It Makes Sense, So I See It Better! Contextual Information About the Visual Environment Increases Its Perceived Sharpness

Predictive coding theories of visual perception postulate that expectations based on prior knowledge modulate the processing of information by sharpening the representation of expected features of a stimulus in visual cortex but few studies directly investigated whether expectations qualitatively affect perception. Our study investigated the influence of expectations based on prior experience and contextual information on the perceived sharpness of objects and scenes. In Experiments 1 and 2, we used a perceptual matching task. Participants saw two blurred images depicting the same object or scene and had to adjust the blur level of the right image to match the blur level of the left one. We manipulated the availability of relevant information to form expectations about the image's content: one of the two images contained predictable information while the other one unpredictable. At an equal level of blur, predictable objects and scenes were perceived as sharper than unpredictable ones. Experiment 3 involving explicit sharpness judgments confirmed these results. Our findings support the sharpening account of predictive coding theories by showing that expectations increase the perceived sharpness of the visual signal. Expectations about the visual environment help us understand it more easily, but also makes us perceive it better. Public Significance Statement Many studies have shown that what we know or expect based on past experience and contextual information can influence how easily we can see and interpret the visual world: for example, a cow is recognized faster when presented in a field than a kitchen context or in isolation. Here we show that expectations also affect how we see. In three experiments, we found that blurred scenes and objects that could be related to prior knowledge (upright scenes and objects in predictable context) were perceived as sharper than the same blurred scenes and objects that could not (inverted scenes and objects in unpredictable contexts). Prior knowledge and expectations about the visual environment not only help us understand it more easily, but also makes us perceive it better.

Automated summary

Predictive coding theories propose that expectations based on prior knowledge can modulate information processing in the visual cortex by sharpening the representation of expected features. This study investigates the qualitative impact of expectations on perception, particularly on the perceived sharpness of objects and scenes. The results support the sharpening account of predictive coding theories, demonstrating that expectations enhance the perceived sharpness of visual signals.