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

Lower-level oculomotor deficits in schizophrenia during multi-line reading: Evidence from return-sweeps

Reading fluency deficits in schizophrenia (Sz) have been attributed to dysfunction in both lower-level, oculomotor processing and higher-level, lexical processing, according to the two-hit deficit model. Given that prior work examining reading deficits in individuals with Sz has primarily focused on single-line and single-word reading tasks, eye movements that are unique to passage reading, such as return-sweep saccades, have not yet been examined in Sz. Return-sweep saccades are large eye movements that are made when readers move from the end of one line to the beginning of the next line during natural passage reading. Examining return-sweeps provides an opportunity to examine lower-level, oculomotor deficits during reading under circumstances when upcoming higher-level, lexical information is not available for visual processing because visual acuity constraints do not permit detailed lexical processing of line-initial words when return-sweeps are programmed. To examine the source of reading deficits in Sz, we analysed an existing data set in which participants read multi-line passages with manipulations to line spacing. Readers with Sz made significantly more return-sweep targeting errors followed by corrective saccades compared with healthy controls. Both groups showed similar effects of line spacing on return-sweep targeting accuracy, suggesting similar sensitivities to visual crowding during reading. Furthermore, the patterns of fixation durations in readers with Sz corroborate prior work indicating reduced parafoveal processing of upcoming words. Together, these findings suggest that lower-level visual and oculomotor dysfunction contribute to reading deficits in Sz, providing support for the two-hit deficit model.

A systematic review of users experiences of using digital interventions within psychosis: a thematic synthesis of qualitative research

PURPOSE

Although the development of digital mental health support for people with psychosis has been increasing, the development and opportunities to access this have been more limited compared to other mental health conditions. Qualitative research exploring the experiences of using digital interventions amongst people with psychosis is even less well developed; however, such research is crucial in capturing the experiences of using digital interventions to ensure they are meeting the needs of people with psychosis. This paper aimed to synthesise qualitative data related to the experiences of people with psychosis who have used digital interventions.

METHODS

A systematic literature search was conducted of articles published between 1992 and October 2023 using PubMed, MBase, PsycINFO, & OVID Medline. Two reviewers independently reviewed and screened 268 papers. Papers that met inclusion criteria were quality assessed using The Critical Appraisal Skills Programme (CASP) qualitative studies checklist. The Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) checklist was used to guide the structure of the report.

RESULTS

A thematic synthesis of 19 studies revealed six overarching themes which related to different aspects and features of the digital interventions: participants' relationship with technology; the accessibility of the interventions; how the interventions could impact on individuals' awareness and management of mental health; enhanced communication and relationships; and opportunities for reflection.

CONCLUSIONS

Benefits of using digital interventions are discussed. Areas for development and improvements are highlighted. Finally, recommendations for stakeholders who develop and implement digital interventions for psychosis are made.

Eye movements and the perceptual span in disordered reading: A comparison of schizophrenia and dyslexia

Increasing evidence of a common neurodevelopmental etiology between schizophrenia and developmental dyslexia suggests that neurocognitive functions, such as reading, may be similarly disrupted. However, direct comparisons of reading performance in these disorders have yet to be conducted. To address this gap in the literature, we employed a gaze-contingent moving window paradigm to examine sentence-level reading fluency and perceptual span (breadth of parafoveal processing) in adults with schizophrenia (dataset from Whitford et al., 2013) and psychiatrically healthy adults with dyslexia (newly collected dataset). We found that the schizophrenia and dyslexia groups exhibited similar reductions in sentence-level reading fluency (e.g., slower reading rates, more regressions) compared to matched controls. Similar reductions were also found for standardized language/reading and executive functioning measures. However, despite these reductions, the dyslexia group exhibited a larger perceptual span (greater parafoveal processing) than the schizophrenia group, potentially reflecting a disruption in normal foveal-parafoveal processing dynamics. Taken together, our findings suggest that reading and reading-related functions are largely similarly disrupted in schizophrenia and dyslexia, providing additional support for a common neurodevelopmental etiology.

Clarifying the roles of schizotypy and psychopathic traits in lexical decision performance

INTRODUCTION

Some studies suggest that lexical recognition is impaired in people with schizophrenia, psychopathy and/or antisocial personality disorders, but not affective disorders. We examined the extent to which various traits dimensionally linked to one or more of these disorders are associated with lexical recognition performance in the general population.

METHODS

Seventy-eight healthy English-speaking participants completed self-report measures of schizotypy, psychopathy, impulsivity, depression, anxiety and stress. All participants were assessed on a one-choice variant of a lexical decision task (LDT).

RESULTS

Meanness and Boldness traits of psychopathy (Triarchic Psychopathy Measure), and positive schizotypy (Unusual Experiences, Oxford-Liverpool Inventory of Feelings and Experiences) were associated with poor word-nonword accuracy, and predicted a significant amount of unique variance (Meanness, 12%; Boldness, 4.8%; Positive Schizotypy, 4.4%; total 21%) in performance. Higher motor impulsivity predicted 30% of the variance in low-frequency words recognition accuracy, but only in non-native English speakers. Affective traits were not associated with LDT performance.

CONCLUSION

Psychopathic traits show stronger negative associations with lexical recognition performance than schizotypal traits, and impulsivity may differently influence lexical decision performance in native and non-native speakers. Further studies are needed to replicate these findings, especially the influence of language familiarity in the impulsivity-performance relationship, and to clarify the influence of corresponding symptom dimensions in lexical recognition abilities, taking language familiarity, migration status, and comorbidity into account, in people with schizophrenia, psychopathy, and/or antisocial personality disorders.

Reading abilities and dopamine D2/D3 receptor availability: An inverted U-shaped association in subjects with schizophrenia

Reading impairments are prominent trait-like features of cognitive deficits in schizophrenia, predictive of overall cognitive functioning and presumably linked to dopaminergic abnormalities. To evaluate this, we used ¹⁸F-fallypride PET in 19 healthy and 21 antipsychotic-naïve schizophrenia subjects and correlated dopamine receptor binding potentials in relevant AFNI-derived regions and voxelwise with group performance on WRAT4 single-word reading subtest. Healthy subjects' scores were positively and linearly associated with D₂/D₃ receptor availability in the rectus, orbital and superior frontal gyri, fusiform and middle temporal gyri, as well as middle occipital gyrus and precuneus, all predominantly in the left hemisphere and previously implicated in reading, hence suggesting that higher dopamine receptor density is cognitively advantageous. This relationship was weakened in schizophrenia subjects and in contrast to healthy participants followed an inverted U-shaped curve both in the cortex and dorsal striatum, indicating restricted optimal range of dopamine D₂/D₃ receptor availability for cognitive performance in schizophrenia.

Phonological processing in psychopathic offenders

Recent research has demonstrated that psychopathic offenders exhibit dynamic cognitive and behavioral deficits on a variety of lab tasks that differentially activate left hemisphere resources. The Left Hemisphere Activation (LHA) hypothesis is a cognitive perspective that aims to address these deficits by conceptualizing psychopathy as a disorder in which behavior and cognitive processing change dynamically as a function of the differential taxation of left hemisphere resources. This study aimed to investigate whether psychopathic traits are associated with electrophysiological anomalies under conditions that place differential demands on left hemisphere language processing systems. We examined in a sample of 43 incarcerated indivdiuals the evocation of the N320, an event-related potential (ERP) elicited by nontarget stimuli during a phonological/phonetic decision task that has been shown to elicit greater activation and cognitive processing within the left hemisphere than the right hemisphere. Findings for a subsample of 18 offenders low in psychopathic traits were generally consistent with previous findings in healthy individuals, suggesting similar electrophysiological activity during phonological processing. However, psychopathic traits impacted the amplitude of the N320. Higher levels of psychopathic traits were associated with reduced left-lateralization in phonological processing as well as enhanced ERP differentiation between pronounceable and nonpronounceable stimuli. These findings provide physiological evidence of a relationship between psychopathic traits and anomalous language processing at the phonological level of word processing.