Self-evaluation in vision of monkeys and humans

Symposium 2-5Time:15:00 - 16:30
Akihiko Nikkuni
Kyoto University, Japan,

When we are conscious of a sensory event, we can assess a certain or uncertain status of sensory experience. Such a self-evaluation, the confidence, is regarded as a key index of conscious awareness. However, it has been not well understood how humans and other primates compute confidence for their perceptual experiences.  Using a modified wagering task, we first estimated confidence levels of visual percepts in monkeys. In this task, we gave the monkeys the option of abandoning the visual discrimination (associated with a big reward only in correct trials) and choosing an opt-out bar (always associated with a small reward). The monkeys touched the opt-out bar more frequently when the stimulus ambiguity increased. The behavioral data were consistent with the view that they opted out when they were less confident in their judgment.  During the task, we recorded single unit activities from the pulvinar (a higher-order nucleus of visual thalamus) and found out that the pulvinar response magnitude decreased in the order of correct trials, error trials and opt-out trials. While this result suggested that the pulvinar responses correlate with the confidence levels of monkeys, it remains unclear whether the monkeys’ confidence really corresponds to the subjective form of humans’ confidence. To examine this issue, we second performed the human psychophysics with six ratings of subjective confidence. We found that human’s confidence scores showed the same patterns as the modulations of monkey’s pulvinar activities. In line with a statistical framework, these results indicate that a common computation works for confidence reports in monkeys and humans, thereby bridging gaps between the findings on conscious awareness from different species.

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 Important Dates

Submissions Open:
December 10, 2016

Symposia submissions due:
March 1, 2017

Abstract submissions due:
April 10, 2017

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May 20-22, 2017

Registration open:
May 21, 2017

September 1-3, 2017