Sensation and inferences in perception, metacognition and action

Project Information

SENCES

Grant agreement ID: 101001250

DOI

10.3030/101001250

EC signature date 14 April 2021

Start date 1 July 2021

End date 31 March 2027

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 996 738,00

EU contribution

€ 1 996 738,00

Coordinated by

PHILIPPS UNIVERSITAET MARBURG
Germany

Periodic Reporting for period 3 - SENCES (Sensation and inferences in perception, metacognition and action)

Reporting period: 2024-07-01 to 2025-12-31

Summary of the context and overall objectives of the project

Contrary to our daily experience, the information from our sensory organs is not seamless. Gaps in visual information occur due to inherent properties of the visual system, like the absence of functioning photoreceptors in natural and pathological scotomata or due to external properties of the environment, like (partial) occlusion by other objects. These gaps in visual information are completed based on perceptual inferences. The projects aims to provide insights how perceptual inferences contribute to a seamless representation of the environment and how they are treated relative to veridical sensory information at higher stages of processing.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Examining external causes of gaps in information, we were able to show that humans underestimate the number of objects that are hidden from plain sight in a visual scene. This underestimation occurs although the number of visible objects and the amount of occlusion in the scene can be estimated accurately. At the same time, confidence ratings are similar for partially occluded and fully visible scenes, suggesting that the lack of information due to occlusion is not accurately reflected in metacognition. A (Bayesian) model suggests that the underestimation results from the high stochastic uncertainty about the number of hidden objects combined with a prior for a low number of hidden objects.

Examining internal causes of gaps in information, we investigated perception in the rod-scotoma in the center of the visual field under different lighting conditions. The results show that perceptual completion of the rod-scotoma occurs not only under scotopic conditions, when only rod photoreceptors are active, but also under mesopic conditions, when both rod and cone photoreceptors are active. Flickering the background makes the scotoma visible as a blurry spot in the center of the visual field, which shows that the perceptual completion requires time and can be disturbed by fast changes in the environment.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Our results so far show that the perceptual completion of sensory gaps underestimates the complexity of the visual environment. We plan to study the plasticity of perceptual completion in patients with pathological scotomata. Furthermore, we plan to investigate metacognitive confidence for other cases of perceptual completion in the visual and the auditory modality.