A psychometric measure of working memory capacity for configured body movement.

Working memory (WM) models have traditionally assumed at least two domain-specific storage systems for verbal and visuo-spatial information. We review data that suggest the existence of an additional slave system devoted to the temporary storage of body movements, and present a novel instrument for its assessment: the movement span task. The movement span task assesses individuals' ability to remember and reproduce meaningless configurations of the body. During the encoding phase of a trial, participants watch short videos of meaningless movements presented in sets varying in size from one to five items. Immediately after encoding, they are prompted to reenact as many items as possible. The movement span task was administered to 90 participants along with standard tests of verbal WM, visuo-spatial WM, and a gesture classification test in which participants judged whether a speaker's gestures were congruent or incongruent with his accompanying speech. Performance on the gesture classification task was not related to standard measures of verbal or visuo-spatial working memory capacity, but was predicted by scores on the movement span task. Results suggest the movement span task can serve as an assessment of individual differences in WM capacity for body-centric information

Look at Me: Early Gaze Engagement Enhances Corticospinal Excitability During Action Observation

Direct gaze is a powerful social cue able to capture the onlooker's attention. Beside gaze, head and limb movements as well can provide relevant sources of information for social interaction. This study investigated the joint role of direct gaze and hand gestures on onlookers corticospinal excitability (CE). In two experiments we manipulated the temporal and spatial aspects of observed gaze and hand behavior to assess their role in affecting motor preparation. To do this, transcranial magnetic stimulation (TMS) on the primary motor cortex (M1) coupled with electromyography (EMG) recording was used in two experiments. In the crucial manipulation, we showed to participants four video clips of an actor who initially displayed eye contact while starting a social request gesture, and then completed the action while directing his gaze toward a salient object for the interaction. This way, the observed gaze potentially expressed the intention to interact. Eye tracking data confirmed that gaze manipulation was effective in drawing observers' attention to the actor's hand gesture. In the attempt to reveal possible time-locked modulations, we tracked CE at the onset and offset of the request gesture. Neurophysiological results showed an early CE modulation when the actor was about to start the request gesture looking straight to the participants, compared to when his gaze was averted from the gesture. This effect was time-locked to the kinematics of the actor's arm movement. Overall, data from the two experiments seem to indicate that the joint contribution of direct gaze and precocious kinematic information, gained while a request gesture is on the verge of beginning, increases the subjective experience of involvement and allows observers to prepare for an appropriate social interaction. On the contrary, the separation of gaze cues and body kinematics can have adverse effects on social motor preparation. CE is highly susceptible to biological cues, such as averted gaze, which is able to automatically capture and divert observer's attention. This point to the existence of heuristics based on early action and gaze cues that would allow observers to interact appropriately

Potential for social involvement modulates activity within the mirror and the mentalizing systems

Processing biological motion is fundamental for everyday life activities, such as social interaction, motor learning and nonverbal communication. The ability to detect the nature of a motor pattern has been investigated by means of point-light displays (PLD), sets of moving light points reproducing human kinematics, easily recognizable as meaningful once in motion. Although PLD are rudimentary, the human brain can decipher their content including social intentions. Neuroimaging studies suggest that inferring the social meaning conveyed by PLD could rely on both the Mirror Neuron System (MNS) and the Mentalizing System (MS), but their specific role to this endeavor remains uncertain. We describe a functional magnetic resonance imaging experiment in which participants had to judge whether visually presented PLD and videoclips of human-like walkers (HL) were facing towards or away from them. Results show that coding for stimulus direction specifically engages the MNS when considering PLD moving away from the observer, while the nature of the stimulus reveals a dissociation between MNS -mainly involved in coding for PLD- and MS, recruited by HL moving away. These results suggest that the contribution of the two systems can be modulated by the nature of the observed stimulus and its potential for social involvement

Face Image and Video Analysis in Biometrics and Health Applications

Computer Vision (CV) enables computers and systems to derive meaningful information from acquired visual inputs, such as images and videos, and make decisions based on the extracted information. Its goal is to acquire, process, analyze, and understand the information by developing a theoretical and algorithmic model. Biometrics are distinctive and measurable human characteristics used to label or describe individuals by combining computer vision with knowledge of human physiology (e.g., face, iris, fingerprint) and behavior (e.g., gait, gaze, voice). Face is one of the most informative biometric traits. Many studies have investigated the human face from the perspectives of various different disciplines, ranging from computer vision, deep learning, to neuroscience and biometrics. In this work, we analyze the face characteristics from digital images and videos in the areas of morphing attack and defense, and autism diagnosis. For face morphing attacks generation, we proposed a transformer based generative adversarial network to generate more visually realistic morphing attacks by combining different losses, such as face matching distance, facial landmark based loss, perceptual loss and pixel-wise mean square error. In face morphing attack detection study, we designed a fusion-based few-shot learning (FSL) method to learn discriminative features from face images for few-shot morphing attack detection (FS-MAD), and extend the current binary detection into multiclass classification, namely, few-shot morphing attack fingerprinting (FS-MAF). In the autism diagnosis study, we developed a discriminative few shot learning method to analyze hour-long video data and explored the fusion of facial dynamics for facial trait classification of autism spectrum disorder (ASD) in three severity levels. The results show outstanding performance of the proposed fusion-based few-shot framework on the dataset. Besides, we further explored the possibility of performing face micro- expression spotting and feature analysis on autism video data to classify ASD and control groups. The results indicate the effectiveness of subtle facial expression changes on autism diagnosis

Action Recognition in Videos: from Motion Capture Labs to the Web

This paper presents a survey of human action recognition approaches based on visual data recorded from a single video camera. We propose an organizing framework which puts in evidence the evolution of the area, with techniques moving from heavily constrained motion capture scenarios towards more challenging, realistic, "in the wild" videos. The proposed organization is based on the representation used as input for the recognition task, emphasizing the hypothesis assumed and thus, the constraints imposed on the type of video that each technique is able to address. Expliciting the hypothesis and constraints makes the framework particularly useful to select a method, given an application. Another advantage of the proposed organization is that it allows categorizing newest approaches seamlessly with traditional ones, while providing an insightful perspective of the evolution of the action recognition task up to now. That perspective is the basis for the discussion in the end of the paper, where we also present the main open issues in the area.Comment: Preprint submitted to CVIU, survey paper, 46 pages, 2 figures, 4 table

Comprehension in-situ: how multimodal information shapes language processing

The human brain supports communication in dynamic face-to-face environments where spoken words are embedded in linguistic discourse and accompanied by multimodal cues, such as prosody, gestures and mouth movements. However, we only have limited knowledge of how these multimodal cues jointly modulate language comprehension. In a series of behavioural and EEG studies, we investigated the joint impact of these cues when processing naturalistic-style materials. First, we built a mouth informativeness corpus of English words, to quantify mouth informativeness of a large number of words used in the following experiments. Then, across two EEG studies, we found and replicated that native English speakers use multimodal cues and that their interactions dynamically modulate N400 amplitude elicited by words that are less predictable in the discourse context (indexed by surprisal values per word). We then extended the findings to second language comprehenders, finding that multimodal cues modulate L2 comprehension, just like in L1, but to a lesser extent; although L2 comprehenders benefit more from meaningful gestures and mouth movements. Finally, in two behavioural experiments investigating whether multimodal cues jointly modulate the learning of new concepts, we found some evidence that presence of iconic gestures improves memory, and that the effect may be larger if information is presented also with prosodic accentuation. Overall, these findings suggest that real-world comprehension uses all cues present and weights cues differently in a dynamic manner. Therefore, multimodal cues should not be neglected for language studies. Investigating communication in naturalistic contexts containing more than one cue can provide new insight into our understanding of language comprehension in the real world

Gesture and Speech in Interaction - 4th edition (GESPIN 4)

International audienceThe fourth edition of Gesture and Speech in Interaction (GESPIN) was held in Nantes, France. With more than 40 papers, these proceedings show just what a flourishing field of enquiry gesture studies continues to be. The keynote speeches of the conference addressed three different aspects of multimodal interaction:gesture and grammar, gesture acquisition, and gesture and social interaction. In a talk entitled Qualitiesof event construal in speech and gesture: Aspect and tense, Alan Cienki presented an ongoing researchproject on narratives in French, German and Russian, a project that focuses especially on the verbal andgestural expression of grammatical tense and aspect in narratives in the three languages. Jean-MarcColletta's talk, entitled Gesture and Language Development: towards a unified theoretical framework,described the joint acquisition and development of speech and early conventional and representationalgestures. In Grammar, deixis, and multimodality between code-manifestation and code-integration or whyKendon's Continuum should be transformed into a gestural circle, Ellen Fricke proposed a revisitedgrammar of noun phrases that integrates gestures as part of the semiotic and typological codes of individuallanguages. From a pragmatic and cognitive perspective, Judith Holler explored the use ofgaze and hand gestures as means of organizing turns at talk as well as establishing common ground in apresentation entitled On the pragmatics of multi-modal face-to-face communication: Gesture, speech andgaze in the coordination of mental states and social interaction.Among the talks and posters presented at the conference, the vast majority of topics related, quitenaturally, to gesture and speech in interaction - understood both in terms of mapping of units in differentsemiotic modes and of the use of gesture and speech in social interaction. Several presentations explored the effects of impairments(such as diseases or the natural ageing process) on gesture and speech. The communicative relevance ofgesture and speech and audience-design in natural interactions, as well as in more controlled settings liketelevision debates and reports, was another topic addressed during the conference. Some participantsalso presented research on first and second language learning, while others discussed the relationshipbetween gesture and intonation. While most participants presented research on gesture and speech froman observer's perspective, be it in semiotics or pragmatics, some nevertheless focused on another importantaspect: the cognitive processes involved in language production and perception. Last but not least,participants also presented talks and posters on the computational analysis of gestures, whether involvingexternal devices (e.g. mocap, kinect) or concerning the use of specially-designed computer software forthe post-treatment of gestural data. Importantly, new links were made between semiotics and mocap data

Development of the Mu Rhythm: Understanding Function Through Translational Research

The incidental discovery of mirror neurons (MN) has renewed interest in motor theories of development and has sparked considerable debate as to the existence and potential function of mirror neurons in humans. The use of invasive single-cell recordings, however, has precluded identification of single MNs in humans or developmental populations of non-human primates. Non-invasive techniques, such as the modulation of the mu rhythm in the electroencephalogram (EEG) of young infants and children, have demonstrated the existence of an action observation/execution matching system in humans. Moreover, the mu rhythm has become an effective tool for addressing questions of MN system ontogeny in other species. The aim of this project is to address two questions that have thus far remained untested. The goal of study one is to address the question of whether or not we can identify activation of the human action observation/execution system under conditions in which the participants cannot see themselves executing a grasping action. Evidence from study one further validates our EEG measures as representing activation of the putative human MN system. The goal of study two is to examine the origins of MNs in 3-day-old mother- and nursery-reared infant rhesus macaques and the extent to which differential experience may contribute to the MN system during episodes of neonatal imitation. The results of study one demonstrated activation of the putative human MN system to actions completed in the absence of visual feedback in both human adults and infants. The magnitude of mu rhythm activity in infants was significantly less than in the adults suggesting a role of experience in the formation of the putative human MN system. The results from study two further emphasized the role of early experience showing significantly greater modulation of the mu rhythm in the mother-reared compared to the nursery-reared infants to the observation of socio-affiliative facial gestures. The evidence of studies one and two are discussed within a developmental framework of ongoing behavioral development and highlight the role experience plays, not in the foundation of, but rather the elaboration of the MN system