An ERP investigation of location invariance in masked repetition priming

Abstract

222Over the last two decades, masked priming has become a central tool for behavioral research aimed at decomposing the fast, highly automatized processing performed b by skilled readers during visual word comprehension. In recent work, this technique has been combined with the recording of event-related potentials (ERPs) in order to p provide a detailed analysis of the time course of component processes, and to provide some insight into the neural mechanisms involved. This research, combining ERP recordings and masked repetition priming of visual word stimuli, has outlined a cascade of ERP components sensitive to the priming manipulation Kiyonaga, Grainger, Midgley, & Holcomb). As well as the classic N400 component, Holcomb and Grainger described two earlier components that are of particular relevance for the present study. We will first summarize these findings.The first of these, the P150 (here referred to as the N N/P150), started as early as 90 msec and was over by 180 msec. This was a spatially focal component that produced p priming effects that were positive-going at occipital sites (especially over the right hemisphere) and negative-going at more anterior sites (priming here refers to targets that are unrelated to the prior prime, compared to targets that were repetitions of the prime). The distributional and temp poral similarity of this effect across several studies using

Timing the impact of literacy on visual processing

“…Moreover, strings was the sole category exhibiting an overall hemisphere effect (F 1,47 = 4.1, P < 0.05), with more positive values on the right hemisphere of the scalp. Together with the absence of a significant reading ability × hemisphere interaction for this category, this result suggests that letter strings are processed spontaneously more over the right hemisphere than over the left hemisphere at this early post-P1 stage, as reported previously (7,(34)(35)(36), independent of the literacy factor.…”

“…The vast majority of studies on reading (48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58), including ERP studies of masked priming (53)(54)(55)(56), support a classical feedforward model in which information is passed on from visual areas to language areas in a series of stages. Low-level orthographic processing peaks at posterior sites at ∼150 ms post-target onset (35,36,53,59). This processing stage is already letter size-invariant (36), but still case-sensitive (59), font-sensitive (36), and position-sensitive (35).…”

“…Low-level orthographic processing peaks at posterior sites at ∼150 ms post-target onset (35,36,53,59). This processing stage is already letter size-invariant (36), but still case-sensitive (59), font-sensitive (36), and position-sensitive (35). Just after 150 ms, a shift occurs in the orthographic code from position-specific to position-invariant (8,35), suggesting a transition from low-level visual feature processing to more abstract orthographic processing.…”

“…This processing stage is already letter size-invariant (36), but still case-sensitive (59), font-sensitive (36), and position-sensitive (35). Just after 150 ms, a shift occurs in the orthographic code from position-specific to position-invariant (8,35), suggesting a transition from low-level visual feature processing to more abstract orthographic processing. In ERPs, lexical effects do not arise until 220 ms (51) or 250 ms (52,53,55,56).…”

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

“…The P150 priming effect elicited by letter and false font targets was not significantly different, consistent with the literature indicating that the P150 is sensitive to a visual featural level of analysis in letter (Petit et al, 2006), word (e.g., Chauncey et al, 2008;Dufau et al, 2008;, and object (e.g., Allison, Puce, Spencer, & McCarthy, 1999;Eddy, Schmid, & Holcomb, 2006, for a P190) processing. At the word level, the P150 has been related to processes of visual classification, particularly in terms of familiar visual features (Proverbio, Vecchi, & Zani, 2004;Schendan, Ganis, & Kutas, 1998).…”