<p>Research on biological motion, using point-light displays to present the motions, have been unravelling what information factors are still embedded in those impoverished stimuli and which of these factors are essential in visual processing of biological motion. Earlier studies suggest that orientation is a crucial factor in biological motion processing. The short-term priming experiment presented in this paper will further investigate the legitimacy of the primacy of orientation and suggest different solutions based on contradicting findings in previously published studies.</p><p>In a serial two-choice reaction-time task, participants were presented with a patch-light display of a human engaged in one of three possible actions: climbing up a rope, jumping jacks, and walking. Participants had to identify the in-plane orientation of the human figure emerging from the moving patch-lights. Reliable facilitation effect was established for transitions containing same-oriented upright trails and same-oriented inverted trials. Interestingly, transitions of same-oriented upright trials produced significantly greater facilitation effect than transitions of same-oriented inverted trials.</p>

Four experiments are presented that explore social interactivity in a visually communicating species: the pigeon, Columba livia. A closed-loop teleprompter system was used to isolate, control and manipulate social contingency in a natural courtship interaction. Experiment 1 tested different ways to measure pigeon behaviour and developed an automatic method for measuring the pigeon’s circle walking display using motion energy analysis. In Experiment, 2 the subject’s courtship behaviour towards the video image of an opposite sex partner streamed live (Live), was compared with their behaviour towards a pre-recorded video image of the same partner (Playback). The only difference between the Live and Playback condition was the presence or absence of social contingency. The results showed that pigeons behaved interactively: their behaviour was determined, in part, by the social contingencies between visual signals. To investigate what types of social contingencies are behaviourally relevant, the effects of the partner’s facing direction and the timing of social contingencies on behaviour were investigated in Experiment 3 and 4, respectively. To manipulate partner facing direction, the camera was rotated so that the partner appears to be courting 90° away from the subject. To manipulate social timing, three time delays, 1, 3 and 9s, were implemented within the closed-circuit communication. In Experiment 4, the context-specificity of interactive behaviour was also investigated by testing behavioural sensitivity to social contingency and timing in both opposite sex and same sex social interactions. The results showed that the partner’s facing direction did not significantly influence behaviour, whereas the timing of social contingencies had a significant impact on behaviour: in courtship only. These findings suggest that temporal relations between display bouts in courtship are behaviourally relevant. A post hoc analysis was then used to evaluate the behavioural relevance of two social contingencies in particular: partner responsiveness and simultaneous display. The results showed that females may be sensitive to the male responsiveness in courtship. Also, simultaneous display appeared to create a perceptual interaction which acted to potentiate the courtship dynamic. These studies provide a basis for further developing the pigeon and its courtship behaviour as a model for visual communication. / Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2011-04-25 14:37:19.888

The ability to recognise the movements made by humans and other animals, referred to as biological motion, is a specialised human ability that develops at an early age. This perceptual ability is strong even for the minimal amount of information contained in a point-light display, which has been used to study specific features of biological motion to find out what properties contribute to this ability. The perception of biological motion depends on visual perception, visual attention and motor cognition, and perception depends both on the global form, configural information and local information of a body in motion. Depending on the situation, either global or local motions will be more salient and processed to a greater extent by the perceptual system. Previous research has shown that the local and configural information contained in the feet play an important role for identification, direction discrimination and the inversion effect. The salience of the feet for perception has previously been studied when they are subjected to focused attention, but not reflexive attention. The goal of this study was to investigate if the local and configural information of the feet can trigger reflexive attention and be incidentally processed by the visual system in a direction discrimination task. To test this experimentally, a masking paradigm was used where the feet were placed in a mask consisting of scrambled walkers. The results show that the feet affect recognition of target direction when the target is upright, but not when inverted. An interesting and unexpected finding was that for upright targets, the feet aid recognition when they move in the opposite direction of the target. Due to the experimental setup, it is difficult to say with certainty what the results imply, and suggestions for a follow-up study are presented. / Kognitionsvetenskap handlar om hur människor tänker, uppfattar världen och interagerar med omgivningen och med andra människor. Inom kognitiv psykologi har människors förmåga att uppfatta andra människors och djurs rörelser studerats länge. Vi kan känna igen vänner och familj på det unika sätt som de rör sig och forskningen har visat att vi har förmågan att identifiera många olika typer av rörelser och handlingar även när den tillgängliga informationen är minimal. Studier som använt s.k. punktljusdisplayer, där endast vita punkter som representerar kroppens stora leder visas mot en svart bakgrund, har visat att förmågan att känna igen biologiska rörelser är mycket känslig och robust för störningar. Forskare har undersökt vilken information hos rörelser som vi använder för att lyckas med detta, och hur visuell perception och uppmärksamhet fungerar då vi tittar på punktljusdisplayer. Det har visat sig att fötterna har en stor inverkan på igenkänning av rörelseriktning och att det framförallt är på grund av fötterna som det är svårt att känna igen rörelser som presenteras uppochner. Något som inte har testats tidigare är om fötterna är så starka signaler att de kan påverka vår perception även om vi inte riktar fokuserad uppmärksamhet mot dem, utan endast reflexiv uppmärksamhet. Den här studien har testat om fötter kan trigga just reflexiv uppmärksamhet och påverka hur vi känner igen rörelseriktningen hos en gående punktljus-figur. Resultaten visar att fötternas specifika rörelsemönster kan trigga reflexiv uppmärksamhet i situationer då rörelserna är upprätta och då fötterna rör sig i motsatt riktning från den figur som deltagare fokuserar på. Experimentdesignen har dock inneburit att resultaten är svåra att tolka. För att säkrare kunna säga huruvida resultaten beror på fötterna föreslås en ny studie, och detaljer kring vilka justeringar som borde göras i en sådan studie presenteras.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12979号 / 論医博第2105号 / 新制||医||1012(附属図書館) / 32449 / (主査)教授 髙橋 良輔, 教授 佐藤 俊哉, 教授 渡邉 大 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

<p>Recent efforts to explain the underlying mechanisms of action observation have resulted in several theoretical frameworks. The Common Coding framework proposes that the perception and action areas of the brain share representations of visual and motor feedback such that areas are activated concurrently, there is a benefit to an individual’s perceptual ability and confidence. The MOSAIC framework, on the other hand, proposes that these benefits derive from self generations of motor commands during voluntary movement. This study aimed to observe the effects of concurrent motor activity on perceptual ability and judgments of performance. Participants observed an animated avatar performing pairs of symbol tracings on a screen. Participants were also placed into one of three concurrent movement groups: voluntary concurrent symbol tracing, non-voluntary concurrent symbol tracing or observation (no concurrent symbol tracing). It was expected that the group with voluntary concurrent movement would exhibit a higher perceptual accuracy and greater ability to judge performance than both the non-voluntary concurrent movement group and the observation group. However, all participants demonstrated the same level of perceptual accuracy, regardless of the level of concurrent movement. The decreased ability for voluntary movement participants was likely due to significant movement initiation time delays associated with cognitive processing of visual stimuli. As such, voluntary participants did not move in synchrony with the display. Nevertheless, both movement groups had a greater ability of judging performance, suggesting that judgments of performance may be obtained using different pathways than those involved in perceptual accuracy. Findings support both the Common Coding and MOSAIC frameworks, suggesting that a perceptual benefit can only be obtained when movement is in synchrony with perception.</p> / Master of Science (MSc)

La perception d’un mouvement biologique correspond à l’aptitude à recueillir des informations (comme par exemple, le type d’activité) issues d’un objet animé en mouvement à partir d’indices visuels restreints. Cette méthode a été élaborée et instaurée par Johansson en 1973, à l’aide de simples points lumineux placés sur des individus, à des endroits stratégiques de leurs articulations. Il a été démontré que la perception, ou reconnaissance, du mouvement biologique joue un rôle déterminant dans des activités cruciales pour la survie et la vie sociale des humains et des primates. Par conséquent, l’étude de l’analyse visuelle de l’action chez l’Homme a retenu l’attention des scientifiques pendant plusieurs décennies. Ces études sont essentiellement axées sur informations cinématiques en provenance de différents mouvements (comme le type d’activité ou les états émotionnels), le rôle moteur dans la perception des actions ainsi que les mécanismes sous-jacents et les substrats neurobiologiques associés. Ces derniers constituent le principal centre d’intérêt de la présente étude, dans laquelle nous proposons un nouveau modèle descriptif de simulation bayésienne avec minimisation du risque. Ce modèle est capable de distinguer la direction d’un ballon à partir d’un mouvement biologique complexe correspondant à un tir de soccer. Ce modèle de simulation est inspiré de précédents modèles, neurophysiologiquement possibles, de la perception du mouvement biologique ainsi que de récentes études. De ce fait, le modèle présenté ici ne s’intéresse qu’à la voie dorsale qui traite les informations visuelles relatives au mouvement, conformément à la théorie des deux voies visuelles. Les stimuli visuels utilisés, quant à eux, proviennent d’une précédente étude psychophysique menée dans notre laboratoire chez des athlètes. En utilisant les données psychophysiques de cette étude antérieure 3 et en ajustant une série de paramètres, le modèle proposé a été capable de simuler la fonction psychométrique ainsi que le temps de réaction moyen mesurés expérimentalement chez les athlètes. Bien qu’il ait été établi que le système visuel intègre de manière optimale l’ensemble des indices visuels pendant le processus de prise de décision, les résultats obtenus sont en lien avec l’hypothèse selon laquelle les indices de mouvement sont plus importants que la forme dynamique dans le traitement des informations relatives au mouvement. Les simulations étant concluantes, le présent modèle permet non seulement de mieux comprendre le sujet en question, mais s’avère également prometteur pour le secteur de l’industrie. Il permettrait, par exemple, de prédire l’impact des distorsions optiques, induites par la conception de verres progressifs, sur la prise de décision chez l’Homme. Mots-clés : Mouvement biologique, Bayésien, Voie dorsale, Modèle de simulation hiérarchique, Fonction psychométrique, Temps de réaction / The ability to recover information (e.g., identity or type of activity) about a moving living object from a sparse input is known as Biological Motion perception. This sparse input has been created and introduced by Johansson in 1973, using only light points placed on an individual's strategic joints. Biological motion perception/recognition proves to play a significant role in activities that are critical to the survival and social life of humans and primates. In this regard, the study of visual analysis of human action had the attention of scientists for decades. These studies are mainly focused on: kinematics information of the different movements (such as type of activity, emotional states), motor role in the perception of actions and underlying mechanisms, and associated neurobiological substrates. The latter being the main focus of the present study, a new descriptive risk-averse Bayesian simulation model, capable of discerning the ball’s direction from a set of complex biological motion soccer-kick stimuli is proposed. Inspired by the previous, neurophysiologically plausible, biological motion perception models and recent studies, the simulation model only represents the dorsal pathway as a motion information processing section of the visual system according to the two-stream theory, while the stimuli used have been obtained from a previous psychophysical study on athletes. Moreover, using the psychophysical data from the same study and tuning a set of parameters, the model could successfully simulate the psychometric function and average reaction time of the athlete participants of the aforementioned study. 5 Although it is established that the visual system optimally integrates all available visual cues in the decision-making process, the results conform to the speculations favouring motion cue importance over dynamic form by only depending on motion information processing. As a functioning simulator, the present simulation model not only introduces some insight into the subject at hand but also shows promise for industry use. For example, predicting the impact of the lens-induced distortions, caused by various lens designs, on human decision-making. Keywords: Biological motion, Bayesian, Dorsal pathway, Hierarchical simulation model, Psychometric function, Reaction time

L'interaction sociale représente l’une des difficultés majeures des patients atteints de troubles envahissants du développement (TED). Or, la perception des mouvements humains contribue à la mise en place des comportements sociaux et représenterait un « marqueur » du développement de la cognition sociale. Cette étude de suivi du regard et de pupillométrie visait à caractériser l’attention visuo-spatiale et la charge cognitive au cours de la perception de mouvements biologiques humains porteurs d'intention sociale (MHS) chez 139 participants typiques (PaTYP) et 62 patients atteints d’un TED (PaTED). Chez les PaTYP, l’exploration augmente pour les MHS. Chez les PaTED, un déficit d’exploration des MHS est corrélé à la sévérité de la symptomatologie autistique globale. Ces anomalies de l’attention visuo-spatiale des PaTED réduiraient leur accès à l’information sociale et pourraient participer au trouble de l’interaction sociale et de la communication. / Social interaction is one of the main difficulties for patients with pervasive developmental disorders (PDD). However, the perception of human movement contributes to the development of social behavior and represents a "marker" for the development of social cognition. This eye tracking and pupillometric study aims to characterize the visuospatial attention and cognitive load during perception of social human biological motion (SHM) in 139 typical participants (PaTYP) and 62 patients with ASD (PaTED). In PaTYP, exploration increases for SHM. In PaTED, deficit of the exploration of MHS is correlated with the severity of the global autistic symptomatology. These abnormalities of visuospatial attention in PaTED could reduce their access to social information and participate in social interaction and communication disorders.

Research on biological motion, using point-light displays to present the motions, have been unravelling what information factors are still embedded in those impoverished stimuli and which of these factors are essential in visual processing of biological motion. Earlier studies suggest that orientation is a crucial factor in biological motion processing. The short-term priming experiment presented in this paper will further investigate the legitimacy of the primacy of orientation and suggest different solutions based on contradicting findings in previously published studies. In a serial two-choice reaction-time task, participants were presented with a patch-light display of a human engaged in one of three possible actions: climbing up a rope, jumping jacks, and walking. Participants had to identify the in-plane orientation of the human figure emerging from the moving patch-lights. Reliable facilitation effect was established for transitions containing same-oriented upright trails and same-oriented inverted trials. Interestingly, transitions of same-oriented upright trials produced significantly greater facilitation effect than transitions of same-oriented inverted trials.

No description available.