Summary: Changes of mind could be caused by heightened uncertainty about an initial decision.
Source: University of Ulster
People can sometimes change their mind while making a decision. For instance, at a supermarket and after initially deciding on purchasing a specific brand of a product, a customer may eventually change their mind and grab a product from a different brand. Another scenario is driving in the rain – the bad weather conditions make it fairly easy to misinterpret a road sign, and subsequently change direction in response to this misinterpretation.
Several research studies have shown that changes-of-mind occur shortly after making the initial commitment to a choice, and are primarily caused by sensory evidence that has not yet been completely processed when the person first decides, but the person changes their mind when it is. However, a new study, recently published in the journal PLoS Computational Biology, challenges this notion by showing that changes-of-mind can occur in the absence of such delayed sensory evidence.
This new study made use of a widely-used perceptual decision-making task in which participants are asked to identify the dominant direction of motion of a cloud of randomly-moving dots. Dr. Arkady Zgonnikov, who led the experimental work, supported by the Irish Research Council at the National University of Ireland (NUI) Galway in Ireland, said: “Our participants occasionally changed their mind after the initial decision even though no extra information was presented to them. We were surprised to find that changes-of-mind were preceded by long deliberations during an initial decision – a signature of heightened sense of conflict.” In the same paper, the experimental results were replicated by Dr. Stefan Scherbaum and his Ph.D. student, Martin Schoemann, at Technische Universität Dresden in Germany, validating the robustness of the results.
To provide insights on the experimental observations, the authors developed a neurocomputational model that was able to account for the behavioural observations. Dr. Nadim Atiya, who was at the time a Ph.D. student at Ulster University in the UK and led the development of this computational model, stated: “Our model suggests that changes-of-mind observed in the experiment could be caused by heightened uncertainty about the initial decision.” He further explained: “The model shows that this uncertainty delays the initial response – allowing for prolonged deliberations prior to committing to an initial choice.”
Dr. Denis O’Hora from NUI Galway’s School of Psychology, and Dr. KongFatt Wong-Lin from Ulster University’s Intelligent Systems Research Centre, both senior and corresponding authors of the paper, added: “We are delighted to be part of this international initiative that integrates novel experiments and computational modelling to understand decision confidence. This study links changes-of-mind with decision uncertainty monitoring – an important human metacognitive ability connected to our conscious awareness of what we experience. Understanding metacognition is especially crucial in the longstanding quest to understand consciousness.”
Neuroscience News would like to thank KongFatt Wong-Lin from the University of Ulster for submitting this research news to us for inclusion on the website.
University of Ulster
KongFatt Wong-Lin – University of Ulster
The image is in the public domain.
Original Research: Open access
“Changes-of-mind in the absence of new post-decision evidence”. Atiya NAA, Zgonnikov A, O’Hora D, Shoemann M, Scherbaum S, Wong-Lin K.
University of Ulster Computational Biology doi:10.1371/journal.pcbi.1007149.
Changes-of-mind in the absence of new post-decision evidence
Decisions are occasionally accompanied by changes-of-mind. While considered a hallmark of cognitive flexibility, the mechanisms underlying changes-of-mind remain elusive. Previous studies on perceptual decision making have focused on changes-of-mind that are primarily driven by the accumulation of additional noisy sensory evidence after the initial decision. In a motion discrimination task, we demonstrate that changes-of-mind can occur even in the absence of additional evidence after the initial decision. Unlike previous studies of changes-of-mind, the majority of changes-of-mind in our experiment occurred in trials with prolonged initial response times. This suggests a distinct mechanism underlying such changes. Using a neural circuit model of decision uncertainty and change-of-mind behaviour, we demonstrate that this phenomenon is associated with top-down signals mediated by an uncertainty-monitoring neural population. Such a mechanism is consistent with recent neurophysiological evidence showing a link between changes-of-mind and elevated top-down neural activity. Our model explains the long response times associated with changes-of-mind through high decision uncertainty levels in such trials, and accounts for the observed motor response trajectories. Overall, our work provides a computational framework that explains changes-of-mind in the absence of new post-decision evidence.