The fate of visual long term memories for images across weeks in adults and children

Abstract

What is the content and the format of visual memories in Long Term Memory (LTM)? Is it similar in adults and children? To address these issues, we investigated, in both adults and 9-year-old children, how visual LTM is affected over time and whether visual vs semantic features are affected differentially. In a learning phase, participants were exposed to hundreds of meaningless and meaningful images presented once or twice for either 120 ms or 1920 ms. Memory was assessed using a recognition task either immediately after learning or after a delay of three or six weeks. The results suggest that multiple and extended exposures are crucial for retaining an image for several weeks. Although a benefit was observed in the meaningful condition when memory was assessed immediately after learning, this benefit tended to disappear over weeks, especially when the images were presented twice for 1920 ms. This pattern was observed for both adults and children. Together, the results call into question the dominant models of LTM for images: although semantic information enhances the encoding & maintaining of images in LTM when assessed immediately, this seems not critical for LTM over weeks.

The influence of semantics on long‐term visual memory capacity in children and adults

“…This is in agreement with the results outlined in Boucher et al (2016) where children's memory performance was better for concrete than for abstract pictures, marked by larger P600 repetition effects elicited by concrete compared to abstract designs and a more pronounced and localized recruitment of the left frontal region for concrete pictures. This also agrees with results highlighted in Shoval et al (2022) where they established that meaning is important for remembering massive amounts of visual information in adults and in Goujon et al (2022) where they found that semantic information does enhance the encoding and maintaining of images in long-term memory when assessed immediately (but not when assessed after weeks). Building on these findings, our comparative data on children and adults' performance additionally shows that the 'concrete-superiority effect' or the relative advantage conferred by meaningfulness is higher for children.…”

“…Familiarity may also play a role in modulating performance as a function of age, in that people acquire more familiarity with real-world images as they age. It is also possible that meaningful images, which are more nameable, may be dual-coded (as visual and verbal), whereas meaningless images may be encoded only visually as discussed in Goujon et al (2022) and this strategy may vary between children and adults.…”

“…It is possible that these indirectly-mediated associations were used as an encoding strategy by some participants, and the tendency to do so might have differed as a function of age. Interestingly, Goujon et al (2022) found that when asked to assign a name to real or abstract images at two time points, people were highly consistent across time with the assignments for real images, but much less so for the abstract patterns. This reduction of consistency would weaken the influence of a naming strategy on the kind of task we have employed here, but would not eliminate it.…”

“…Starr et al (2020) also found evidence for a mnemonic benefit for familiar compared to unfamiliar objects in children as well as adults in working memory. In another study, Goujon et al (2022) investigated, in both adults and 9-year-old children, how visual long-term memory for images is affected over time, depending on whether they were meaningful or meaningless.…”

Drawings reveal changes in object memory, but not spatial memory, across time

“…This is supported by the findings of participants first forgetting objects due to their saliency, rather than their meaning, recalling more false objects semantically consistent with the recalled scene over time, and participants forgetting more objects over time. Interestingly, the parallel found in the current study between gist-based processing and the generalization of memory supports the idea that the first information in memory may also the last to leave (Potter, 2012), despite other recent studies challenging this idea (Goujon et al, 2022).…”