The Functional Neuroanatomy of Reading Intervention

Abstract

The present article reviews the literature on the brain mechanisms underlying reading improvements following behavioral intervention for reading disability. This includes evidence of neuroplasticity concerning functional brain activation, brain structure, and brain connectivity related to reading intervention. Consequently, the functional neuroanatomy of reading intervention is compared to the existing literature on neurocognitive models and brain abnormalities associated with reading disability. A particular focus is on the left hemisphere reading network including left occipito-temporal, temporo-parietal, and inferior frontal language regions. In addition, potential normalization/compensation mechanisms involving right hemisphere cortical regions, as well as bilateral sub-cortical and cerebellar regions are taken into account. The comparison of the brain systems associated with reading intervention and the brain systems associated with reading disability enhances our understanding of the neurobiological basis of typical and atypical reading development. All in all, however, there is a lack of sufficient evidence regarding rehabilitative brain mechanisms in reading disability, which we discuss in this review.

Macular Anatomy Differs in Dyslexic Subjects

“…Second, the participants included in this study are mainly adolescents and young adults, so we cannot extrapolate our results to other age groups. Third, this study is cross-sectional, so we cannot know whether the found differences are stable over time and whether reading interventions are able to remodel retinal structures, similarly to what has been found in other investigations on the CNS in dyslexia [ 7 , 8 ]. Fourth, the grouping of this study is based on a diagnosis and not on specific reading measurements.…”

“…The pathophysiology of dyslexia is still controversial and has been attributed to phonological, auditory or visual alterations [ 3 , 4 ]. A number of neuroimaging investigations focused on the central nervous system (CNS) have been performed so far to study normal [ 5 ] and abnormal reading process [ 2 , 6 ], and also reading interventions [ 7 , 8 ]. However, we have to keep in mind that the first steps of a successful reading process are entirely visual and are related to the retina, a part of the CNS located in the eye [ 9 ].…”

White Matter Microstructural Plasticity Associated with Educational Intervention in Reading Disability

“…In functional MRI, a meta-analysis of 8 studies with longitudinal neuroimaging and cognitive scores concluded that there were no consistent locations where longitudinal changes in reading-invoked BOLD signal and intervention response covaried (Perdue et al, 2022). However, individual studies, including those that may have only contained one session of neuroimaging either prior or after intervention, have found functional correlates of intervention response both in putative reading regions as well as more globally (reviewed in Barquero et al, 2014; Braid & Richlan, 2022; Perdue et al, 2022). One of the few studies of gray matter morphometric correlates of intervention response was conducted on the same participant pool as in the present study (Romeo et al, 2018).…”

“…While longitudinal studies of long-term reading development seem to have converged on the importance of left-hemispheric reading circuitry in predicting and tracking reading outcomes, neuroimaging studies focusing on short-term reading instruction (on the order of days-to-weeks) have yielded few and mixed findings on rapid anatomical correlates of reading remediation (as well as functional correlates – for reviews, see Barquero et al, 2014; Braid & Richlan, 2022; Perdue et al, 2022). Huber et al, (2018) found that decreases in MD across the brain, not limited to core reading circuitry, were related to better reading intervention benefits across participants.…”

Dyslexia: Causes and Concomitant Impairments

“…The question of whether an impairment is a cause of DD or whether it is merely an accompanying deficit with no causal significance is also fundamental to the assessment of neural dysfunctions that may occur together with impaired abilities such as dyslexia [ 161 , 162 ]. Theories regarding the neural basis of DD mainly rely on functional magnetic resonance imaging (fMRI) studies [ 125 , 126 , 127 , 128 , 129 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 , 175 , 176 , 177 , 178 , 179 , 180 , 181 , 182 , 183 , 184 , 185 , 186 , 187 , 188 , 189 , 190 ]. An increase in the blood-oxygen-level-dependent (BOLD) signal in an area of the brain shows that this area is receiving sensory afferents or input from other brain areas [ 191 , 192 ].…”