Yutaka Komura, Akihiko Nikkuni, Noriko Hirashima, Teppei Uetake & Aki Miyamoto
Nature Neuroscience (2013) doi:10.1038/nn.3393
Received 26 December 2012 Accepted 05 April 2013 Published online 12 May 2013
When we recognize a sensory event, we experience a confident feeling that we certainly know the perceived world 'here and now'. However, it is unknown how and where the brain generates such 'perceptual confidence'. Here we found neural correlates of confidence in the primate pulvinar, a visual thalamic nucleus that has been expanding markedly through evolution. During a categorization task, the majority of pulvinar responses did not correlate with any 'perceptual content'. During an opt-out task, pulvinar responses decreased when monkeys chose 'escape' options, suggesting less confidence in their perceptual categorization. Functional silencing of the pulvinar increased monkeys' escape choices in the opt-out task without affecting categorization performance; this effect was specific to the contralateral visual target. These data were supported by a theoretical model of confidence, indicating that pulvinar activities encode a subject's certainty of visual categorization and contribute to perceptual confidence.