*3.1.2 Captive effect*

In the literature of serious game studies, various factors have been identified that help to engage participants and prolong the learning experience: graphic aesthetics and the soundscape; the fluidity of the user experience, allowing the player to lose themselves in the game and forget about the outside world; the narration, which helps to maintain suspense and makes the player want to continue playing; the right level of difficulty and challenge, which maintains the player's concentration and motivation; and the captive effect of the interfaces. This captive effect that a computer interface (whether in a computer game or a digital interface in general) has on its user can be stronger or weaker depending on the person [27]. Researchers in the field attribute this captive effect to two aspects of the computer interface. Firstly, the screen itself *"contributes to drawing our attention towards the screen. [… It] paradoxically forms a 'boundary frame' that restricts our visual perception [and] in a certain way immobilises our gaze, creating a centring that explains why we feel as if we are absorbed, even hypnotised by the screen"* [28]. Secondly, the computer interface has the unique characteristic of juxtaposing different types of visual information – *"the screen is a frame (interface) that contains other frames"* [28] – and this tends to monopolise our attention: *"It then functions as a capture device: we become absorbed, captivated by light, writings, images […]"* [28]. In fact, in a computerised game, where game design calls for both human-machine interactions and social interactions, the computer interface tends to take up too much of the participants' attention to the detriment of direct exchanges between people.
