Publications

Abstract

Objectives: Metallic compounds present in the oral and maxillofacial regions (OMRs) cause large artefacts during MR scanning. We quantitatively assessed these artefacts embedded within a phantom according to standards set by the American Society for Testing and Materials (ASTM).
Methods: Seven metallic dental materials (each of which was a 10-mm(3) cube embedded within a phantom) were scanned [i.e. aluminium (Al), silver alloy (Ag), type IV gold alloy (Au), gold-palladium-silver alloy (Au-Pd-Ag), titanium (Ti), nickel-chromium alloy (NC) and cobalt-chromium alloy (CC)] and compared with a reference image. Sequences included gradient echo (GRE), fast spin echo (FSE), gradient recalled acquisition in steady state (GRASS), a spoiled GRASS (SPGR), a fast SPGR (FSPGR), fast imaging employing steady state (FIESTA) and echo planar imaging (EPI; axial/sagittal planes). Artefact areas were determined according to the ASTM-F2119 standard, and artefact volumes were assessed using OsiriX MD software (Pixmeo, Geneva, Switzerland).
Results: Tukey-Kramer post hoc tests were used for statistical comparisons. For most materials, scanning sequences eliciting artefact volumes in the following (ascending) order FSE-T-1/FSE-T-2 < FSPGR/SPGR < GRASS/GRE < FIESTA < EPI. For all scanning sequences, artefact volumes containing Au, Al, Ag and Au-Pd-Ag were significantly smaller than other materials (in which artefact volume size increased, respectively, from Ti < NC < CC). The artefact-specific shape (elicited by the cubic sample) depended on the scanning plane (i.e. a circular pattern for the axial plane and a "clover-like" pattern for the sagittal plane).
Conclusions: The availability of standardized information on artefact size and configuration during MRI will enhance diagnosis when faced with metallic compounds in the OMR.

Abstract

Purpose
To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients.
Methods
First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations.
Results
With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant) distances to the source.
Conclusions
The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT.

Abstract

Recent research has revealed that the way phonology is constructed during word production differs across languages. Dutch and English native speakers are suggested to incrementally insert phonemes into a metrical frame, whereas Mandarin Chinese speakers use syllables and Japanese speakers use a unit called the mora (often a CV cluster such as "ka" or "ki"). The present study is concerned with the question how bilinguals construct phonology in their L2 when the phonological unit size differs from the unit in their L1. Japanese English bilinguals of varying proficiency read aloud English words preceded by masked primes that overlapped in just the onset (e.g., bark-BENCH) or the onset plus vowel corresponding to the mora-sized unit (e.g., bell-BENCH). Low proficient Japanese English bilinguals showed CV priming but did not show onset priming, indicating that they use their L1 phonological unit when reading L2 English words. In contrast, high-proficient Japanese English bilinguals showed significant onset priming. The size of the onset priming effect was correlated with the length of time spent in English-speaking countries, which suggests that extensive exposure to L2 phonology may play a key role in the emergence of a language-specific phonological unit in L2 word production.

Abstract

Person names and common nouns differ in how they are stored in the mental lexicon. Using event-related potentials, this study compared the integration of names and nouns into sentence contexts. Both person names and common nouns were highly related in meaning and either congruent or incongruent within the previous contexts. Name incongruence elicited an N400 effect, suggesting that people were able to rapidly retrieve the semantic meaning of names from long-term memory even when this process was mediated by person identification. Conversely, participants showed a “good enough” processing of the nouns due to their low specificity level and, thus, rich semantic associations, leading to a P600 effect. These distinctive ERP effects provide clear evidence for the distinctive semantic representations of these word categories by showing that the activation of a name’s meaning is mediated by a single connection between identity-specific information and person identity, whereas multiple connections exist between nouns and their meanings.

Abstract

Bilingual language control (BLC) is a much-debated issue in recent literature. Some models assume BLC is achieved by various types of inhibition of the non-target language, whereas other models do not assume any inhibitory mechanisms. In an event-related potential (ERP) study involving a long-lag morphological priming paradigm, participants were required to name pictures and read aloud words in both their L1 (Dutch) and L2 (English). Switch blocks contained intervening L1 items between L2 primes and targets, whereas non-switch blocks contained only L2 stimuli. In non-switch blocks, target picture names that were morphologically related to the primes were named faster than unrelated control items. In switch blocks, faster response latencies were recorded for morphologically related targets as well, demonstrating the existence of morphological priming in the L2. However, only in non-switch blocks, ERP data showed a reduced N400 trend, possibly suggesting that participants made use of a post-lexical checking mechanism during the switch block.

Abstract

The effect of phonological similarity on L1-L2 cognate translation priming was examined with Japanese-English bilinguals. According to the phonological account, the cognate priming effect for different-script bilinguals consists of additive effects of phonological and conceptual facilitation. If true, then the size of the cognate priming effect would be directly influenced by the phonological similarity of cognate translation equivalents. The present experiment tested and confirmed this prediction: the cognate priming effect was significantly larger for cognate prime-target pairs with high-phonological similarity than pairs with low-phonological similarity. Implications for the nature of lexical processing in same-versus different-script bilinguals are discussed.

Abstract

E-Prime, the software suite by Psychology Software Tools, is used for designing, developing and running custom psychological experiments. Aimed at students and researchers alike, this book provides a much needed, down-to-earth introduction into a wide range of experiments that can be set up using E-Prime. Many tutorials are provided to teach the reader how to develop experiments typical for the broad fields of psychological and cognitive science. Apart from explaining the basic structure of E-Prime and describing how it fits into daily scientific practice, this book also offers an introduction into programming using E-Prime’s own E-Basic language. The authors guide the readers step-by-step through the software, from an elementary to an advanced level, enabling them to benefit from the enormous possibilities for experimental design offered by E-Prime.

Abstract

Not unlike the tonal system in Chinese, Japanese habitually attaches pitch accents to the production of words. However, in contrast to Chinese, few homophonic word-pairs are really distinguished by pitch accents (Shibata & Shibata, 1990). This predicts that pitch accent plays a small role in lexical selection for Japanese language comprehension. The present study investigated whether native Japanese speakers necessarily use pitch accent in the processing of accent-contrasted homophonic pairs (e.g., ame [LH] for 'candy' and ame [HI] for 'rain') measuring electroencephalographic (EEG) potentials. Electrophysiological evidence (i.e., N400) was obtained when a word was semantically incorrect for a given context but not for incorrectly accented homophones. This suggests that pitch accent indeed plays a minor role when understanding Japanese. (C) 2013 Elsevier Ltd. All rights reserved.

Abstract

The process of reading aloud bare nouns in alphabetic languages is immune to semantic context effects from pictures. This is accounted for by assuming that words in alphabetic languages can be read aloud relatively fast through a sub-lexical grapheme-phoneme conversion (GPC) route or by a direct route from orthography to word form. We examined semantic context effects in a word-naming task in two languages with logographic scripts for which GPC cannot be applied: Japanese kanji and Chinese hanzi. We showed that reading aloud bare nouns is sensitive to semantically related context pictures in Japanese, but not in Chinese. The difference between these two languages is attributed to processing costs caused by multiple pronunciations for Japanese kanji. (C) 2010 Elsevier B.V. All rights reserved.