The Morra Game: Developing an Automatic Gesture Recognition System to Interface Human and Artificial Players

Morra is an ancient hand game still played nowadays. In its more popular variant, two players simultaneously extend one hand in front of the opponent to show a number of fingers, while uttering a number from 2 to 10. The player who successfully guesses the total number of fingers scores a point. Morra can be defined as a serious game, as it has the potential to positively affect cognition and to improve cognitive and perceptual skills. Moreover, with its involvement of many perceptual, cognitive and motor skills, morra is ideal to test several cognitive processes. This paper describes aspects of Gavina 2121, an artificial Morra player that successfully predicts the numbers of human opponents taking advantage of the limited ability of humans in random sequence generation. This study focuses on automatic gesture recognition. We developed and tested a system to allow Gavina 2121 to detect and count in real time the number of extended fingers in a human hand. The system is based on the open source MediaPipe Hand framework developed by Google. Our tests indicate that the system is able to accurately recognize the number of fingers extended by a human hand in real time, both in prone and supine positions. The system is still imprecise in semi-naturalistic conditions of an actual morra game, where the fingers of two hands need to be computed simultaneously. Our test, still in its pilot phase, shows promising results towards a flexible implementation of an artificial morra player that can sensibly expand the educational, rehabilitation and research applications of Morra.