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Understanding Body Language

Being social creatures, humans rely on the nuances of body language to function well in society. Understanding the way body language works could help researchers gain a deeper understanding of neuroscience, improve human-machine interfaces, and develop more efficient ways to train people on the autism spectrum to read social cues.

Prof. Uri Alon of the Department of Molecular Cell Biology investigates the two main theories in the filed: the "Emotional body language" theory, that originates in psychology, and the "Dramatic action theory", that focuses in transitive verbs: to encourage, to comfort, to threaten, to scold, etc.

Testing these theories required a large and unbiased set of body posture stimuli in a social context. While most studies employ pictures of actors or cartoons in a small range of postures, Prof. Alon used a different approach: namely, stick figures.

Because stick figures represent the human body with just a few angle coordinates, this method allowed him to generate a systematic and unbiased set of body postures and, consequently, enabled him to more accurately and methodically analyze different body configurations. By varying these angles, Prof. Alon systematically compiled 1,470 body configurations in pairs of stick figures.

Online participants of the study scored these stick-figure images using a defined set of eight dramatic actions and 20 emotions. Prof. Alon found that not only did subjects assign dramatic actions to images more frequently, but they more often agreed on the type of dramatic action for a given image. Emotions were assigned to fewer images and primarily centered around the more general adjectives “angry,” “confused,” and “embarrassed.”

Through this process, Prof. Alon and his team created a dictionary of stick-figure body postures with defined dramatic action and emotional meanings, which they hope will be useful for future research, automated image understanding, and to train people (perhaps those with Autism Spectrum Disorder, for example) to understand body language.

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Fake or duplicate e-identities

Fake or duplicate e-identities—called sybils—can cause serious harm to digital communities, by undermining consensus, tilting decisions, or even taking over. Preventing sybil infiltration may prove crucial to an e-community’s survival. Prof. Ehud Shapiro from the departments of Departments of Computer Science and Biological Chemistry set out to explore and identify the conditions under which an online community of predominantly genuine digital identities would be able to grow without generating an increased risk of the presence of sybils.

He considered an initial community with low sybil penetration, and that wished to admit new members without admitting too many sybils. As it is not realistic to expect that zero sybils would be admitted, Prof. Shapiro’s goal was to keep the fraction of sybils below a certain threshold. He showed that an e-community can tolerate up to one-third sybil penetration and still function democratically. Still, the fewer the sybils, the smaller the majority of genuine e-identities needed to be, in order to maintain the integrity of the decision-making process despite the sybils’ presence.

In a separate study, Prof. Shapiro delved deeper into the specific conditions needed to maintain a safe digital community by creating a “trust graph.” In this graph, depicting a model community, he assigned a vertex for each identity, categorized the relationships between the owners of the corresponding identities, and distinguished the genuine identities from the sybil identities. Additionally, he differentiated between the genuine identities, labeling those do not trust sybils as “honest” and those that do as “corrupt.”

Using these trust graphs, Prof. Shapiro proposed a method that identified the conditions (e.g. the type of identities, their relative fractions, and their trust relations) under which a digital community may grow while keeping the percentage of sybils low.

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Behavioral psychophysics of 3D vision

Research in the Department of Neurobiology—sponsored by the Braginsky Center for the Interface between Science and the Humanities—has revealed a new model for the emergence of visual perceptual awareness of three-dimensional (3D) objects in space. In 2D vision, enhanced perception occurs when the eyes are stably fixed at the right distance from an object, whereas in 3D vision, perception improves when individuals move their eyes between two fixation points. Working under the supervision of Active Sensing Lab director Dr. Amos Arieli, postdoctoral fellow Dr. Shira Ozana combined behavioral and psychophysics data with participants’ subjective experience of viewing 3D objects. The resulting data helped clarify the role played by unconscious vergence eye movements (VeyeM)—the simultaneous movement of both eyes in opposite directions—in the emergence of visual awareness and perception.

Bio-based networks of creativity

Since 2011, Prof. Uri Alon’s “Theater Lab” has been integrating ideas from improvisational theater with principles of physics to study human interactions and cognitive processes. In his recent work, he has been using this approach to explore the system-wide biological networks that govern the human search for creativity. Focusing on a sensory mechanism called fold-change detection (FCD), as well as scale invariance—a property that allows sensory systems to adapt to environmental signals at different orders of magnitude—Prof. Alon identified a scale-invariant FCD model that best describes human creative exploration, thereby clarifying the network dynamics behind the creative process.

Modeling the transmission of cultural memory

Using the cultural memory of the Jewish people as a model system, Prof. Yadin Dudai has devised a novel, mechanistic approach to the analysis of cross-generational long-term memory in large human populations. Drawing on cultural memory concepts and experimental approaches used in neurobiology and cognitive science, Prof. Dudai analyzed the encoding, consolidation, persistence over time, transformation, and modification of distinct mnemonic items in Jewish culture that contribute to a “core memory” that has remained essentially unchanged for millennia. Studying both ancient and more recent Jewish textual and archaeological memory elements, Prof. Dudai also performed behavioral recall experiments in extant Jewish populations. This process shed light on the persistence of elements of core memory, the mechanisms of adding to and removing elements from it, and the splitting of cultural memory among selected Jewish populations.

A new model for online democracy

In research that helps clarify the principles of online democracy and offers strategies for protecting and enhancing it in the future, Prof. Ehud Shapiro and his colleagues have presented principles for a decentralized process in which every human being would be able to easily create and own a genuine global identity. Based on a “public key” encrypted system that does not use biometrics and does not store any personal information, the new approach uses distributed ledger/blockchain technology to form a “web of trust” that would close up vulnerabilities—like bot-driven messaging and identity theft—that are associated with today’s online environment.

Braginsky lecture: Prof. Diederik Meijer

Prof. Diederik Meijer from the Faculty of Archaeology at Leiden University in the Netherlands was hosted at the Weizmann Institute by Prof. Elisabetta Boaretto, with the support of the Braginsky Center. A leading researcher in Near East Archaeology, Prof. Meijer focuses on the beginning of urbanism and state-formation processes in the Ancient Near East, from the fourth millennium BCE. His major excavation at Tell Hammam in Syria has influenced the understanding of the socioeconomic conditions and increasing role of trade practices in the region during the Early Bronze Age.

During his visit to the Institute, Prof. Meijer delivered a seminar entitled, “Can we harmonize history, archaeology, and the "exact" sciences? The problem of the two rival cities in the third millennium BCE in Mesopotamia.” He also met and discussed archaeology research with students currently engaged in archaeological sciences curricula.

Processing “personal space”

Awareness of the space surrounding the body—the so-called peri-personal space or PPS—is encoded in the brain through a dedicated neural system that maps multisensory stimuli. As neural representation of the space beyond the body is vital for the coordination of goal-directed movement, Prof. Tamar Flash and postdoctoral fellow Dr. France Lerner designed a virtual reality (VR) system for identifying factors that affect this process. Using this system, they are exploring how object depth, as well as temporal and geometric characteristics, affect perception of visual stimuli inside, at the boundary of, and outside the peri-personal space. They are also studying the perception of group motion, versus the motion of a single element, at varying distances from the body.

Braginsky lecture: Thomas Murray

The Braginsky Center hosted Thomas Murray, a California-based independent researcher, collector, lecturer, and private dealer of Asian and tribal art, who authored a book called C-14 Dating of Dayak Art in 2015. Interacting with Weizmann Institute scientists who specialize in carbon-14 dating, Murray presented a lecture on the use of radiocarbon testing to date artistic artifacts, predominantly those of the Dayak people in Borneo.

Braginsky lecture: Dr. Mario Livio

Dr. Mario Livio, an Israeli-American author and astrophysicist, was hosted by the Braginsky Center. Dr. Livio, author of Why? What Makes Us Curious, which explores different types of human curiosity and how they activate different parts of the brain, received his master’s degree in theoretical particle physics at the Weizmann Institute in 1972.

Genealogy and the Sciences conference

The Genealogy and the Sciences conference, generously supported by the Braginsky Center, took place at the David Lopatie Conference Centre at the Weizmann Institute from December 17-18, 2018. It was, to the eyes and ears of many, a very successful event, and an important milestone in the field of genealogy. This was the first forum of its kind, which saw a large number of lecturers from around the world—all respected scholars in their own fields, from a wide range of disciplines—gathered in an academic setting to exchange their thoughts and views about genealogy, a field usually considered a simple hobby.

Representatives from the “hard” (exact) sciences sat alongside scholars from the social sciences, arts, and humanities. Lecturers and audience members included mathematicians, biologists, engineers, physicists, chemists, forensic experts, and physicians, on the one hand, and anthropologists, geographers, historians, psychologists, archaeologists, and experts in onomastics on the other. Link to the program