Pure alexia (PA) is an isolated reading impairment following brain damage, yet the mechanisms underlying reading recovery remain unclear. We present a Korean patient with PA following a posterior cerebral artery infarction who showed severe impairment in Hangul reading despite preserved writing and spoken language, with substantial recovery of sentence-level reading within six months. Structural and functional connectivity were investigated using diffusion tensor tractography (DTT) and functional connectivity (FC) analyses. DTT revealed degeneration of affected white matter tracts, including the forceps major, inferior longitudinal fasciculus and inferior fronto-occipital fasciculus. Interhemispheric FC was significantly lower than that of healthy controls (HCs) across perilesional regions. In contrast, FC between the left angular gyrus and perilesional regions differed significantly from HCs at specific follow-up time points during behavioral recovery. These findings suggest that functional reorganization of distributed reading networks may support behavioral recovery despite persistent structural disconnection.
This study examined the temporal dynamics of lexical and sublexical processing in Chinese spelling-to-dictation using two ERP experiments. Participants either wrote the initial character of two-character disyllabic words dictated to them (Experiment 1) or performed an auditory lexical decision task (Experiment 2), with character frequency (CF) and regularity manipulated. Results showed consistent CF effects in the N2 and late N400 windows across tasks, indicating shared lexical access and lexical competition processes. Crucially, CF-by-regularity interactions emerged only in spelling-to-dictation within the P2 and P3 intervals, suggesting processes specific to orthographic production. The P2 interaction may reflect early modulation of lexical activation by sublexical syllable-to-phonetic radical mappings, whereas the P3 interaction suggests enhanced orthographic encoding and response preparation when lexical and sublexical orthographic outputs converge. These findings support an interactive dual-route account of spelling and highlight how the Chinese writing system shapes the time course of written word production.
This study investigated mechanisms underlying oral reading of two-character kanji nonwords in Japanese. Unlike alphabetic orthographies, kanji does not permit straightforward grapheme-to-phoneme conversion because individual characters often have multiple readings whose typicality varies across lexical and positional contexts. We compared a lexical-only account with an account in which lexical processing is supplemented by character-based sublexical processing. Twenty-one Japanese-speaking persons with aphasia and 24 healthy controls read aloud two-character kanji words, pseudohomophone nonwords (PSH), and non-pseudohomophone nonwords (NPSH). In persons with aphasia, PSH accuracy exceeded NPSH accuracy but remained below word reading accuracy. Errors included legitimate alternative reading of components (LARC)-type responses, lexicalizations, and phonological nonword errors. Model-informed classification identified phonological dyslexia, surface dyslexia, mixed patterns, and unclassifiable cases. The findings suggest that kanji nonword reading depends on interactions between whole-word lexical activation and character-based candidate reading processes, supporting a dual-route account adapted to the specific properties of Japanese kanji.
Chinese written word forms are visually complex and structurally distinct from picture stimuli (line drawings of objects), yet the neural processing differences between these two stimulus categories are not well understood when phonological and semantic factors are controlled. We recorded stereoelectroencephalography (SEEG) from 27 adults with epilepsy during oral reading and picture naming. Stimuli included 36 words and corresponding object pictures, matched in phonology and semantics but differing in visual form. Compared with matched pictures, written words elicited relative low-frequency suppression in the hippocampus and middle occipital gyrus, and stronger high-frequency activation across parietal, frontal, temporal, and occipital cortices. Subregional analyses and Granger causality analyses further revealed spatial specificity and directed information flow among regions showing preferential responses to written words. These findings suggest that Chinese written word form processing involves distinct neural dynamics from general visual object recognition, characterized by frequency-specific, distributed cortical responses, advancing understanding of Chinese reading.
Developmental prosopagnosia (DP) causes difficulty recognizing familiar faces, but little is known about which stage(s) of the face-processing system difficulties occur, or whether these are identical in all DP cases. Twenty DPs and matched controls completed six face perception tasks. The DP group performed significantly poorer than controls on face detection and gender categorization tasks and on a global (averaged) face perception measure. 40% of individual DPs showed significant impairments on tasks not involving identity perception (face detection and categorization, age and gender categorization). By contrast, 50% showed broadly typical face perception and thus support for the idea of apperceptive (affecting both face perception and face memory) and mnemonic (affecting only face memory) subtypes of DP. Intraclass correlations revealed clear inter- and intra-individual differences, confirming that data from a single perceptual task cannot be taken as evidence of broader face-perception ability spanning beyond the results of that test..
