Proceedings of the Annual Meeting of the Cognitive Science Society

This study utilises an experiment famous in quantum physics,the Stern-Gerlach experiment, to inform the structure of an ex-perimental protocol from which a quantum cognitive decisionmodel can be developed. The ’quantumness’ of this modelis tested by computing a discrete quasi-probabilistic Wignerfunction. Based on theory from quantum physics, our hypothe-sis is that the Stern-Gerlach protocol will admit negative valuesin the Wigner function, thus signalling that the cognitive de-cision model is quantum. A crowdsourced experiment of twoimages was used to collect decisions around three questions re-lated to image trustworthiness. The resultant data was used toinstantiate the quantum model and compute the Wigner func-tion. Negative values in the Wigner functions of both imageswere encountered, thus substantiating our hypothesis. Find-ings also revealed that the quantum cognitive model was amore accurate predictor of decisions when compared to pre-dictions computed using Bayes’ rule.