International Journal of Computer Applications (0975 – 8887) Volume 178 – No. 45, September 2019 16 A Tangible Interface System for People with Down Syndrome Gabriel dos Santos Dourado Pontifícia Universidade Católica de Goiás, PUC Goiás Goiânia/Go Brasil Josef Augusto Oberdan Souza Silva Pontifícia Universidade Católica de Goiás, PUC Goiás Goiânia/Go Brasil Ariane Ruben Calaça Di Menezes Pontifícia Universidade Católica de Goiás, PUC Goiás Goiânia/Go Brasil Kárita Cecília Rodrigues Silva Pontifícia Universidade Católica de Goiás, PUC Goiás Goiânia/Go Brasil Juliana Santos de Souza Hannum Pontifícia Universidade Católica de Goiás, PUC Goiás Goiânia/Go Brasil Talles Marcelo Gonçalves de Andrade Barbosa Pontifícia Universidade Católica de Goiás, PUC Goiás Goiânia/Go Brasil ABSTRACT In general, people with Down syndrome have cognitive limitations and motor difficulties that may compromise the individual's development throughout life. It is due to the genetic condition that imposes peculiarities, such as low muscle tone and difficulty in learning, making it difficult to understand and interact with and around the environment. However, the use of new technologies proves to be a promising route because it offers new stimuli that can be used as reinforcers in rehabilitation, training, and entertainment activities. An example is a provision and use of systems with tangible interfaces, whose interaction between the user and the machine happens through touch. It promotes proprioception, incites attention, interest, and concentration. This work describes the development and evaluation of a computational system with a tangible interface, called 3D Sandplay. This system offers a sandbox, which enables user interaction with the virtual world, amplified by Augmented Reality, for creating scenarios and understanding abstract concepts. 3D Sandplay was evaluated by a group of people with Down syndrome in three distinct activities and, in addition to achieving the events, the interest, attention, and resistance to complete the activities were evaluated. All research volunteers are students of the Alfadown project, an extension project maintained by PUC Goiás. Results have shown that 3D Sandplay is a tool that can contribute to the cognitive and motor development of children, adolescents, and adults with Down syndrome. Keywords Down Syndrome, Tangible Interface, Augmented Reality. 1. INTRODUCTION Augmented Reality (AR) proposes the integration of real- world elements with the virtual world. For this, the capture of gestures, movements, or touches can be transformed into electronic information. In a complementary way, a Tangible Interface (TI) is one that allows interaction between the user and the computer system through touch [1]. Sandplay is a tool commonly used by health professionals for therapy, entertainment, and teaching. The apparatus consists of a sandbox and a set of archetypes, whose purpose is to offer the user the environment and the objects to construct scenarios or narratives related to the subjectivity itself. According to Kalff, the central aspect of the sand play is to provide the patient with free and protected space [2]. It promotes synesthesia and facilitates interaction between the patient and the therapist. According to Antunes and Vicentini [3], many reflexes are triggered tactilely by proprioception, recognition of the spatial location of the body. The tactile system provides information on what is in contact with the skin, temperature, texture, shape, and movement. The use of AR with support in TI has led to the emergence of a new technology known as Augmented Reality SandBox or simply ARSandBox. This technology extends the functionality of a game in the sand, by the possibility of multimedia projection, in three dimensions, triggered by the touch. ARSandbox systems have become famous for topography learning and entertainment. For example, the work developed by CHUTCHOMCHUEN [4] presents the results of a study carried out with elementary school students, in which the participants used an ARSandBox to learn Geography concepts. Because of this, it is speculated that this technology can also contribute to the training of vulnerable people, particularly those with Autism Spectrum Disorder (ASD) and people with Down syndrome. Down Syndrome (DS) is a disorder of genetic origin that causes cognitive and motor difficulties to affected individuals, in addition to anatomical differences when these individuals are compared to typical individuals. In general, people with DS present deficits in learning and muscle hypotonia, leading to delays in intellectual and motor development. Customized activities and the use of technological tools that stimulate attention, engagement, and proprioception can contribute to the cognitive, emotional, and motor development of individuals with DS. Faced with this, the Pontifical Catholic University of Goiás (PUC Goiás) maintains an extension project, called Alfadown. The goal of the Alfadown project is to facilitate literacy and social inclusion of people with DS, with access to computer resources [5]. Recently, in the framework of the Alfadown project, applications for the mobile platform with support for biofeedback [6] and systems with augmented reality were developed, introduced and evaluated through tangible and fluid interfaces [7].