It is unclear if, and to what extent, the human memory system is biased towards food and food relevant stimuli. Drawing upon existing demonstrations of attentional biases to high calorie food images, and findings that evolutionarily relevant stimuli are preferentially remembered, we hypothesized that images of high calorie foods would be better remembered than images of low calorie foods and nonfood items. Investigating this is important because a general bias towards remembering high calorie images might facilitate greater incentive learning towards these images which could result in cue-induced overconsumption. We tested this in two pre-registered, within-subject studies (ns = 38). In Experiment 1, using a rapid stream visual presentation procedure and recognition memory test, we found no effect of image type (high calorie, low calorie, nonfood) on recognition for previously seen images (F < 1.0). However, we did observe fewer correct rejections (i.e. more false memories) for novel low calorie images. In Experiment 2, we used a longer encoding procedure and free recall memory test and similarly failed to observe an effect of image type on recall (F < 1.0). We did discover several other factors that correlate with image memory which we discuss along with the implications of these results and directions for future research.

Although we must experience our lives chronologically, storytellers often manipulate the order in which they relay events. How the brain processes temporal information while encoding a nonlinear narrative remains unclear. Here, we use functional magnetic resonance imaging during movie watching to investigate which brain regions are sensitive to information about time in a narrative and test whether the representation of temporal context across a narrative is more influenced by the order in which events are presented or their underlying chronological sequence. Results indicate that medial parietal regions are sensitive to cued jumps through time over and above other changes in context (i.e., location). Moreover, when processing non-chronological narrative information, the precuneus and posterior cingulate engage in on-the-fly temporal unscrambling to represent information chronologically. Specifically, days that are closer together in chronological time are represented more similarly regardless of when they are presented in the movie, and this representation is consistent across participants. Additional analyses reveal a strong spatial signature associated with higher magnitude jumps through time. These findings are consistent with prior theorizing on medial parietal regions as central to maintaining and updating narrative situation models, and suggest the priority of chronological information when encoding narrative events.

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Psychologists use experiments to understand causal relationships. The effects that we observe are typically shown in subsets of people using specific stimuli, yet we assume these specific effects can generalize to many different populations and circumstances than specifically tested. Here, we provide a clear demonstration of how the set of stimuli chosen in an experiment can dramatically influence the observed results. We asked whether there exists a memory bias for high-calorie food images, as others have previously reported such a bias. Using a 650% increase in the number of stimuli relative to previous reports, we find no evidence of such a bias, and instead show the perils of testing for categorical differences in psychological phenomena when only using a few stimuli in each category. We discuss how this relates to the field more broadly and ways to reduce the influence of stimulus selection on performance.