14/ Needless to say, I am very happy that this is finally out there, and am super excited to share it with the world.

13/ This project saw me write my PhD thesis, defend it, become a parent, move to a different country to start a postdoc, take on a new scientific adventure doing NHP electrophysiology, and many more all while trying to stay sane & alive during a pandemic.

12/ Because information use is more susceptible to deliberative control, our results imply that confirmation bias may be malleable, contingent on appropriate feedback and incentives.

11/ We conclude that confirmation bias originates from the way in which decision-makers utilize information encoded in the brain, which sheds new light on an important cognitive phenomenon that has occupied scholars for centuries.

10/ By contrast, an information-theoretic measure of the use (“readout”) of encoded evidence for the final estimate (“intersection information”) in parietal and visual cortex was bigger for consistent than for inconsistent samples, in line with the selective use scenario.

9/ We also used MEG to measure cortical population dynamics in participants’ brains during the task. The evidence samples were precisely encoded in population activity in visual and parietal cortex, irrespective of their consistency with the previous choice.

8/ Interestingly, this consistency effect on behavioral evidence weighting was bigger when participants had to report their own categorical judgment of the evidence halfway through the trial, compared to when they instead received an external categorical cue.

7/ Participants’ final estimation reports were more strongly affected by evidence samples in the second half of the trial that were consistent (compared to inconsistent) with the previous left/right choice: a behavioral signature of confirmation bias.

6/ After viewing half of the samples, participants judged whether the mean of the source distribution was to the left or right from the vertical meridian. After viewing the rest of the samples, they reported a continuous estimation of the source with a joystick.

5/ To arbitrate between these scenarios, we asked participants to evaluate sequences of 12 noisy visual evidence samples: small discs with varying angles to the vertical meridian. Each sample was drawn from a hidden source: a probability distribution with constant mean per trial.

4/ We reasoned that such selective weighting of evidence could be brought about by two distinct neural mechanisms: (i) selective encoding of incoming evidence in the brain, or (ii) biased utilization of encoded evidence for reasoning and action.

3/ In earlier work (www.cell.com/current-biol..., we showed that such biases are also present in simple perceptual decisions.

2/ Human decision-makers often interpret information selectively, depending on whether that evidence aligns with the decision-maker’s previous beliefs and judgments: Consistent evidence is weighted more, and inconsistent evidence is weighted less. This is confirmation bias.