Memory takes time: Images viewed for longer time are better remembered during naturalistic encoding

It is unclear how exposure time contributes to image memory during naturalistic visual behavior since most perceptual and memory investigations involve instructed experimental tasks that modulate resource allocation and affect processing from very early stages. We have recently assumed that during naturalistic encoding, without task-based modulations, more physically salient images register better in memory since they entail higher recruitment of early visual system processing leading to better quality signals passing downstream. After finding that spatial image saliency positively contributes to memory (bigger and higher-contrast images are better remembered), here we tested whether during naturalistic encoding temporal image saliency contributes to memory, assuming that images viewed for longer will be better remembered. In a set of experiments (n=182, 250-2000ms exposure time) we found that images viewed for longer (2000ms) were remembered better (13% higher accuracy, 1.43 times more) than images presented for shorter times (250ms), and that this effect was independent of image size effect on memory. These findings suggest that temporal aspects of visual input, much like spatial aspects, play a significant and independent role in memory formation under naturalistic conditions. This underscores the importance of considering exposure time in models of visual memory that aim to reflect real-world behavior.