Evidence for early morphological decomposition: Combining masked priming with magnetoencephalography
TL;DR: Data regarding the transitional probability from stem to affix in a post hoc comparison is presented, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words.
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.
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01 Jan 1985
TL;DR: This paper discusses one aspect of the lexicon, namely its morphological organization, and describes this kind of lexicon system as most suited for describing suffixing languages with a comparatively high degree of agglutination.
Abstract: 1. In trod u otion In this paper, I w ill discuss one aspect of the lexicon, namely its morphological organization. For about two years I have been working with Koakenniemi's twolevel model (Koakenniemi 1983)i on a Polish two-level description. In this work, I have become more and more Interested in the formalism it s e l f , something that has tended to push work on the language description into the background. It seems to be the case that in moat concrete two-level descriptions, the rule component is forced to carry too heavy a burden in comparison with the lexicon, perhaps because the lexicon is very simple as to its implementation. Like many other lexical systems in computer applications i t is implemented as a tree, with a root node and leaves, from which the lexical entries eire retrieved when the analysts routine has traversed the tree. The twolevel lexicon la a bit more sophisticated than th is , however, in that there la not only one, but several lexicon trees, the so called minilexicons. The user links the mlnilexicona into a whole, moat often into a root lexicon and a number of su ffix lexicons. In Hockett'a terminology, we could apeak of an Itern-and-Arrangement (lA) model (Hockett 1958, pp 386ff). Elsewhere I have characterized this kind of lexicon system as most suited for describing suffixing languages with a comparatively high degree of agglutination (Borin 1985f p 35); This is mainly due to the fact that the system works according to what Blåberg (1984, p 6 l) aptly has termed the "forget-where-you-came-from"
261 citations
TL;DR: The data support a model of word recognition in which decomposition is attempted, and possibly utilized, for complex words containing bound roots as well as free word-stems, and find evidence of decomposition for both free stems and bound roots at the M170 stage in processing.
Abstract: We employ a single-trial correlational MEG analysis technique to investigate early processing in the visual recognition of morphologically complex words. Three classes of affixed words were presented in a lexical decision task: free stems (e.g., taxable), bound roots (e.g., tolerable), and unique root words (e.g., vulnerable, the root of which does not appear elsewhere). Analysis was focused on brain responses within 100-200 msec poststimulus onset in the previously identified letter string and visual word-form areas. MEG data were analyzed using cortically constrained minimum-norm estimation. Correlations were computed between activity at functionally defined ROIs and continuous measures of the words' morphological properties. ROIs were identified across subjects on a reference brain and then morphed back onto each individual subject's brain (n = 9). We find evidence of decomposition for both free stems and bound roots at the M170 stage in processing. The M170 response is shown to be sensitive to morphological properties such as affix frequency and the conditional probability of encountering each word given its stem. These morphological properties are contrasted with orthographic form features (letter string frequency, transition probability from one string to the next), which exert effects on earlier stages in processing (â¼130 msec). We find that effects of decomposition at the M170 can, in fact, be attributed to morphological properties of complex words, rather than to purely orthographic and form-related properties. Our data support a model of word recognition in which decomposition is attempted, and possibly utilized, for complex words containing bound roots as well as free word-stems.
129 citations
TL;DR: The view that learning to appreciate morphological relationships may be a vital part of acquiring a direct mapping between printed words and their meanings, represented in the ventral brain pathway of the reading network is developed.
91 citations
TL;DR: This work uses MEG to provide evidence for the temporally-differentiated stages of the Full Decomposition model, and demonstrates an early effect of derivational family entropy, corresponding to the stem lookup stage, and a late effect of a novel statistical measure, semantic coherence, which quantifies the gradient semantic well-formedness of complex words.
68 citations
Cites background from "Evidence for early morphological de..."
...Taking advantage of the temporal resolution of MEG, here we separately examine both the hypothesized earlier derivational family entropy effect on lexical access for a stem, as well as the hypothesized later surface frequency effect on recombination of stem and affix....
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...Using MEG, Lehtonen, Monahan, and Poeppel (2011) found similar effects for regular derived words at a latency of !...
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References
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TL;DR: These findings support the notion that properties of the MEG response index specific lexical processes and demonstrate that masked priming can be effectively combined with MEG to investigate the nature of lexical processing.
21 citations
"Evidence for early morphological de..." refers methods or result in this paper
...MEG has also been shown to be able to be effectively combined with masked priming (Monahan et al., 2008)....
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...In line with previous experiments that combined MEG with masked priming (Monahan et al., 2008), no consistent pattern of peaks was observed across all participants in later time-windows beyond the component peaking at about 220 msec....
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...Yet, this pattern is consistent with the morphology of the MEG temporal waveform elicited in identity masked priming (Monahan et al., 2008), also with regard to themagnetic field distribution of the peak....
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...This peak, as predicted, was exceptionally similar in timing, distribution, and magnetic field contour to that reported in Monahan et al. (2008)....
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TL;DR: It is shown that if a Japanese word is presented in a script it never appears in, this presentation immediately activates the (“actual”) visual word form of that lexical item, suggesting that Japanese orthographic codes are not only shape-invariant, but also script invariant.
Abstract: What kind of mental objects are letters? Research on letter perception has mainly focussed on the visual properties of letters, showing that orthographic representations are abstract and size/shape invariant. But given that letters are, by definition, mappings between symbols and sounds, what is the role of sound in orthographic representation? We present two experiments suggesting that letters are fundamentally sound-based representations. To examine the role of sound in orthographic representation, we took advantage of the multiple scripts of Japanese. We show two types of evidence that if a Japanese word is presented in a script it never appears in, this presentation immediately activates the (“actual”) visual word form of that lexical item. First, equal amounts of masked repetition priming are observed for full repetition and when the prime appears in an atypical script. Second, visual word form frequency affects neuromagnetic measures already at 100–130 ms whether the word is presented in its conventional script or in a script it never otherwise appears in. This suggests that Japanese orthographic codes are not only shape-invariant, but also script invariant. The finding that two characters belonging to different writing systems can activate the same form representation suggests that sound identity is what determines orthographic identity: as long as two symbols express the same sound, our minds represent them as part of the same character/letter.
17 citations
"Evidence for early morphological de..." refers background in this paper
...…to left (or bilateral) posterior occipital and temporal regions, similar to the sources that have been found for the M170 component (see, e.g., Pylkkänen & Okano, 2010; Harris et al., 2008; Pylkkänen et al., 2006; see also Gold & Rastle, 2007, for an fMRI study onmaskedmorphological priming)....
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TL;DR: This study examined the online processing of concealed questions, in which the meaning of a complex noun phrase shifts to a covert question when mandated by a sub-class of question-selecting verbs (e.g., guess).
17 citations
"Evidence for early morphological de..." refers background in this paper
...…to left (or bilateral) posterior occipital and temporal regions, similar to the sources that have been found for the M170 component (see, e.g., Pylkkänen & Okano, 2010; Harris et al., 2008; Pylkkänen et al., 2006; see also Gold & Rastle, 2007, for an fMRI study onmaskedmorphological priming)....
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...As the sources of this peak were localized to similar regions as are those of the M170 (e.g., Harris et al., 2008), the present peak may be an M170-related component....
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TL;DR: The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish and confirmed that the results from masked priming were modulated by the morphological structure of the words but not by the prime-target form overlap alone.
Abstract: The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish. Experiment 1 showed equal facilitation for all prime types with a short 60-ms stimulus onset asynchrony (SOA) but significant facilitation for unambiguous words only with a long 300-ms SOA. Experiment 2 showed that all potential readings of ambiguous inflections were activated under a short SOA. Whereas the prime-target form overlap did not affect the results under a short SOA, it significantly modulated the results with a long SOA. Experiment 3 confirmed that the results from masked priming were modulated by the morphological structure of the words but not by the prime-target form overlap alone. The results support approaches in which early prelexical morphological processing is driven by morph-based segmentation and form is used to cue selection between 2 candidates only during later processing.
15 citations