A masked priming ERP study of letter processing using single letters and false fonts.

Previous event-related potential (ERP) research on letter processing has suggested that a P150 reflects low-level, featural processing, whereas a P260 reflects high-level, abstract letter processing. In order to investigate the specificity of these effects, ERPs were recorded in a masked priming paradigm using matching and nonmatching pairs of letters (e.g., g-g, g-j) and false fonts (e.g.,[SYMBOL: SEE TEXT], [SYMBOL: SEE TEXT]). If the P150 priming effect indexes featural processing, there should be no effect of condition on the P150, since the letters and false fonts shared visual features. If the P260 priming effect indexes the processing of abstract letter representations, it should be evident only in the letter condition. As was expected, the P150 priming effect was similar for letters and false fonts; however, the P260 priming effect was also similar between conditions. Thus, the P260 priming effect may not be sensitive to abstract letter processing per se, or such processing may be extremely abstract.