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Towards metacognitive agents: integrating confidence in sequential decision-making

Towards metacognitive agents: integrating confidence in sequential decision-making

Confidence in natural cognition

Decision-making as a sequential process

  • A decision is a deliberative process leading to a choice.
  • Decision-makers need time to collect and process informative cues.
  • Decinion-making is often modeled as an accumulation-to-threshold process [Gold and Shadlen, 2007].
  • The balance between response time and accuracy (when available) is called the Speed/Accuracy Trade-off [Heitz, 2014].

Models of sequential decision-making

For binary choices, a popular model is the Diffision Decision Model [Ratcliff and McKoon, 2008].

Illustration of the DDM model

Image credits: [Forstmann et al., 2016]

Multi-alternative decisions are often modeled as a race between accumulators for each possible choice.

Illustration of a race model

Image credits: [Mamassian, 2016]

Confidence in decision-making

  • Uncertainty is inherent to all stages of neural computation [Fleming, 2024].
    • It refers to probabilistic representations of information in the brain.
  • Confidence quantifies the degree of certainty associated with a decision.
  • More formally, confidence can be defined as the probability that a choice is correct given the evidence [Pouget et al., 2016].

Computing confidence in sequential decision-making models

In decisional focus models, confidence is directly indexed by the state of evidence at the time of choice.

Race model with BoE

Image credits: Kepecs et al., 2008

Post-decisional focus models posit that evidence accumulation goes on after decision time to account for confidence.

2DSD model

Image credits: Pleskac and Busemeyer, 2008

Confidence as a doorway to metacognition

  • Metacognition is the ability to monitor and regulate one’s cognitive processes [Flavell, 1979].
    • Example: should I study more (or differently) for this exam?
  • As part of metacognitive monitoring, confidence judgments may inform the processes of cognitive control [Fleming and Lau, 2014].

An emerging field: the neuroscience of confidence

  • Activity in the parietal cortex seems related to evidence accumulation during decision-making.

  • Separate and perhaps multiple brain areas are involved in confidence monitoring and reporting [Grimaldi et al., 2015]:

    • Importance of the prefrontal cortex, more precisely the ventromedial prefrontal cortex (vmPFC), in the formation of confidence.
    • Firing rates of many single neurons in the orbitofrontal cortex (OFC) of rats match confidence models [Kepecs et al., 2008].

Proposed approach

Agent architecture

Model combining:

  • a decision module based on an evidence accumulation model;
  • a metacognitive module in which confidence is used to tune the decision hyperparameters [Desender and Verguts, 2024].

Experimental validation

Model was assessed on a classic perceptual task: Random Dot Motion discrimination.

Confident agent model

Preliminary results

  • As expected, confidence is correlated with dot motion coherence, as is (oppositely) decision time.
  • Model is able to implement the SAT.

First model results

Future works

  • Refine the hyperparameters tuning process.
  • Add different metacognitive strategies.
  • Implement model on a human/robot collaborative task.

Thanks for your attention!

Any questions?