Neural and functional correlates of impaired reading ability in schizophrenia

Abstract

Deficits in early auditory processing (EAP) are a core component of schizophrenia (SZ) and contribute significantly to impaired overall function. Here, we evaluate the potential contributions of EAP-related impairments in reading to functional capacity and outcome, relative to effects of auditory social cognitive and general neurocognitive dysfunction. Participants included 30-SZ and 28-controls of similar age, sex, and educational achievement. EAP was assessed using an auditory working memory (tone-matching) task. Phonological processing and reading Fluency were assessed using the Comprehensive Test of Phonological Processing and Woodcock-Johnson reading batteries, respectively. Auditory-related social cognition was assessed using measures of emotion/sarcasm recognition. Functional capacity and outcome were assessed using the UCSD Performance-based Skills Assessment and Specific Level of Functioning scale, respectively. fMRI resting-state functional-connectivity (rsFC) was used to evaluate potential underlying substrates. As predicted, SZ patients showed significant and interrelated deficits in both phonological processing (d = 0.74, p = 0.009) and reading fluency (d = 1.24, p < 0.00005). By contrast, single word reading (d = 0.35, p = 0.31) was intact. In SZ, deficits in EAP and phonological reading ability significantly predicted reduced functional capacity, but not functional outcome. By contrast, deficits in reading fluency significantly predicted impairments in both functional capacity and functional outcome. Moreover, deficits in reading fluency correlated with rsFC alterations among auditory thalamus, early auditory and auditory association regions. These findings indicate significant contributions of EAP deficits and functional connectivity changes in subcortical and early auditory regions to reductions in reading fluency, and of impaired reading ability to impaired functional outcome in SZ.

Reading skills deficits in people with mental illness: A systematic review and meta-analysis

“…There were, however, significant test differences for both rate (p = 0.04, I 2 = 64.9%) and accuracy (p = 0.01, I 2 = 77.1%), with the GORT-4 revealing large deficits [17,21], and the Alouette [75] showing no deficit [76] (Figures 2(2.4-2.5)). In fluency [17,18,21,41,77], there was a highly significant deficit in SZ (Hedge's g = À2.03, df = 4, p < 0.00001, CI = [À2.82, À1.24]), but with large heterogeneity within results (84%) ( Figure 2(2.6)). In reading speed (time taken to read certain content) [24,76], the effect of diagnosis was nonsignificant (Hedge's g = À0.50, df = 1, p = 0.11, CI = [À1.11, À0.11]) ( Figure 2(2.7)).…”

“…. In fluency [17,18,21,24,43], there was a highly significant deficit in SZ (Hedge's g=-2.03, df=4, p<0.00001, CI=[-2.82, -1.24]), but with large heterogeneity within results (84%) ( Figure 2.6). In reading speed (time taken to read certain content) [33,41], the effect of diagnosis was non-significant (Hedge's g=-0.50, df=1, p=0.11, CI=[-1.11, -0.11]) ( Figure 2.7).…”

“…Single-Word Reading: Across 10 studies [17,18,21,[29][30][31][32][33][34][35], there was a significant medium-size deficit (Figure 2.3) in SZ relative to HC (Hedge's g=-0.70, df=9, p<0.00001, CI=[-0.94, -0.46]). There was significant heterogeneity within the results (p=0.01, I 2 =58%) but no test performed better than others (p=0.20, I 2 =35.6%).…”

“…In SZ, three studies [17,21,41] examined the influence of education and all found reading skills significantly below achieved academic levels. Six studies [18,24,39,62,76,81] matched their groups on education or entered it as a covariate [85], and all found significant impairments in various reading skills. Nonforensic populations with general MIs had single-word reading equivalent to their achieved education but their comprehension was lower [51].…”

“…In people with various MIs, undiagnosed reading problems, and dyslexia result in scholastic failure, in turn raising the risk for mood problems [14] and future criminal behavior [15]. Poor reading skills also pose a challenge for accessibility of mental health interventions [16] and predict poor psychosocial outcomes [17,18]. There is thus a need to consider reading deficits as a therapeutic target and address them, for example, with interventions used for dyslexia [7,19].…”