The ND250 indexes a visual-orthographic familiarity effect in visual word recognition: evidence from Chinese components.

Reading pseudowords (or low-frequency words) typically elicits stronger brain activation than real words (or high-frequency words) in the ventral occipitotemporal cortex (vOT). The ND250 has been proposed as an event-related potential (ERP) component indexing this enhanced neural response. However, the neural basis of the ND250 and its functional role in visual word recognition remain unclear. Within the framework of the Interactive Account, the ND250 has been interpreted as a prediction error signal, reflecting phonological-semantic top-down influences on orthographic processing. Alternatively, it can be interpreted as a visual-orthographic familiarity effect, with greater neural responses to unfamiliar orthographic stimuli than to familiar ones. The present study employed Chinese components as stimuli to dissociate visual-form frequency from phonological and semantic associations. ERPs to Chinese components were recorded during an implicit reading task. The results showed that the ND250 effect was not modulated by the frequency with which an orthographic stimulus (i.e., a Chinese component) is associated with phonological and semantic information. Instead, it was selectively modulated by the frequency with which the component's visual form appears in written text. These findings challenge the interpretation of the ND250 as a prediction error signal proposed by the Interactive Account. Rather, they suggest that, under implicit task conditions, the ND250 is more consistent with the visual-orthographic familiarity account. By dissociating visual-form frequency from phonological and semantic associations, the present study advances our understanding of the neural basis of the ND250 and provides new insights into early visual-orthographic processing in visual word recognition.