Brain Functional Correlates of Episodic Memory Using an Ecological Free Recall Task

Abstract

Episodic Memory (EM) allows us to revive a past event through mental time-travel. The neural correlates of memories recollection have been identified in hippocampal regions and multiple neocortical areas, but few neuroimaging studies have used an ecological task such as a free recall of a structured story. Using an ecological fMRI-free recall (FR) task, we aimed to investigate the relevant recruitment of the brain networks associated with the story recollection process and its performance. Fourteen healthy participants listened to a brief story and were tested for Immediate-Recall (IR), a task that is widely used in a neuropsychological evaluation. Then, the subjects underwent an fMRI session, where they had to perform a free recall (FR) of the story subvocally. Finally, the participants were tested for Delayed-Recall (DR). IR and DR scores were significantly (r = 0.942; p < 0.001) correlated. FR enhanced the activity of the Language, the Left Executive Control, the Default Mode and the Precuneus brain networks, with the strongest BOLD signal localized in the left Angular Gyrus (AG) (p < 0.05; FWE-corrected). Furthermore, the story recall performance covaried with specific network activation patterns and the recruitment of the left anterior/posterior AG correlated, respectively, with higher/lower performance scores (p > 0.05). FR seems to be a promising task to investigate ecologically the neural correlates of EM. Moreover, the recruitment of the anterior AG might be a marker for an optimal functioning of the recall process. Preliminary outcomes lay the foundation for the investigation of the brain networks in the healthy and pathological elderly population during FR.

Mapping of Language-and-Memory Networks in Patients With Temporal Lobe Epilepsy by Using the GE2REC Protocol

“…Independently of its application in TLE patients, in comparison to other standard tasks (such as list reading, for example), GE2REC also has an ecological dimension by including a more natural, unintentional, or everyday life-like sequence of situations, particularly important for memory functioning (Helmstaedter et al, 1998;Strandberg et al, 2017). Undeniably, this protocol is not as ecological as some previously proposed (Bohil et al, 2011;Neri et al, 2021) due to limitations imposed by the clinical setting, hospital equipment, and patient abilities.…”

The developmental trajectory of 1H-MRS brain metabolites from childhood to adulthood

“…2008 ; Ciaramelli et al. 2008 ; Rugg and King 2018 ; Neri et al. 2021 ), we also aim to explore whether neurodevelopmental differences in PPC 1 H-MRS trajectories are associated with development of cognitive function, by observing if GABA+/Glx concentrations in particular associate with recognition memory scores.…”

The developmental trajectory of1H-MRS brain metabolites from childhood to adulthood

“…Accordingly, here we aim to characterize the developmental trajectory of six brain metabolites (GABA, Glu, Gln, NAA, tCho and tCr), as measured by edited 1 H-MRS from a posterior parietal cortex voxel (PPC) in a large typically developing sample (117 participants) from childhood to early adulthood (5 – 35 years old). As the PPC is associated with episodic memory formation and retrieval (Wagner et al 2005; Vincent et al 2006; Ciaramelli et al 2008; Cabeza et al 2008; Rugg and King 2018; Neri et al 2021), we also aim to explore whether neurodevelopmental differences in 1 H-MRS trajectories are associated with development of cognitive function, by observing if GABA/Glu concentrations in particular associate with recognition memory scores.…”