Confidence Is the Bridge between Multi-stage Decisions

(van den Berg, Zylberberg, Kiani, Shadlen, & Wolpert, 2016)

The context of this article lies within multi-stage perceptual decision making. The authors are trying to understand whether the concept of confidence (which they define as “an internal prediction about the success or failure of one’s decisions”) has an influence on the speed and accuracy of a second decision in perceptual multi-stage decisions. They tested this by way of a series of experiments involving eye tracking used to gage a participant’s decision to look left/right or up/down. The decision was deemed to have been made according to which direction the eye fixated.

The theory that informed this study was the bounded drift diffusion model. It was found that both accuracy and response time (RT) of the second decision depended on the experience of the first decision with the implication that experience of the first decision may affect the second in that part of the study where feedback was provided after each decision. Where feedback was not provided, the researchers suggested that confidence in the veracity of the first decision affected their second decision. The instruments the researchers used was eye-tracking and a movement of dots on the screen of a computer. The study consisted of four subjects.

Analysis used by the researchers included:

1. logistic regression to determine is accuracy of the second decision is affected by the coherence of the first.
2. Chi square test with Yates correction to determine if the accuracy of the second decision is affected by the first
3. ANOVAs of confidence rating with the factors -trial type, motion strength and accuracy

MY NOTES:

• Context is Perceptual decision making, Multi-stage decision making
• Uniting of decision accuracy, speed, confidence to a common framework of bounded evidence accumulation
• Strategy applied (eg. Speed-accuracy trade-off) affected by previous decisions
• transduced
• Unknown feedback of the accuracy of the decision
• When this is the case – confidence in previous decisions will affect subsequent decisions
• Speed and accuracy explained by noisy evidence accumulation to a terminating bound
• Termination bound elevated in proportion to their confidence in their first decision.\Single stage perceptual decisions – bounded evidence accumulation
• Confidence thus conforms to an internal prediction about the success or failure of one’s decisions.
• Our results therefore point to a more general capacity to adjust decision-making on a fast timescale, based on the confidence one has in a previous decision.
• No feedback offered until after both decisions had been made

REFERENCE

van den Berg, R., Zylberberg, A., Kiani, R., Shadlen, M. N., & Wolpert, D. M. (2016). Confidence Is the Bridge between Multi-stage Decisions. Current Biology, 26(23), 3157–3168.