Developmental dyslexia (DD) affects 5–10% of children worldwide. Although phonological theories predominate, they may not fully explain reading difficulties in orthographically dense scripts such as Chinese. We investigated whether Chinese children with DD exhibit differences in early visual cortical responses and how these differences relate to reading-related skills. Steady-state visual evoked potentials (ssVEPs) were recorded from 50 children with DD and 50 typically developing controls aged 7–11 years using gratings that preferentially bias magnocellular or parvocellular processing. Global motion perception, visuospatial attention, verbal working memory, and linguistic skills were also assessed. Children with DD showed reduced ssVEP amplitudes to low-spatial-frequency stimuli (partial η2 = .43, p < .001), whereas responses to high-spatial-frequency stimuli were preserved. Among the domains examined, the visual-processing model provided the strongest within-sample discrimination between groups (Nagelkerke R2 = .68), with low-spatial-frequency ssVEP amplitude as its only significant visual predictor. Exploratory cross-sectional mediation analyses identified significant indirect associations between ssVEP amplitude and linguistic skills through verbal working memory. For phonological awareness, the indirect association was significant, whereas the corresponding direct association was not; for morphological awareness, both associations remained significant. Visuospatial-attention differences were limited to retrospective selection from working memory rather than initial attentional orienting. For most measures, age-related associations did not differ detectably between groups. These findings are compatible with a hypothesized visual-cognitive cascade involving early visual cortical processing, working memory, and reading-related difficulties. However, the cross-sectional design does not establish temporal or causal relationships; longitudinal and intervention studies are needed to test the proposed model.
In everyday life, we receive social evaluative feedback from specific interaction partners that shapes our expectations about future feedback. It has been proposed that feedback processing and expectations are biased toward positive social feedback. However, the neuronal processes underlying biased social feedback processing remain unclear. In the current Event-Related Potentials (ERPs) study, we exposed participants to seemingly real social evaluations from three senders, each providing dichotomous positive or negative feedback on trait adjectives. In reality, feedback contingencies were manipulated with different ratios of positive versus negative feedback (rare 20 vs 80; equal 50 vs 50; frequent 80 vs 20 per cent of all trials). Participants' expectation ratings followed the general feedback ratios, though they indicated higher expectations for positive feedback. A lower probability of feedback increased all investigated ERP components, except the P1. Furthermore, positive versus negative feedback led to relatively more positive amplitudes in the Feedback-Related Negativity (FRN) and Late Positive Potential (LPP) time windows. Interactions between valence and probability were found for exploratory analyses of the Early Posterior Negativity (EPN) and theory-driven analyses of the P3, with specifically increased amplitudes for rare negative feedback compared to rare positive feedback. The results suggest that, even though negative feedback elicited higher prediction-error-related effects in ERPs associated with general surprise responses (P3) and perceptual attentional enhancement (EPN), the LPP, which is related to elaborate processing, integration, and updating, exhibited larger amplitudes for positive feedback, possibly reflecting biased processing of positive feedback. This may be fundamental for maintaining a positively biased self-view.
Behavioral-variant frontotemporal dementia (bvFTD) is typically described in terms of progressive loss of social and behavioral control. However, the earliest stages of the disease may also involve active, developed forms of compensation that remain largely invisible to standard assessment. These strategies are rarely characterized, yet they may offer a unique entry point into the mechanisms by which social functioning is temporarily preserved despite emerging degeneration. Here, I report a longitudinal single-case study of a young C9orf72 repeat-expansion carrier followed from the prodromal stage to established moderate bvFTD. Based on more than a dozen hours of semi-structured interviews initiated at symptom emergence, thematic analysis identified five compensatory subthemes. Together, these strategies suggested a coherent shift in the architecture of behavioral control that remain largely invisible to standard medical or neuropsychological assessment. As implicit, flexible, and internally sustained regulation became less reliable, functioning appeared to rely on control processes that were more explicit, environmentally distributed, routine-based, and effortful. These observations can be organized around three broader principles: explicitation, externalization, and stabilization. The case suggests that early preservation in bvFTD may reflect not only residual capacities, but also an active and fragile reorganization of social and behavioral control. By foregrounding the patient's own compensatory work, this study provides a hypothesis-generating conceptual framework for understanding how everyday functioning may be maintained during the prodromal-to-dementia transition, and highlights qualitative longitudinal single-case designs and participatory research as a powerful tool for identifying hidden forms of adaptation in neurodegenerative disease and refine theoretical models of social behavior.
Imaginal (representational) neglect—typically revealed by contralesional omissions when patients describe familiar places from long-term memory—provides a test case for theories of mental scene construction. Unlike propositional recall of place-related facts, imaginal tasks require that semantic knowledge be “spatialized” into a viewpoint-dependent scene that can be actively sampled. We review converging evidence from classic behavioral dissociations (viewpoint inversion; preserved semantic knowledge with impaired spatialized retrieval), oculomotor measures during imagery, sensory interventions (caloric vestibular stimulation; prismatic adaptation), and lesion/disconnection findings. Reconsidering the long-standing opposition between a primary “representational scotoma” and a pure attentional/exploratory bias, we argue that this dichotomy may not correspond to how scenes are actually built: construction and exploration are tightly coupled processes, partly implemented through attentional/oculomotor control. Building on convergent lesion, meta-analytic and neuroimaging evidence that a left-lateralized image-generation system (including the Fusiform Imagery Node) supports the generation of visual content, we propose as a working hypothesis that balanced, viewpoint-dependent spatial organization depends on right-hemisphere attentional control and inter-hemispheric integration, plausibly involving posterior callosal pathways. We specify construction and exploration as sets of operations, relate the framework to accounts of conscious access, and set out empirical tests of its network-level claims.
