Non-verbal signals for grounding in embodied conversational agent

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.Includes bibliographical references (leaves 79-82).In face-to-face conversation, speakers present non-verbal signals collateral with verbal information. Nodding and gazing at a speaker are known to provide positive feedback from listeners, which contributes to establishing common ground (a process called grounding). However, previous theories and computational models of grounding were mainly concerned with verbal grounding acts, and there have not been enough discussion about how nonverbal behaviors are used in the process of grounding. This thesis first compares face-to-face conversation to conversation without co-presence, revealing how nonverbal behaviors are used in the process of grounding in human communication. Results of the analysis show that, in face-to-face communication, non-verbal behaviors are changing during an utterance and a typical transition pattern of non-verbal behaviors is also different depending on the type of verbal act. Then, the implementation of grounding functionality onto an Embodied Conversational Agent is presented. The dialogue state updating mechanism in the Dialogue Manager accesses non-verbal information conveyed by a user and judges the groundedness of presented materials based on the results of empirical study.by Yukiko I. Nakano.S.M

EEG potentials associated with artificial grammar learning in the primate brain

AbstractElectroencephalography (EEG) has identified human brain potentials elicited by Artificial Grammar (AG) learning paradigms, which present participants with rule-based sequences of stimuli. Nonhuman animals are sensitive to certain AGs; therefore, evaluating which EEG Event Related Potentials (ERPs) are associated with AG learning in nonhuman animals could identify evolutionarily conserved processes. We recorded EEG potentials during an auditory AG learning experiment in two Rhesus macaques. The animals were first exposed to sequences of nonsense words generated by the AG. Then surface-based ERPs were recorded in response to sequences that were ‘consistent’ with the AG and ‘violation’ sequences containing illegal transitions. The AG violations strongly modulated an early component, potentially homologous to the Mismatch Negativity (mMMN), a P200 and a late frontal positivity (P500). The macaque P500 is similar in polarity and time of occurrence to a late EEG positivity reported in human AG learning studies but might differ in functional role

Exploration of Finite 2D Square Grid by a Metamorphic Robotic System

We consider exploration of finite 2D square grid by a metamorphic robotic system consisting of anonymous oblivious modules. The number of possible shapes of a metamorphic robotic system grows as the number of modules increases. The shape of the system serves as its memory and shows its functionality. We consider the effect of global compass on the minimum number of modules necessary to explore a finite 2D square grid. We show that if the modules agree on the directions (north, south, east, and west), three modules are necessary and sufficient for exploration from an arbitrary initial configuration, otherwise five modules are necessary and sufficient for restricted initial configurations

Auditory artificial grammar learning in macaque and marmoset monkeys.

Artificial grammars (AG) are designed to emulate aspects of the structure of language, and AG learning (AGL) paradigms can be used to study the extent of nonhuman animals' structure-learning capabilities. However, different AG structures have been used with nonhuman animals and are difficult to compare across studies and species. We developed a simple quantitative parameter space, which we used to summarize previous nonhuman animal AGL results. This was used to highlight an under-studied AG with a forward-branching structure, designed to model certain aspects of the nondeterministic nature of word transitions in natural language and animal song. We tested whether two monkey species could learn aspects of this auditory AG. After habituating the monkeys to the AG, analysis of video recordings showed that common marmosets (New World monkeys) differentiated between well formed, correct testing sequences and those violating the AG structure based primarily on simple learning strategies. By comparison, Rhesus macaques (Old World monkeys) showed evidence for deeper levels of AGL. A novel eye-tracking approach confirmed this result in the macaques and demonstrated evidence for more complex AGL. This study provides evidence for a previously unknown level of AGL complexity in Old World monkeys that seems less evident in New World monkeys, which are more distant evolutionary relatives to humans. The findings allow for the development of both marmosets and macaques as neurobiological model systems to study different aspects of AGL at the neuronal level

Near-Infrared Adaptive Optics Spectroscopy of Binary Brown Dwarf HD 130948B and C

We present near-infrared spectroscopy of low-mass companions in a nearby triple system HD 130948 (Gliese 564, HR 5534). Adaptive optics on the Subaru Telescope allowed spectroscopy of the individual components of the 0".13 binary system. Based on a direct comparison with a series of template spectra, we determined the spectral types of HD 130948B and C to be L4 +- 1. If we take the young age of the primary star into account (0.3-0.8 Gyr), HD 130948B and C most likely are a binary brown dwarf system.Comment: 6 pages, 3 figures, accepted for publication in ApJ Letter

Socio-Economic Marginalization and Compliance Motivation Among Students and Freeters in Japan

This study examines the compliance motivation of students and Freeters when facing a marginalization risk situation evoked by priming. Freeter (part-time employers), NEET (not in education, employment, or training), and Hikikomori (social withdrawal) represent the socio-economically marginalized population in Japan. People at higher risk of becoming NEET and Hikikomori have shown a motivation pattern deviant from mainstream Japanese culture, including lower willingness to conform to in-group members, thus showing less cultural fit (Norasakkunkit and Uchida, 2014). In this study we explore the effect of the macro socio-economic situation (job-hunting prospects being good or bad) on individual's compliance motivation in both students and Freeters. Sixty-five Kyoto University students and 74 Freeters were randomly assigned to one of the two priming conditions (marginalization risk or non-marginalization) before completing the NEET-Hikikomori Risk (NHR) scale and measurements of compliance motivation to conform to in-group members or to be self-consistent (Cialdini et al., 1999). Twenty-three control group students and 22 control group Freeters were also recruited online for comparison. Results showed that marginalization risk priming led to lower tendency to be self-consistent among students, but did not lead to lower tendency to conform to in-group members. For Freeters, marginalization risk priming led to higher compliance motivation to conform to in-group members. The results confirmed the framework proposed by Toivonen et al. (2011) that both Freeters and students in Japan have ritualist reactions, continuing to maintain the cultural norms despite the difficulty of attaining the cultural goals

Auditory sequence processing reveals evolutionarily conserved regions of frontal cortex in macaques and humans.

An evolutionary account of human language as a neurobiological system must distinguish between human-unique neurocognitive processes supporting language and evolutionarily conserved, domain-general processes that can be traced back to our primate ancestors. Neuroimaging studies across species may determine whether candidate neural processes are supported by homologous, functionally conserved brain areas or by different neurobiological substrates. Here we use functional magnetic resonance imaging in Rhesus macaques and humans to examine the brain regions involved in processing the ordering relationships between auditory nonsense words in rule-based sequences. We find that key regions in the human ventral frontal and opercular cortex have functional counterparts in the monkey brain. These regions are also known to be associated with initial stages of human syntactic processing. This study raises the possibility that certain ventral frontal neural systems, which play a significant role in language function in modern humans, originally evolved to support domain-general abilities involved in sequence processing

Cultural modulation of face and gaze scanning in young children

Previous research has demonstrated that the way human adults look at others’ faces is modulated by their cultural background, but very little is known about how such a culture-specific pattern of face gaze develops. The current study investigated the role of cultural background on the development of face scanning in young children between the ages of 1 and 7 years, and its modulation by the eye gaze direction of the face. British and Japanese participants’ eye movements were recorded while they observed faces moving their eyes towards or away from the participants. British children fixated more on the mouth whereas Japanese children fixated more on the eyes, replicating the results with adult participants. No cultural differences were observed in the differential responses to direct and averted gaze. The results suggest that different patterns of face scanning exist between different cultures from the first years of life, but differential scanning of direct and averted gaze associated with different cultural norms develop later in life

First Detection of NaI D lines in High-Redshift Damped Lyman-alpha Systems

A Near-infrared (1.18-1.35 micron) high-resolution spectrum of the gravitationally-lensed QSO APM 08279+5255 was obtained with the IRCS mounted on the Subaru Telescope using the AO system. We detected strong NaI D 5891,5897 doublet absorption in high-redshift DLAs at z=1.062 and 1.181, confirming the presence of NaI, which was first reported for the rest-frame UV NaI 3303.3,3303.9 doublet by Petitjean et al. This is the first detection of NaI D absorption in a high-redshift (z>1) DLA. In addition, we detected a new NaI component in the z=1.062 DLA and four new components in the z=1.181 DLA. Using an empirical relationship between NaI and HI column density, we found that all "components" have large HI column density, so that each component is classified as DLA absorption. We also detected strong NaI D absorption associated with a MgII system at z=1.173. Because no other metal absorption lines were detected in this system at the velocity of the NaI absorption in previously reported optical spectra (observed 3.6 years ago), we interpret this NaI absorption cloud probably appeared in the line of sight toward the QSO after the optical observation. This newly found cloud is likely to be a DLA based upon its large estimated HI column density. We found that the N(NaI)/N(CaII) ratios in these DLAs are systematically smaller than those observed in the Galaxy; they are more consistent with the ratios seen in the Large Magellanic Cloud. This is consistent with dust depletion generally being smaller in lower metallicity environments. However, all five clouds of the z=1.181 system have a high N(NaI)/N(CaII) ratio, which is characteristic of cold dense gas. We tentatively suggest that the host galaxy of this system may be the most significant contributor to the gravitational-lens toward APM 08279+5255.Comment: 22 pages, 6 Postscript figures, 3 tables, ApJ in press (Vol.643, 2 June 2006