Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

Abstract

Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime– target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner–CLEAN) and opaque (corner–CORN) prime–target pairs, but not for prime–target pairs with only an orthographic relationship (brothel–BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime–target pairs can be used to further understand the neural substrates and the time course of lexical processing.

Real-time Functional Architecture of Visual Word Recognition

“…It is also consistent with earlier MEG evidence that orthographic processing in inferior and posterior temporal regions, over early 150-250 time windows, is sensitive to the presence of potential stems or affixes (e.g., Lehtonen et al, 2011). More generally, these can be seen as aspects of a ventral stream object recognition process tuned to orthographic analysis over decades of intensive experience with written text.…”

“…Several studies, stimulated by the masked priming results, ask whether there is electrophysiological evidence for early sensitivity to the morphological content of visual word forms, independent of lexical constraints. Working primarily with sets of morphologically complex and pseudo-complex word forms, masked priming has been combined with both EEG (e.g., Morris, Grainger, & Holcomb, 2008;Lavric, Clapp, & Rastle, 2007) and MEG (Lehtonen, Monahan, & Poeppel, 2011), whereas a further set of studies have used unprimed lexical decision tasks (e.g., Lavric, Elchlepp, & Rastle, 2012;Lewis, Solomyak, & Marantz, 2011;Zwieg & Pylkkänen, 2009). Taken as a whole, these and similar studies provide evidence for sensitivity to potential morphological structure, where complex and pseudo-complex forms like farmer and corner initially group together relative to orthographic controls like scandal, consistent with a morpho-orthographic view where these processes are not lexically driven.…”

Behavioural and ERP effects of paradigm complexity on visual word recognition

“…Using a connectionist network account (e.g., Rueckl, Mikolinski, Raveh, Miner, & Mars, 1997), we may suppose that when a word is processed, the connections among its features (e.g., allomorphs) strengthen and facilitate its subsequent identification. In the same vein, morphologically related words (when they are similar in both form and meaning) prime target words (Crepaldi, Rastle, Coltheart, & Nickels, 2010;Feldman, O'Connor, & Moscoso del Prado Martín, 2009;Järvikivi & Niemi, 2002b;Kielar, Joanisse, & Hare, 2008;Lehtonen, Monahan, & Poeppel, 2011;Morris & Stockall, 2012).…”

The real-time comprehension of WH-dependencies in a WH-agreement language

“…Fiebach et al 2001). Closed-class morphology is accessed very early in word identification, probably before the perceptual stimulus is matched against the open-class lexicon (Taft & Forster 1975, Dikker et al 2009, Solomyak & Marantz 2010, Lehtonen et al 2011. This suggests that morphological cues could have a temporal advantage over lexically specific cues in comprehension.…”