Resting-state networks and reading in adults with and without reading impairments

Abstract

In recent years, there has been much interest in understanding the functional architecture of the brain networks in skilled and poor readers with resting-state methodology. To date, the evidence points to minimal connectivity differences between skilled and impaired readers, even when their behavioural performances are markedly different, leading to claims that more domain general networks (e.g., attention) may be contributing to behavioural outcomes. Here we sought to 1) further characterize the reading network at rest (RdN) in skilled and impaired readers, 2) determine the extent to which RdN are related to reading behaviour, 3) outline the connections between domain-specific RdN and domain-general resting-state networks (RSNs), and 4) assess the extent to which domain-general RSNs are related to reading behavior in skilled and impaired readers. Participants (N = 33; N = 14 adults with reading impairment and N = 19 skilled readers) took part in the study. Our key findings include: 1) there are differential relationships between connectivity and reading behaviour, with connectivity of the left inferior frontal gyrus being highly related to reading behaviour for impaired readers but less so for skilled readers, 2) the default mode network and salience RSNs were found to be less integrated with major reading-associated areas including the fusiform gyrus and inferior frontal gyrus, in the impaired group, and 3) while RSNs are connected to the RdN regions, RSNs are not related to reading behaviour. We discuss these findings in terms of intrinsic brain organization and the potential developmental trajectories for individuals with reading impairments.