Abstract: The orthographic neighborhood effect (N effect) is the phenomenon that words with more neighbors (other words than can be formed by changing one letter) are identified faster. Lexical decision task, semantic category task, and speeded naming task, etc., have been used to investigate the N effect. Affecting factors of the N effect, such as the frequency of the target words, the language of the stimuli, and the neighborhood site, were summarized. An early component in 150~300ms window and larger N400 amplitudes reflect the N effect. The semantic activation in the left hemisphere and the executive control processes in the mid-dorsolateral prefrontal cortex are related to the N effect. The major models of the N effect include the Multiple Read-Out Model, the Interactive-Activation Model, and the Dual-Route Cascaded Model. In conclusion, future research should be focused on experimental materials, research method, etc.

Key words: the N effect, orthography, N400, lexical activation