Publications

Abstract

Affective behaviors enable social robots to not only establish better connections with humans but also serve as a tool for the robots to express their internal states. It has been well established that emotions are important to signal understanding in Human-Robot Interaction (HRI). This work aims to harness the power of Large Language Models (LLM) and proposes an approach to control the affective behavior of robots. By interpreting emotion appraisal as an Emotion Recognition in Conversation (ERC) tasks, we used GPT-3.5 to predict the emotion of a robot’s turn in real-time, using the dialogue history of the ongoing conversation. The robot signaled the predicted emotion using facial expressions. The model was evaluated in a within-subjects user study (N = 47) where the model-driven emotion generation was compared against conditions where the robot did not display any emotions and where it displayed incongruent emotions. The participants interacted with the robot by playing a card sorting game that was specifically designed to evoke emotions. The results indicated that the emotions were reliably generated by the LLM and the participants were able to perceive the robot’s emotions. It was found that the robot expressing congruent model-driven facial emotion expressions were perceived to be significantly more human-like, emotionally appropriate, and elicit a more positive impression. Participants also scored significantly better in the card sorting game when the robot displayed congruent facial expressions. From a technical perspective, the study shows that LLMs can be used to control the affective behavior of robots reliably in real-time. Additionally, our results could be used in devising novel human-robot interactions, making robots more effective in roles where emotional interaction is important, such as therapy, companionship, or customer service.

Abstract

The current study explored the role of sentential inference in connecting lexical/grammatical knowledge and overall text comprehension in foreign language learning. Using structural equation modeling (SEM), causal relationships were examined between four latent variables: lexical knowledge, grammatical knowledge, sentential inference, and text comprehension. The study analyzed 281 Chinese university students learning Japanese as a second language and compared two causal models: (1) the partially-mediated model, which suggests that lexical knowledge, grammatical knowledge, and sentential inference concurrently influence text comprehension, and (2) the wholly-mediated model, which posits that both lexical and grammatical knowledge impact sentential inference, which then further affects text comprehension. The SEM comparison analysis supported the wholly-mediated model, showing sequential causal relationships from lexical knowledge to sentential inference and then to text comprehension, without significant contribution from grammatical knowledge. The results indicate that sentential inference serves as a crucial bridge between lexical knowledge and text comprehension.

Abstract

This study is the first to report chronometric evidence on Tongan language production. It has been speculated that the mora plays an important role during Tongan phonological encoding. A mora follows the (C)V form, so /a/ and /ka/ (but not /k/) denote a mora in Tongan. Using a picture-word naming paradigm, Tongan native speakers named pictures containing superimposed non-word distractors. This task has been used before in Japanese, Korean, and Vietnamese to investigate the initially selected unit during phonological encoding (IPU). Compared to control distractors, both onset and mora overlapping distractors resulted in faster naming latencies. Several alternative explanations for the pattern of results - proficiency in English, knowledge of Latin script, and downstream effects - are discussed. However, we conclude that Tongan phonological encoding likely natively uses the phoneme, and not the mora, as the IPU..

Abstract

Does the way a word is written influence its spoken production? Previous studies suggest that orthography is involved only when the orthographic representation is highly relevant during speaking (e.g., in reading-aloud tasks). To address this issue, we carried out two experiments using the blocked cyclic picture-naming paradigm. In both experiments, participants were asked to name pictures repeatedly in orthographically homogeneous or heterogeneous blocks. In the naming task, the written form was not shown; however, the radical of the first character overlapped between the four pictures in this block type. A facilitative orthographic effect was found when picture names shared part of their written forms, compared with the heterogeneous condition. This facilitative effect was independent of the position of orthographic overlap (i.e., the left, the lower, or the outer part of the character). These findings strongly suggest that orthography can influence speaking even when it is not highly relevant (i.e., during picture naming) and the orthographic effect is less likely to be attributed to strategic preparation.

Abstract

The phonological Stroop task, in which the participant names the color of written distractors, is being used increasingly to study the phonological encoding process in speech production. A brief review of experimental paradigms used to study the phonological encoding process indicated that currently it is not known whether the onset overlap benefit (faster color naming when the distractor shares the onset segment with the color name) in a phonological Stroop task is due to phonology or orthography. The present paper investigated this question using a picture variant of the phonological Stroop task. Participants named a small set of line drawings of animals (e.g., camel) with a pseudoword distractor printed on it. Picture naming was facilitated when the distractor shared the onset segment with the picture name regardless of orthographic overlap (CUST–camel = KUST–camel < NUST–camel). We conclude that the picture variant of the phonological Stroop task is a useful tool to study the phonological encoding process, free of orthographic influence.

Abstract

Are letters with a diacritic (e.g., a) recognized as a variant of the base letter (e.g., a), or as a separate letter identity? Two recent masked priming studies, one in French and one in Spanish, investigated this question, concluding that this depends on the language-specific linguistic function served by the diacritic. Experiment 1 tested this linguistic function hypothesis using Japanese kana, in which diacritics signal consonant voicing, and like French and unlike Spanish, provide lexical contrast. Contrary to the hypothesis, Japanese kana yielded the pattern of diacritic priming like Spanish. Specifically, for a target kana with a diacritic (e.g., (sic), /ga/), the kana prime without the diacritic (e.g., (sic), /ka/) facilitated recognition almost as much as the identity prime (e.g., (sic) = (sic)), whereas for a target kana without a diacritic, the kana prime with the diacritic produced less facilitation than the identity prime (e.g., (sic) < (sic)). We suggest that the pattern of diacritic priming has little to do with linguistic function, and instead it stems from a general property of visual object recognition. Experiment 2 tested this hypothesis using visually similar letters of the Latin alphabet that differ in the presence/absence of a visual feature (e.g., O and Q). The same asymmetry in priming was observed. These findings are consistent with the noisy channel model of letter/word recognition (Norris & Kinoshita, Psychological Review, 119, 517-545, 2012a).

Abstract

Objectives The aim of this study was to observe the dental condition in a group of elderly patients over a period of 10 years in order to clarify important risk factors. Materials and methods Participants were elderly patients (in their eighties) who took panoramic radiographs between 2015 and 2016, and for whom panoramic radiographs taken around 10 year earlier were also available. The number of remaining and lost teeth, the Eichner Index, the presence or absence of molar occlusion, the respective condition of dental pulp, dental crowns, alveolar bone resorption, as well as periapical lesions were investigated through the analysis of panoramic radiographs. Additionally, other important variables were collected from patients' medical records. From the obtained panoramic radiograph sets, the patients' dental condition was investigated, and a systematic comparison was conducted. Results The analysis of the panoramic radiographs showed that the number of remaining teeth decreased from an average of 20.8-15.5, and the percentage of patients with 20 or more teeth decreased from 69.2 to 26.9%. A factor analysis investigating tooth loss risk suggested that tooth loss was associated with the bridge, P2 or greater resorption of the alveolar bone, and apical lesions, and gender (with males having a higher risk compared to females). Conclusions Teeth showing P2 or greater alveolar bone resorption, bridge, and apical lesions on panoramic radiographs are most likely to be lost in an elderly patient's near future. Consequently, this group should be encouraged to visit their dental clinics regularly and receive comprehensive instruction on individual self-care methods.

Abstract

Purpose: The purpose of this study was to investigate the relationship between the visual characteristics of tongue lesion images obtained through intraoral ultrasonographic examination and the occurrence of late cervical lymph node metastasis in patients with tongue cancer.
Patients and Methods: This study investigated patients with primary tongue cancer who were examined using intraoral ultrasonography at Hiroshima University Hospital between January 2014 and December 2017. The inclusion criteria were squamous cell carcinoma, curative treatment administration, lateral side of tongue, surgery or brachytherapy alone, no cervical lymph node or distant metastasis as primary treatment, and treatment in our hospital. The exclusion criteria were carcinoma in situ, palliative treatment, dorsum of tongue, and multiple primary cancers. The follow-up period was more than 1 year. The primary endpoint was the occurrence of late cervical lymph node metastasis, and the primary predictor variables were age, gender, longest diameter, thickness, margin or border shapes of the lesion, and treatment methods. The relationship between the occurrence of late cervical lymph node metastasis and the longest diameter, thickness, margin types, and border types as evaluated through intraoral ultrasonography were assessed. The data were collected through a retrospective chart review.
Results: Fifty-four patients were included in this study. The analysis indicated that irregular lesion margins were significantly associated with the occurrence of late cervical lymph node metastasis (P < .0001). The cutoff value for late cervical lymph node metastasis was 21.2 mm for the longest diameter and 3.9 mm for the thickness.
Conclusions: The results of this study indicates that the irregular lesion margin assessed using intraoral ultrasonography may serve as an effective predictor of late cervical lymph node metastasis in N0 cases. (C) 2020 American Association of Oral and Maxillofacial Surgeons

Abstract

It is often challenging to determine the accurate size and shape of oral lesions through computed tomography (CT) or magnetic resonance imaging (MRI) when they are very small or obscured by metallic artifacts, such as dental prostheses. Intraoral ultrasonography (IUS) has been shown to be beneficial in obtaining precise information about total tumor extension, as well as the exact location and guiding the insertion of catheters during interstitial brachytherapy. We evaluated the role of IUS in assessing the clinical outcomes of interstitial brachytherapy with 198Au grains in tongue cancer through a retrospective medical chart review. The data from 45 patients with T1 (n = 21) and T2 (n = 24) tongue cancer, who were mainly treated with 198Au grain implants between January 2005 and April 2019, were included in this study. 198Au grain implantations were carried out, and positioning of the implants was confirmed by IUS, to ensure that 198Au grains were appropriately placed for the deep border of the tongue lesion. The five-year local control rates of T1 and T2 tongue cancers were 95.2% and 95.5%, respectively. We propose that the use of IUS to identify the extent of lesions and the position of implanted grains is effective when performing brachytherapy with 198Au grains.

Abstract

We investigated the “proximate unit” in Korean, that is, the initial phonological unit selected in speech production by Korean speakers. Previous studies have shown mixed evidence indicating either a phoneme-sized or a syllable-sized unit. We conducted two experiments in which participants named pictures while ignoring superimposed non-words. In English, for this task, when the picture (e.g., dog) and distractor phonology (e.g., dark) initially overlap, typically the picture target is named faster. We used a range of conditions (in Korean) varying from onset overlap to syllabic overlap, and the results indicated an important role for the syllable, but not the phoneme. We suggest that the basic unit used in phonological encoding in Korean is different from Germanic languages such as English and Dutch and also from Japanese and possibly also Chinese. Models dealing with the architecture of language production can use these results when providing a framework suitable for all languages in the world, including Korean.

Abstract

Objective: Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities' usage and findings of MRONJ to provide possible approaches for early detection.

Methods: Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ.

Results: Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T1WI and hyperintense on T2WI and STIR when necrotic bone shows hypointensity on all T1WI, T2WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ.

Conclusion: Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.

Abstract

In attempting to understand mental processes, it is important to use a task that appropriately reflects the underlying processes being investigated. Recently, Verdonschot and Kinoshita (Memory & Cognition, 46,410-425, 2018) proposed that a variant of the Stroop task-the "phonological Stroop task"-might be a suitable tool for investigating speech production. The major advantage of this task is that the task is apparently not affected by the orthographic properties of the stimuli, unlike other, commonly used, tasks (e.g., associative-cuing and word-reading tasks). The viability of this proposal was examined in the present experiments by manipulating the script types of Japanese distractors. For Romaji distractors (e.g., "kushi"), color-naming responses were faster when the initial phoneme was shared between the color name and the distractor than when the initial phonemes were different, thereby showing a phoneme-based phonological Stroop effect (Experiment1). In contrast, no such effect was observed when the same distractors were presented in Katakana (e.g., "< ") pound, replicating Verdonschot and Kinoshita's original results (Experiment2). A phoneme-based effect was again found when the Katakana distractors used in Verdonschot and Kinoshita's original study were transcribed and presented in Romaji (Experiment3). Because the observation of a phonemic effectdirectly depended on the orthographic properties of the distractor stimuli, we conclude that the phonological Stroop task is also susceptible to orthographic influences.

Abstract

We argue, based on a study of brain responses to speech sound differences in Japanese, that memory encoding of functional speech sounds-phonemes-are highly abstract. As an example, we provide evidence for a theory where the consonants/p t k b d g/ are not only made up of symbolic features but are underspecified with respect to voicing or laryngeal features, and that languages differ with respect to which feature value is underspecified. In a previous study we showed that voiced stops are underspecified in English [Hestvik, A., & Durvasula, K. (2016). Neurobiological evidence for voicing underspecification in English. Brain and Language], as shown by asymmetries in Mismatch Negativity responses to /t/ and /d/. In the current study, we test the prediction that the opposite asymmetry should be observed in Japanese, if voiceless stops are underspecified in that language. Our results confirm this prediction. This matches a linguistic architecture where phonemes are highly abstract and do not encode actual physical characteristics of the corresponding speech sounds, but rather different subsets of abstract distinctive features.

Abstract

Objectives: A new computer-aided screening system for osteoporosis using panoramic radiographs was developed. The conventional system could detect porotic changes within the lower border of the mandible, but its severity could not be evaluated. Our aim was to enable the system to measure severity by implementing a linear bone resorption severity index (BRSI) based on the cortical bone shape.
Methods: The participants were 68 females (>50 years) who underwent panoramic radiography and lumbar spine bone density measurements. The new system was designed to extract the lower border of the mandible as region of interests and convert them into morphological skeleton line images. The total perimeter length of the skeleton lines was defined as the BRSI. 40 images were visually evaluated for the presence of cortical bone porosity. The correlation between visual evaluation and BRSI of the participants, and the optimal threshold value of BRSI for new system were investigated through a receiver operator characteristic analysis. The diagnostic performance of the new system was evaluated by comparing the results from new system and lumbar bone density tests using 28 participants.
Results: BRSI and lumbar bone density showed a strong negative correlation (p < 0.01). BRSI showed a strong correlation with visual evaluation. The new system showed high diagnostic efficacy with sensitivity of 90.9%, specificity of 64.7%, and accuracy of 75.0%.
Conclusions: The new screening system is able to quantitatively evaluate mandibular cortical porosity. This allows for preventive screening for osteoporosis thereby enhancing clinical prospects.

Abstract

An ongoing debate in the speech production literature suggests that the initial building block to build up speech sounds differs between languages. That is, Germanic languages are suggested to use the phoneme, but Japanese and Chinese are proposed to use the mora or syllable, respectively. Several studies investigated this matter from a chronometric perspective (i.e., RTs and accuracy). However, a less attention has been paid to the actual acoustic utterances. The current study investigated the verbal responses of two Japanese-English bilingual groups of different proficiency levels (i.e., high and low) when naming English words and found that the presence or absence of vowel epenthesis depended on proficiency. The results indicate that: (1) English word pronunciation by low-proficient Japanese English bilinguals is likely based on their L1 (Japanese) building block and (2) that future studies would benefit from analyzing the acoustic data as well when making inferences from chronometric data.

Abstract

Previous studies suggest that bilinguals' lexical access is language non-selective, especially for orthographically identical translation equivalents across languages (i.e., identical cognates). The present study investigated how such words (e.g., meaning "school" in both Chinese and Japanese) are processed in the (late) Chinese - Japanese bilingual brain. Using an L2-Japanese lexical decision task, both behavioral and electrophysiological data were collected. Reaction times (RTs), as well as the N400 component, showed that cognates are more easily recognized than non-cognates. Additionally, an early component (i.e., the N250), potentially reflecting activation at the word-form level, was also found. Cognates elicited a more positive N250 than non-cognates in the frontal region, indicating that the cognate facilitation effect occurred at an early stage of word formation for languages with logographic scripts.

Abstract

In a masked priming word-naming task, a facilitation due to the initial-segmental sound overlap for 2-character kanji prime-target pairs was affected by certain orthographic properties (Yoshihara, Nakayama, Verdonschot, & Hino, 2017). That is, the facilitation that was due to the initial mora overlap occurred only when the mora was the whole pronunciation of their initial kanji characters (i.e., match pairs; e.g., /ka-se.ki/-/ka-rjo.ku/). When the shared initial mora was only a part of the kanji characters' readings, however, there was no facilitation (i.e., mismatch pairs; e.g., /ha.tu-a.N/-/ha.ku-bu.tu/). In the present study, we used a masked priming picture-naming task to investigate whether the previous results were relevant only when the orthography of targets is visually presented. In Experiment 1. the main findings of our word-naming task were fully replicated in a picture-naming task. In Experiments 2 and 3. the absence of facilitation for the mismatch pairs were confirmed with a new set of stimuli. On the other hand, a significant facilitation was observed for the match pairs that shared the 2 initial morae (in Experiment 4), which was again consistent with the results of our word-naming study. These results suggest that the orthographic properties constrain the phonological expression of masked priming for kanji words across 2 tasks that are likely to differ in how phonology is retrieved. Specifically, we propose that orthography of a word is activated online and constrains the phonological encoding processes in these tasks.