Spatiotemporal Dynamics of the Processing of Spoken Inflected and Derived Words: A Combined EEG and MEG Study

Abstract

The spatiotemporal dynamics of the neural processing of spoken morphologically complex words are still an open issue. In the current study, we investigated the time course and neural sources of spoken inflected and derived words using simultaneously recorded electroencephalography (EEG) and magnetoencephalography (MEG) responses. Ten participants (native speakers) listened to inflected, derived, and monomorphemic Finnish words and judged their acceptability. EEG and MEG responses were time-locked to both the stimulus onset and the critical point (suffix onset for complex words, uniqueness point for monomorphemic words). The ERP results showed that inflected words elicited a larger left-lateralized negativity than derived and monomorphemic words approximately 200 ms after the critical point. Source modeling of MEG responses showed one bilateral source in the superior temporal area ∼100 ms after the critical point, with derived words eliciting stronger source amplitudes than inflected and monomorphemic words in the right hemisphere. Source modeling also showed two sources in the temporal cortex approximately 200 ms after the critical point. There, inflected words showed a more systematic pattern in source locations and elicited temporally distinct source activity in comparison to the derived word condition. The current results provide electrophysiological evidence for at least partially distinct cortical processing of spoken inflected and derived words. In general, the results support models of morphological processing stating that during the recognition of inflected words, the constituent morphemes are accessed separately. With regard to derived words, stem and suffix morphemes might be at least initially activated along with the whole word representation.

How Linearity and Structural Complexity Interact and Affect the Recognition of Italian Derived Words

“…It is difficult to see how the contrary findings obtained for prefixed compared to suffixed stimuli, particularly the difference between the lexicalized words, could be explained by strictly dichotomous proposals that derived words must all be stored and processed in either decomposed (Boudelaa et al 2009;Meinzer et al 2009;Taft 1979Taft , 2004Gold and Rastle 2007;Taft and Forster 1975) or whole word form (Bozic et al 2013;Bybee 1985Bybee , 1995Cole et al 1989;Davis et al 2004). The present findings also appear to present a difficulty for standard dual-route "horse race" models with both decompositional and holistic full-form access pathways operating in parallel and independently, with performance determined by whichever route produces the fastest recognition of the word (Caramazza et al 1988;Leminen et al 2011;Niswander et al 2000;Schreuder and Baayen 1995). For both prefixed and suffixed lexicalized words, this should have been the holistic route according to the initial prediction from prior research (Bozic et al 2013;Leminen et al 2011Leminen et al , 2013Schreuder and Baayen 1994), particularly since these words were generally equivalent in whole-word, base, and affix frequencies.…”

“…The present findings also appear to present a difficulty for standard dual-route "horse race" models with both decompositional and holistic full-form access pathways operating in parallel and independently, with performance determined by whichever route produces the fastest recognition of the word (Caramazza et al 1988;Leminen et al 2011;Niswander et al 2000;Schreuder and Baayen 1995). For both prefixed and suffixed lexicalized words, this should have been the holistic route according to the initial prediction from prior research (Bozic et al 2013;Leminen et al 2011Leminen et al , 2013Schreuder and Baayen 1994), particularly since these words were generally equivalent in whole-word, base, and affix frequencies. However, these words showed the largest processing differences.…”

“…An early and influential theory by Taft and Forster (1975), more recently identified as the "Obligatory Decomposition" process (Boudelaa et al 2009;Gold and Rastle 2007;Marslen-Wilson and Tyler 2007;Meinzer et al 2009;Taft 1979Taft , 2004Taft and Ardasinski 2006) claims that only morphemes and their combinatorial constraints are part of the mental lexicon, meaning that complex words are typically broken down and processed according to the constituent morphemes. Other models have advocated that morphological information is either represented holistically, in whole word form (Bozic et al 2013;Bybee 1985Bybee , 1995Cole et al 1989;Davis et al 2004), or proposed a "Dual-Route" theory that allows morphemic and whole word representations to coexist and be accessed via separate routes depending on a word's linguistic features (Caramazza et al 1988;El Yagoubi et al 2008;Leminen et al 2011;Longtin and Meunier 2005;Meunier and Longtin 2007;Niswander et al 2000;Rastle and Davis 2003;Schreuder and Baayen 1995;Taft 1994).…”

Flexible, rapid and automatic neocortical word form acquisition mechanism in children as revealed by neuromagnetic brain response dynamics

“…Eye blinks were detected on the basis of the activity in the bipolar vertical EOG channel, and corrected for using Brainstorm's signal-space projection (SSP) algorithm, as were artifacts arising from heart beats. After SSP processing, the data were bandpass filtered (0.1 to 45 Hz) in accordance with previous MEG studies ( Leminen et al, 2011) and in order to exclude the noise arising from continuous high positioning process, and divided into epochs of 1000 ms, starting from 100 ms prior to stimulus onset.…”

The role of attention in processing morphologically complex spoken words: an EEG/MEG study

“…In the non-attended task, the participants were instructed to ignore the incoming auditory stimuli and concentrate on the silent cartoon. In the attended task, previously reported by Leminen et al (2011), the participants were to judge the acceptability of each stimulus. Importantly, EEG and MEG responses were time-locked to the onset of critical information [suffix onset for the complex words and uniqueness point (UP) for the monomorphemic words].…”