The Influence of Culture on Mnemonic Processes: A Comparison of Easterners and Westerners
Creators: name: Leger, Krystal
Publisher: name: Brandeis University
Year: 2023
Subjects: cross-cultural
fmri
memory
object memory
semantic organization

description: Perception, attention, and memory can differ across members of Eastern and Western cultures. Easterners (generally defined as those from East or Southeast Asian countries) pay more attention to and prioritize contextual information and relationships (Boduroglu et al., 2009; Masuda &amp; Nisbett, 2001) whereas Westerners (including Americans) have better memory for specific details and features (Leger &amp; Gutchess, 2021; Millar et al., 2013; Paige &amp; Gutchess, 2017; Paige, Ksander, et al., 2017; Wang, 2001). Cultures also differ in how semantic information is organized, with Easterners tending to organize based on functional relationships and Westerners tending to sort items categorically (Chiu, 1972; Ji et al., 2004; S. J. Unsworth et al., 2005). Across these different cognitive domains, neuroimaging studies have revealed the neural underpinnings of these group differences (Gutchess &amp; Indeck, 2009; Gutchess, Welsh, et al., 2006; Kitayama &amp; Uskul, 2011; Ksander et al., 2018; Paige, Ksander, et al., 2017). Although there is ample evidence for the existence of cultural influences on cognitive processes, the exact mechanisms by which these differences emerge are still unclear. Prior work has indicated Americans have greater memory specificity for objects compared to East Asians (Millar et al., 2013), and neuroimaging studies have identified underlying differences in encoding activity (Ksander et al., 2018; Paige, Ksander, et al., 2017). However, the influence of culture on neural activity at retrieval is not fully understood. Study 1 used functional neuroimaging to investigate cultural effects on retrieval activity underlying object memory specificity. While in the MRI scanner, American and Taiwanese young adults completed the Mnemonic Similarity Task (MST), an object recognition paradigm in which they discriminated between old targets, similar lures, and novel foils. The primary aim of this study was to test for group differences in activity related to discriminating similar lures from studied targets (pattern separation). I also tested neural activity related to old vs. new discrimination and true vs. false memories. Results showed significant cultural difference in the relationship between pattern separation activity in left fusiform gyrus and behavioral discrimination between target and lure objects. Analyses of activity during lure correct rejections also indicated that groups differed in left superior parietal cortex response to variations in lure similarity. Exploratory analyses of old vs. new activity indicated Americans and Taiwanese also differ in the neural activity supporting general object recognition, specifically within the hippocampus, left inferior frontal gyrus, and middle frontal gyrus. In addition to investigating neural differences between groups, I also tested for activity that was common across cultures for memory domains of interest: pattern separation, old vs. new, and true vs. false. In each of these domains, multiple regions emerged as having shared patterns of activity across culture groups. Overall, findings suggest Americans and Taiwanese differ in the extent to which they recruit visual processing and attention modulating brain regions to support object memory.
description: Study 2 tested whether patterns of cross-cultural memory differences observed in concrete object paradigms also generalize to other stimuli and task demands. I tested American and East Asian young adults using a recognition memory task employing abstract stimuli for which attention to conjunctions of features was critical for discrimination. Additionally, in order to more precisely determine the influence of stimulus complexity and task on culture differences, participants also completed a concrete objects memory task identical to the one used in prior research, including Study 1 of this dissertation. The results of the abstract objects task mirrored the pattern seen in prior studies with concrete objects: Americans showed generally higher levels of recognition memory performance than East Asians for studied abstract items, whether discriminating them from similar or entirely new items. Results from the current concrete object task generally replicated this pattern. This suggests cross-cultural memory differences generalize across stimulus types and task demands, rather than reflecting differential sensitivity to low-level features or higher-level conjunctions.
description: Study 3 assessed a mechanistic account of how culture influences working memory processes via semantic organization. This experiment consisted of two main components. First, to assay semantic organization, I measured Americans’ and Turks’ preferences for categorical and functional relationships. The second component of this experiment tested working memory interference using a 2-back working memory paradigm in which lure items were categorically and functionally related to targets. A mediation model was used to analyze direct effects of culture and semantic organization on working memory task behavior, as well as the indirect effect of semantic organization mediating the relationship between culture and working memory interference. Results showed that Americans had slower correct response times to functional lures compared to categorical lures whereas Turks showed no meaningful difference between conditions. However this cultural difference in working memory interference was not significantly mediated by semantic organization. Across cultures, tendency to endorse categorical as opposed to functional relationships between words significantly predicted the relative frequency of categorical vs. functional errors made in the working memory task. Findings from this study align with prior work that suggests Americans use categorical organization to support recall processes, and this facilitatory functionality may extend to working memory processes.