Traces of spelling and reading deficits in the neural phonological network

Traces of spelling and reading deficits in the neural phonological network

First Author: Agnieszka Debska -- Nencki Institute of Experimental Biology
Additional authors/chairs: 
Katarzyna Chyl; Gabriela Dziegiel; Agnieszka Kacprzak; Magdalena Łuniewska; Joanna Plewko; Artur Marchewka; Anna Grabowska; Katarzyna Jednoróg
Abstract / Summary: 

Purpose
There is an ongoing debate whether reading and spelling share the same phonological and orthographic representations and overlapping processing patterns. Thus the central aim of our study was to identify alterations and compensatory mechanisms associated selectively with spelling and reading difficulties in the language-related brain network during phonological processing tasks.
Method
We examined 170 Polish-speaking children (aged 8-13 years) with different cognitive profiles: typical in reading and spelling (n=65), with isolated reading impairment (n=20) and spelling impairment (n=30) and with deficits in both spelling and reading (n=55). All participants performed a battery of phonological tasks in fMRI (minimal pair discrimination, rhyming, first phoneme matching). Series of two-ways ANOVAs were used to distinguish the unique contribution of spelling and reading effects in each task.
Results
Regarding in-scanner performance, poor spellers performed significantly worse than children without this deficit. Main effect of reading deficit and interaction effect were not significant. On the neural level, the main effect of spelling deficit was characterized by the hypoactivation of the left ventral occipitotemporal cortex, encompassing the Visual Word Form Area. Reading deficit was associated with reduced activation in the left temporo-parietal cortex, typically linked to the phoneme-to-grapheme integration. The presumably compensatory mechanisms in the right hemisphere were present as overactivations in ventral regions for poor readers and in dorsal for poor spellers.
Conclusions
Our study provides the first direct comparison between spelling and reading deficits in a language-relevant brain network within a relatively transparent orthography (Polish).