Computational Phenotyping of Decision-Making over Voice Interfaces.

AbstractResearch on human reinforcement learning and decision-making behaviour has traditionally used visual-based symbols and graphics in the experimental paradigms. Such research leads to improved understanding of human decision-making and has application in fundamental research in cognitive neuroscience. In clinical domains, the approach holds out the possibility for the development of computationally-derived biomarkers suitable for use in psychiatry. Scaling this experimental approach through pervasive computing can help create larger datasets which will be necessary for normative studies. This will require the expansion of these experimental approaches beyond conventional visual representations. People receive information and interact with their environments through various senses. In particular, our sense of hearing in conjunction with speech represents a ubiquitous modality for learning and for updating our knowledge of the world. Consequently, it represents an important path for the investigation of human decision-making which is now experimentally accessible via rapid advances in voice-enabled intelligent personal assistants (IPAs). Examples include Amazon’s Alexa technology and Google’s Voice Assistant. However, to date no studies have demonstrated the feasibility of delivering such experimental paradigms over such voice technologies. Consequently in this study, we compared the performance of the same group of participants on the traditional visual-based and for the first time, a conversational voice-based, two-armed bandit task. Reinforcement learning models were fitted to the data to represent the characteristics of the underlying cognitive mechanisms in the task. Both model-independent behavioural measures and model-derived parameters were compared. The results suggest that participants demonstrated higher shifting rates in the voice-based version of the task. The computational modelling analysis revealed that participants adopted similar learning rates under the two versions of the interfaces, but more decision noise was introduced in the voice-based task as reflected by the decreased value of the inverse temperature parameter. We suggest that the elevated shifting rate is derived from the increased noise in the voice interface instead of a change in the learning strategy of the participants. Higher intensity of the control adjustments (click touch versus speak) might be one of the sources of noise, thus it is important to think further regarding the design of the voice interface if we wish to apply voice-enabled IPAs to measure human decision-making in their daily environments in the future.