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].
Image credits: [Forstmann et al., 2016]
Multi-alternative decisions are often modeled as a race between accumulators for each possible choice.
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.
- It refers to scalar values derived from those distributions [Meyniel et al., 2015].
- 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.
Image credits: Kepecs et al., 2008
Post-decisional focus models posit that evidence accumulation goes on after decision time to account for confidence.
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.
Preliminary results
- As expected, confidence is correlated with dot motion coherence, as is (oppositely) decision time.
- Model is able to implement the SAT.
Future works
- Refine the hyperparameters tuning process.
- Add different metacognitive strategies.
- Implement model on a human/robot collaborative task.
- …
Thanks for your attention!
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