Judgments during perceptual comparisons predict distinct forms of memory updating

Abstract

Comparing a visual memory with new visual stimuli can bias memory content, especially when the new stimuli are perceived as similar. Perceptual comparisons of this kind may play a mechanistic role in memory updating and can explain how memories can become erroneous in daily life. To test this possibility, we investigated whether comparisons can produce other types of memory distortion beyond memory bias that are commonly implicated in erroneous memories (e.g., memory misattribution). We hypothesized that the type of memory distortion induced during a comparison depends on the perceived overlap between the memory and incoming stimulus—when the input is perceived as similar, it biases memory content; when perceived as the same, it replaces memory content. Participants completed a delayed-estimation task in which they compared their memories of color (Exp.1) and shape stimuli (Exp.2) to probe stimuli before reporting memory content. We found systematic errors in participants’ memory reports following perceived similarity and sameness that were towards the probes and larger following perceived sameness. Simulations confirmed that these errors were not explained by noisy encoding processes that occurred before comparisons. Instead, computational modeling suggested that these errors were likely explained by probabilistic replacement of the memory by the probe following perceived sameness and integration between the memory and the probe following perceived similarity. Together, these findings suggest that perceptual comparisons can prompt distinct forms of memory updating that have been described previously and may explain how memories become erroneous during their use in everyday behavior.

Comparing visual memories to similar visual inputs risks lasting memory distortion.

“…Here, memories were biased when individuals compared the similarity between memories and inputs. However, when memories and novel inputs are endorsed as being the same rather than similar , memories appear to be replaced by (i.e., “swapped with”) novel inputs instead (Saito, Bae, & Fukuda, 2022). These preliminary findings are broadly consistent with the view that source misattribution and other related memory distortions are the result of memory-updating processes that are typically viewed as functionally adaptive for behavior (Schacter et al, 2011).…”

Perceptual comparisons induce lasting and generalizing changes to face memory reports

“…Indeed, our recent work applied computational modeling on continuous memory report data and demonstrated both mechanisms can underlie systematic shifts in memory reports with more simplistic stimuli (e.g., color and shape; Saito, Bae, et al, 2023). More precisely, when participants perceive subjective similarity between the original memory representation and the new perceptual input, the shift in memory reports is better explained by the shift of the original memory representation.…”