Orthographic deficits but typical visual perceptual processing in Chinese adults with reading disability

Abstract

Visual orthographic deficits have been reported as one of the core deficits in reading disability (RD), however, whether the deficits are orthographic-specific or domain general in all visual processing is still in debate. Hereby, we conducted an fMRI and an EEG study to examine visual orthographic deficits in Chinese adults with RD. In the fMRI study, we found that there was reduced brain activation in the left inferior temporal gyrus and right cuneus gyrus in orthographic processing (lexical minus perceptual), but not in visual perceptual processing (perceptual minus null) in adults with RD, suggesting orthographic-specific deficits. In the EEG study, adults with RD showed typical visual binding as indicated by intermodulation SSVEPs (steady-state visual-evoked potentials) for both real and pseudo characters, suggesting normal neural phase locking in the visual modality. These results consistently suggest orthographic specific deficits but normal visual perceptual processing in adults with RD, deepening our understanding of the underlying deficits associated with RD.

Negligible contribution of adaptation of ocular opponency neurons to the effect of short-term monocular deprivation

“…Moreover, we extracted the SSVEP signals at the intermodulation frequencies which were considered to reflect the neural activities of interocular competition ( Poggio and Talbot, 1981 ; May et al, 2012 ; Said and Heeger, 2013 ; Katyal et al, 2016 , 2018 ; Du et al, 2023 ). Consistent with previous research ( Govenlock et al, 2008 ; Cai et al, 2020 ; Gu et al, 2020 ; Mersad and Caristan, 2021 ; Song et al, 2023a ; Yan et al, 2023 ), intermodulation responses were identified at the commonly used frequency of 6.75 Hz (f1 + f2), exhibiting a superior response signal. The signal-to-noise ratio (SNR) was calculated by dividing the power at the extracted frequency by the mean power of the 20 surrounding (10 on each side, excluding the immediately adjacent bin) frequency bins ( Zhang et al, 2011 ; Lyu et al, 2020 ; Song et al, 2023b ).…”