No / In order to maintain a coherent, unified percept of the external environment, the brain must continuously combine information encoded by our different sensory systems. Contemporary models suggest that multisensory integration produces a weighted average of sensory estimates, where the contribution of each system to the ultimate multisensory percept is governed by the relative reliability of the information it provides (maximum-likelihood estimation). In the present study, we investigate interactions between auditory and visual rate perception, where observers are required to make judgments in one modality while ignoring conflicting rate information presented in the other. We show a gradual transition between partial cue integration and complete cue segregation with increasing inter-modal discrepancy that is inconsistent with mandatory implementation of maximum-likelihood estimation. To explain these findings, we implement a simple Bayesian model of integration that is also able to predict observer performance with novel stimuli. The model assumes that the brain takes into account prior knowledge about the correspondence between auditory and visual rate signals, when determining the degree of integration to implement. This provides a strategy for balancing the benefits accrued by integrating sensory estimates arising from a common source, against the costs of conflating information relating to independent objects or events.

With the increasing interest in Virtual/Augmented Reality, the next generation of application platforms is emerging in the form of immersive and engaging experiences. The company Dewire Knightec is exploring an application platform based on the web technology WebXR where users can interact with multiple applications simultaneously. However, numerous independent applications rendering content in the same 3D environment can lead to objects intersecting and occluding, leading to visual conflicts. In this thesis work, we discuss the concept of visual conflicts and avoidance strategies. We present a fully working prototype of a conflict mitigation framework for concurrent WebXR applications. The framework mitigates conflicts using two main collision avoidance strategies in the form of multiple render options and position offsetting. The proposed framework is demonstrated in a scenario where applications render contents on top of buildings in the user’s surroundings. By running multiple applications, a user can for example read a restaurant menu, see mall opening hours, and get travel directions simultaneously. The feasibility and efficiency of the proposed avoidance strategy in developed framework has been evaluated using a focus group of developers and software architects. After the evaluation, the framework can be summarized as a good foundation for future multi-application XR platforms.