central lines which is in line with previous studies and may result from asymmetrical distribution of spatial attention in favour of the right space (e.g. Michel et al, 2011;Sireteanu et al, 2005;Waldie & Hausmann, 2010). Furthermore, when children viewed lines in the left visual space they exhibited a significant leftward bias; when they viewed lines in the right visual space they exhibited a significant rightward bias.…”

“…Milner et al, 1992). This behaviour testifies the preservation of the capacity to orient the spatial attention as previously shown with spatial cueing paradigm (Michel et al, 2011). Moreover, we could note that the spatial context processing was asymmetrically more efficient in the left space.…”

“…Conversely if this rightward bias can be assimilated to an 'inverse pseudoneglect' manifestation, i.e. a rightward bias with a healthy processing of the spatial context, as we proposed (Michel et al, 2011), its amplitude would decrease (or reverse to become leftward) from right-to left-sided locations and with the increase of line length. Therefore the present work was aimed to clarify whether the behavioural performance of children with dyslexia in line bisection is related to neglect-like or inverse pseudoneglect hypothesis.…”

“…Indeed children with dyslexia showed a displacement of their spontaneous rightward bias in the direction of the unilaterally cued extremities. This means that children with dyslexia showed a distinctive bias in space representation with an intermediate level between left neglect (mild rightward bias in space representation compared to brain damaged neglect patients) and pseudoneglect (healthy preservation of the attentional modulation of the space representation) that we have proposed to name 'inverse pseudoneglect' in a previous study (Michel, Bidot, Bonnetblanc, & Quercia, 2011).…”

“…First, the radial dimension to consider (20 cm) was shorter than previously used in circle centering task (30 cm) in adults without dyslexia (Girardi et al, 2004) and neglect patients (McIntosh et al, 2002) which may reduce the sensitivity of the test in this dimension as shown in line bisection (Halligan & Marshall, 1989) or other geometrical figures (Tegner & Levander, 1991). Second, even if the lateral dimension to consider was the same as the one used in line bisection by Michel et al (2011), i.e. 20 cm, the sensitivity of the task could have been reduced by the geometrical configuration of the stimulus.…”