This document summarizes a study which found that neurons in the orbitofrontal cortex (OFC) represent decision confidence in an abstract, modality-general manner. Researchers recorded neural activity in the OFC of rats performing sensory decisions and found that a subset of neurons encoded the confidence of choices, independently of outcome. Activity of these "confidence neurons" could predict choice and was consistent with computational models of decision confidence. Manipulating the activity of confidence neurons altered choice behavior in a way that depended on decision confidence. The findings suggest the OFC plays a key role in metacognition by representing abstract decision confidence.

1. Behavior- and Modality-General Representation of
Confidence in Orbitofrontal Cortex
Paul Masset, Torben Ott, Armin Lak, Junya Hirokawa, Adam Kepecs
Current Literature: Vic Shao-Chih Chiang &
Jamie Beshore, 2021

2. ● “Thinking about thinking”
● Cognitive processes used in monitoring,
assessing behavior
● Prone to inaccuracies &
reliability problems
● Subjectivity makes it difficult to
study objectively
https://www.edutopia.org/blog/metacognition-gift-that-keeps-giving-donna-wilson-marcus-conyers
S. Fleming and R. Dolan (2012) Phil. Trans. R. Soc. B
What is metacognition?

3. ● Objective task paired with self-report
● Adaptations for animal studies
● Signal detection theory (SDT) -- decouples response bias and
sensitivity
● PFC implicated in metacognition
● brain injury and disease affecting PFC can cause changes to
metacognitive ability
S. Fleming and R. Dolan (2012) Phil. Trans. R. Soc. B
How can we measure metacognition?

4. S. Fleming and R. Dolan (2012) Phil. Trans. R. Soc. B
Dissociating task performance from metacognition

5. ● rlPFC (& other areas of PFC) at the top of a hierarchy in integrating
● Also some independent signal for representing and manipulating
internally generated information
● A current hypothesis: metacognitive ability is socially adaptive
Social Role?

6. M. Dixon et al. K. Christoff (2017) Psychological Bulletin

7. Do OFC neurons signal abstract decision confidence?
1. Neural activity = statistical decision confidence
2. Predictive of choice
3. Abstract and centralized representation
P Masset et al. A Kepecs (2020) Cell
Present study

8. Behavioral paradigm
P Masset et al. A Kepecs (2020) Cell

9. P Masset et al. A Kepecs (2020) Cell
Psychometric curves

10. Time investment behavior consistent with decision confidence models
P Masset et al. A Kepecs (2020) Cell
E F G

11. Potential confounds
● Could be intuitively similar processes at play, e.g., attention
● These signals do not by themselves satisfy all 3 signatures
● These signals probably act more like a gain than a reproduction
of confidence
J. Sanders (2014) PhD Thesis

12. P Masset et al. A Kepecs (2020) Cell
Choice and confidence prediction model

13. P Masset et al. A Kepecs (2020) Cell
Estimating confidence mapping function

14. P Masset et al. A Kepecs (2020) Cell
Choice and confidence prediction model

15. TA Stalnaker, NK Cooch, G Schoenbaum (2015) Nat Neurosci
• S-O: stimulus outcome
• OFC: orbitofrontal cortex
Orbitofrontal Cortex

16. Orbitofrontal cortex neurons are tuned to
decision confidence
• Sp/s: spikes per second
P Masset et al. A Kepecs (2020) Cell

17. Confidence neuron
subtypes generalize
outcome prediction across
sensory modalities
• OPI: outcome predictive index
• R: regression
P Masset et al. A Kepecs (2020) Cell

18. Reinforcement
learning model
P Masset et al. A Kepecs (2020) Cell
• P: probability that a choice is
rewarded
• L: left
• R: right
• Q: action values
• V: cached values
• Qchoice : choice values
• α: learning rate
• Δ: prediction error
• r: reward

19. Confidence-guided choice updating
P Masset et al. A Kepecs (2020) Cell
• P: probability

20. Orbitofrontal cortex neurons in choice updating
P Masset et al. A Kepecs (2020) Cell
• Repeat: probability of
repeating the same choice
• k: trial
• f: logistic function
• β0: constant term
• β1:evidence for choice
• β2: previous trial’s evidence
• β3: average firing rate of
neuron
• P: probability
• A: auditory
• O: olfactory

21. Single-cell RNA sequencing of activated
confidence(+) neurons with FLiCRE?
CK Kim et al. AY Ting (2020) Biorxiv
• FLiCRE: Fast Light & Calcium-
Regulated Expression
• MKII: calmodulin-binding peptide
• LOV: evolved light-oxygen-voltage
photosensory domain
• Gal4: transcription factor
• TEV: tobacco etch virus
• uTEVp: truncated TEV protease
• TEVcs: TEV cleavage site
• UAS: upstream activating
sequence
• CD4: cluster of differentiation 4

22. Manipulating
confidence(+) neuron
activity during
decision-making with
non-invasive
optogenetics SOUL?
X Gong et al. GP Feng (2020) Neuron
• SOUL: step-function opsin with ultra-
high light sensitivity
• LH: lateral hypothalamus

23. Summary
P Masset et al. A Kepecs (2020) Cell

24. JI Sanders et al. A Kepecs (2016) Neuron
Statistical
decision
confidence in
primates?
Blackboard Comments

25. A Lak et al. A Kepecs (2014) Neuron
Is statistical decision confidence strictly in the OFC?
Blackboard Comments
• WT: waiting time
• AP: anterior-posterior
• Ctrl: control
• Mus: muscimol

26. Taking accuracy out of the equation?
Blackboard Comments
P Masset et al. A Kepecs (2020) Cell
• β: coefficient
• t: time
• TI: time investment
• R: firing rate
• r: regression
• FR: firing rate
• Olf: olfactory
• Aud: auditory