embodiedPerspective
Description
This folder contains scripts and results detailed in "An embodied perspective: angular gyrus and precuneus decode selfhood in memories of naturalistic events" by Heather Iriye and Peggy L. St. Jacques. We investigated the interaction between embodiment and visual perspective during encoding, and how this interplay shapes the recall of past events. We hypothesized that the angular gyrus, precuneus, and hippocampus would be involved in integrating the visual perspective and sense of embodiment initially present during memory encoding within memories for naturalistic events as they were retrieved from memory. Patterns of activity during retrieval in the left angular gyrus and bilateral precuneus predicted embodiment on its own separated from visual perspective. In contrast, we observed only inconclusive evidence that these posterior parietal regions predicted visual perspective independent of embodiment. While the left angular gyrus distinguished between in-body and out-of-body perspectives during the retrieval of events associated with both strong and weak embodiment, decoding accuracy predicting visual perspective was only above chance for events encoded with strong embodiment in the precuneus bilaterally. Our results suggest that the contribution of posterior parietal regions in establishing visual perspectives within memories is tightly interconnected with embodiment. Encoding events from an embodied in-body perspective compared to embodied out-of-body perspective led to higher memory accuracy following repeated retrieval. These results elucidate how fundamental feelings of being located in and experiencing the world from our own body’s perspective are integrated within memory. scripts subfolder: run_crossvalidation_measure_ROI_ST_final.m - Matlab script to perform ROI decoding analyses using the CoSMoMVPA toolbox. ROIs subfolder: Contains binarized ROI masks of the left and right angular gyrus, precuneus, and hippocampus. results subfolder: behavioralResults.csv - results of the illusion induction questionnaire and cued recall test/subjective ratings from immediate testing, scanning, and post-scanning sessions. decodingAccuraciesSingleHemiAll.xlsx - results of the ROI decoding analyses with one tab per analysis Abbreviations: Sess1 = session one (immediate testing) Scan = scanning session Sess2 = session 2 (post-scanning) illMinCont = average illusion minus control statement ratings Corr = cued recall accuracy (proportion correct) Viv = vividness EI = emotional intensity Belief = belief in memory accuracy InBodyRat = average 1PP rating OutofBodyRat = average 3PP rating accLDA = LDA classifier accuracy accMinChLDA = accuracy minus chance LDA classifier sscore
Files
Steps to reproduce
Participants formed memories for naturalistic events following a manipulation of their sense of embodiment from in-body and out-of-body perspectives and recalled them during functional scanning. Region of interest multivariate analyses examined how the angular gyrus, precuneus, and hippocampus reflected visual perspective, embodiment, and their interaction (sync in-body vs sync out-of-body, async in-body vs async out-of-body) during remembering. Unsmoothed trial-wise beta estimates from first-level GLMs were used as input for the decoding analyses. Decoding analyses were carried out in Matlab using the CoSMoMVPA toolbox (https://www.cosmomvpa.org/index.html). ROIs were created in WFU Pickatlas based on the Individual Brain Atlases Using Statistical Parametric Mapping, converted into binary format using the MarsBar toolbox for SPM, and resampled to 2mm cubic voxels to match the dimensions of the betas estimates from the first-level models. Behavioral data was analyzed with repeated measures ANOVAs using JASP version 0.19 software. Please see our pre-print for more detailed instructions of the experiment and analysis (https://www.biorxiv.org/content/10.1101/2024.09.09.612088v4.abstract).