82 research outputs found

    Towards attochemistry: Control of nuclear motion through conical intersections and electronic coherences

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    The effect of nuclear dynamics and conical intersections on electronic coherences is investigated employing a two-state, two-mode linear vibronic coupling model. Exact quantum dynamical calculations are performed using the multi-configuration time-dependent Hartree method (MCTDH). It is found that the presence of a non-adiabatic coupling close to the Franck-Condon point can preserve electronic coherence to some extent. Additionally, the possibility of steering the nuclear wavepackets by imprinting a relative phase between the electronic states during the photoionization process is discussed. It is found that the steering of nuclear wavepackets is possible given that a coherent electronic wavepacket embodying the phase difference passes through a conical intersection. A conical intersection close to the Franck-Condon point is thus a necessary prerequisite for control, providing a clear path towards attochemistry.Comment: 12 pages, 3 figure

    Simulated XUV Photoelectron Spectra of THz-pumped Liquid Water

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    Highly intense, sub-picosecond terahertz (THz) pulses can be used to induce ultrafast temperature jumps (T-jumps) in liquid water. A supercritical state of gas-like water with liquid density is established, and the accompanying structural changes are expected to give rise to time-dependent chemical shifts. We investigate the possibility of using extreme ultraviolet (XUV) photoelectron spectroscopy as a probe for ultrafast dynamics induced by sub-picosecond THz pulses of varying intensities and frequencies. To this end, we use ab initio methods to calculate photoionization cross sections and photoelectron energies of (H2O)20_{20} clusters embedded in an aqueous environment represented by point charges. The cluster geometries are sampled from ab initio molecular dynamics simulations modeling the THz-water interactions. We find that the peaks in the valence photoelectron spectrum are shifted by up to 0.4 eV after the pump pulse, and that they are broadened with respect to unheated water. The shifts can be connected to structural changes caused by the heating, but due to saturation effects they are not sensitive enough to serve as a thermometer for T-jumped water

    "AI enhances our performance, I have no doubt this one will do the same": The Placebo effect is robust to negative descriptions of AI

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    Heightened AI expectations facilitate performance in human-AI interactions through placebo effects. While lowering expectations to control for placebo effects is advisable, overly negative expectations could induce nocebo effects. In a letter discrimination task, we informed participants that an AI would either increase or decrease their performance by adapting the interface, but in reality, no AI was present in any condition. A Bayesian analysis showed that participants had high expectations and performed descriptively better irrespective of the AI description when a sham-AI was present. Using cognitive modeling, we could trace this advantage back to participants gathering more information. A replication study verified that negative AI descriptions do not alter expectations, suggesting that performance expectations with AI are biased and robust to negative verbal descriptions. We discuss the impact of user expectations on AI interactions and evaluation and provide a behavioral placebo marker for human-AI interactio

    (Don’t) stand by me: How trait psychopathy and NPC emotion influence player perceptions, verbal responses, and movement behaviours in a gaming task

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    Social interactions are an essential part of many digital games, and provide benefts to players; however, problematic social interactions also lead to harm. To inform our understanding of the origins of harmful social behaviours in gaming contexts, we examine how trait psychopathy infuences player perceptions and behaviours within a gaming task. After measuring participants’ (n=385) traitlevel boldness, meanness, and disinhibition, we expose them to neutral and angry social interactions with a non-player character (NPC) in a gaming task and assess their perceptions, verbal responses, and movement behaviours. Our fndings demonstrate that the traits signifcantly infuence interpretation of NPC emotion, verbal responses to the NPC, and movement behaviours around the NPC. These insights can inform the design of social games and communities and can help designers and researchers better understand how social functioning translates into gaming contexts

    Virtual Reality Adaptation Using Electrodermal Activity to Support the User Experience

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    Virtual reality is increasingly used for tasks such as work and education. Thus, rendering scenarios that do not interfere with such goals and deplete user experience are becoming progressively more relevant. We present a physiologically adaptive system that optimizes the virtual environment based on physiological arousal, i.e., electrodermal activity. We investigated the usability of the adaptive system in a simulated social virtual reality scenario. Participants completed an n-back task (primary) and a visual detection (secondary) task. Here, we adapted the visual complexity of the secondary task in the form of the number of non-player characters of the secondary task to accomplish the primary task. We show that an adaptive virtual reality can improve users' comfort by adapting to physiological arousal regarding the task complexity. Our findings suggest that physiologically adaptive virtual reality systems can improve users' experience in a wide range of scenarios

    Feeling the Temperature of the Room: Unobtrusive Thermal Display of Engagement during Group Communication

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    Thermal signals have been explored in HCI for emotion-elicitation and enhancing two-person communication, showing that temperature invokes social and emotional signals in individuals. Yet, extending these findings to group communication is missing. We investigated how thermal signals can be used to communicate group affective states in a hybrid meeting scenario to help people feel connected over a distance. We conducted a lab study (N=20 participants) and explored wrist-worn thermal feedback to communicate audience emotions. Our results show that thermal feedback is an effective method of conveying audience engagement without increasing workload and can help a presenter feel more in tune with the audience. We outline design implications for real-world wearable social thermal feedback systems for both virtual and in-person communication that support group affect communication and social connectedness. Thermal feedback has the potential to connect people across distances and facilitate more effective and dynamic communication in multiple contexts.Comment: In IMWUT 202

    Die Kölner Silvesternacht 2015/2016 : Eine Analyse der Strafanzeigen

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    Es wird ein Gutachten des Kriminologen Rudolf Egg vorgestellt, welches für den parlamentarischen Untersuchungsausschuss IV des Landtags Nordrhein-Westfalens im Hinblick auf die Geschehnisse in der Kölner Silvesternacht 2015/2016 erstattet wurde. Ziel des Gutachtens ist es, insbesondere die damals verübten Straftaten zu typisieren sowie einer allfälligen Organisationsstruktur der Täter nachzugehen. Hierfür wurden 1022 anonymisierte Strafanzeigen ausgewertet. Im Rahmen der Analyse der Strafanzeigen kommen nicht nur die verübten Delikte und deren statistische Verteilung zur Sprache, sondern unter anderem auch Ort sowie Zeit der Tatbegehung. Es wird gezeigt, dass die Opfer nur wenig zu einer hinreichenden Täterbeschreibung beitragen konnten. Vereinzelt wurden in den Strafanzeigen die Tätigkeit der Polizei sowie die Anzahl der anwesenden Beamten bzw. Beamtinnen thematisiert. Eine Absprache zur Tatbegehung unter allen Tätern wird allein schon ob ihrer Vielzahl als kaum wahrscheinlich eingeschätzt. Es wird vermutet, dass die massive Begehung von Eigentums- sowie Sexualdelikten in dem Gefühl der Täter, sie könnten in der Menschenmasse anonym agieren und man befinde sich in einem rechtsfreien Raum, ihre Grundlage hatte. Es wird darauf hingewiesen, dass für eine hinreichende Betrachtung der Vorfälle die Auswertung weiterer Datenquellen erforderlich ist, vor allem um darauf basierend präventive Maßnahmen zu ergreifen

    Gender, Age, and Technology Education Influence the Adoption and Appropriation of LLMs

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    Large Language Models (LLMs) such as ChatGPT have become increasingly integrated into critical activities of daily life, raising concerns about equitable access and utilization across diverse demographics. This study investigates the usage of LLMs among 1,500 representative US citizens. Remarkably, 42% of participants reported utilizing an LLM. Our findings reveal a gender gap in LLM technology adoption (more male users than female users) with complex interaction patterns regarding age. Technology-related education eliminates the gender gap in our sample. Moreover, expert users are more likely than novices to list professional tasks as typical application scenarios, suggesting discrepancies in effective usage at the workplace. These results underscore the importance of providing education in artificial intelligence in our technology-driven society to promote equitable access to and benefits from LLMs. We urge for both international replication beyond the US and longitudinal observation of adoption

    Sexual attraction modulates interpersonal distance and approach-avoidance movements towards virtual agents in males

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    How does sexual attraction alter social interaction behavior? We examined the influence of sexual orientation on locomotor approach-avoidance behavior and interpersonal distance. We immersed androphilic and gynophilic male subjects into a virtual environment and presented various male and female virtual persons. In the first experiment, subjects took a step forward (approach) or backward (avoidance) in response to the sex of the virtual person. We measured reaction time, peak velocity, and step size, and obtained ratings of sexual attractiveness in every trial. In the second experiment, subjects had to approach the virtual person as if they were to engage in a social interaction. Here, we analyzed interpersonal distance and peak velocity of the approaches. Our results suggest that sexual attraction facilitates the approach response and reduces the preferred interpersonal distance. We discuss our findings in terms of proxemics, current findings in sex research, and the applicability of our novel task in other fields of psychological research

    Evaluating Interactive AI: Understanding and Controlling Placebo Effects in Human-AI Interaction

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    In the medical field, patients often experience tangible benefits from treatments they expect will improve their condition, even if the treatment has no mechanism of effect. This phenomenon often obscuring scientific evaluation of human treatment is termed the "placebo effect." Latest research in human-computer interaction has shown that using cutting-edge technologies similarly raises expectations of improvement, culminating in placebo effects that undermine evaluation efforts for user studies. This workshop delves into the role of placebo effects in human-computer interaction for cutting-edge technologies such as artificial intelligence, its influence as a confounding factor in user studies, and identifies methods that researchers can adopt to reduce its impact on study findings. By the end of this workshop, attendees will be equipped to incorporate placebo control measures in their experimental designs
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