Luca Chittaro

YNIMG Journal 2014 Journal Article

Brain activity and prosocial behavior in a simulated life-threatening situation

• Marco Zanon
• Giovanni Novembre
• Nicola Zangrando
• Luca Chittaro
• Giorgia Silani

To study the neuronal basis of altruistic behavior, we investigated functional connectivity within brain networks of participants who exhibited either a self-benefit behavior or an altruistic one in a life-threatening situation simulated in a virtual environment. In particular, participants were asked to evacuate a virtual building on fire and, without being previously informed, they were faced with a decision on whether to stop and help a trapped virtual human, at the possible cost of losing their own life in the virtual experience. Group independent component analysis (gICA) applied on blood-oxygen-level-dependent (BOLD) functional images revealed significant differences between the group of participants who showed selfish behavior and those who acted prosocially. Specifically, an increased functional connectivity in the salience network, comprising the anterior insula (AI) and the anterior mid cingulate cortex (aMCC), was observed in the selfish group compared to the prosocial one. Conversely, higher ICA weights in the medial prefrontal cortex and temporo-parietal junction (TPJ), were observed in the prosocial group. The findings show that an increased functional connectivity of the salience network, which suggests an enhanced sensitivity to the threatening situation and potential danger for the individual, resulted in more selfish choices, while the engagement of the medial prefrontal and temporo-parietal cortices subserved prosocial behavior, possibly due to their role in perspective-taking. The study provides the first online neurophysiological measurement of prosocial decision-making during threatening situations, opening new avenues to the investigation of neuronal substrates of complex social behaviors.

AIIM Journal 2008 Journal Article

MOPET: A context-aware and user-adaptive wearable system for fitness training

• Fabio Buttussi
• Luca Chittaro

Objective Cardiovascular disease, obesity, and lack of physical fitness are increasingly common and negatively affect people’s health, requiring medical assistance and decreasing people’s wellness and productivity. In the last years, researchers as well as companies have been increasingly investigating wearable devices for fitness applications with the aim of improving user’s health, in terms of cardiovascular benefits, loss of weight or muscle strength. Dedicated GPS devices, accelerometers, step counters and heart rate monitors are already commercially available, but they are usually very limited in terms of user interaction and artificial intelligence capabilities. This significantly limits the training and motivation support provided by current systems, making them poorly suited for untrained people who are more interested in fitness for health rather than competitive purposes. To better train and motivate users, we propose the mobile personal trainer (MOPET) system. Methods and material MOPET is a wearable system that supervises a physical fitness activity based on alternating jogging and fitness exercises in outdoor environments. By exploiting real-time data coming from sensors, knowledge elicited from a sport physiologist and a professional trainer, and a user model that is built and periodically updated through a guided autotest, MOPET can provide motivation as well as safety and health advice, adapted to the user and the context. To better interact with the user, MOPET also displays a 3D embodied agent that speaks, suggests stretching or strengthening exercises according to user’s current condition, and demonstrates how to correctly perform exercises with interactive 3D animations. Results and conclusion By describing MOPET, we show how context-aware and user-adaptive techniques can be applied to the fitness domain. In particular, we describe how such techniques can be exploited to train, motivate, and supervise users in a wearable personal training system for outdoor fitness activity.

IS Journal 2007 Journal Article

Adaptive Hypermedia Techniques for 3D Educational Virtual Environments

• Luca Chittaro
• Roberto Ranon

Based on a well-known adaptive hypermedia framework, the proposed system creates a 3D educational virtual environment that selects and personalizes interactive learning content for users. In EVEs, users not only see concepts visualized, but they can perform tasks in a suitable fictional world or a real-world reproduction. Moreover, compared to 2D multimedia, using interactive 3D graphics lets developers create representations of subjects or phenomena that are more informative and make it possible for users to analyze a single subject from different viewpoints. In EVEs, adaptivity can play an important role in increasing both learning-process effectiveness and interface usability.

AIJ Journal 2004 Journal Article

Hierarchical model-based diagnosis based on structural abstraction

• Luca Chittaro
• Roberto Ranon

Abstraction has been advocated as one of the main remedies for the computational complexity of model-based diagnosis. However, after the seminal work published in the early nineties, little research has been devoted to this topic. In this paper, we consider one of the types of abstraction commonly used in diagnosis, i. e. , structural abstraction, investigating it both from a theoretical and practical point of view. First, we provide a new formalization for structural abstraction that generalizes and extends previous ones. Then, we present two new different techniques for model-based diagnosis that automatically derive easier-to-diagnose versions of a (hierarchical) diagnosis problem on the basis of the available observations. The two proposed techniques are formulated as extensions of the well-known Mozetic's algorithm [I. Mozetic, Hierarchical diagnosis, in: W. H. L. Console, J. de Kleer (Eds.), Readings in Model-Based Diagnosis, Morgan Kaufmann, San Mateo, CA, 1992, pp. 354–372], and experimentally contrasted with it to evaluate the obtained efficiency gains.

AIIM Journal 2001 Journal Article

Information visualization and its application to medicine

• Luca Chittaro

This paper provides an introduction to the field of information visualization (IV) and a discussion of its application to medical systems. More specifically, it aims at: (i) defining what IV is and what are its goals (ii) highlighting the similarities and differences between IV and traditional medical imaging (iii) illustrating the potential of IV for medical applications by examining several examples of implemented systems and (iv) giving some general indications about the purposes and the effective exploitation of an IV component into a medical system.

TIME Conference 2001 Conference Paper

Representation of Temporal Intervals and Relations: Information Visualization Aspects and their Evaluation

• Luca Chittaro
• Carlo Combi

A crucial component for turning any temporal reasoning system into a real-world application that can be adopted by a wide base of users is given by its user interface. After analyzing and discussing the state of the art for the visualization of temporal intervals and relations, this paper proposes three new solutions, also evaluating them with a proper user study.

AIIM Journal 1999 Journal Article

Abstraction on clinical data sequences: an object-oriented data model and a query language based on the event calculus

• Carlo Combi
• Luca Chittaro

In this work, we deal with temporal abstraction of clinical data. Abstractions are, for example, blood pressure state (e. g. normal, high, low) and trend (e. g. increasing, decreasing and stationary) over time intervals. The goal of our work is to provide clinicians with automatic tools to extract high-level, concise, important features of available collections of time-stamped clinical data. This capability is especially important when the available collections constantly increase in size, as in long-term clinical follow-up, leading to information overload. The approach we propose exploits the integration of the deductive and object-oriented approaches in clinical databases. The main result of this work is an object-oriented data model based on the event calculus to support temporal abstraction. The proposed approach has been validated building the CARDIOTABS system for the abstraction of clinical data collected during echocardiographic tests.

ECAI Conference 1996 Conference Paper

A General Modal Framework for the Event Calculus and its Skeptical and Credulous Variants

• Angelo Montanari
• Luca Chittaro
• Iliano Cervesato

AAAI Conference 1996 Conference Paper

Augmenting the Diagnostic Power of Flow-Based Approaches to Functional Reasoning

• Luca Chittaro

In this paper, we consider flow-based approaches to functional diagnosis. First, we contrast the existing approaches, pointing out the major limitations of each. Then, we choose one of them and extend it in order to overcome the identified limitations. Finally, we show how the proposed extension can be introduced into the other flow-based approaches.

KER Journal 1996 Journal Article

Trends in temporal representation and reasoning

• Luca Chittaro
• Angelo Montanari

Time is one of the most relevant topics in AI. It plays a major role in several of AI research areas, ranging from logical foundations to applications of knowledge-based systems. Despite the ubiquity of time in AI, researchers tend to specialise and focus on time in particular contexts or applications, overlooking meaningful connections between different areas. In an attempt to promote crossfertilisation and reduce isolation, the Temporal Representation and Reasoning (TIME) workshop series was started in 1994. The third edition of the workshop was held on May 19–20 1996 in Key West, FL, with S. D. Goodwin and H. J. Hamilton as General Chairs, and L. Chittaro and A. Montanari as Program Chairs. A particular emphasis was given to the foundational aspects of temporal representation and reasoning through an investigation of the relationships between different approaches to temporal issues in AI, computer science and logic.

TIME Conference 1994 Conference Paper

Efficient Handling of Context Dependency in the Cached Event Calculus

• Luca Chittaro
• Angelo Montanari

This article deals with the problem of providing Kowalski and Sergot's event calculus, extended with context dependency, with an efficient implementation in a logic programming framework. Despite a widespread recognition that a positive solution to efficiency issues is necessary to guarantee the computational feasibility of existing approaches to temporal reasoning, the problem of analyzing the complexity of temporal reasoning programs has been largely overlooked. This article provides a mathematical analysis of the efficiency of query and update processing in the event calculus and defines a cached version of the calculus that (i) moves computational complexity from query to update processing and (ii) features an absolute improvement of performance, because query processing in the event calculus costs much more than update processing in the proposed cached version.

ECAI Conference 1994 Conference Paper

Skeptical and Credulous Event Calculi for Supporting Modal Queries

• Luca Chittaro
• Angelo Montanari
• Alessandro Provetti