Evidence for a visual bias when recalling complex narratives

First-person and third-person lifelogging improves episodic memory

Lifelogging, the practice of recording daily activities through photographs or videos, enhances memory in healthy individuals and those with memory disorders by aiding both memory consolidation and retrieval processes. This study, involving 32 adults in controlled settings, investigated its effectiveness on episodic memory from first and third-person perspectives. Contrary to expectations, perspective did not influence memory performance. Results indicated that lifelogging significantly improves subjective memory and the recall of visual, but not non-visual, information compared to non-lifelogging conditions. These findings suggest that lifelogging, regardless of perspective, holds promise for supporting episodic memory, especially for visual content, advocating for its wider application.

Studying memory narratives with natural language processing

Cognitive neuroscience research has begun to use natural language processing (NLP) to examine memory narratives with the hopes of gaining a nuanced understanding of the mechanisms underlying differences in memory recall, both across groups and tasks. However, the diversity of NLP approaches can make it challenging for researchers to know which techniques to use and when to apply them. We outline how different NLP techniques can be applied to narrative descriptions to address specific questions about the neurocognitive processes underlying memory narratives. We also discuss the strengths and limitations of NLP methods for use in memory research, highlighting both their potential and their constraints in uncovering the mechanisms of remembering.

Specialization for different memory dimensions in brain activity evoked by cued recollection

Cued recollection involves the retrieval of different features of the encoded event. Previous research has shown that the recollection of complex events jointly recruits the Default Mode and the Frontoparietal Control networks, but the degree to which activity within these networks varies as a function of the particular memory dimension (e.g., the "when-what-where" information) remains largely unknown. In the present functional Magnetic Resonance Imaging (fMRI) study, human participants retrieved specific information about a previously encoded TV show to assess the veracity of detailed sentences along four memory dimensions (i.e., object and character details, spatial layouts, temporal sequences, verbal dialogues). A common activity for all dimensions was observed in a left-lateralized network of regions that largely overlaps with the Frontoparietal Control Network (FPCN), including the lateral prefrontal, lateral superior parietal, and lateral temporal cortex. Instead, a larger degree of specialization for different memory dimensions was observed within the Default Mode Network (DMN), particularly in its posterior nodes. Dimension-related specificity in both networks was associated with memory performance across subjects. Finally, a clear leftward asymmetry was observed in the DMN for all dimensions except for the temporal one, whereas the FPCN showed a bilateral activation across dimensions. The present results generally support the view that specific memory information is processed by a mosaic of regions within large portions of the associative cortex involved in higher-order mnemonic functions.

The role of surface and structural similarities in the retrieval of realistic perceptual events

This study investigated whether structural similarities (i.e. abstract frames, e.g. once bitten twice shy) can prevail over surface similarities (i.e. contexts, e.g. restaurant) in driving the retrieval of realistic events involving dynamic, multimodal and perceptually crowded data. After watching an initial set of video clips, participants had to indicate whether a new video clip, that shared surface similarities with an initial event and structural similarities with another one, elicited a retrieval. The results of Experiment 1A showed that retrieval was more likely to be elicited by structural rather than by surface similarities. Experiment 1B confirmed that the surface similarities manipulated in this study were strong enough to elicit substantial retrievals when the competing structural match was neutralized. The pattern of results obtained in Experiment 1A remained unchanged when the number of unrelated video clips within the initial set was increased. The findings suggest that structurally based retrievals still prevail when familiar structures underlie realistic perceptual events. They open new perspectives regarding the settings that promote structurally based retrievals in educational contexts where unfamiliar principles are introduced.

Long-term memory for movie details: selective decay for verbal information at one week

Mnemonic representations of complex events are multidimensional, incorporating information about objects and characters, their interactions and their spatial-temporal context. The present study investigated the degree to which detailed verbal information (i.e., dialogues), as well as semantic and spatiotemporal (i.e., "what", "where", and "when") elements of episodic memories for movies, are forgotten over the course of a week. Moreover, we tested whether the amount of dimension-specific forgetting differed as a function of the participant's age. In a mixed design, younger and middle-aged participants were asked to watch a ∼90 min movie and provide yes/no answers to detailed questions about different dimensions of the presented material after 1, 3 days, and 1 week. The results indicate that memory decay mainly affects the verbal dimension, both in terms of response accuracy and confidence. Instead, detailed information about objects/characters' features and spatiotemporal context seems to be relatively preserved, despite a general decrease in response confidence. Furthermore, younger adults were in general more accurate and confident than middle-aged participants, although, again, the verbal dimension exhibited a significant age-related difference. We propose that this selective forgetting depends on the progressive advantage of visual compared to auditory/verbal information in memory for complex events.

Machine-learning as a validated tool to characterize individual differences in free recall of naturalistic events

The use of naturalistic stimuli, such as narrative movies, is gaining popularity in many fields, characterizing memory, affect, and decision-making. Narrative recall paradigms are often used to capture the complexity and richness of memory for naturalistic events. However, scoring narrative recalls is time-consuming and prone to human biases. Here, we show the validity and reliability of using a natural language processing tool, the Universal Sentence Encoder (USE), to automatically score narrative recalls. We compared the reliability in scoring made between two independent raters (i.e., hand scored) and between our automated algorithm and individual raters (i.e., automated) on trial-unique video clips of magic tricks. Study 1 showed that our automated segmentation approaches yielded high reliability and reflected measures yielded by hand scoring. Study 1 further showed that the results using USE outperformed another popular natural language processing tool, GloVe. In Study 2, we tested whether our automated approach remained valid when testing individuals varying on clinically relevant dimensions that influence episodic memory, age, and anxiety. We found that our automated approach was equally reliable across both age groups and anxiety groups, which shows the efficacy of our approach to assess narrative recall in large-scale individual difference analysis. In sum, these findings suggested that machine learning approach implementing USE is a promising tool for scoring large-scale narrative recalls and perform individual difference analysis for research using naturalistic stimuli.