The parahippocampal gyrus links the default-mode cortical network with the medial temporal lobe memory system

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.

Download Full-text

Medial temporal lobe (MTL) ‐ default‐mode network (DMN) functional connectivity disruption in the progression of Alzheimer’s disease

Alzheimer s & Dementia ◽

10.1002/alz.045410 ◽

2020 ◽

Vol 16 (S4) ◽

Author(s):

Kamil A Grajski ◽

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Functional Connectivity ◽

Temporal Lobe ◽

Default Mode Network ◽

Medial Temporal Lobe ◽

Default Mode

Download Full-text

An Exploratory Study of the Relationship between Face Recognition Memory and the Volume of Medial Temporal Lobe Structures in Healthy Young Males

Behavioural Neurology ◽

10.1155/1998/285061 ◽

1998 ◽

Vol 11 (1) ◽

pp. 3-20 ◽

Cited By ~ 30

Author(s):

Clare E. Mackay ◽

Neil Roberts ◽

Andrew R. Mayes ◽

John J. Downes ◽

Jonathan K. Foster ◽

...

Keyword(s):

Face Recognition ◽

Recognition Memory ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Multiple Comparisons ◽

Cerebral Hemispheres ◽

Parahippocampal Gyrus ◽

Bonferroni Correction ◽

Temporal Pole ◽

The Right

A rigorous new methodology was applied to the study of structure function relationships in the living human brain. Face recognition memory (FRM) and other cognitive measures were made in 29 healthy young male subjects (mean age = 21.7 years) and related to volumetric measurements of their cerebral hemispheres and of structures in their medial temporal lobes, obtained using the Cavalieri method in combination with high resolution Magnetic Resonance Imaging (MRI. Greatest proportional variability in volumes was found for the lateral ventricles (57%) for the cerebral hemispheres (8%) in the mean volumes of the hippocampus, parahippocampal gyrus, amygdala, caudate nucleus, temporal pole and temporal lobe on the right and left sides of the brain. The volumes of the right and left parahippocampal gyrus, temporal pole, temporal lobe, and left hippocampus were, prior to application of the Bonferroni correction to take account of 12 multiple comparisons, significantly correlated with the volume of the corresponding hemisphere (p< 0.05). The volumes of all structures were highly correlated (p< 0.0002 for all comparisons) between the two cerebral hemispheres. There were no positive relationships between structure volumes and FRM score. However, the volume of the right amygdala was, prior to application of the Bonferroni correction to take account of 38~multiple comparisons, found to be significantly smaller in the five most consistent high scorers compared to the five most consistent low scorers (t= 2.77,p= 0.025). The implications for possible relationships between healthy medial temporal lobe structures and memory are discussed.

Download Full-text

Distinct Cortical Anatomy Linked to Subregions of the Medial Temporal Lobe Revealed by Intrinsic Functional Connectivity

Journal of Neurophysiology ◽

10.1152/jn.00077.2008 ◽

2008 ◽

Vol 100 (1) ◽

pp. 129-139 ◽

Cited By ~ 288

Author(s):

Itamar Kahn ◽

Jessica R. Andrews-Hanna ◽

Justin L. Vincent ◽

Abraham Z. Snyder ◽

Randy L. Buckner

Keyword(s):

Functional Connectivity ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Temporal Cortex ◽

Memory System ◽

Retrosplenial Cortex ◽

The Body ◽

Parallel Pathways ◽

Ventral Medial Prefrontal Cortex ◽

Adjacent Structures

The hippocampus and adjacent cortical structures in the medial temporal lobe (MTL) contribute to memory through interactions with distributed brain areas. Studies of monkey and rodent anatomy suggest that parallel pathways converge on distinct subregions of the MTL. To explore the cortical areas linked to subregions of the MTL in humans, we examined cortico-cortical and hippocampal-cortical correlations using high-resolution, functional connectivity analysis in 100 individuals. MTL seed regions extended along the anterior to posterior axis and included hippocampus and adjacent structures. Results revealed two separate brain pathways that correlated with distinct subregions within the MTL. The body of the hippocampus and posterior parahippocampal cortex correlated with lateral parietal cortex, regions along the posterior midline including posterior cingulate and retrosplenial cortex, and ventral medial prefrontal cortex. By contrast, anterior hippocampus and the perirhinal/entorhinal cortices correlated with distinct regions in the lateral temporal cortex extending into the temporal pole. The present results are largely consistent with known connectivity in the monkey and provide a novel task-independent dissociation of the parallel pathways supporting the MTL memory system in humans. The cortical pathways include regions that have undergone considerable areal expansion in humans, providing insight into how the MTL memory system has evolved to support a diverse array of cognitive domains.

Download Full-text