Form-based Representation Research Articles

Neural representation of phonological wordform in temporal cortex.

While the neural bases of the earliest stages of speech categorization have been widely explored using neural decoding methods, there is still a lack of consensus on questions as basic as how wordforms are represented and in what way this word-level representation influences downstream processing in the brain. Isolating and localizing the neural representations of wordform is challenging because spoken words activate a variety of representations (e.g., segmental, semantic, articulatory) in addition to form-based representations. We addressed these challenges through a novel integrated neural decoding and effective connectivity design using region of interest (ROI)-based, source-reconstructed magnetoencephalography/electroencephalography (MEG/EEG) data collected during a lexical decision task. To identify wordform representations, we trained classifiers on words and nonwords from different phonological neighborhoods and then tested the classifiers' ability to discriminate between untrained target words that overlapped phonologically with the trained items. Training with word neighbors supported significantly better decoding than training with nonword neighbors in the period immediately following target presentation. Decoding regions included mostly right hemisphere regions in the posterior temporal lobe implicated in phonetic and lexical representation. Additionally, neighbors that aligned with target word beginnings (critical for word recognition) supported decoding, but equivalent phonological overlap with word codas did not, suggesting lexical mediation. Effective connectivity analyses showed a rich pattern of interaction between ROIs that support decoding based on training with lexical neighbors, especially driven by right posterior middle temporal gyrus. Collectively, these results evidence functional representation of wordforms in temporal lobes isolated from phonemic or semantic representations.

PLATON: Developing a Graphical Lesson Planning System for Prospective Teachers

Lesson planning is both an important and demanding task—especially as part of teacher training. This paper presents the requirements for a lesson planning system and evaluates existing systems regarding these requirements. One major drawback of existing software tools is that most are limited to a text- or form-based representation of the lesson designs. In this article, a new approach with a graphical, time-based representation with (automatic) analyses methods is proposed and the system architecture and domain model are described in detail. The approach is implemented in an interactive, web-based prototype called PLATON, which additionally supports the management of lessons in units as well as the modelling of teacher and student-generated resources. The prototype was evaluated in a study with 61 prospective teachers (bachelor’s and master’s preservice teachers as well as teacher trainees in post-university teacher training) in Berlin, Germany, with a focus on usability. The results show that this approach proofed usable for lesson planning and offers positive effects for the perception of time and self-reflection.

Temporal changes in semantic and lexical access related to mild cognitive impairment.

It has been hypothesized that the deterioration in the ability to name famous people in normal aging and cognitive impairment is a continuum in which meaning-based representations and form-based representations are differentially impaired, with early impairments in lexical access but not in semantic access. This hypothesis is tested in a follow-up study comparing the performance of fifty-six participants with amnestic mild cognitive impairment and forty-one control participants were assessed. A lexical task was conducted involving recognition and naming of famous people from photographs. Proportional semantic and phonological access measures were calculated. Comparisons revealed significant differences between baseline and follow-up, with improvements in semantic access in the control group and decrements in phonological access in the group with amnestic mild cognitive impairment. Phonological access and reaction time measures were significantly and positively correlated, and semantic access and reaction time were significantly and negatively correlated. These results add evidence to the hypothesis that the decrease of processing resources is related to the increase of difficulties in lexical access throughout aging. Patterns of change must be replicated over longer periods of time.

Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

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.

Word Cognate Status and Concreteness: ERPs in L1 and L2 processing

Event Abstract Back to Event Word Cognate Status and Concreteness: ERPs in L1 and L2 processing Ivo Popivanov1*, A. Janyan1 and E. Andonova1, 2 1 New Bulgarian University, Bulgaria 2 Bremen University, Germany To address the issue of bilingual language representation and processing we crossed a semantic variable (concreteness) and the cognate status of words in a translation verification task. Cognates are words that have a similar form and meaning in both languages (L1 & L2) while non-cognates in a translation task have similarity in meaning but not in word form. The general finding is that cognates are recognized and produced faster than non-cognates (e.g., Kroll & Stewart, 1994) which are usually attributed to a common set of form-based representations across the two languages. Models of bilingual language processing disagree on the issue whether cognate processing is affected by overlapping representations at the lexical level only or the semantics beyond (Kroll & De Groot, 1997). We test the models’ predictions and examine the extent to which semantics (more specifically, concreteness, i.e., concrete vs. abstract words) is involved in cognate vs. non-cognate processing. 11 young Bulgarian-English bilinguals performed a single word translation verification task from L2 (English) into L1 (Bulgarian). The words were presented for 300 ms with a 500-ms interstimulus interval and with an intertrial interval that varied between 1700 and 2200 ms. We used a go/no go task (to press a button if a non-equivalent translation is detected and do not press a button if the second word is a translation equivalent). Grand average ERPs were analysed during both L2 and L1 processing in two time windows on mean amplitude. A repeated-measure ANOVA showed that during L2 word processing the semantics of non-cognates was activated starting from 140 ms after stimulus onset while for cognates it was only activated later, starting at word offset. In addition, the magnitude of the cognate effect was larger during the second time interval, i.e., at later stages of processing. Furthermore, the analyses suggested that during the phase of translation recognition (L1 word processing) cognate processing did not involve semantics in either time window while non-cognate processing did activate it starting from 200 ms after word onset till the end of the second window (600 ms). This study shows for the first time that cognate processing in L2 activates semantics very early which is consistent with studies on monolinguals (see Pulvermüller, 2007). Overall, the results offer support to word processing in the bilingual’s two languages being semantically mediated and affected by the cognate status of words, and it thus contributes to our understanding of language representation in bilinguals. Findings are discussed in terms of the models of bilingual language representaion (Kroll & De Groot, 1997).

Representation of Lexical Form: Evidence From Studies of Sublexical Ambiguity.

The authors examined the role of intermediate, sublexical representations in spoken word perception. In particular, they tested whether flaps, which are neutralized allophones of intervocalic /t/s and /d/s, map onto their underlying phonemic counterparts. In 2 shadowing tasks, the authors found that flaps primed their carefully articulated counterparts, and vice versa. Because none of the flapped stimuli were lexically ambiguous (e.g., between rater and raider), these results provide evidence that such priming is sublexically mediated. Therefore, the current study provides further insights into when underlying form-based representations are activated during spoken word processing. In particular, the authors argue that phonological ambiguity, inherent in their flapped stimuli, is one of the conditions leading to the activation of underlying representations.

Representation of lexical form.

The authors attempted to determine whether surface representations of spoken words are mapped onto underlying, abstract representations. In particular, they tested the hypothesis that flaps--neutralized allophones of intervocalic /t/s and /d/s--are mapped onto their underlying phonemic counterparts. In 6 repetition priming experiments, participants responded to stimuli in 2 blocks of trials. Stimuli in the 1st block served as primes and those in the 2nd as targets. Primes and targets consisted of English words containing intervocalic /t/s and /d/s that, when produced casually, were flapped. In all 6 experiments, reaction times to target items were measured as a function of prime type. The results provide evidence for both surface and underlying form-based representations.

Form-Based Representation in the Mental Lexicon: Priming (with) Bound Stem Allomorphs in Finnish

A series of four visual–visual priming experiments investigates the role of bound stem allomorphs in the representation and processing of Finnish case inflected nouns. Niemi et al. (1994) and Laine et al. (1994) argue that Finnish nouns are parsed into stem and affix in reception and that the bound stem allomorphs have separate (visual) lexical representations. Recently Järvikivi and Niemi (in press) have provided converging evidence for their claim based on a series of lexical decision experiments with Finnish stem allomorphs. The results from the present series of four follow-up experiments reported here showed that (isolated) bound stem allomorphs primed the recognition of the corresponding monomorphemic nouns significantly compared both to phonologically unrelated pseudowords and to phonologically minimally different pseudowords. Furthermore, not only did both phonologically transparent and opaque case inflected nouns prime the corresponding nominative singulars, but also there was no difference in priming between the two. The results are well in accordance and corroborate the hypotheses drawn from the earlier investigations. Moreover, they further indicate that bound stem allomorphs have representations on a purely formal level only, i.e., they serve as indices of and entering points to morphological/morphosyntactic information.

The interaction of meaning and sound in spoken word recognition.

Models of spoken word recognition vary in the ways in which they capture the relationship between speech input and meaning. Modular accounts prohibit a word's meaning from affecting the computation of its form-based representation, whereas interactive models allow activation at the semantic level to affect phonological processing. We tested these competing hypotheses by manipulating word familiarity and imageability, using lexical decision and repetition tasks. Responses to high-imageability words were significantly faster than those to low-imageability words. Repetition latencies were also analyzed as a function of cohort variables, revealing a significant imageability effect only for words that were members of large cohorts, suggesting that when the mapping from phonology to semantics is difficult, semantic information can help the discrimination process. Thus, these data support interactive models of spoken word recognition.