P2-19: The Effect of item Repetition on Item-Context Association Depends on the Prior Exposure of Items

Previous studies have reported conflicting findings on whether item repetition has beneficial or detrimental effects on source memory. To reconcile such contradictions, we investigated whether the degree of pre-exposure of items can be a potential modulating factor. The experimental procedures spanned two consecutive days. On Day 1, participants were exposed to a set of unfamiliar faces. On Day 2, the same faces presented on the previous day were used again in half of the participants, whereas novel faces were used for the other half. Day 2 procedures consisted of three successive phases: item repetition, source association, and source memory test. In the item repetition phase, half of the face stimuli were repeatedly presented while participants were making male/female judgments. During the source association phase, both the repeated and the unrepeated faces appeared in one of the four locations on the screen. Finally, participants were tested on the location in which a given face was presented during the previous phase and reported the confidence of their memory. Source memory accuracy was measured as the percentage of correct non-guess trials. As results, we found a significant interaction between prior exposure and repetition. Repetition impaired source memory when the items had been pre-exposed on Day 1, while it led to greater accuracy in novel ones. These results show that pre-experimental exposure can modulate the effects of repetition on associative binding between an item and its contextual information, suggesting that pre-existing representation and novelty signal interact to form new episodic memory

What can narratives tell us about the neural bases of human memory?

Narratives are increasingly used to study naturalistic human memory and its brain mechanisms. Narratives—audiovisual movies, spoken stories, and written stories—consist of multiple inter-related and temporally unfolding events which are rich in semantic and emotional content. These characteristics drive intersubject neural synchrony in the default mode network, where abstract situation models are represented and reinstated. Medial temporal lobe structures interact with the cortical sub-regions of the default mode network to support the encoding and recall of narrative events. Narrative memories are frequently communicated across individuals, resulting in the transmission of experiences and neural activity patterns between people. Recent advances in neuroimaging and naturalistic stimulus analysis provide valuable insights into narrative memory and the human memory system in general

A functional neuroimaging dataset acquired during naturalistic movie watching and narrated recall of a series of short cinematic films

Whole-brain functional magnetic resonance imaging (fMRI) data from twenty healthy human participants were collected during naturalistic movie watching and free spoken recall tasks. Participants watched ten short (approximately 2 – 8 min) audiovisual movies and then verbally described what they remembered about the movies in their own words. Participants’ verbal responses were audio recorded using an MR-compatible microphone. The audio recordings were transcribed and timestamped by independent coders. The neural and behavioral data were organized in the Brain Imaging Data Structure (BIDS) format and made publicly available via OpenNeuro.org. The dataset can be used to explore the neural bases of naturalistic memory and other cognitive functions including but not limited to visual/auditory perception, language comprehension, and speech generation

Pre-experimental stimulus familiarity modulates the effects of item repetition on source memory

[Citation: Lee, H., Kim, K., & Yi, D.-J. (2020). Preexperimental stimulus familiarity modulates the effects of item repetition on source memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 46(3), 539–548. https://doi.org/10.1037/xlm0000743] Previous studies have reported contradictory findings regarding the effects of item repetition on the subsequent encoding of contextual details associated with items (i.e., source memory). Whereas some studies reported repetition-induced enhancement in source memory, other studies observed repetition-induced impairment. To resolve these conflicting results, we examined the modulatory role of pre-experimental stimulus familiarity in the relationship between item repetition and new source memory formation by orthogonally manipulating pre-experimental stimulus familiarity and intra-experimental item repetition. In a series of experiments consisting of three phases (item repetition, item-source association, and source memory test), we found that item repetition impaired source memory for pre-experimentally familiar items (famous faces or words), whereas the same manipulation improved source memory for pre-experimentally novel items (non-famous faces or pseudowords). Crucially, item repetition impaired, rather than improved, source memory for pre-experimentally novel items when these items had been pre-exposed to participants prior to the three-phase procedure. Collectively, these findings provide strong evidence that pre-experimental stimulus familiarity determines the relative costs and benefits of experimental item repetition on the encoding of new item-source associations. By demonstrating the interaction between different types of stimulus familiarity, the present findings advance our understanding of how prior experience affects the formation of new episodic memories

Word-timestamped transcripts of two spoken narrative recall functional neuroimaging datasets

After watching audiovisual movies, human participants produced spoken narrative recollections during functional magnetic resonance imaging (fMRI); presented here are word-level timestamps of their speech, temporally aligned to the publicly shared fMRI data. For the “FilmFestival” dataset, twenty participants watched ten short audiovisual movies, approximately 2-8 minutes each. For the “Sherlock” dataset, seventeen participants watched the first half of the first episode of BBC's Sherlock (48 minutes). After viewing, participants then verbally described what they remembered about the movies in their own words. Participants’ speech was recorded using an MR-compatible microphone. The audio recordings were transcribed, then timestamped by a forced aligner; missing timestamps were filled in manually by human transcriptionists referencing the audio recording. Each file contains the participant's recall word by word, onset of each word in seconds with 1/10th-second precision, and the corresponding fMRI volume number (TR). This dataset can be used to investigate topics such as naturalistic memory and language production

Variability in the analysis of a single neuroimaging dataset by many teams

Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses1. The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset2–5. Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed.Depto. de Psicobiología y Metodología en Ciencias del ComportamientoFac. de PsicologíaTRUEpu