Brain mechanisms underlying cue-based memorizing during free viewing of movie Memento

Abstract

How does the human brain recall and connect relevant memories with unfolding events? To study this, we presented 25 healthy subjects, during functional magnetic resonance imaging, the movie 'Memento' (director C. Nolan). In this movie, scenes are presented in chronologically reverse order with certain scenes briefly overlapping previously presented scenes. Such overlapping "key-frames" serve as effective memory cues for the viewers, prompting recall of relevant memories of the previously seen scene and connecting them with the concurrent scene. We hypothesized that these repeating key-frames serve as immediate recall cues and would facilitate reconstruction of the story piece-by-piece. The chronological version of Memento, shown in a separate experiment for another group of subjects, served as a control condition. Using multivariate event-related pattern analysis method and representational similarity analysis, focal fingerprint patterns of hemodynamic activity were found to emerge during presentation of key-frame scenes. This effect was present in higher-order cortical network with regions including precuneus, angular gyrus, cingulate gyrus, as well as lateral, superior, and middle frontal gyri within frontal poles. This network was right hemispheric dominant. These distributed patterns of brain activity appear to underlie ability to recall relevant memories and connect them with ongoing events, i.e., "what goes with what" in a complex story. Given the real-life likeness of cinematic experience, these results provide new insight into how the human brain recalls, given proper cues, relevant memories to facilitate understanding and prediction of everyday life events.

Enhanced reinstatement of naturalistic event memories due to hippocampal-network-targeted stimulation

“…These findings demonstrate that perturbing one node of the episodic memory network can alter large-scale, multimodal patterns of neural activity which are considered to be fundamental to memory.Episodic memory is thought to critically depend on cortical reinstatement mediated by the hippocampus[1][2][3]. Consistent with prior research[9,27,34], we identified reinstatement of video-specific patterns of neural activity within a set of posterior parietal and occipital regions following control stimulation. A greater number of regions showed significant reinstatement…”

Relating the past with the present: Information integration and segregation during ongoing narrative processing

“…In one relevant study, Milivojevic et al (2016) used an audio-visual movie with interleaved storylines ("Sliding Doors") and found coding of storyline information in the hippocampus (but not in the DMN areas that are the focus of our study). In another relevant study, Kauttonen et al (2018) scanned participants who watched the movie "Memento", in which recurring cues were embedded to trigger memory recall, similar to the motifs in our story; they found that recurring scenes activated matching, scene-specific neural patterns in low-level sensory regions, and also that there was a common (i.e., not-scene-specific) neural pattern that was evoked in DMN regions whenever participants viewed a scene for a second time.…”

“…Our study resolves this confound because both storylines were presented auditorily by the same speaker and thus did not differ in low-level sensory properties. Likewise, a limitation of the design of Kauttonen et al (2018) is that recurring scenes were repeated exactly; as such, pattern similarity between matching cues could be due to matching sensory inputs (as opposed to memory). In contrast, in our study, recurring motifs were embedded in different scenes, making it easier to distinguish between the influences of perception and memory.…”

Body and brain responses underlying salient emotional information processing

“…To study real-life sensory experience, neuroscientists are increasingly employing naturalistic paradigms such as dynamic videos, speech and music that incorporate sensory stimuli typically encountered in everyday life (Bartels and Zeki 2004, Hasson, Nir et al 2004, Wagner and Kelley 2016, Kauttonen, Hlushchuk et al 2018.…”

“…Analysis using MVPA identified patterns of activation in higher-order cortical network (precuneus, angular gyrus, cingulate gyrus, frontal poles) during presentation of key-frame scenes which revealed contextual information about prior events. This clever use of (re-)editing a film design provides a unique insight into the pattern of brain activity in recalled memories which connect a narrative to its relevant context (Kauttonen, Hlushchuk et al 2018).…”